scsi: ibmvscsi: Convert snprintf() to sysfs_emit()

Per filesystems/sysfs.rst, show() should only use sysfs_emit() or
sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

> ./drivers/scsi/ibmvscsi/ibmvfc.c:3483:8-16: WARNING: please use sysfs_emit
> ./drivers/scsi/ibmvscsi/ibmvfc.c:3493:8-16: WARNING: please use sysfs_emit
> ./drivers/scsi/ibmvscsi/ibmvfc.c:3503:8-16: WARNING: please use sysfs_emit
> ./drivers/scsi/ibmvscsi/ibmvfc.c:3513:8-16: WARNING: please use sysfs_emit
> ./drivers/scsi/ibmvscsi/ibmvfc.c:3522:8-16: WARNING: please use sysfs_emit
> ./drivers/scsi/ibmvscsi/ibmvfc.c:3530:8-16: WARNING: please use sysfs_emit

No functional change intended

CC: Tyrel Datwyler <tyreld@linux.ibm.com>
CC: Michael Ellerman <mpe@ellerman.id.au>
CC: Nicholas Piggin <npiggin@gmail.com>
CC: Christophe Leroy <christophe.leroy@csgroup.eu>
CC: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
CC: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
CC: James E.J. Bottomley <jejb@linux.ibm.com>
CC: Martin K. Petersen <martin.petersen@oracle.com>
CC: linux-scsi@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240116045151.3940401-23-lizhijian@fujitsu.com
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Replace deprecated strncpy() with strscpy()

strncpy() is deprecated for use on NUL-terminated destination strings [1]
and as such we should prefer more robust and less ambiguous string
interfaces.

We expect these fields to be NUL-terminated as the property names from
which they are derived are also NUL-terminated.

Moreover, NUL-padding is not required as our destination buffers are
already NUL-allocated and any future NUL-byte assignments are redundant
(like the ones that strncpy() does).
ibmvfc_probe() ->
| struct ibmvfc_host *vhost;
| struct Scsi_Host *shost;
...
| shost = scsi_host_alloc(&driver_template, sizeof(*vhost));
... **side note: is this a bug? Looks like a type to me ^^^^^**
...
| vhost = shost_priv(shost);

... where shost_priv() is:
| static inline void *shost_priv(struct Scsi_Host *shost)
| {
| return (void *)shost->hostdata;
| }

.. and:
scsi_host_alloc() ->
| shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);

And for login_info->..., NUL-padding is also not required as it is
explicitly memset to 0:
| memset(login_info, 0, sizeof(*login_info));

Considering the above, a suitable replacement is strscpy() [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20231030-strncpy-drivers-scsi-ibmvscsi-ibmvfc-c-v1-1-5a4909688435@google.com
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Open-code reset loop for target reset

For target reset we need a device to send the target reset to, so open-code
the loop in target reset to send the target reset TMF to the correct
device.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231002154328.43718-11-hare@suse.de
Cc: Tyrel Datwyler <tyreld@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Make discovery buffer per protocol channel group

The target discovery buffer that the VIOS populates with targets is
currently a host adapter field. To facilitate the discovery of NVMe targets
as well as SCSI another discovery buffer is required. Move the discovery
buffer out of the host struct and into the ibmvfc_channels struct so that
each channels instance for a given protocol has its own discovery buffer.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-11-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add protocol field to ibmvfc_channels

There are cases in the generic code where protocol specific configuration
or actions may need to be taken. Add a protocol field to struct
ibmvfc_channels and initial IBMVFC_PROTO_[SCSI/NVME] definitions.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-10-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Make channel allocation generic

With the coming of NVMeoF support the driver will need to also allocate
channels for NVMe. Implement generic channel allocation wrappers that can
be used for both SCSI and NVMeoF protocol setup.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-9-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Track max and desired queue size in ibmvfc_channels

Add fields for desired and max number of queues to ibmvfc_channels. With
support for NVMeoF protocol coming these sorts of values should be tracked
in the protocol specific channel struct instead of the overarching host
adapter.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-8-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Rename ibmvfc_scsi_channels to ibmvfc_channels

There is nothing scsi specific about the ibmvfc_scsi_channels struct. It is
meant to encapsulate a set of channels regardless of protocol.

Remove _scsi from the struct name to reflect this genric nature.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-7-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix erroneous use of rtas_busy_delay with hcall return code

Commit 0217a272fe13 ("scsi: ibmvfc: Store return code of H_FREE_SUB_CRQ
during cleanup") wrongly changed the busy loop check to use
rtas_busy_delay() instead of H_BUSY and H_IS_LONG_BUSY(). The busy return
codes for RTAS and hypercalls are not the same.

Fix this issue by restoring the use of H_BUSY and H_IS_LONG_BUSY().

Fixes: 0217a272fe13 ("scsi: ibmvfc: Store return code of H_FREE_SUB_CRQ during cleanup")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-5-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Limit max hw queues by num_online_cpus()

An LPAR could potentially be configured with a small logical cpu count that
is less then the default hardware queue max. Ensure that we don't allocate
more hw queues than available cpus.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-4-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Implement channel queue depth and event buffer accounting

Extend ibmvfc_queue, ibmvfc_event, and ibmvfc_event_pool to provide queue
depths for general I/O commands and reserved commands as well as proper
accounting of the free events of each type from the general event
pool. Further, calculate the negotiated max command limit with the VIOS at
NPIV login time as a function of the number of queues times their total
queue depth (general and reserved depths combined).

This does away with the legacy max_request value, and allows the driver to
better manage and track it resources.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-3-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Remove BUG_ON in the case of an empty event pool

In practice the driver should never send more commands than are allocated
to a queue's event pool. In the unlikely event that this happens, the code
asserts a BUG_ON, and in the case that the kernel is not configured to
crash on panic returns a junk event pointer from the empty event list
causing things to spiral from there. This BUG_ON is a historical artifact
of the ibmvfc driver first being upstreamed, and it is well known now that
the use of BUG_ON is bad practice except in the most unrecoverable
scenario. There is nothing about this scenario that prevents the driver
from recovering and carrying on.

Remove the BUG_ON in question from ibmvfc_get_event() and return a NULL
pointer in the case of an empty event pool. Update all call sites to
ibmvfc_get_event() to check for a NULL pointer and perfrom the appropriate
failure or recovery action.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20230921225435.3537728-2-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Declare SCSI host template const

Make it explicit that the SCSI host template is not modified.

Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-45-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Avoid path failures during live migration

Fix an issue reported when performing a live migration when multipath is
configured with a short fast fail timeout of 5 seconds and also to have
no_path_retry set to fail. In this scenario, all paths would go into the
devloss state while the ibmvfc driver went through discovery to log back
in. On a loaded system, the discovery might take longer than 5 seconds,
which was resulting in all paths being marked failed, which then resulted
in a read only filesystem.

This patch changes the migration code in ibmvfc to avoid deleting rports at
all in this scenario, so we avoid losing all paths.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20221026181356.148517-1-brking@linux.vnet.ibm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Store vhost pointer during subcrq allocation

Currently the back pointer from a queue to the vhost adapter isn't set
until after subcrq interrupt registration. The value is available when a
queue is first allocated and can/should be also set for primary and async
queues as well as subcrqs.

This fixes a crash observed during kexec/kdump on Power 9 with legacy XICS
interrupt controller where a pending subcrq interrupt from the previous
kernel can be replayed immediately upon IRQ registration resulting in
dereference of a garbage backpointer in ibmvfc_interrupt_scsi().

Kernel attempted to read user page (58) - exploit attempt? (uid: 0)
BUG: Kernel NULL pointer dereference on read at 0x00000058
Faulting instruction address: 0xc008000003216a08
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c008000003216a08] ibmvfc_interrupt_scsi+0x40/0xb0 [ibmvfc]
LR [c0000000082079e8] __handle_irq_event_percpu+0x98/0x270
Call Trace:
[c000000047fa3d80] [c0000000123e6180] 0xc0000000123e6180 (unreliable)
[c000000047fa3df0] [c0000000082079e8] __handle_irq_event_percpu+0x98/0x270
[c000000047fa3ea0] [c000000008207d18] handle_irq_event+0x98/0x188
[c000000047fa3ef0] [c00000000820f564] handle_fasteoi_irq+0xc4/0x310
[c000000047fa3f40] [c000000008205c60] generic_handle_irq+0x50/0x80
[c000000047fa3f60] [c000000008015c40] __do_irq+0x70/0x1a0
[c000000047fa3f90] [c000000008016d7c] __do_IRQ+0x9c/0x130
[c000000014622f60] [0000000020000000] 0x20000000
[c000000014622ff0] [c000000008016e50] do_IRQ+0x40/0xa0
[c000000014623020] [c000000008017044] replay_soft_interrupts+0x194/0x2f0
[c000000014623210] [c0000000080172a8] arch_local_irq_restore+0x108/0x170
[c000000014623240] [c000000008eb1008] _raw_spin_unlock_irqrestore+0x58/0xb0
[c000000014623270] [c00000000820b12c] __setup_irq+0x49c/0x9f0
[c000000014623310] [c00000000820b7c0] request_threaded_irq+0x140/0x230
[c000000014623380] [c008000003212a50] ibmvfc_register_scsi_channel+0x1e8/0x2f0 [ibmvfc]
[c000000014623450] [c008000003213d1c] ibmvfc_init_sub_crqs+0xc4/0x1f0 [ibmvfc]
[c0000000146234d0] [c0080000032145a8] ibmvfc_reset_crq+0x150/0x210 [ibmvfc]
[c000000014623550] [c0080000032147c8] ibmvfc_init_crq+0x160/0x280 [ibmvfc]
[c0000000146235f0] [c00800000321a9cc] ibmvfc_probe+0x2a4/0x530 [ibmvfc]

Link: https://lore.kernel.org/r/20220616191126.1281259-2-tyreld@linux.ibm.com
Fixes: 3034ebe26389 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Cc: stable@vger.kernel.org
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Allocate/free queue resource only during probe/remove

Currently, the sub-queues and event pool resources are allocated/freed for
every CRQ connection event such as reset and LPM. This exposes the driver
to a couple issues. First the inefficiency of freeing and reallocating
memory that can simply be resued after being sanitized. Further, a system
under memory pressue runs the risk of allocation failures that could result
in a crippled driver. Finally, there is a race window where command
submission/compeletion can try to pull/return elements from/to an event
pool that is being deleted or already has been deleted due to the lack of
host state around freeing/allocating resources. The following is an example
of list corruption following a live partition migration (LPM):

Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: vfat fat isofs cdrom ext4 mbcache jbd2 nft_counter nft_compat nf_tables nfnetlink rpadlpar_io rpaphp xsk_diag nfsv3 nfs_acl nfs lockd grace fscache netfs rfkill bonding tls sunrpc pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth vmx_crypto dm_multipath dm_mirror dm_region_hash dm_log dm_mod ipmi_devintf ipmi_msghandler fuse
CPU: 0 PID: 2108 Comm: ibmvfc_0 Kdump: loaded Not tainted 5.14.0-70.9.1.el9_0.ppc64le #1
NIP: c0000000007c4bb0 LR: c0000000007c4bac CTR: 00000000005b9a10
REGS: c00000025c10b760 TRAP: 0700 Not tainted (5.14.0-70.9.1.el9_0.ppc64le)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 2800028f XER: 0000000f
CFAR: c0000000001f55bc IRQMASK: 0
GPR00: c0000000007c4bac c00000025c10ba00 c000000002a47c00 000000000000004e
GPR04: c0000031e3006f88 c0000031e308bd00 c00000025c10b768 0000000000000027
GPR08: 0000000000000000 c0000031e3009dc0 00000031e0eb0000 0000000000000000
GPR12: c0000031e2ffffa8 c000000002dd0000 c000000000187108 c00000020fcee2c0
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 c008000002f81300
GPR24: 5deadbeef0000100 5deadbeef0000122 c000000263ba6910 c00000024cc88000
GPR28: 000000000000003c c0000002430a0000 c0000002430ac300 000000000000c300
NIP [c0000000007c4bb0] __list_del_entry_valid+0x90/0x100
LR [c0000000007c4bac] __list_del_entry_valid+0x8c/0x100
Call Trace:
[c00000025c10ba00] [c0000000007c4bac] __list_del_entry_valid+0x8c/0x100 (unreliable)
[c00000025c10ba60] [c008000002f42284] ibmvfc_free_queue+0xec/0x210 [ibmvfc]
[c00000025c10bb10] [c008000002f4246c] ibmvfc_deregister_scsi_channel+0xc4/0x160 [ibmvfc]
[c00000025c10bba0] [c008000002f42580] ibmvfc_release_sub_crqs+0x78/0x130 [ibmvfc]
[c00000025c10bc20] [c008000002f4f6cc] ibmvfc_do_work+0x5c4/0xc70 [ibmvfc]
[c00000025c10bce0] [c008000002f4fdec] ibmvfc_work+0x74/0x1e8 [ibmvfc]
[c00000025c10bda0] [c0000000001872b8] kthread+0x1b8/0x1c0
[c00000025c10be10] [c00000000000cd64] ret_from_kernel_thread+0x5c/0x64
Instruction dump:
40820034 38600001 38210060 4e800020 7c0802a6 7c641b78 3c62fe7a 7d254b78
3863b590 f8010070 4ba309cd 60000000 <0fe00000> 7c0802a6 3c62fe7a 3863b640
---[ end trace 11a2b65a92f8b66c ]---
ibmvfc 30000003: Send warning. Receive queue closed, will retry.

Add registration/deregistration helpers that are called instead during
connection resets to sanitize and reconfigure the queues.

Link: https://lore.kernel.org/r/20220616191126.1281259-3-tyreld@linux.ibm.com
Fixes: 3034ebe26389 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Cc: stable@vger.kernel.org
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Switch to attribute groups

struct device supports attribute groups directly but does not support
struct device_attribute directly. Hence switch to attribute groups.

Link: https://lore.kernel.org/r/20211012233558.4066756-25-bvanassche@acm.org
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvscsi: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-39-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix up duplicate response detection

Commit a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale
response detection") introduced a regression in detecting duplicate
responses. This was observed in test where a command was sent to the VIOS
and completed before ibmvfc_send_event() set the active flag to 1, which
resulted in the atomic_dec_if_positive() call in ibmvfc_handle_crq()
thinking this was a duplicate response, which resulted in scsi_done() not
getting called, so we then hit a SCSI command timeout for this command once
the timeout expires. This simply ensures the active flag gets set prior to
making the hcall to send the command to the VIOS, in order to close this
window.

Link: https://lore.kernel.org/r/20211019152129.16558-1-brking@linux.vnet.ibm.com
Fixes: a264cf5e81c7 ("scsi: ibmvfc: Fix command state accounting and stale response detection")
Cc: stable@vger.kernel.org
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Do not wait for initial device scan

The initial device scan might take some time, and there really is no need
to wait for it during probe(). So return immediately from scsi_scan_host()
during probe() and avoid any udev stalls during booting.

Link: https://lore.kernel.org/r/20210817075306.11315-1-mwilck@suse.com
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Stop using scsi_cmnd.tag

Use scsi_cmd_to_rq(scsi_cmnd)->tag in preference to scsi_cmnd.tag.

Link: https://lore.kernel.org/r/1629207817-211936-1-git-send-email-john.garry@huawei.com
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-24-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix command state accounting and stale response detection

Prior to commit 1f4a4a19508d ("scsi: ibmvfc: Complete commands outside the
host/queue lock") responses to commands were completed sequentially with
the host lock held such that a command had a basic binary state of active
or free. It was therefore a simple affair of ensuring the assocaiated
ibmvfc_event to a VIOS response was valid by testing that it was not
already free. The lock relexation work to complete commands outside the
lock inadverdently made it a trinary command state such that a command is
either in flight, received and being completed, or completed and now
free. This breaks the stale command detection logic as a command may be
still marked active and been placed on the delayed completion list when a
second stale response for the same command arrives. This can lead to double
completions and list corruption. This issue was exposed by a recent VIOS
regression were a missing memory barrier could occasionally result in the
ibmvfc client receiving a duplicate response for the same command.

Fix the issue by introducing the atomic ibmvfc_event.active to track the
trinary state of a command. The state is explicitly set to 1 when a command
is successfully sent. The CRQ response handlers use
atomic_dec_if_positive() to test for stale responses and correctly
transition to the completion state when a active command is received.
Finally, atomic_dec_and_test() is used to sanity check transistions when
commands are freed as a result of a completion, or moved to the purge list
as a result of error handling or adapter reset.

Link: https://lore.kernel.org/r/20210716205220.1101150-1-tyreld@linux.ibm.com
Fixes: 1f4a4a19508d ("scsi: ibmvfc: Complete commands outside the host/queue lock")
Cc: stable@vger.kernel.org
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Reinit target retries

If rport target discovery commands fail for some reason, they get retried
up to a set number of retries. Once the retry limit is exceeded, the target
is deleted. In order to delete the target, we either need to do an implicit
logout or a move login. In the move login case, if the move login fails, we
want to retry it. This ensures the retry counter gets reinitialized so the
move login will get retried.

Link: https://lore.kernel.org/r/1620756740-7045-4-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Avoid move login if fast fail is enabled

If fast fail is enabled and we encounter a WWPN moving from one port id to
another port id with I/O outstanding, if we use the move login MAD,
although it will work, it will leave any outstanding I/O still outstanding
to the old port id. Eventually, the SCSI command timers will fire and we
will abort these commands, however, this is generally much longer than the
fast fail timeout, which can lead to I/O operations being outstanding for a
long time. This patch changes the behavior to avoid the move login if fast
fail is enabled. Once terminate_rport_io cleans up the rport, then we force
the target back through the delete process, which re-drives the implicit
logout, then kicks us back into discovery where we will discover the WWPN
at the new location and do a PLOGI to it.

Link: https://lore.kernel.org/r/1620756740-7045-3-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Handle move login failure

When service is being performed on an SVC with NPIV enabled, the WWPN of
the canister / node being serviced fails over to the another canister /
node. This looks to the ibmvfc driver as a WWPN moving from one SCSI ID to
another. The driver will first attempt to do an implicit logout of the old
SCSI ID. If this works, we simply delete the rport at the old location and
add an rport at the new location and the FC transport class handles
everything. However, if there is I/O outstanding, this implicit logout will
fail, in which case we will send a "move login" request to the VIOS. This
will cancel any outstanding I/O to that port, logout the port, and PLOGI
the new port. Recently we've encountered a scenario where the move login
fails. This was resulting in an attempted plogi to the new scsi id, without
the old scsi id getting logged out, which is a VIOS protocol violation. To
solve this, we want to keep tracking the old scsi id as the current scsi
id. That way, once terminate_rport_io cancels the outstanding i/o, it will
send us back through to do an implicit logout of the old scsi id, rather
than the new scsi id, and then we can plogi the new scsi id.

Link: https://lore.kernel.org/r/1620756740-7045-2-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi/ibmvscsi: Directly include linux/{of.h,irqdomain.h}

A couple of ibmvscsi files are missing the inclusion of linux/of.h
and linux/irqdomain.h, relying on transitive inclusion from another
file.

As we are about to break this dependency, make sure these dependencies
are explicit.

Signed-off-by: Marc Zyngier <maz@kernel.org>

scsi: ibmvfc: Fix invalid state machine BUG_ON()

This fixes an issue hitting the BUG_ON() in ibmvfc_do_work(). When going
through a host action of IBMVFC_HOST_ACTION_RESET, we change the action to
IBMVFC_HOST_ACTION_TGT_DEL, then drop the host lock, and reset the CRQ,
which changes the host state to IBMVFC_NO_CRQ. If, prior to setting the
host state to IBMVFC_NO_CRQ, ibmvfc_init_host() is called, it can then end
up changing the host action to IBMVFC_HOST_ACTION_INIT. If we then change
the host state to IBMVFC_NO_CRQ, we will then hit the BUG_ON().

Make a couple of changes to avoid this. Leave the host action to be
IBMVFC_HOST_ACTION_RESET or IBMVFC_HOST_ACTION_REENABLE until after we drop
the host lock and reset or reenable the CRQ. Also harden the host state
machine to ensure we cannot leave the reset / reenable state until we've
finished processing the reset or reenable.

Link: https://lore.kernel.org/r/20210413001009.902400-1-tyreld@linux.ibm.com
Fixes: 73ee5d867287 ("[SCSI] ibmvfc: Fix soft lockup on resume")
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
[tyreld: added fixes tag]
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
[mkp: fix comment checkpatch warnings]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvscsi: Fix a bunch of misdocumentation

Fixes the following W=1 kernel build warning(s):

drivers/scsi/ibmvscsi/ibmvfc.c:331: warning: Function parameter or member 'vhost' not described in 'ibmvfc_get_err_result'
drivers/scsi/ibmvscsi/ibmvfc.c:653: warning: Excess function parameter 'job_step' description in 'ibmvfc_del_tgt'
drivers/scsi/ibmvscsi/ibmvfc.c:773: warning: Function parameter or member 'queue' not described in 'ibmvfc_init_event_pool'
drivers/scsi/ibmvscsi/ibmvfc.c:773: warning: Function parameter or member 'size' not described in 'ibmvfc_init_event_pool'
drivers/scsi/ibmvscsi/ibmvfc.c:823: warning: Function parameter or member 'queue' not described in 'ibmvfc_free_event_pool'
drivers/scsi/ibmvscsi/ibmvfc.c:1413: warning: Function parameter or member 'vhost' not described in 'ibmvfc_gather_partition_info'
drivers/scsi/ibmvscsi/ibmvfc.c:1483: warning: Function parameter or member 'queue' not described in 'ibmvfc_get_event'
drivers/scsi/ibmvscsi/ibmvfc.c:1483: warning: Excess function parameter 'vhost' description in 'ibmvfc_get_event'
drivers/scsi/ibmvscsi/ibmvfc.c:1630: warning: Function parameter or member 't' not described in 'ibmvfc_timeout'
drivers/scsi/ibmvscsi/ibmvfc.c:1630: warning: Excess function parameter 'evt' description in 'ibmvfc_timeout'
drivers/scsi/ibmvscsi/ibmvfc.c:1893: warning: Function parameter or member 'shost' not described in 'ibmvfc_queuecommand'
drivers/scsi/ibmvscsi/ibmvfc.c:1893: warning: Excess function parameter 'done' description in 'ibmvfc_queuecommand'
drivers/scsi/ibmvscsi/ibmvfc.c:2324: warning: Function parameter or member 'rport' not described in 'ibmvfc_match_rport'
drivers/scsi/ibmvscsi/ibmvfc.c:2324: warning: Excess function parameter 'device' description in 'ibmvfc_match_rport'
drivers/scsi/ibmvscsi/ibmvfc.c:3133: warning: Function parameter or member 'evt_doneq' not described in 'ibmvfc_handle_crq'
drivers/scsi/ibmvscsi/ibmvfc.c:3317: warning: Excess function parameter 'reason' description in 'ibmvfc_change_queue_depth'
drivers/scsi/ibmvscsi/ibmvfc.c:3390: warning: Function parameter or member 'attr' not described in 'ibmvfc_show_log_level'
drivers/scsi/ibmvscsi/ibmvfc.c:3413: warning: Function parameter or member 'attr' not described in 'ibmvfc_store_log_level'
drivers/scsi/ibmvscsi/ibmvfc.c:3413: warning: Function parameter or member 'count' not described in 'ibmvfc_store_log_level'
drivers/scsi/ibmvscsi/ibmvfc.c:4121: warning: Function parameter or member 'done' not described in '__ibmvfc_tgt_get_implicit_logout_evt'
drivers/scsi/ibmvscsi/ibmvfc.c:4438: warning: Function parameter or member 't' not described in 'ibmvfc_adisc_timeout'
drivers/scsi/ibmvscsi/ibmvfc.c:4438: warning: Excess function parameter 'tgt' description in 'ibmvfc_adisc_timeout'
drivers/scsi/ibmvscsi/ibmvfc.c:4641: warning: Function parameter or member 'target' not described in 'ibmvfc_alloc_target'
drivers/scsi/ibmvscsi/ibmvfc.c:4641: warning: Excess function parameter 'scsi_id' description in 'ibmvfc_alloc_target'
drivers/scsi/ibmvscsi/ibmvfc.c:5068: warning: Function parameter or member 'evt' not described in 'ibmvfc_npiv_logout_done'
drivers/scsi/ibmvscsi/ibmvfc.c:5068: warning: Excess function parameter 'vhost' description in 'ibmvfc_npiv_logout_done'

Link: https://lore.kernel.org/r/20210317091230.2912389-35-lee.jones@linaro.org
Cc: Tyrel Datwyler <tyreld@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: linux-scsi@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Switch to using kobj_to_dev()

Fix the following coccicheck warnings:

./drivers/scsi/ibmvscsi/ibmvfc.c:3483:60-61: WARNING opportunity for
kobj_to_dev().

Link: https://lore.kernel.org/r/1614850124-54111-1-git-send-email-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Make ibmvfc_wait_for_ops() MQ aware

During MQ enablement of the ibmvfc driver ibmvfc_wait_for_ops() was
missed. This function is responsible for waiting on commands to complete
that match a certain criteria such as LUN or cancel key. The implementation
as is only scans the CRQ for events ignoring any sub-queues and as a result
will exit successfully without doing anything when operating in MQ
channelized mode.

Check the MQ and channel use flags to determine which queues are
applicable, and scan each queue accordingly. Note in MQ mode SCSI commands
are only issued down sub-queues and the CRQ is only used for driver
specific management commands. As such the CRQ events are ignored when
operating in MQ mode with channels.

Link: https://lore.kernel.org/r/20210319205029.312969-3-tyreld@linux.ibm.com
Fixes: 9000cb998bcf ("scsi: ibmvfc: Enable MQ and set reasonable defaults")
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix potential race in ibmvfc_wait_for_ops()

For various EH activities the ibmvfc driver uses ibmvfc_wait_for_ops() to
wait for the completion of commands that match a given criteria be it
cancel key, or specific LUN. With recent changes commands are completed
outside the lock in bulk by removing them from the sent list and adding
them to a private completion list. This introduces a potential race in
ibmvfc_wait_for_ops() since the criteria for a command to be outstanding is
no longer simply being on the sent list, but instead not being on the free
list.

Avoid this race by scanning the entire command event pool and checking that
any matching command that ibmvfc needs to wait on is not already on the
free list.

Link: https://lore.kernel.org/r/20210319205029.312969-2-tyreld@linux.ibm.com
Fixes: 1f4a4a19508d ("scsi: ibmvfc: Complete commands outside the host/queue lock")
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Free channel_setup_buf during device tear down

The buffer for negotiating channel setup is DMA allocated at device probe
time. However, the remove path fails to free this allocation which will
prevent the hypervisor from releasing the virtual device in the case of a
hotplug remove.

Fix this issue by freeing the buffer allocation in ibmvfc_free_mem().

Link: https://lore.kernel.org/r/20210311012212.428068-1-tyreld@linux.ibm.com
Fixes: e95eef3fc0bc ("scsi: ibmvfc: Implement channel enquiry and setup commands")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Reinitialize sub-CRQs and perform channel enquiry after LPM

A live partition migration (LPM) results in a CRQ disconnect similar to a
hard reset. In this LPM case the hypervisor mostly preserves the CRQ
transport such that it simply needs to be reenabled. However, the
capabilities may have changed such as fewer channels, or no channels at
all. Further, its possible that there may be sub-CRQ support, but no
channel support. The CRQ reenable path currently doesn't take any of this
into consideration.

For simplicity release and reinitialize sub-CRQs during reenable, and set
do_enquiry and using_channels with the appropriate values to trigger
channel renegotiation.

Link: https://lore.kernel.org/r/20210302230543.9905-6-tyreld@linux.ibm.com
Fixes: 3034ebe26389 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Reviewed-by: Brian King <brking@linux.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Store return code of H_FREE_SUB_CRQ during cleanup

The H_FREE_SUB_CRQ hypercall can return a retry delay return code that
indicates the call needs to be retried after a specific amount of time
delay. The error path to free a sub-CRQ in case of a failure during channel
registration fails to capture the return code of H_FREE_SUB_CRQ which will
result in the delay loop being skipped in the case of a retry delay return
code.

Store the return code result of the H_FREE_SUB_CRQ call such that the
return code check in the delay loop evaluates a meaningful value. Also, use
the rtas_busy_delay() to check the rc value and delay for the appropriate
amount of time.

Link: https://lore.kernel.org/r/20210302230543.9905-5-tyreld@linux.ibm.com
Fixes: 39e461fddff0 ("scsi: ibmvfc: Map/request irq and register Sub-CRQ interrupt handler")
Reviewed-by: Brian King <brking@linux.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Treat H_CLOSED as success during sub-CRQ registration

A non-zero return code for H_REG_SUB_CRQ is currently treated as a failure
resulting in failing sub-CRQ setup. The case of H_CLOSED should not be
treated as a failure. This return code translates to a successful sub-CRQ
registration by the hypervisor, and is meant to communicate back that there
is currently no partner VIOS CRQ connection established as of yet. This is
a common occurrence during a disconnect where the client adapter can
possibly come back up prior to the partner adapter.

For non-zero return code from H_REG_SUB_CRQ treat a H_CLOSED as success so
that sub-CRQs are successfully setup.

Link: https://lore.kernel.org/r/20210302230543.9905-4-tyreld@linux.ibm.com
Fixes: 3034ebe26389 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Reviewed-by: Brian King <brking@linux.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix invalid sub-CRQ handles after hard reset

A hard reset results in a complete transport disconnect such that the CRQ
connection with the partner VIOS is broken. This has the side effect of
also invalidating the associated sub-CRQs. The current code assumes that
the sub-CRQs are perserved resulting in a protocol violation after trying
to reconnect them with the VIOS. This introduces an infinite loop such that
the VIOS forces a disconnect after each subsequent attempt to re-register
with invalid handles.

Avoid the aforementioned issue by releasing the sub-CRQs prior to CRQ
disconnect, and driving a reinitialization of the sub-CRQs once a new CRQ
is registered with the hypervisor.

Link: https://lore.kernel.org/r/20210302230543.9905-3-tyreld@linux.ibm.com
Fixes: 3034ebe26389 ("scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels")
Reviewed-by: Brian King <brking@linux.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Simplify handling of sub-CRQ initialization

If ibmvfc_init_sub_crqs() fails ibmvfc_probe() simply parrots registration
failure reported elsewhere, and futher vhost->scsi_scrq.scrq == NULL is
indication enough to the driver that it has no sub-CRQs available. The
mq_enabled check can also be moved into ibmvfc_init_sub_crqs() such that
each caller doesn't have to gate the call with a mq_enabled check. Finally,
in the case of sub-CRQ setup failure setting do_enquiry can be turned off
to putting the driver into single queue fallback mode.

The aforementioned changes also simplify the next patch in the series that
fixes a hard reset issue, by tying a sub-CRQ setup failure and do_enquiry
logic into ibmvfc_init_sub_crqs().

Link: https://lore.kernel.org/r/20210302230543.9905-2-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

vio: make remove callback return void

The driver core ignores the return value of struct bus_type::remove()
because there is only little that can be done. To simplify the quest to
make this function return void, let struct vio_driver::remove() return
void, too. All users already unconditionally return 0, this commit makes
it obvious that returning an error code is a bad idea.

Note there are two nominally different implementations for a vio bus:
one in arch/sparc/kernel/vio.c and the other in
arch/powerpc/platforms/pseries/vio.c. This patch only adapts the powerpc
one.

Before this patch for a device that was bound to a driver without a
remove callback vio_cmo_bus_remove(viodev) wasn't called. As the device
core still considers the device unbound after vio_bus_remove() returns
calling this unconditionally is the consistent behaviour which is
implemented here.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Acked-by: Lijun Pan <ljp@linux.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[mpe: Drop unneeded hvcs_remove() forward declaration, squash in
change from sfr to drop ibmvnic_remove() forward declaration]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210225221834.160083-1-uwe@kleine-koenig.org

scsi: ibmvfc: Fix spelling mistake "succeded" -> "succeeded"

There is a spelling mistake in a ibmvfc_dbg debug message. Fix it.

Link: https://lore.kernel.org/r/20210118111346.70798-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Provide modules parameters for MQ settings

Add the various module parameter toggles for adjusting the MQ
characteristics at boot/load time as well as a device attribute for
changing the client scsi channel request amount.

Link: https://lore.kernel.org/r/20210114203148.246656-22-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Purge SCSI channels after transport loss/reset

Grab the queue and list lock for each Sub-CRQ and add any uncompleted
events to the host purge list.

Link: https://lore.kernel.org/r/20210114203148.246656-20-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Send Cancel MAD down each hw SCSI channel

In general the client needs to send Cancel MADs and task management
commands down the same channel as the command(s) intended to cancel or
abort. The client assigns cancel keys per LUN and thus must send a Cancel
down each channel commands were submitted for that LUN. Further, the client
then must wait for those cancel completions prior to submitting a LUN RESET
or ABORT TASK SET.

Add a cancel rsp iu syncronization field to the ibmvfc_queue struct such
that the cancel routine can sync the cancel response to each queue that
requires a cancel command. Build a list of each cancel event sent and wait
for the completion of each submitted cancel.

Link: https://lore.kernel.org/r/20210114203148.246656-19-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add cancel mad initialization helper

Add a helper routine for initializing a Cancel MAD. This will be useful for
a channelized client that needs to send Cancel commands down every channel
commands were sent for a particular LUN.

Link: https://lore.kernel.org/r/20210114203148.246656-18-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Register Sub-CRQ handles with VIOS during channel setup

If the ibmvfc client adapter requests channels it must submit a number of
Sub-CRQ handles matching the number of channels being requested. The VIOS
in its response will overwrite the actual number of channel resources
allocated which may be less than what was requested. The client then must
store the VIOS Sub-CRQ handle for each queue. This VIOS handle is needed as
a parameter with h_send_sub_crq().

Link: https://lore.kernel.org/r/20210114203148.246656-17-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Send commands down HW Sub-CRQ when channelized

When the client has negotiated the use of channels all vfcFrames are
required to go down a Sub-CRQ channel or it is a protocoal violation. If
the adapter state is channelized submit vfcFrames to the appropriate
Sub-CRQ via the h_send_sub_crq() helper.

Link: https://lore.kernel.org/r/20210114203148.246656-16-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Set and track hw queue in ibmvfc_event struct

Extract the hwq id from a SCSI command and store it in the ibmvfc_event
structure to identify which Sub-CRQ to send the command down when channels
are being utilized.

Link: https://lore.kernel.org/r/20210114203148.246656-15-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Advertise client support for using hardware channels

Previous patches have plumbed the necessary Sub-CRQ interface and channel
negotiation MADs to fully channelize via hardware backed queues.

Advertise client support via NPIV Login capability IBMVFC_CAN_USE_CHANNELS
when the client bits have MQ enabled via vhost->mq_enabled, or when
channels were already in use during a subsequent NPIV Login. The later is
required because channel support is only renegotiated after a CRQ pair is
broken. Simple NPIV Logout/Logins require the client to continue to
advertise the channel capability until the CRQ pair between the client is
broken.

Link: https://lore.kernel.org/r/20210114203148.246656-14-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Implement channel enquiry and setup commands

New NPIV_ENQUIRY_CHANNEL and NPIV_SETUP_CHANNEL management datagrams (MADs)
were defined in a previous patchset. If the client advertises a desire to
use channels and the partner VIOS is channel capable then the client must
proceed with channel enquiry to determine the maximum number of channels
the VIOS is capable of providing, and registering SubCRQs via channel setup
with the VIOS immediately following NPIV Login. This handshaking should not
be performed for subsequent NPIV Logins unless the CRQ connection has been
reset.

Implement these two new MADs and issue them following a successful NPIV
login where the VIOS has set the SUPPORT_CHANNELS capability bit in the
NPIV Login response.

Link: https://lore.kernel.org/r/20210114203148.246656-13-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Map/request irq and register Sub-CRQ interrupt handler

Create an irq mapping for the hw_irq number provided from phyp firmware.
Request an irq assigned our Sub-CRQ interrupt handler. Unmap these irqs at
Sub-CRQ teardown.

Link: https://lore.kernel.org/r/20210114203148.246656-12-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Define Sub-CRQ interrupt handler routine

Simple handler that calls Sub-CRQ drain routine directly.

Link: https://lore.kernel.org/r/20210114203148.246656-11-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add handlers to drain and complete Sub-CRQ responses

The logic for iterating over the Sub-CRQ responses is similiar to that of
the primary CRQ. Add the necessary handlers for processing those responses.

Link: https://lore.kernel.org/r/20210114203148.246656-10-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add Sub-CRQ IRQ enable/disable routine

Each Sub-CRQ has its own interrupt. A hypercall is required to toggle the
IRQ state. Provide the necessary mechanism via a helper function.

Link: https://lore.kernel.org/r/20210114203148.246656-9-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add alloc/dealloc routines for SCSI Sub-CRQ Channels

Allocate a set of Sub-CRQs in advance. During channel setup the client and
VIOS negotiate the number of queues the VIOS supports and the number that
the client desires to request. Its possible that the final channel
resources allocated is less than requested, but the client is still
responsible for sending handles for every queue it is hoping for.

Also, provide deallocation cleanup routines.

Link: https://lore.kernel.org/r/20210114203148.246656-8-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Define hcall wrapper for registering a Sub-CRQ

Sub-CRQs are registred with firmware via a hypercall. Abstract that
interface into a simpler helper function.

Link: https://lore.kernel.org/r/20210114203148.246656-6-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add size parameter to ibmvfc_init_event_pool()

With the upcoming addition of Sub-CRQs the event pool size may vary
per-queue.

Add a size parameter to ibmvfc_init_event_pool() such that different size
event pools can be requested by ibmvfc_alloc_queue().

Link: https://lore.kernel.org/r/20210114203148.246656-5-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Init/free event pool during queue allocation/free

The event pool and CRQ used to be separate entities of the adapter host
structure and as such were allocated and freed independently of each
other. Recent work as defined a generic queue structure with an event pool
specific to each queue. As such the event pool for each queue shouldn't be
allocated/freed independently, but instead performed as part of the queue
allocation/free routines.

Move the calls to ibmvfc_event_pool_{init|free} into
ibmvfc_{alloc|free}_queue respectively. The only functional change here is
that the CRQ cannot be released in ibmvfc_remove until after the event pool
has been successfully purged since releasing the queue will also free the
event pool.

Link: https://lore.kernel.org/r/20210114203148.246656-4-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Move event pool init/free routines

The next patch in this series reworks the event pool allocation calls to
happen within the individual queue allocation routines instead of as
independent calls.

Move the init/free routines earlier in ibmvfc.c to prevent undefined
reference errors when calling these functions from the queue allocation
code. No functional change.

Link: https://lore.kernel.org/r/20210114203148.246656-3-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add vhost fields and defaults for MQ enablement

Introduce several new vhost fields for managing MQ state of the adapter as
well as initial defaults for MQ enablement.

Link: https://lore.kernel.org/r/20210114203148.246656-2-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Relax locking around ibmvfc_queuecommand()

The driver's queuecommand routine is still wrapped to hold the host lock
for the duration of the call. This will become problematic when moving to
multiple queues due to the lock contention preventing asynchronous
submissions to mulitple queues. There is no real legitimate reason to hold
the host lock, and previous patches have insured proper protection of
moving ibmvfc_event objects between free and sent lists.

Link: https://lore.kernel.org/r/20210106201835.1053593-6-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Complete commands outside the host/queue lock

Drain the command queue and place all commands on a completion list.
Perform command completion on that list outside the host/queue locks.
Further, move purged command compeletions outside the host_lock as well.

Link: https://lore.kernel.org/r/20210106201835.1053593-5-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Define per-queue state/list locks

Define per-queue locks for protecting queue state and event pool sent/free
lists. The evt list lock is initially redundant but it allows the driver to
be modified in the follow-up patches to relax the queue locking around
submissions and completions.

Link: https://lore.kernel.org/r/20210106201835.1053593-4-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Make command event pool queue specific

There is currently a single command event pool per host. In anticipation of
providing multiple queues add a per-queue event pool definition and
reimplement the existing CRQ to use its queue defined event pool for
command submission and completion.

Link: https://lore.kernel.org/r/20210106201835.1053593-3-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Define generic queue structure for CRQs

The primary and async CRQs are nearly identical outside of the format and
length of each message entry in the dma mapped page that represents the
queue data. These queues can be represented with a generic queue structure
that uses a union to differentiate between message format of the mapped
page.

This structure will further be leveraged in a followup patcheset that
introduces Sub-CRQs.

Link: https://lore.kernel.org/r/20210106201835.1053593-2-tyreld@linux.ibm.com
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Set default timeout to avoid crash during migration

While testing live partition mobility, we have observed occasional crashes
of the Linux partition. What we've seen is that during the live migration,
for specific configurations with large amounts of memory, slow network
links, and workloads that are changing memory a lot, the partition can end
up being suspended for 30 seconds or longer. This resulted in the following
scenario:

CPU 0 CPU 1
------------------------------- ----------------------------------
scsi_queue_rq migration_store
-> blk_mq_start_request -> rtas_ibm_suspend_me
-> blk_add_timer -> on_each_cpu(rtas_percpu_suspend_me
_______________________________________V
|
V
-> IPI from CPU 1
-> rtas_percpu_suspend_me
-> __rtas_suspend_last_cpu

-- Linux partition suspended for > 30 seconds --
-> for_each_online_cpu(cpu)
plpar_hcall_norets(H_PROD
-> scsi_dispatch_cmd
-> scsi_times_out
-> scsi_abort_command
-> queue_delayed_work
-> ibmvfc_queuecommand_lck
-> ibmvfc_send_event
-> ibmvfc_send_crq
- returns H_CLOSED
<- returns SCSI_MLQUEUE_HOST_BUSY
-> __blk_mq_requeue_request

-> scmd_eh_abort_handler
-> scsi_try_to_abort_cmd
- returns SUCCESS
-> scsi_queue_insert

Normally, the SCMD_STATE_COMPLETE bit would protect against the command
completion and the timeout, but that doesn't work here, since we don't
check that at all in the SCSI_MLQUEUE_HOST_BUSY path.

In this case we end up calling scsi_queue_insert on a request that has
already been queued, or possibly even freed, and we crash.

The patch below simply increases the default I/O timeout to avoid this race
condition. This is also the timeout value that nearly all IBM SAN storage
recommends setting as the default value.

Link: https://lore.kernel.org/r/1610463998-19791-1-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix missing cast of ibmvfc_event pointer to u64 handle

Commit 2aa0102c6688 ("scsi: ibmvfc: Use correlation token to tag commands")
sets the vfcFrame correlation token to the pointer handle of the associated
ibmvfc_event. However, that commit failed to cast the pointer to an
appropriate type which in this case is a u64. As such sparse warnings are
generated for both correlation token assignments.

ibmvfc.c:2375:36: sparse: incorrect type in argument 1 (different base types)
ibmvfc.c:2375:36: sparse: expected unsigned long long [usertype] val
ibmvfc.c:2375:36: sparse: got struct ibmvfc_event *[assigned] evt

Add the appropriate u64 casts when assigning an ibmvfc_event as a
correlation token.

Link: https://lore.kernel.org/r/20210106203721.1054693-1-tyreld@linux.ibm.com
Fixes: 2aa0102c6688 ("scsi: ibmvfc: Use correlation token to tag commands")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Advertise client support for targetWWPN using v2 commands

The previous patch added support for the targetWWPN field in version 2 MADs
and vfcFrame structures.

Set the IBMVFC_CAN_SEND_VF_WWPN bit in our capabailites flag during NPIV
Login to inform the VIOS that this client supports the feature.

Link: https://lore.kernel.org/r/20201118011104.296999-7-tyreld@linux.ibm.com
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add support for target_wwpn field in v2 MADs and vfcFrame

Several version 2 MADs and the version 2 vfcFrame structures introduced a
new targetWWPN field for better identification of a target over the
scsi_id.

Set this field and MAD versioning fields when the VIOS advertises the
IBMVFC_HANDLE_VF_WWPN capability.

Link: https://lore.kernel.org/r/20201118011104.296999-6-tyreld@linux.ibm.com
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add FC payload retrieval routines for versioned vfcFrames

The FC iu and response payloads are located at different offsets depending
on the ibmvfc_cmd version. This is a result of the version 2 vfcFrame
definition adding an extra 64bytes of reserved space to the structure prior
to the payloads.

Add helper routines to determine the current vfcFrame version and return a
pointer to the proper iu or response structure within that ibmvfc_cmd.

Link: https://lore.kernel.org/r/20201118011104.296999-5-tyreld@linux.ibm.com
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add helper for testing capability flags

Testing the NPIV Login response capabilities is a long winded process of
dereferencing the vhost->login_buf->resp.capabilities field, then byte
swapping that value to host endian, and performing the bitwise test.
Currently we only ever check this in ibmvfc_cancel_all(), but follow-up
patches will need to regularly check for targetWWPN and channelization
support.

Add a helper to simplify checking various VIOS capabilities, namely
ibmvfc_check_caps().

Link: https://lore.kernel.org/r/20201118011104.296999-4-tyreld@linux.ibm.com
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add new fields for version 2 of several MADs

Introduce a target_wwpn field to several MADs. Its possible that a SCSI ID
of a target can change due to some fabric changes. The WWPN of the SCSI
target provides a better way to identify the target. Also, add flags for
receiving MAD versioning information and advertising client support for
targetWWPN with the VIOS. This latter capability flag will be required for
future clients capable of requesting multiple hardware queues from the host
adapter.

Link: https://lore.kernel.org/r/20201118011104.296999-3-tyreld@linux.ibm.com
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Deduplicate common ibmvfc_cmd init code

The virtual FC frame command exchanged with the VIOS is used for device
reset and command abort TMF as well as normally queued commands. When
initializing the ibmvfc_cmd there are several elements of the command that
are set the same way regardless of the command type.

Deduplicate code by moving these commonally set fields into a
initialization helper routine, namely ibmvfc_init_vfc_cmd().

Link: https://lore.kernel.org/r/20201118011104.296999-2-tyreld@linux.ibm.com
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Use correlation token to tag commands

The vfcFrame correlation field is a 64bit handle that is intended to trace
I/O operations through both the client stack and VIOS stack when the
underlying physical FC adapter supports tagging.

Tag vfcFrames with the associated ibmvfc_event pointer handle.

Link: https://lore.kernel.org/r/20201117185031.129939-3-tyreld@linux.ibm.com
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Remove trailing semicolon

Remove a superfluous semicolon following a closing function block bracket.

Link: https://lore.kernel.org/r/20201117185031.129939-2-tyreld@linux.ibm.com
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Byte swap login_buf.resp values in attribute show functions

Both ibmvfc_show_host_(capabilities|npiv_version) functions retrieve values
from vhost->login_buf.resp buffer. This is the MAD response buffer from the
VIOS and as such any multi-byte non-string values are in big endian format.

Byte swap these values to host CPU endian format for better human
readability.

Link: https://lore.kernel.org/r/20201117185031.129939-1-tyreld@linux.ibm.com
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Protect vhost->task_set increment by the host lock

In the discovery thread, ibmvfc does a vhost->task_set++ without any lock
held. This could result in two targets getting the same cancel key, which
could have strange effects in error recovery. The actual probability of
this occurring should be extremely small, since this should all be done in
a single threaded loop from the discovery thread, but let's fix it up
anyway to be safe.

Link: https://lore.kernel.org/r/1600286999-22059-1-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Avoid link down on FS9100 canister reboot

When a canister on a FS9100, or similar storage, running in NPIV mode, is
rebooted, its WWPNs will fail over to another canister. When this occurs,
we see a WWPN going away from the fabric at one N-Port ID, and, a short
time later, the same WWPN appears at a different N-Port ID. When the
canister is fully operational again, the WWPNs fail back to the original
canister. If there is any I/O outstanding to the target when this occurs,
it will result in the implicit logout the ibmvfc driver issues before
removing the rport to fail. When the WWPN then shows up at a different
N-Port ID, and we issue a PLOGI to it, the VIOS will see that it still has
a login for this WWPN at the old N-Port ID, which results in the VIOS
simulating a link down / link up sequence to the client, in order to get
the VIOS and client LPAR in sync.

The patch below improves the way we handle this scenario so as to avoid the
link bounce, which affects all targets under the virtual host adapter. The
change is to utilize the Move Login MAD, which will work even when I/O is
outstanding to the target. The change only alters the target state machine
for the case where the implicit logout fails prior to deleting the rport.
If this implicit logout fails, we defer deleting the ibmvfc_target object
after calling fc_remote_port_delete. This enables us to later retry the
implicit logout after terminate_rport_io occurs, or to issue the Move Login
request if a WWPN shows up at a new N-Port ID prior to this occurring.

This has been tested by IBM's storage interoperability team on a FS9100,
forcing the failover to occur. With debug tracing enabled in the ibmvfc
driver, we confirmed the move login was sent in this scenario and confirmed
the link bounce no longer occurred.

[mkp: fix checkpatch warnings]

Link: https://lore.kernel.org/r/1599859706-8505-1-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix error return in ibmvfc_probe()

Fix to return error code PTR_ERR() from the error handling case instead of
0.

Link: https://lore.kernel.org/r/20200907083949.154251-1-jingxiangfeng@huawei.com
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

scsi: Fix trivial spelling

The word 'descriptor' is misspelled throughout the tree.

Fix it up accordingly:
decriptors -> descriptors

Link: https://lore.kernel.org/r/20200609124610.3445662-7-kieran.bingham+renesas@ideasonboard.com
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Don't send implicit logouts prior to NPIV login

Commit ed830385a2b1 ("scsi: ibmvfc: Avoid loss of all paths during SVC node
reboot") introduced a regression where when the client resets or re-enables
its CRQ with the hypervisor there is a chance that if the server side
doesn't issue its INIT handshake quick enough the client can issue an
Implicit Logout prior to doing an NPIV Login. The server treats this
scenario as a protocol violation and closes the CRQ on its end forcing the
client through a reset that gets the client host state and next host action
out of agreement leading to a BUG assert.

ibmvfc 30000003: Partner initialization complete
ibmvfc 30000002: Partner initialization complete
ibmvfc 30000002: Host partner adapter deregistered or failed (rc=2)
ibmvfc 30000002: Partner initialized
------------[ cut here ]------------
kernel BUG at ../drivers/scsi/ibmvscsi/ibmvfc.c:4489!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Supported: No, Unreleased kernel
CPU: 16 PID: 1290 Comm: ibmvfc_0 Tainted: G OE X 5.3.18-12-default
NIP: c00800000d84a2b4 LR: c00800000d84a040 CTR: c00800000d84a2a0
REGS: c00000000cb57a00 TRAP: 0700 Tainted: G OE X (5.3.18-12-default)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24000848 XER: 00000001
CFAR: c00800000d84a070 IRQMASK: 1
GPR00: c00800000d84a040 c00000000cb57c90 c00800000d858e00 0000000000000000
GPR04: 0000000000000000 0000000000000000 0000000000000000 00000000000000a0
GPR08: c00800000d84a074 0000000000000001 0000000000000014 c00800000d84d7d0
GPR12: 0000000000000000 c00000001ea28200 c00000000016cd98 0000000000000000
GPR16: c00800000d84b7b8 0000000000000000 0000000000000000 c00000542c706d68
GPR20: 0000000000000005 c00000542c706d88 5deadbeef0000100 5deadbeef0000122
GPR24: 000000000000000c 000000000000000b c00800000d852180 0000000000000001
GPR28: 0000000000000000 c00000542c706da0 c00000542c706860 c00000542c706828
NIP [c00800000d84a2b4] ibmvfc_work+0x3ac/0xc90 [ibmvfc]
LR [c00800000d84a040] ibmvfc_work+0x138/0xc90 [ibmvfc]

This scenario can be prevented by rejecting any attempt to send an Implicit
Logout if the client adapter is not logged in yet.

Link: https://lore.kernel.org/r/20200427214824.6890-1-tyreld@linux.ibm.com
Fixes: ed830385a2b1 ("scsi: ibmvfc: Avoid loss of all paths during SVC node reboot")
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix NULL return compiler warning

Fix up a compiler warning introduced via 54b04c99d02e

Link: https://lore.kernel.org/r/1583159961-15903-1-git-send-email-brking@linux.vnet.ibm.com
Fixes: 54b04c99d02e ("scsi: ibmvfc: Avoid loss of all paths during SVC node reboot")
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Avoid loss of all paths during SVC node reboot

When an SVC node goes down as part of a node reboot, its WWPNs are moved to
the remaining node. When the node is back online, its WWPNs are moved
back. The result is that the WWPN moves from one NPort_ID to another, then
back again. The ibmvfc driver was forcing the old port to be removed, but
not sending an implicit logout. When the WWPN showed up at the new
location, the PLOGI failed as there was already a login established for the
old scsi id. The patch below fixes this by ensuring we always send an
implicit logout for any scsi id associated with an rport prior to calling
fc_remote_port_delete.

Link: https://lore.kernel.org/r/1582767943-16611-1-git-send-email-brking@linux.vnet.ibm.com
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Mark expected switch fall-throughs

Mark switch cases where we are expecting to fall through.

This patch fixes the following warnings:

drivers/scsi/ibmvscsi/ibmvfc.c: In function 'ibmvfc_npiv_login_done':
drivers/scsi/ibmvscsi/ibmvfc.c:4022:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
ibmvfc_retry_host_init(vhost);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/ibmvscsi/ibmvfc.c:4023:2: note: here
case IBMVFC_MAD_DRIVER_FAILED:
^~~~
drivers/scsi/ibmvscsi/ibmvfc.c: In function 'ibmvfc_bsg_request':
drivers/scsi/ibmvscsi/ibmvfc.c:1830:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
port_id = (bsg_request->rqst_data.h_els.port_id[0] << 16) |
~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(bsg_request->rqst_data.h_els.port_id[1] << 8) |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bsg_request->rqst_data.h_els.port_id[2];
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/ibmvscsi/ibmvfc.c:1833:2: note: here
case FC_BSG_RPT_ELS:
^~~~
drivers/scsi/ibmvscsi/ibmvfc.c:1838:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
port_id = (bsg_request->rqst_data.h_ct.port_id[0] << 16) |
~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(bsg_request->rqst_data.h_ct.port_id[1] << 8) |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bsg_request->rqst_data.h_ct.port_id[2];
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/ibmvscsi/ibmvfc.c:1841:2: note: here
case FC_BSG_RPT_CT:
^~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: fix WARN_ON during event pool release

While removing an ibmvfc client adapter a WARN_ON like the following
WARN_ON is seen in the kernel log:

WARNING: CPU: 6 PID: 5421 at ./include/linux/dma-mapping.h:541
ibmvfc_free_event_pool+0x12c/0x1f0 [ibmvfc]
CPU: 6 PID: 5421 Comm: rmmod Tainted: G E 4.17.0-rc1-next-20180419-autotest #1
NIP: d00000000290328c LR: d00000000290325c CTR: c00000000036ee20
REGS: c000000288d1b7e0 TRAP: 0700 Tainted: G E (4.17.0-rc1-next-20180419-autotest)
MSR: 800000010282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 44008828 XER: 20000000
CFAR: c00000000036e408 SOFTE: 1
GPR00: d00000000290325c c000000288d1ba60 d000000002917900 c000000289d75448
GPR04: 0000000000000071 c0000000ff870000 0000000018040000 0000000000000001
GPR08: 0000000000000000 c00000000156e838 0000000000000001 d00000000290c640
GPR12: c00000000036ee20 c00000001ec4dc00 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 00000100276901e0 0000000010020598
GPR20: 0000000010020550 0000000010020538 0000000010020578 00000000100205b0
GPR24: 0000000000000000 0000000000000000 0000000010020590 5deadbeef0000100
GPR28: 5deadbeef0000200 d000000002910b00 0000000000000071 c0000002822f87d8
NIP [d00000000290328c] ibmvfc_free_event_pool+0x12c/0x1f0 [ibmvfc]
LR [d00000000290325c] ibmvfc_free_event_pool+0xfc/0x1f0 [ibmvfc]
Call Trace:
[c000000288d1ba60] [d00000000290325c] ibmvfc_free_event_pool+0xfc/0x1f0 [ibmvfc] (unreliable)
[c000000288d1baf0] [d000000002909390] ibmvfc_abort_task_set+0x7b0/0x8b0 [ibmvfc]
[c000000288d1bb70] [c0000000000d8c68] vio_bus_remove+0x68/0x100
[c000000288d1bbb0] [c0000000007da7c4] device_release_driver_internal+0x1f4/0x2d0
[c000000288d1bc00] [c0000000007da95c] driver_detach+0x7c/0x100
[c000000288d1bc40] [c0000000007d8af4] bus_remove_driver+0x84/0x140
[c000000288d1bcb0] [c0000000007db6ac] driver_unregister+0x4c/0xa0
[c000000288d1bd20] [c0000000000d6e7c] vio_unregister_driver+0x2c/0x50
[c000000288d1bd50] [d00000000290ba0c] cleanup_module+0x24/0x15e0 [ibmvfc]
[c000000288d1bd70] [c0000000001dadb0] sys_delete_module+0x220/0x2d0
[c000000288d1be30] [c00000000000b284] system_call+0x58/0x6c
Instruction dump:
e8410018 e87f0068 809f0078 e8bf0080 e8df0088 2fa30000 419e008c e9230200
2fa90000 419e0080 894d098a 794a07e0 <0b0a0000> e9290008 2fa90000 419e0028

This is tripped as a result of irqs being disabled during the call to
dma_free_coherent() by ibmvfc_free_event_pool(). At this point in the code path
we have quiesced the adapter and its overly paranoid anyways to be holding the
host lock.

Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: ibmvfc: Clean up transport events

No change to functionality. Simply make transport event messages a little
clearer, and rework CRQ format enums such that we have separate enums for
INIT messages and XPORT events.

[mkp: typo]

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Byte swap status and error codes when logging

Status and error codes are returned in big endian from the VIOS. The values
are translated into a human readable format when logged, but the values are
also logged. This patch byte swaps those values so that they are consistent
between BE and LE platforms.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Add failed PRLI to cmd_status lookup array

The VIOS uses the SCSI_ERROR class to report PRLI failures. These errors
are indicated with the combination of a IBMVFC_FC_SCSI_ERROR return status
and 0x8000 error code. Add these codes to cmd_status[] with appropriate
human readable error message.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Remove "failed" from logged errors

The text of messages logged with ibmvfc_log_error() always contain the term
"failed". In the case of cancelled commands during EH they are reported
back by the VIOS using error codes. This can be confusing to somebody
looking at these log messages as to whether a command was successfully
cancelled. The following real log message for example it is unclear if the
transaction was actaully cancelled.

<6>sd 0:0:1:1: Cancelling outstanding commands.
<3>sd 0:0:1:1: [sde] Command (28) failed: transaction cancelled (2:6) flags: 0 fcp_rsp: 0, resid=0, scsi_status: 0

Remove prefixing of "failed" to all error logged messages. The
ibmvfc_log_error() function translates the returned error/status codes to a
human readable message already.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: flip the default on use_clustering

Most SCSI drivers want to enable "clustering", that is merging of
segments so that they might span more than a single page. Remove the
ENABLE_CLUSTERING define, and require drivers to explicitly set
DISABLE_CLUSTERING to disable this feature.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: remove Scsi_Cmnd typedef

This will make subsequent refactoring easier to handle.

Note: this patch is nowhere checkpatch clean.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Avoid unnecessary port relogin

Following an RSCN, ibmvfc will issue an ADISC to determine if the
underlying target has changed, comparing the SCSI ID, WWPN, and WWNN to
determine how to handle the rport in discovery. However, the comparison
of the WWPN and WWNN was performing a memcmp between a big endian field
against a CPU endian field, which resulted in the wrong answer on LE
systems. This was observed as unexpected errors getting logged at boot
time as targets were getting relogins when not needed.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Remove unneeded semicolons

Trivial fix removes unneeded semicolons after switch blocks.

This issue was detected by using the Coccinelle software.

Signed-off-by: Christopher Díaz Riveros <chrisadr@gentoo.org>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvscsi: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: linux-scsi@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>

scsi: ibmvfc: ibmvscsi: ibmvscsi_tgt: constify vio_device_id

vio_device_id are not supposed to change at runtime. All functions
working with vio_device_id provided by <asm/vio.h> work with const
vio_device_id. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Do not call fc_block_scsi_eh() on host reset

When we're resetting the host any remote port states will be reset
anyway, so it's pointless to wait for dev_loss_tmo during host reset.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: constify dev_pm_ops structures.

dev_pm_ops are not supposed to change at runtime. All functions
working with dev_pm_ops provided by <linux/device.h> work with const
dev_pm_ops. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
41937 1296 20 43253 a8f5 drivers/scsi/ibmvscsi/ibmvfc.o

File size After adding 'const':
text data bss dec hex filename
42129 1104 20 43253 a8f5 drivers/scsi/ibmvscsi/ibmvfc.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: don't check for failure from mempool_alloc()

mempool_alloc() cannot fail when passed GFP_NOIO or any other gfp
setting that is permitted to sleep. So remove this pointless code.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove eh_timed_out methods in the transport template

Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates. This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fc: use bsg_job_done

fc_bsg_jobdone() and bsg_job_done() are 1:1 copies now so use the
bsg-lib one instead of the FC private implementation.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: change FC drivers to use 'struct bsg_job'

Change FC drivers to use 'struct bsg_job' from bsg-lib.h instead of
'struct fc_bsg_job' from scsi_transport_fc.h and remove 'struct
fc_bsg_job'.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fc: provide fc_bsg_to_rport() helper

Provide fc_bsg_to_rport() helper that will become handy when we're
moving from struct fc_bsg_job to a plain struct bsg_job. Also move all
LLDDs to use the new helper.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fc: provide fc_bsg_to_shost() helper

Provide fc_bsg_to_shost() helper that will become handy when we're
moving from struct fc_bsg_job to a plain struct bsg_job. Also use this
little helper in the LLDDs.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fc: Export fc_bsg_jobdone and use it in FC drivers

Export fc_bsg_jobdone so drivers can use it directly instead of doing
the round-trip via struct fc_bsg_job::job_done() and use it in the
LLDDs. That way we can also unify the interfaces of fc_bsg_jobdone and
bsg_job_done.

As we've converted all LLDDs over to use fc_bsg_jobdone() directly, we
can remove the function pointer from struct fc_bsg_job as well.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: don't use fc_bsg_job::request and fc_bsg_job::reply directly

Don't use fc_bsg_job::request and fc_bsg_job::reply directly, but use
helper variables bsg_request and bsg_reply. This will be helpful when
transitioning to bsg-lib.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Fix I/O hang when port is not mapped

If a VFC port gets unmapped in the VIOS, it may not respond with a CRQ
init complete following H_REG_CRQ. If this occurs, we can end up having
called scsi_block_requests and not a resulting unblock until the init
complete happens, which may never occur, and we end up hanging I/O
requests. This patch ensures the host action stay set to
IBMVFC_HOST_ACTION_TGT_DEL so we move all rports into devloss state and
unblock unless we receive an init complete.

Cc: <stable@vger.kernel.org>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: fix typo in parameter description

Fix typo in parameter description.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: add FC Class 3 Error Recovery support

The ibmvfc driver currently doesn't support FC Class 3 Error Recovery.
However, it is simply a matter of informing the VIOS that the payload
expects to use sequence level error recovery via a bit flag in the
ibmvfc_cmd structure.

This patch adds a module parameter to enable error recovery support at
boot time. When enabled the RETRY service parameter bit is set during
PRLI, and ibmvfc_cmd->flags includes the IBMVFC_CLASS_3_ERR bit.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ibmvfc: Set READ FCP_XFER_READY DISABLED bit in PRLI

The READ FCP_XFER_READY DISABLED bit is required to always be set to one
since FCP-3. Set it in the service parameter page frame during process
login.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ibmvfc: prevent a potential deadlock

My static checker complains that we need to unlock on this path. Seems
true.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ibmvfc: byteswap scsi_id, wwpn, and node_name prior to logging

When logging async events the scsi_id, wwpn, and node_name values are
used directly from the CRQ struct which are of type __be64. This can be
confusing to someone looking through the log on a LE system. Instead
byteswap these values to host endian prior to logging.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: use host wide tags by default

This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags. We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

ibmvfc: remove unused tag variable

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Brian King <brking@linux.vnet.ibm.com>

scsi: remove ->change_queue_type method

Since we got rid of ordered tag support in 2010 the prime use case of
switching on and off ordered tags has been obsolete. The other function
of enabling/disabling tagging entirely has only been correctly implemented
by the 53c700 driver and isn't generally useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: avoid ->change_queue_depth indirection for queue full tracking

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq. This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove abuses of scsi_populate_tag

Unless we want to build a SPI tag message we should just check SCMD_TAGGED
instead of reverse engineering a tag type through the use of
scsi_populate_tag_msg.

Also rename the function to spi_populate_tag_msg, make it behave like the
other spi message helpers, and move it to the spi transport class.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: provide a generic change_queue_type method

Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

ibmvfc: fix little endian issues

Added big endian annotations to relevant data structure fields, and necessary
byte swappings to support little endian builds.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: use 64-bit value for 'max_luns'

Now that we're using 64-bit LUNs internally we need to increase
the size of max_luns to 64 bits, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

sched, treewide: Replace hardcoded nice values with MIN_NICE/MAX_NICE

Replace various -20/+19 hardcoded nice values with MIN_NICE/MAX_NICE.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ff13819fd09b7a5dba5ab5ae797f2e7019bdfa17.1394532288.git.yangds.fnst@cn.fujitsu.com
Cc: devel@driverdev.osuosl.org
Cc: devicetree@vger.kernel.org
Cc: fcoe-devel@open-fcoe.org
Cc: linux390@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-s390@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: nbd-general@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: openipmi-developer@lists.sourceforge.net
Cc: qla2xxx-upstream@qlogic.com
Cc: linux-arch@vger.kernel.org
[ Consolidated the patches, twiddled the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

[SCSI] ibmvfc: Fix for offlining devices during error recovery

This fixes an issue seen with devices getting marked offline
in a scenario where a VIOS was getting rebooted while a
client VFC adapter is in SCSI EH and prevents unnecessary
EH escalation in some scenarios.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] ibmvfc: Suppress ABTS if target gone

Adds support for a new VIOS feature that allows ibmvfc to
optimize terminate_rport_io by telling the VIOS the target
is no longer accessible on the fabric and that it should
not send an ABTS out on the fabric to the device.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] ibmvfc: Send cancel when link is down

If attempting to abort requests due to a fail fail timeout
or error handling while the link is down, we cannot send
an abort out on the fabric. We can, however, send a cancel
to the VIOS. This fixes ibmvfc to send a cancel in this
case to prevent error handling from failing and/or
escalating.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] ibmvfc: Support FAST_IO_FAIL in EH handlers

Adds support for receiving FAST_IO_FAIL from fc_block_scsi_eh
when in error recovery. This fixes cases of devices being
taken offline when they are no longer accessible on the fabric,
preventing them from coming back online when the fabric recovers.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] ibmvfc: Properly set cancel flags when cancelling abort

The flags on a cancel operation are intended to indicate what,
if any, TMF will follow the cancel request. This fixes a case
where we were incorrectly setting the abort task set flag on
the cancel flag when we were cancelling an abort task set.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Drivers: scsi: remove __dev* attributes.

CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Adam Radford <linuxraid@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[SCSI] ibmvfc: Ignore fabric RSCNs when link is dead

This fixes an issues seen where a Fabric RSCN event was received
while the link was down, which resulted in repeated attempts to log back
into the fabric, which then failed, resulting in the ibmvfc driver
taking the host offline. Fix this by delaying taking any action
regarding the fabric RSCN until the link comes back up.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] ibmvfc: Fix double completion on abort timeout

If an abort request times out to the virtual fibre channel adapter,
the ibmvfc driver will kick off a reset of the adapter. This
patch ensures we wait for the both the abort request and the
request being aborted to be completed prior to exiting the
eh_abort handler. This fixes a bug where the ibmvfc driver
was erroneously returning success to the eh_abort handler
then later sending back a response to the same command.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

powerpc+sparc/vio: Modernize driver registration

This makes vio_register_driver() get the module owner & name at compile
time like PCI drivers do, and adds a name pointer directly in struct
vio_driver to avoid having to explicitly initialize the embedded
struct device.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David S. Miller <davem@davemloft.net>

[SCSI] ibmvfc: Fix Virtual I/O failover hang

If a Virtual I/O server fails in a dual virtual I/O server multipath
configuration, ensure we delete all remote ports so that path failover
can occur. For a single path configuration, the remote ports will
go into devloss state.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] ibmvfc: Improve ibmvfc_async_desc memory layout

By changing field ordering we can avoid a couple of memory holes in
the tables that use the ibmvfc_async_desc structure.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

SCSI host lock push-down

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] ibmvfc: Handle Virtual I/O Server reboot

If a Virtual I/O server is rebooted, the client fibre channel sees a
transport event on its CRQ, which causes it to attempt to reconnect
to the CRQ. For a period of time during the VIOS reboot, the client's
attempts to register the CRQ will return H_CLOSED, indicating the server
side is not currently registered. The ibmvfc driver was not handling
this well and was taking the virtual adapter offline. Fix this by
re-enabling our interrupt and waiting for the event on our CRQ
indicating the server is back, at which point we can reconnect.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: prep for fc host dev loss tmo support

This removes the driver's get_host_def_dev_loss_tmo
callback and just has the driver set the dev loss
using the fc class fc_host_dev_loss_tmo macro like is
done for other fc params.

This patch also removes the module dev loss param.
To override the value the fc host sysfs value being
added in the fc class patch can be used instead of the driver
module param.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Log link up/down events

By default, ibmvfc does not log any async events in order
to avoid flooding the log with them. Improve on this by
logging by default events that are not likely to flood the
log, such as link up/down. Having these events in the log
will improve the ability to debug issues with ibmvfc.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: do not reset dev_loss_tmo in slave callout

This fixes a bug where the driver was resetting the
rport dev_loss_tmo when devices were added by adding
support for the get_host_def_dev_loss_tmo callout.

Patch has only been compile tested.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fix terminate_rport_io

The ibmvfc driver was incorrectly obtaining a scsi_target pointer
from an fc_rport. The way it is coded ensures that ibmvfc's
terminate_rport_io handler does absolutely nothing. Fix this up
to iterate through affected devices differently, sending cancel
and abort task set as appropriate. Without this patch,
fast_io_fail_tmo is broken for ibmvfc.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fix rport add/delete race resulting in oops

Commit 43c8da907ccc656935d1085701f4db83385d8a59 introduced a race
condition which can occur when adding/deleting rports. There are
two possible threads now that can be deleting rports in the ibmvfc
driver, which can result in list_del being called twice, resulting
in an oops. This patch adds a new state to the ibmvfc_target struct
to indicate the target has been removed from the list and is in
the process of being deleted.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Add support for fc_block_scsi_eh

Adds support for fc_block_scsi_eh to block the EH handlers if
the target device is in the blocked state to ensure we don't
take devices offline.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fix soft lockup on resume

This fixes a softlockup seen on resume. During resume, the CRQ
must be reenabled. However, the H_ENABLE_CRQ hcall used to do
this may return H_BUSY or H_LONG_BUSY. When this happens, the
caller is expected to retry later. Normally the H_ENABLE_CRQ
succeeds relatively soon. However, we have seen cases where
this can take long enough to see softlockup warnings.
This patch changes a simple loop, which was causing the
softlockup, to a loop at task level which sleeps between
retries rather than simply spinning.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

sysfs: add struct file* to bin_attr callbacks

This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

of: Always use 'struct device.of_node' to get device node pointer.

The following structure elements duplicate the information in
'struct device.of_node' and so are being eliminated. This patch
makes all readers of these elements use device.of_node instead.

(struct of_device *)->node
(struct dev_archdata *)->prom_node (sparc)
(struct dev_archdata *)->of_node (powerpc & microblaze)

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

[SCSI] ibmvfc: Reduce error recovery timeout

If a command times out resulting in EH getting invoked, we wait for the
aborted commands to come back after sending the abort. Shorten
the amount of time we wait for these responses, to ensure we don't
get stuck in EH for several minutes.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fix command completion handling

Commands which are completed by the VIOS are placed on a CRQ
in kernel memory for the ibmvfc driver to process. Each CRQ
entry is 16 bytes. The ibmvfc driver reads the first 8 bytes
to check if the entry is valid, then reads the next 8 bytes to get
the handle, which is a pointer the completed command. This fixes
an issue seen on Power 7 where the processor reordered the
loads from memory, resulting in processing command completion
with a stale handle. This could result in command timeouts,
and also early completion of commands.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

[SCSI] ibmvfc: Add suspend/resume support

Adds support for resuming from suspend for IBM VFC devices. We may have
lost an interrupt over the suspend, so we just kick the interrupt handler
to process anything that is outstanding. We expect to find a transport event
indicating we need to reestablish our CRQ.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

block: Consolidate phys_segment and hw_segment limits

Except for SCSI no device drivers distinguish between physical and
hardware segment limits. Consolidate the two into a single segment
limit.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[SCSI] modify change_queue_depth to take in reason why it is being called

This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
Also converted pmcraid_change_queue_depth and then verified
all modules compile using "make allmodconfig" for any new build
warnings on X86_64.

Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Add FC Passthru support

Adds support for FC passthru via BSG.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fix adapter cancel flags for terminate_rport_io

When issuing a Cancel to the virtual fibre channel adapter,
the interface specifies a flags field for the client to indicate
what kind of error recovery is being performed. Fix up these
flags for terminate_rport_io to indicate an abort task set
rather than a target reset.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Remove unnecessary parameter to ibmvfc_init_host

Remove a parameter to ibmvfc_init_host which is always set to
zero by all callers.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fix locking in ibmvfc_remove

Need to grab the host lock around the call to ibmvfc_link_down.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvfc: Fixup TMF response handling

When processing the response to either a LUN reset,
target reset, or an abort task set, the ibmvfc driver needs to
treat as success receiving a response with a non-zero
status in the response IU along with a general transport
error with the FCP response code being zero. The VIOS
currently guarantees this cannot happen, but a future version
of VIOS may allow this to be returned, so ensure we handle
this response combination correctly for TMFs, as we already
do for SCSI commands.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] ibmvscsi: avoid unnecessary use of kzalloc_pool

The allocated struct is manually zeroed after allocation, so avoid using
the (broken) kzalloc mempool (which does not re-zero previously used items
when they are returned to the pool).

Acked-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

ibmvfc: Fix endless PRLI loop in discovery

Fixes a problem seen where sending a PRLI to a target
resulted in it sending a LOGO. This caused the ibmvfc
driver to go back through discovery again, which caused
another PRLI attempt, which caused another LOGO. Fix this
behavior by ignoring LOGO if we haven't even logged into
the target yet.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

ibmvfc: Process async events before command responses

Since async events could indicate changes to link status, or
events which could affect decisions made during discovery, we should
process async events prior to command completion responses.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Improve LOGO/PRLO ELS handling

There are several scenarios where the ibmvfc driver needs to
try to log back into a target on the fabric. Today when these events
occur, we simply go through re-discovery for all attached targets,
assuming that either the query of the name server or an ADISC will
indicate we might need to log back into the target, which doesn't
work for all scenarios. Fix this by taking note of the affected target(s)
in these conditions and ensuring we try to PLOGI back into the target.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Improve device rediscovery

For certain scenarios during device rediscovery, we detect we need
to log back into a target. Currently we do just that - PLOGI/PRLI
back into the target. Change the code to delete and add the target
from the FC transport layer as well, to ensure we handle any cases
where the target may have changed.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Add flush on halt support

The virtual I/O server controlling the NPIV adapter associated with
a virtual fibre channel adapter can send a HALT event to the client.
When this occurs, the client can no longer send commands until a RESUME
is received. By adding support for flush on halt, we will get all of
our outstanding commands flushed back before the Virtual I/O server
enters the halt state, eliminating potential command timeouts for
outstanding commands which might occur if we did not support this feature.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Add support for NPIV Logout

This patch adds support for a new command supported by the Virtual I/O
Server, NPIV Logout. The command will abort all outstanding commands
and log out of the fabric. Currently, the only way to do this is
by breaking the CRQ, which can take a fairly long time when lots of
commands are outstanding. The NPIV Logout commands provides a mechanism
to accomplish virtually the same function, but is much faster.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix deadlock in EH

Fixes the following deadlock scenario shown below. We currently allow
queuecommand to send commands when the ibmvfc workqueue is scanning for
new rports, so we should also allow EH to function at this time as well.

scsi_eh_3 D 0000000000000000 12304 1279 2
Call Trace:
[c0000002f7257730] [c0000002f72577e0] 0xc0000002f72577e0 (unreliable)
[c0000002f7257900] [c0000000000118f4] .__switch_to+0x158/0x1a0
[c0000002f72579a0] [c0000000004f8b40] .schedule+0x8d4/0x9dc
[c0000002f7257b60] [c0000000004f8f08] .schedule_timeout+0xa8/0xe8
[c0000002f7257c50] [d0000000001d23e0] .ibmvfc_wait_while_resetting+0xe4/0x140 [ibmvfc]
[c0000002f7257d20] [d0000000001d3984] .ibmvfc_eh_abort_handler+0x60/0xe4 [ibmvfc]
[c0000002f7257dc0] [d000000000366714] .scsi_error_handler+0x38c/0x674 [scsi_mod]
[c0000002f7257f00] [c0000000000a7470] .kthread+0x78/0xc4
[c0000002f7257f90] [c000000000029b8c] .kernel_thread+0x4c/0x68
ibmvfc_3 D 0000000000000000 12432 1280 2
Call Trace:
[c0000002f7253540] [c0000002f72535f0] 0xc0000002f72535f0 (unreliable)
[c0000002f7253710] [c0000000000118f4] .__switch_to+0x158/0x1a0
[c0000002f72537b0] [c0000000004f8b40] .schedule+0x8d4/0x9dc
[c0000002f7253970] [c0000000004f8e98] .schedule_timeout+0x38/0xe8
[c0000002f7253a60] [c0000000004f80cc] .wait_for_common+0x138/0x220
[c0000002f7253b40] [c0000000000a2784] .flush_cpu_workqueue+0xac/0xcc
[c0000002f7253c10] [c0000000000a2960] .flush_workqueue+0x58/0xa0
[c0000002f7253ca0] [d0000000000827fc] .fc_flush_work+0x4c/0x64 [scsi_transport_fc]
[c0000002f7253d20] [d000000000082db4] .fc_remote_port_add+0x48/0x6c4 [scsi_transport_fc]
[c0000002f7253dd0] [d0000000001d7d04] .ibmvfc_work+0x820/0xa7c [ibmvfc]
[c0000002f7253f00] [c0000000000a7470] .kthread+0x78/0xc4
[c0000002f7253f90] [c000000000029b8c] .kernel_thread+0x4c/0x68
fc_wq_3 D 0000000000000000 10720 1283 2
Call Trace:
[c0000002f559ac30] [c0000002f559ace0] 0xc0000002f559ace0 (unreliable)
[c0000002f559ae00] [c0000000000118f4] .__switch_to+0x158/0x1a0
[c0000002f559aea0] [c0000000004f8b40] .schedule+0x8d4/0x9dc
[c0000002f559b060] [c0000000004f8e98] .schedule_timeout+0x38/0xe8
[c0000002f559b150] [c0000000004f80cc] .wait_for_common+0x138/0x220
[c0000002f559b230] [c0000000002721c4] .blk_execute_rq+0xb4/0x100
[c0000002f559b360] [d00000000036a1f8] .scsi_execute+0x118/0x194 [scsi_mod]
[c0000002f559b420] [d00000000036a32c] .scsi_execute_req+0xb8/0x124 [scsi_mod]
[c0000002f559b500] [d0000000000c1330] .sd_sync_cache+0x8c/0x108 [sd_mod]
[c0000002f559b5e0] [d0000000000c15b4] .sd_shutdown+0x9c/0x158 [sd_mod]
[c0000002f559b660] [d0000000000c16d0] .sd_remove+0x60/0xb4 [sd_mod]
[c0000002f559b700] [c000000000392ecc] .__device_release_driver+0xd0/0x118
[c0000002f559b7a0] [c000000000393080] .device_release_driver+0x30/0x54
[c0000002f559b830] [c000000000392108] .bus_remove_device+0x128/0x16c
[c0000002f559b8d0] [c00000000038f94c] .device_del+0x158/0x234
[c0000002f559b960] [d00000000036f078] .__scsi_remove_device+0x5c/0xd4 [scsi_mod]
[c0000002f559b9f0] [d00000000036f124] .scsi_remove_device+0x34/0x58 [scsi_mod]
[c0000002f559ba80] [d00000000036f204] .__scsi_remove_target+0xb4/0x120 [scsi_mod]
[c0000002f559bb10] [d00000000036f338] .__remove_child+0x2c/0x44 [scsi_mod]
[c0000002f559bb90] [c00000000038f11c] .device_for_each_child+0x54/0xb4
[c0000002f559bc50] [d00000000036f2e0] .scsi_remove_target+0x70/0x9c [scsi_mod]
[c0000002f559bce0] [d000000000083454] .fc_starget_delete+0x24/0x3c [scsi_transport_fc]
[c0000002f559bd70] [c0000000000a2368] .run_workqueue+0x118/0x208
[c0000002f559be30] [c0000000000a2580] .worker_thread+0x128/0x154
[c0000002f559bf00] [c0000000000a7470] .kthread+0x78/0xc4
[c0000002f559bf90] [c000000000029b8c] .kernel_thread+0x4c/0x68

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Reduce error logging noise

The ibmvfc driver currently logs errors during discovery for several
transient fabric errors, which generally get retried. If retries
do not work, we see multiple errors in the log. If retries do work,
we see errors in the log which may be confusing since the retry worked.
This patch enhances the discovery time error logging to only log errors
for command failures during discovery if all allowed retries have been
used up. The existing behavior of logging all failures can be restored
by setting the hosts log_level to a value of 3 or greater.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Use DEVICE_ATTR macro

Use DEVICE_ATTR macro for defining device sysfs attributes.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fixup GFP flags for target allocations

Since target allocations can occur while resetting the virtual adapter,
we shouldn't be using GFP_KERNEL for them as it could hang. Switch to
use GFP_NOIO.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix invalid error response handling

Fix an obvious bug in processing error responses for SCSI commands
which can result in successful responses being incorrectly returned
with DID_ERROR.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Improve ADISC timeout handling

The ibmvfc driver currently breaks the CRQ and essentially
resets the entire virtual FC adapter, killing all outstanding
ops to all attached targets, if an ADISC times out during target
discover/rediscovery. This patch adds some code to cancel the
ADISC if it times out, which prevents a single ADISC timeout from
affecting the other devices attached to the fabric.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Show host maxframe_size

Set show_host_maxframe_size so that maxframe_size gets exported in
sysfs for the host.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fixup module parms attributes

The ibmvfc driver really does not handle dynamically changing disc_threads.
To change this dynamically would cause confusion in the driver regarding
the number of event structs allocated. Fix this by simply not allowing
disc_threads to be changed at runtime.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix dropped interrupts

This patch fixes a problem of possible dropped interrupts. Currently,
the ibmvfc driver has a race condition where after ibmvfc_interrupt
gets run, the platform code clears the interrupt. This can result in
lost interrupts and, in worst case scenarios, result in command
timeouts. Fix this by implementing a tasklet similar to what the
ibmvscsi driver does so that interrupt processing is no longer done in
the actual interrupt handler, which eliminates the race.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Better handle other FC initiators

The ibmvfc driver currently always sets the role of all rports
to FC_PORT_ROLE_FCP_TARGET, which is not correct for other initiators.
This can cause problems if other initiators are on the fabric
when we then try to scan the rport for LUNs. Fix this by looking
at the service parameters returned in the PRLI to set the roles
appropriately. Also look at the returned service parameters to
decide whether or not we were actually able to successfully log into
the target.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix rport relogin

The ibmvfc driver has a bug in its SCN handling. If it receives
an ELS event such asn an N-Port SCN event or an unsolicited PLOGI,
or any other SCN event which causes ibmvfc_reinit_host to be called,
it is possible that we will call fc_remote_port_add for a target
that already has an rport added, which can result in duplicate
rports getting created for the same targets. Fix this by calling
fc_remote_port_rolechg in this scenario instead to report any possible
role change that may have occurred.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix command timeout errors

Currently the ibmvfc driver sets the IBMVFC_CLASS_3_ERR flag
in the VFC Frame if both the adapter and the device claim support
for Class 3. However, this bit actually refers to Class 3 Error
Recovery, which is currently not supported by the VIOS. Setting this
bit can cause lots of command timeout responses from the VIOS resulting
in general instability. Fix this by never setting this bit.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix DMA mapping leak on memory allocation failure

There is currently a DMA mapping leak that can occur in the ibmvfc
driver if we fail to allocate a scatterlist. Fix this by unmapping
the scatterlist in the failure path. Additionally, only log an error
for a scatterlist allocation failure if the log level is greater
than the default, since this can occur when running Active Memory
Sharing and this is not considered an error.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

powerpc: Cleanup from l64 to ll64 change drivers/scsi

This is a powerpc specific driver.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[SCSI] ibmvfc: Fixup command response translation

If a link down event is received, outstanding commands may get
returned to the ibmvfc driver with a "transaction cancelled implicit"
response. This is currently translated to DID_ABORT, which does
not get retried by SCSI core, but rather passes the failure up
the stack. This can result in I/O errors at the filesystem level.
Fix up this response a well as a few other error responses.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] struct device - replace bus_id with dev_name(), dev_set_name()

[jejb: limit ioctl to returning 20 characters to avoid overrun
on long device names and add a few more conversions]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Improve async event handling

While doing various error injection testing, such as cable
pulls and target moves, some issues were observed in handling
these events. This patch improves the way these events are handled
by increasing the delay waiting for the fabric to settle and also
changes the behavior of Link Up to break the CRQ to ensure everything
gets cleaned up properly on the VIOS.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix errors due to inconsistent command data

In order to ensure the VIOS sees a consistent command buffer, we
need to add a memory barrier after building the command buffer
but before sending the command.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Delay NPIV login retry and add retries

Adds a delay prior to retrying a failed NPIV login. This fixes
a scenario if the backing fibre channel adapter is getting reset
due to an EEH event, NPIV login will fail. Currently, ibmvfc
retries three times very quickly, resets the CRQ and tries one
more time. If the adapter is getting reset due to EEH, this isn't
enough time. This adds a delay prior to retrying a failed NPIV
login and also increments the number of retries.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Handle port login required response

The virtual fibre channel stack can return a failure response for a command
indicating the port login has been invalidated without sending the client
an async event. Add code to handle this response and initiate a PLOGI.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix oops in interrupt handler

Fixes an oops that can occur in the interrupt handler
if we get a lot of async events.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Quiet gcc warning in ibmvfc_reset_device

Stops gcc from complaining about a possible uninitialized
variable being used in ibmvfc_reset_device.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix target initialization failure retry handling

If the ibmvfc driver is in discovery attempting to log into a target
and it encounters an error, the command may get retried one or more
times, depending on the error received. If the retries are
unsuccessful such that the discovery thread gives up on discovery to
that target, the target ends up in a state where, if SCSI core had
previously known about the device, the host will get unblocked but the
host will not be logged into the target, causing any commands sent to
the target to fail. This patch fixes this so that if this occurs, the
target is deleted such that the normal dev_loss processing can occur
instead.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Error handling fixes

Due to an ambiguity in the VIOS VFC interface specification,
abort/cancel handling is not done correctly and can result in double
completion of commands. In order to cancel all outstanding commands to
a device, a cancel must be sent, followed by an abort task set. After
the responses are received for these commands, there may still be
commands outstanding, in the process of getting flushed back, in which
case, we need to wait for them. This patch removes the assumption that
if the abort and the cancel both complete successfully that the device
queue has been flushed and waits for all the responses to come back.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix error reporting for some FC errors

If either a "transport fault" or a "general transport" error is received
and no other error information is available, the command is improperly
returned as successful. Fix this to return DID_ERROR in this case.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc, qla2xxx, lpfc: remove scsi_target_unblock calls in terminate callbacks

The fc class now calls scsi_target_unblock after calling the
terminate callback, so this patch removes the calls from the
drivers.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Add details to async event log

When logging async events, also print the payload in addition to the
event received.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Sanitize response lengths

Sanitize the response lengths in order to prevent possible oopses
in the command response path.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix for lost async events

If the client virtual fibre channel adapter is already logged into the
server and does an NPIV Login again, the async queue, which is used for
reporting Link Up/Link Down type of events, does not get reset on the
server side. Fix up the client driver so that we also do not reset it.
This fixes a problem of lost async events following relogins.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fixup host state during reinit

If an ELS is received while the virtual fibre channel adapter is going
through its discovery, a flag is set which causes discovery to get
re-driven. However, the hosts's state does not get set back to
IBMVFC_INITIALIZING and scsi_block_requests does not get called again,
which can result in queuecommand ops getting sent during
discovery. This should not occur and may cause problems. One example
is that we may no longer be logged into the target we send the command
to, resulting in a failure which should not have occurred.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix another hang on module removal

This fixes a hang on module removal. The module removal code was setting
the hosts's state to IBMVFC_HOST_OFFLINE before tearing down the kernel
thread, but, due to a bug in ibmvfc_wait_while_resetting, was not waiting
for the kernel thread's offlining work to be done prior to destroying
the kernel thread, which left the scsi host in a blocked state which we
never got out of.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Add ADISC support

Add an ADISC to the target discovery job in order to sanity check whether or
not we need to re-login to the target.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Miscellaneous fixes

Properly setup the size of the async event queue. This fixes a bug where async events
were not getting processed by the driver.

Setup target_id field in the driver's target struct so that target sysfs attributes
work for multiple targets.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Fix hang on module removal

If certain ELS events are received during module removal, after the kthread
is stopped, the rmmod can hang. This fixes the ibmvfc driver so that ELS
events during rmmod are ignored by stopping all device activity prior to
killing the kthread and also changes reinitialization to not attempt a reinit
if the adapter has been taken offline.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Target refcounting fixes

Fix up some refcounting on the ibmvfc drivers internal target struct
when accessed through some sysfs attributes.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ibmvfc: Reduce unnecessary log noise

Reduces some unnecessary log noise by removing a printk during
host port state query and increasing the log level required to
log received async events.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

dma-mapping: add the device argument to dma_mapping_error()

Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER
architecture does:

This enables us to cleanly fix the Calgary IOMMU issue that some devices
are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423).

I think that per-device dma_mapping_ops support would be also helpful for
KVM people to support PCI passthrough but Andi thinks that this makes it
difficult to support the PCI passthrough (see the above thread). So I
CC'ed this to KVM camp. Comments are appreciated.

A pointer to dma_mapping_ops to struct dev_archdata is added. If the
pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's
NULL, the system-wide dma_ops pointer is used as before.

If it's useful for KVM people, I plan to implement a mechanism to register
a hook called when a new pci (or dma capable) device is created (it works
with hot plugging). It enables IOMMUs to set up an appropriate
dma_mapping_ops per device.

The major obstacle is that dma_mapping_error doesn't take a pointer to the
device unlike other DMA operations. So x86 can't have dma_mapping_ops per
device. Note all the POWER IOMMUs use the same dma_mapping_error function
so this is not a problem for POWER but x86 IOMMUs use different
dma_mapping_error functions.

The first patch adds the device argument to dma_mapping_error. The patch
is trivial but large since it touches lots of drivers and dma-mapping.h in
all the architecture.

This patch:

dma_mapping_error() doesn't take a pointer to the device unlike other DMA
operations. So we can't have dma_mapping_ops per device.

Note that POWER already has dma_mapping_ops per device but all the POWER
IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device
argument.

[akpm@linux-foundation.org: fix sge]
[akpm@linux-foundation.org: fix svc_rdma]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix bnx2x]
[akpm@linux-foundation.org: fix s2io]
[akpm@linux-foundation.org: fix pasemi_mac]
[akpm@linux-foundation.org: fix sdhci]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc]
[akpm@linux-foundation.org: fix ibmvscsi]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ibmvfc: Add support for collaborative memory overcommit

Adds support to the ibmvfc driver for collaborative memory overcommit.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver

This patch adds a new device driver to support the Virtual Fibre Channel
interface on IBM Power based servers. The Virtual I/O Server on IBM Power
servers utilizes N-Port ID Virtualization to export a Virtual Fibre Channel
adapter to the client. This driver is the client device driver.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>