scsi: libsas: Move local functions declarations to sas_internal.h

Move the declarations of functions used only within libsas from
include/scsi/libsas.h to drivers/scsi/libsas/sas_internal.h

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230912230551.454357-2-dlemoal@kernel.org
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Delete enum sas_class

enum sas_class prob would have been useful if function sas_show_class() was
ever implemented, which it wasn't.

enum sas_class is used as asd_sas_port.class and asd_sas_phy.class, which
are only ever set, so delete these members and the enum.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230815115156.343535-3-john.g.garry@oracle.com
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Remove unused declarations

Commit 042ebd293b86 ("scsi: libsas: kill useless ha_event and do some
cleanup") removed sas_hae_reset() but not its declaration. Commit
2908d778ab3e ("[SCSI] aic94xx: new driver") declared but never implemented
other functions.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230809132249.37948-1-yuehaibing@huawei.com
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Add smp_ata_check_ready_type()

Create function smp_ata_check_ready_type() for LLDDs to wait for SATA
devices to come up after a link reset.

Signed-off-by: Jie Zhan <zhanjie9@hisilicon.com>
Link: https://lore.kernel.org/r/20221118083714.4034612-4-zhanjie9@hisilicon.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Introduce SAS address comparison helpers

SAS address comparison is widely used in libsas. However they are all
opencoded and to avoid the line spill over 80 columns, are mostly split
into multi-lines. Introduce some helpers to prepare for some refactoring.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20220928070130.3657183-2-yanaijie@huawei.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Make sas_{alloc, alloc_slow, free}_task() private

We have no users outside libsas any longer, so make sas_alloc_task(),
sas_alloc_slow_task(), and sas_free_task() private.

Signed-off-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1665998435-199946-8-git-send-email-john.garry@huawei.com
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Niklas Cassel <niklas.cassel@wdc.com> # pm80xx
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Introduce struct smp_rps_resp

Similarly to sas report general and discovery responses, define the
structure struct smp_rps_resp to handle SATA PHY report responses using a
structure with a size that is exactly equal to the sas defined response
size.

With this change, struct smp_resp becomes unused and is removed.

Link: https://lore.kernel.org/r/20220609022456.409087-4-damien.lemoal@opensource.wdc.com
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Use bool for queue_work() return code

Function queue_work() returns a bool, so use a bool to hold this value for
the return code from callers, which should make the code a tiny bit more
clear.

Also take this opportunity to condense the code of the those callers, such
as sas_queue_work(), as suggested by Damien.

Link: https://lore.kernel.org/r/1645786656-221630-3-git-send-email-john.garry@huawei.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Make sas_notify_{phy,port}_event() return void

Nobody checks the return codes, so make them return void. Indeed, if the
LLDD cannot send an event, nothing much can be done in the LLDD about it.

Also remove prototype for sas_notify_phy_event() in sas_internal.h, which
should not be there.

Link: https://lore.kernel.org/r/1645786656-221630-2-git-send-email-john.garry@huawei.com
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Add sas_execute_tmf()

Drivers using libsas have to issue their own TMFs, and the code to do this
is duplicated between drivers.

Add a common function to handle TMFs. This will be also used for sending
ATA commands, but use name "tmf" as the purpose is similar between SCSI and
ATA in the usage.

The force_phy_id argument will be used for a hisi_sas HW bug workaround.

We check the sas task status stat field against TMF codes, as according to
the SAS v1.1 spec 9.2.2.5.3, if response_data is in datapres, then the
response code should be a TMF code - see table 128.

Link: https://lore.kernel.org/r/1645112566-115804-10-git-send-email-john.garry@huawei.com
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Move SMP task handlers to core

Move the SMP task handlers to the core host code as they will be re-used
for executing internal abort and TMF tasks.

Link: https://lore.kernel.org/r/1645112566-115804-7-git-send-email-john.garry@huawei.com
Tested-by: Yihang Li <liyihang6@hisilicon.com>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Refactor sas_queue_deferred_work()

In the second part of function __sas_drain_work(), deferred work is queued.
This functionality is required other places so factor it out into the
function sas_queue_deferred_work().

Link: https://lore.kernel.org/r/1639999298-244569-12-git-send-email-chenxiang66@hisilicon.com
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Resume host while sending SMP I/Os

When sending SMP I/Os to the host we need to ensure that the host is not
suspended and can process the commands. This is a better approach than
replying on the host to resume itself to handle such commands. Use
pm_runtime_get_sync() and pm_runtime_put_sync() calls for the host when
executing SMP I/Os.

Link: https://lore.kernel.org/r/1639999298-244569-10-git-send-email-chenxiang66@hisilicon.com
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Remove temporarily-added _gfp() API variants

These variants were added for bisectability. Remove them, as all call sites
have now been convertd to use the original API.

Link: https://lore.kernel.org/r/20210118100955.1761652-20-a.darwish@linutronix.de
Cc: Jason Yan <yanaijie@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Add gfp_t flags parameter to event notifications

All call-sites of below libsas APIs:

- sas_alloc_event()
- sas_notify_port_event()
- sas_notify_phy_event()

have been converted to use the _gfp()-suffixed version. Modify the
original APIs above to take a gfp_t flags parameter by default.

For bisectability, call-sites will be modified again to use the original
libsas APIs (while passing gfp_t). The temporary _gfp()-suffixed versions
can then be removed.

Link: https://lore.kernel.org/r/20210118100955.1761652-13-a.darwish@linutronix.de
Cc: Jason Yan <yanaijie@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Introduce a _gfp() variant of event notifiers

sas_alloc_event() uses in_interrupt() to decide which allocation should be
used.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

The in_interrupt() check is also only partially correct, because it fails
to choose the correct code path when just preemption or interrupts are
disabled. For example, as in the following call chain:

mvsas/mv_sas.c: mvs_work_queue() [process context]
spin_lock_irqsave(mvs_info::lock, )
-> libsas/sas_event.c: sas_notify_phy_event()
-> sas_alloc_event()
-> in_interrupt() = false
-> invalid GFP_KERNEL allocation
-> libsas/sas_event.c: sas_notify_port_event()
-> sas_alloc_event()
-> in_interrupt() = false
-> invalid GFP_KERNEL allocation

Introduce sas_alloc_event_gfp(), sas_notify_port_event_gfp(), and
sas_notify_phy_event_gfp(), which all behave like the non _gfp() variants
but use a caller-passed GFP mask for allocations.

For bisectability, all callers will be modified first to pass GFP context,
then the non _gfp() libsas API variants will be modified to take a gfp_t by
default.

Link: https://lore.kernel.org/r/20210118100955.1761652-4-a.darwish@linutronix.de
Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost")
Cc: Jason Yan <yanaijie@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Remove notifier indirection

LLDDs report events to libsas with .notify_port_event and .notify_phy_event
callbacks.

These callbacks are fixed and so there is no reason why the functions
cannot be called directly, so do that.

This neatens the code slightly, makes it more obvious, and reduces function
pointer usage, which is generally a good thing. Downside is that there are
2x more symbol exports.

[a.darwish@linutronix.de: Remove the now unused "sas_ha" local variables]

Link: https://lore.kernel.org/r/20210118100955.1761652-3-a.darwish@linutronix.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Tidy SAS address print format

Currently we use a mixture of %016llx, %llx, and %16llx when printing a SAS
address.

Since the most significant nibble of the SAS address is always 5 - as per
standard - this formatting is not so important; but some fake SAS addresses
for SATA devices may not be. And we have mangled/invalid address to
consider also. And it's better to be consistent in the code, so use a fixed
format.

The SAS address is a fixed size at 64b, so we want to 0 byte extend to 16
nibbles, so use %016llx globally.

Also make some prints to be explicitly hex, and tidy some whitespace issue.

Link: https://lore.kernel.org/r/1576758957-227350-1-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>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 59

Based on 1 normalized pattern(s):

this file is licensed under gplv2 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 5 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071858.561902672@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: libsas: switch remaining files to SPDX tags

Use the the GPLv2 SPDX tag instead of verbose boilerplate text.

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

scsi: libsas: Drop SAS_DPRINTK() and revise logs levels

Like sas_printk() did previously, SAS_DPRINTK() offers little value now
that libsas logs already have the "sas" prefix through pr_fmt(fmt). So it
can be dropped.

However, after reviewing some logs in libsas, it is noticed that debug
level is too low in many instances.

So this change drops SAS_DPRINTK() and revises some logs to a more
appropriate level. However many stay at debug level, although some
are significantly promoted.

We add -DDEBUG for compilation so that we keep the debug messages by
default, as before.

All the pre-existing checkpatch errors for spanning messages across
multiple lines are also fixed.

Finally, all other references to printk() [apart from special formatting
in sas_ata.c] are removed and replaced with appropriate pr_xxx().

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Drop sas_printk()

The printk wrapper sas_printk() adds little value now that libsas logs
already have the "sas" prefix through pr_fmt(fmt), so just use pr_notice()
directly.

In addition, strings which span multiple lines are reunited.

Originally-from: Joe Perches <joe@perches.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Use pr_fmt(fmt)

In preparation for dropping the libsas printk wrappers, use pr_fmt(fmt)
declaration to add the framework log prefix - "sas".

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: direct call probe and destruct

In commit 87c8331fcf72 ("[SCSI] libsas: prevent domain rediscovery
competing with ata error handling") introduced disco mutex to prevent
rediscovery competing with ata error handling and put the whole
revalidation in the mutex. But the rphy add/remove needs to wait for the
error handling which also grabs the disco mutex. This may leads to dead
lock.So the probe and destruct event were introduce to do the rphy
add/remove asynchronously and out of the lock.

The asynchronously processed workers makes the whole discovery process
not atomic, the other events may interrupt the process. For example,
if a loss of signal event inserted before the probe event, the
sas_deform_port() is called and the port will be deleted.

And sas_port_delete() may run before the destruct event, but the
port-x:x is the top parent of end device or expander. This leads to
a kernel WARNING such as:

[ 82.042979] sysfs group 'power' not found for kobject 'phy-1:0:22'
[ 82.042983] ------------[ cut here ]------------
[ 82.042986] WARNING: CPU: 54 PID: 1714 at fs/sysfs/group.c:237
sysfs_remove_group+0x94/0xa0
[ 82.043059] Call trace:
[ 82.043082] [<ffff0000082e7624>] sysfs_remove_group+0x94/0xa0
[ 82.043085] [<ffff00000864e320>] dpm_sysfs_remove+0x60/0x70
[ 82.043086] [<ffff00000863ee10>] device_del+0x138/0x308
[ 82.043089] [<ffff00000869a2d0>] sas_phy_delete+0x38/0x60
[ 82.043091] [<ffff00000869a86c>] do_sas_phy_delete+0x6c/0x80
[ 82.043093] [<ffff00000863dc20>] device_for_each_child+0x58/0xa0
[ 82.043095] [<ffff000008696f80>] sas_remove_children+0x40/0x50
[ 82.043100] [<ffff00000869d1bc>] sas_destruct_devices+0x64/0xa0
[ 82.043102] [<ffff0000080e93bc>] process_one_work+0x1fc/0x4b0
[ 82.043104] [<ffff0000080e96c0>] worker_thread+0x50/0x490
[ 82.043105] [<ffff0000080f0364>] kthread+0xfc/0x128
[ 82.043107] [<ffff0000080836c0>] ret_from_fork+0x10/0x50

Make probe and destruct a direct call in the disco and revalidate function,
but put them outside the lock. The whole discovery or revalidate won't
be interrupted by other events. And the DISCE_PROBE and DISCE_DESTRUCT
event are deleted as a result of the direct call.

Introduce a new list to destruct the sas_port and put the port delete after
the destruct. This makes sure the right order of destroying the sysfs
kobject and fix the warning above.

In sas_ex_revalidate_domain() have a loop to find all broadcasted
device, and sometimes we have a chance to find the same expander twice.
Because the sas_port will be deleted at the end of the whole revalidate
process, sas_port with the same name cannot be added before this.
Otherwise the sysfs will complain of creating duplicate filename. Since
the LLDD will send broadcast for every device change, we can only
process one expander's revalidation.

[mkp: kbuild test robot warning]

Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Use dynamic alloced work to avoid sas event lost

Now libsas hotplug work is static, every sas event type has its own
static work, LLDD driver queues the hotplug work into shost->work_q. If
LLDD driver burst posts lots hotplug events to libsas, the hotplug
events may pending in the workqueue like

shost->work_q
new work[PORTE_BYTES_DMAED] --> |[PHYE_LOSS_OF_SIGNAL][PORTE_BYTES_DMAED] -> processing
|<-------wait worker to process-------->|

In this case, a new PORTE_BYTES_DMAED event coming, libsas try to queue
it to shost->work_q, but this work is already pending, so it would be
lost. Finally, libsas delete the related sas port and sas devices, but
LLDD driver expect libsas add the sas port and devices(last sas event).

This patch use dynamic allocated work to avoid this issue.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough

Simplify the SMP passthrough code by switching it to the generic bsg-lib
helpers that abstract away the details of the request code, and gets
drivers out of seeing struct scsi_request.

For the libsas host SMP code there is a small behavior difference in
that we now always clear the residual len for successful commands,
similar to the three other SMP handler implementations. Given that
there is no partial command handling in the host SMP handler this should
not matter in practice.

[mkp: typos and checkpatch fixes]

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

scsi: sas: scsi_queue_work can fail, so make callers aware

libsas uses scsi_queue_work() to queue its internal event notifications.
scsi_queue_work() can return -EINVAL if the work queue doesn't exist and
it does call queue_work() which can return false if the work is already
queued.

Make the SAS event code capable of returning errors up to the caller,
which is handy when changing to dynamically allocated work in libsas
as well, as discussed here: https://lkml.org/lkml/2017/6/14/121.

[mkp: fixed typo]

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

scsi: libsas: remove sas_scsi_timed_out

EH_NOT_HANDLED is the default case if no eh_timed_out method is
provided, so there is no need to supply it.

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

libsas: remove task_collector mode

The task_collector mode (or "latency_injector", (C) Dan Willians) is an
optional I/O path in libsas that queues up scsi commands instead of
directly sending it to the hardware. It generall increases latencies
to in the optiomal case slightly reduce mmio traffic to the hardware.

Only the obsolete aic94xx driver and the mvsas driver allowed to use
it without recompiling the kernel, and most drivers didn't support it
at all.

Remove the giant blob of code to allow better optimizations for scsi-mq
in the future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>

[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type

These enums have been separate since the dawn of SAS, mainly because the
latter is a procotol only enum and the former includes additional state
for libsas. The dichotomy causes endless confusion about which one you
should use where and leads to pointless warnings like this:

drivers/scsi/mvsas/mv_sas.c: In function 'mvs_update_phyinfo':
drivers/scsi/mvsas/mv_sas.c:1162:34: warning: comparison between 'enum sas_device_type' and 'enum sas_dev_type' [-Wenum-compare]

Fix by eliminating one of them. The one kept is effectively the sas.h
one, but call it sas_device_type and make sure the enums are all
properly namespaced with the SAS_ prefix.

Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: suspend / resume support

libsas power management routines to suspend and recover the sas domain
based on a model where the lldd is allowed and expected to be
"forgetful".

sas_suspend_ha - disable event processing allowing the lldd to take down
links without concern for causing hotplug events.
Regardless of whether the lldd actually posts link down
messages libsas notifies the lldd that all
domain_devices are gone.

sas_prep_resume_ha - on the way back up before the lldd starts link
training clean out any spurious events that were
generated on the way down, and re-enable event
processing

sas_resume_ha - after the lldd has started and decided that all phys
have posted link-up events this routine is called to let
libsas start it's own timeout of any phys that did not
resume. After the timeout an lldd can cancel the
phy teardown by posting a link-up event.

Storage for ex_change_count (u16) and phy_change_count (u8) are changed
to int so they can be set to -1 to indicate 'invalidated'.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Tested-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work

When requeuing work to a draining workqueue the last work instance may
not be idle, so sas_queue_work() must not touch work->entry. Introduce
sas_work with a drain_node list_head to have a private list for
collecting work deferred due to drain collision.

Fixes reports like:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff810410d4>] process_one_work+0x2e/0x338

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: set attached device type and target protocols for local phys

Before:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
none
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
none

After:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
end device
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
sata

Also downgrade the phy_list_lock to _irq instead of _irqsave since
libsas will never call sas_get_port_device with interrupts disbled.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: async ata scanning

libsas ata error handling is already async but this does not help the
scan case. Move initial link recovery out from under host->scan_mutex,
and delay synchronization with eh until after all port probe/recovery
work has been queued.

Device ordering is maintained with scan order by still calling
sas_rphy_add() in order of domain discovery.

Since we now scan the domain list when invoking libata-eh we need to be
careful to check for fully initialized ata ports.

Acked-by: Jack Wang <jack_wang@usish.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: let libata recover links that fail to transmit initial sig-fis

libsas fails to discover all sata devices in the domain. If a device fails
negotiation and does not transmit a signature fis the link needs recovery.
libata already understands how to manage slow to come up links, so treat these
conditions as ata device attach events for the purposes of creating an
ata_port. This allows libata to manage retrying link bring up.

Rediscovery is modified to be careful about checking changes in dev_type. It
looks like libsas leaks old devices if the sas address changes, but that's a
fix for another patch.

Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: fix sas_unregister_ports vs sas_drain_work

We need to hold drain_mutex across the unregistration as port down events
queue device removal as chained events, so we need to make sure no other
drainers are active.

[ 1118.673968] WARNING: at kernel/workqueue.c:996 __queue_work+0x11a/0x326()
[ 1118.681982] Hardware name: S2600CP
[ 1118.686193] Modules linked in: isci(-) libsas scsi_transport_sas nls_utf8
ipv6 uinput sg iTCO_wdt iTCO_vendor_support i2c_i801 i2c_core ioatdma dca
sd_mod sr_mod cdrom ahci libahci libata [last unloaded: scsi_transport_sas]
[ 1118.709893] Pid: 6831, comm: rmmod Not tainted 3.2.0-isci+ #1
[ 1118.716727] Call Trace:
[ 1118.719867] [<ffffffff8103e9f5>] warn_slowpath_common+0x85/0x9d
[ 1118.727000] [<ffffffff8103ea27>] warn_slowpath_null+0x1a/0x1c
[ 1118.733942] [<ffffffff81056d44>] __queue_work+0x11a/0x326
[ 1118.740481] [<ffffffff81056f99>] queue_work_on+0x1b/0x22
[ 1118.746925] [<ffffffff81057106>] queue_work+0x37/0x3e
[ 1118.753105] [<ffffffffa0120e05>] ? sas_discover_event+0x55/0x82 [libsas]
[ 1118.761094] [<ffffffff813217c3>] scsi_queue_work+0x42/0x44
[ 1118.767717] [<ffffffffa0120e19>] sas_discover_event+0x69/0x82 [libsas]
[ 1118.775509] [<ffffffffa0120f5b>] sas_unregister_dev+0xc3/0xcc [libsas]
[ 1118.783319] [<ffffffffa0120fae>] sas_unregister_domain_devices+0x4a/0xc8 [libsas]
[ 1118.792731] [<ffffffffa0120071>] sas_deform_port+0x60/0x1a6 [libsas]
[ 1118.800339] [<ffffffffa01201ea>] sas_unregister_ports+0x33/0x44 [libsas]
[ 1118.808342] [<ffffffffa011f7e5>] sas_unregister_ha+0x41/0x6b [libsas]
[ 1118.816055] [<ffffffffa0134055>] isci_unregister+0x22/0x4d [isci]
[ 1118.823384] [<ffffffffa0143040>] isci_pci_remove+0x2e/0x60 [isci]

Reported-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: route local link resets through ata-eh

Similar to the conversion of the transport-class reset we want bsg
initiated resets to be managed by libata.

Reported-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: fix sas_find_local_phy(), take phy references

In the direct-attached case this routine returns the phy on which this
device was first discovered. Which is broken if we want to support
wide-targets, as this phy reference can become stale even though the
port is still active.

In the expander-attached case this routine tries to lookup the phy by
scanning the attached sas addresses of the parent expander, and BUG_ONs
if it can't find it. However since eh and the libsas workqueue run
independently we can still be attempting device recovery via eh after
libsas has recorded the device as detached. This is even easier to hit
now that eh is blocked while device domain rediscovery takes place, and
that libata is fed more timed out commands increasing the chances that
it will try to recover the ata device.

Arrange for dev->phy to always point to a last known good phy, it may be
stale after the port is torn down, but it will catch up for wide port
reconfigurations, and never be NULL.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: poll for ata device readiness after reset

Use ata_wait_after_reset() to poll for link recovery after a reset.
This combined with sas_ha->eh_mutex prevents expander rediscovery from
probing phys in an intermediate state. Local discovery does not have a
mechanism to filter link status changes during this timeout, so it
remains the responsibility of lldds to prevent premature port teardown.
Although once all lldd's support ->lldd_ata_check_ready() that could be
used as a gate to local port teardown.

The signature fis is re-transmitted when the link comes back so we
should be revalidating the ata device class, but that is left to a future
patch.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: sas_phy_enable via transport_sas_phy_reset

Execute the link-reset triggered by sas_phy_enable via
transport_sas_phy_reset so that it can be managed by libata.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: execute transport link resets with libata-eh via host workqueue

Link resets leave ata affiliations intact, so arrange for libsas to make
an effort to avoid dropping the device due to a slow-to-recover link.
Towards this end carry out reset in the host workqueue so that it can
check for ata devices and kick the reset request to libata. Hard
resets, in contrast, bypass libata since they are meant for associating
an ata device with another initiator in the domain (tears down
affiliations).

Need to add a new transport_sas_phy_reset() since the current
sas_phy_reset() is a utility function to libsas lldds. They are not
prepared for it to loop back into eh.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: perform sas-transport resets in shost->workq context

Extend the sas transport class to allow transport users to attach extra
data to a sas_phy (->hostdata). Use this area in libsas to move resets
to workq context in preparation for scheduling ata device resets through
libata-eh.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: fix timeout vs completion race

Until we have told the lldd to forget a task a timed out operation can
return from the hardware at any time. Since completion frees the task
we need to make sure that no tasks run their normal completion handler
once eh has decided to manage the task. Similar to
ata_scsi_cmd_error_handler() freeze completions to let eh judge the
outcome of the race.

Task collector mode is problematic because it presents a situation where
a task can be timed out and aborted before the lldd has even seen it.
For this case we need to guarantee that a task that an lldd has been
told to forget does not get queued after the lldd says "never seen it".
With sas_scsi_timed_out we achieve this with the ->task_queue_flush
mutex, rather than adding more time.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: prevent domain rediscovery competing with ata error handling

libata error handling provides for a timeout for link recovery. libsas
must not rescan for previously known devices in this interval otherwise
it may remove a device that is simply waiting for its link to recover.
Let libata-eh make the determination of when the link is stable and
prevent libsas (host workqueue) from taking action while this
determination is pending.

Using a mutex (ha->disco_mutex) to flush and disable revalidation while
eh is running requires any discovery action that may block on eh be
moved to its own context outside the lock. Probing ATA devices
explicitly waits on ata-eh and the cache-flush-io issued during device
removal may also pend awaiting eh completion. Essentially any rphy
add/remove activity needs to run outside the lock.

This adds two new cleanup states for sas_unregister_domain_devices()
'allocated-but-not-probed', and 'flagged-for-destruction'. In the
'allocated-but-not-probed' state dev->rphy points to a rphy that is
known to have not been through a sas_rphy_add() event. At domain
teardown check if this device is still pending probe and cleanup
accordingly. Similarly if a device has already been queued for removal
then sas_unregister_domain_devices has nothing to do.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: introduce sas_drain_work()

When an lldd invokes ->notify_port_event() it can trigger a chain of libsas
events to:

1/ form the port and find the direct attached device

2/ if the attached device is an expander perform domain discovery

A call to flush_workqueue() will only flush the initial port formation work.
Currently libsas users need to call scsi_flush_work() up to the max depth of
chain (which will grow from 2 to 3 when ata discovery is moved to its own
discovery event). Instead of open coding multiple calls switch to use
drain_workqueue() to flush sas work.

drain_workqueue() does not handle new work submitted during the drain so
libsas needs a bit of infrastructure to hold off unchained work submissions
while a drain is in flight. A lldd ->notify() event is considered 'unchained'
while a sas_discover_event() is 'chained'. As Tejun notes:

"For now, I think it would be best to add private wrapper in libsas to
support deferring unchained work items while draining."

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: convert ha->state to flags

In preparation for adding new states (SAS_HA_DRAINING, SAS_HA_FROZEN),
convert ha->state into a set of flags.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: replace event locks with atomic bitops

The locks only served to make sure the pending event bitmask was updated
consistently.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: fix domain_device leak

Arrange for the deallocation of a struct domain_device object when it no
longer has:
1/ any children
2/ references by any scsi_targets
3/ references by a lldd

The comment about domain_device lifetime in
Documentation/scsi/libsas.txt is stale as it appears mainline never had
a version of a struct domain_device that was registered as a kobject.
We now manage domain_device reference counts on behalf of external
agents.

Reviewed-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: fix/amend device gone notification in sas_deform_port()

Commit 56dd2c06 "libsas: Don't issue commands to devices that have been
hot-removed" edited Darrick's original patch to remove setting 'gone' in
the sas_deform_port() path because that prevented scsi sync cache
commands from being issued when the driver was unloaded. However, this
allows true device gone notifications (as signaled port phy events) to
trigger sync cache commands to devices that are known to be unreachable.

Teach libsas which sas_deform_port() invocations are likely device gone
events.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

[SCSI] libsas: convert to standard kernel debugging

Instead of using a config option for debugging, just dump the
messages with KERN_DEBUG.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>

block: unify request timeout handling

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

[SCSI] libsas: add host SMP processing

This adds support for host side SMP processing, via a separate
SMP interpreter file.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libsas: Convert sas_proto users to sas_protocol

sparse complains about the mixing of enums in libsas. Since the
underlying numeric values of both enums are the same, combine them
to get rid of the warning.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] sas_ata: Implement sas_task_abort for ATA devices

ATA devices need special handling for sas_task_abort. If the ATA command
came from SCSI, then we merely need to tell SCSI to abort the scsi_cmnd.
However, internal commands require a bit more work--we need to fill the qc
with the appropriate error status and complete the command, and eventually
post_internal will issue the actual ABORT TASK.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] libsas: Add SAS_HA state flags to avoid queueing events while unloading

Track sas_ha_struct state so that we ignore events that come in while
we're shutting things down.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

WorkStruct: make allyesconfig

Fix up for make allyesconfig.

Signed-Off-By: David Howells <dhowells@redhat.com>

[SCSI] aci94xx: implement link rate setting

This patch implements the ability to set the minimum and maximum
linkrates for both libsas (for expanders) and aic94xx (for the host
phys). It also tidies up the setting of the hardware min and max to
make sure they're updated when the expander emits a change broadcast.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] SAS: consolidate linkspeed definitions

At the moment we have two separate linkspeed enumerations covering
roughly the same values. This patch consolidates on a single one enum
sas_linkspeed in scsi_transport_sas.h and uses it everywhere in the
aic94xx driver. Eventually I'll get around to removing the duplicated
fields in asd_sas_phy and sas_phy ...

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] aic94xx: new driver

This is the end point of the separate aic94xx driver based on the
original driver and transport class from Luben Tuikov
<ltuikov@yahoo.com>

The log of the separate development is:

Alexis Bruemmer:
o aic94xx: fix hotplug/unplug for expanderless systems
o aic94xx: disable split completion timer/setting by default
o aic94xx: wide port off expander support
o aic94xx: remove various inline functions
o aic94xx: use bitops
o aic94xx: remove queue comment
o aic94xx: remove sas_common.c
o aic94xx: sas remove depot's
o aic94xx: use available list_for_each_entry_safe_reverse()
o aic94xx: sas header file merge

James Bottomley:
o aic94xx: fix TF_TMF_NO_CTX processing
o aic94xx: convert to request_firmware interface
o aic94xx: fix hotplug/unplug
o aic94xx: add link error counts to the expander phys
o aic94xx: add transport class phy reset capability
o aic94xx: remove local_attached flag
o Remove README
o Fixup Makefile variable for libsas rename
o Rename sas->libsas
o aic94xx: correct return code for sas_discover_event
o aic94xx: use parent backlink port
o aic94xx: remove channel abstraction
o aic94xx: fix routing algorithms
o aic94xx: add backlink port
o aic94xx: fix cascaded expander properties
o aic94xx: fix sleep under lock
o aic94xx: fix panic on module removal in complex topology
o aic94xx: make use of the new sas_port
o rename sas_port to asd_sas_port
o Fix for eh_strategy_handler move
o aic94xx: move entirely over to correct transport class formulation
o remove last vestages of sas_rphy_alloc()
o update for eh_timed_out move
o Preliminary expander support for aic94xx
o sas: remove event thread
o minor warning cleanups
o remove last vestiges of id mapping arrays
o Further updates
o Convert aic94xx over entirely to the transport class end device and
o update aic94xx/sas to use the new sas transport class end device
o [PATCH] aic94xx: attaching to the sas transport class
o Add missing completion removal from prior patch
o [PATCH] aic94xx: attaching to the sas transport class
o Build fixes from akpm

Jeff Garzik:
o [scsi aic94xx] Remove ->owner from PCI info table

Luben Tuikov:
o initial aic94xx driver

Mike Anderson:
o aic94xx: fix panic on module insertion
o aic94xx: stub out SATA_DEV case
o aic94xx: compile warning cleanups
o aic94xx: sas_alloc_task
o aic94xx: ref count update
o aic94xx nexus loss time value
o [PATCH] aic94xx: driver assertion in non-x86 BIOS env

Randy Dunlap:
o libsas: externs not needed

Robert Tarte:
o aic94xx: sequence patch - fixes SATA support

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>