scsi: libsas: Delete struct scsi_core

Since commit 79855d178557 ("libsas: remove task_collector mode"), struct
scsi_core only contains a reference to the shost. struct scsi_core is only
used in sas_ha_struct.core, so delete scsi_core and replace with a
reference to the shost there.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230815115156.343535-5-john.g.garry@oracle.com
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: Allow libsas to include SCSI header files directly

libsas needs to include some header files in the scsi directory. However
these are currently hardcoded with the path "../" in the C files. Do this
in the Makefile to avoid hardcoding the path.

Link: https://lore.kernel.org/r/20210716074551.771312-1-yanaijie@huawei.com
Cc: John Garry <john.garry@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libsas: only clear phy->in_shutdown after shutdown event done

When the event queue is full of phy up and down events and reached the
threshold, we will queue a shutdown-event, and set phy->in_shutdown so that
we will not queue a shutdown-event again. But before the shutdown-event can
be executed, every phy-down event will clear
phy->in_shutdown and a new shutdown-event will be queued. The queue will
be full of these shutdown-events.

Fix this by only clear phy->in_shutdown in sas_phye_shutdown(), that is
after the first shutdown-event has been executed.

Fixes: f12486e06ae8 ("scsi: libsas: shut down the PHY if events reached the threshold")
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>
CC: Hannes Reinecke <hare@suse.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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: Print expander PHY indexes in decimal

Currently we print expander PHY indexes in a mix of decimal and hex.

It is more consistent and also more convenient to read decimal, so
make this change.

We use width of 2 for expander and 1 for root PHYs prints.

Some lines which were needlessly spilling multiple lines are unified.

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: shut down the PHY if events reached the threshold

If the PHY burst too many events, we will alloc a lot of events for the
worker. This may leads to memory exhaustion.

Dan Williams suggested to shut down the PHY if the events reached the
threshold, because in this case the PHY may have gone into some
erroneous state. Users can re-enable the PHY by sysfs if they want.

We cannot use the fixed memory pool because if we run out of events, the
shut down event and loss of signal event will lost too. The events still
need to be allocated and processed in this case.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
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>
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] 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: 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/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>

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] 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>