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 mor

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>

show more ...

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

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>

show more ...

scsi: libsas: Keep host active while processing events

Processing events such as PORTE_BROADCAST_RCVD may cause dependency issues
for runtime power management support. Such a problem would be that

scsi: libsas: Keep host active while processing events

Processing events such as PORTE_BROADCAST_RCVD may cause dependency issues
for runtime power management support. Such a problem would be that
handling a PORTE_BROADCAST_RCVD event requires that the host is resumed to
send SMP commands. However, in resuming the host, the phyup events
generated from re-enabling the phys are processed in the same workqueue as
the original PORTE_BROADCAST_RCVD event. As such, the host will never
finish resuming (as it waits for the phyup event processing), and then the
PORTE_BROADCAST_RCVD event can't be processed as the SMP commands are
blocked, and so we have a deadlock. Solve this problem by ensuring that
libsas keeps the host active until completely finished phy or port events,
such as PORTE_BYTES_DMAED. As such, we don't have to worry about resuming
the host for processing individual SMP commands in this example.

Link: https://lore.kernel.org/r/1639999298-244569-15-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>

show more ...

scsi: libsas: Defer works of new phys during suspend

During the processing of event PORT_BYTES_DMAED, the driver queues work
DISCE_DISCOVER_DOMAIN and then flushes workqueue ha->disco_q. If a new
p

scsi: libsas: Defer works of new phys during suspend

During the processing of event PORT_BYTES_DMAED, the driver queues work
DISCE_DISCOVER_DOMAIN and then flushes workqueue ha->disco_q. If a new
phyup event occurs during resuming the controller, the work
PORTE_BYTES_DMAED of new phy occurs before suspended phy's. The work
DISCE_DISCOVER_DOMAIN of new phy requires an active SAS controller (it
needs to resume SAS controller by function scsi_sysfs_add_sdev() and some
other functions such as function add_device_link()). However, the
activation of the SAS controller requires completion of work
PORTE_BYTES_DMAED of suspended phys while it is blocked by new phy's work
on ha->event_q. So there is a deadlock and it is released only after resume
timeout.

To solve the issue, defer works of new phys during suspend and queue those
defer works after SAS controller becomes active.

Link: https://lore.kernel.org/r/1639999298-244569-13-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>

show more ...

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
fun

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>

show more ...

scsi: libsas: Add spin_lock/unlock() to protect asd_sas_port->phy_list

Most places that use asd_sas_port->phy_list in libsas are protected by
spinlock asd_sas_port->phy_list_lock. However, there are

scsi: libsas: Add spin_lock/unlock() to protect asd_sas_port->phy_list

Most places that use asd_sas_port->phy_list in libsas are protected by
spinlock asd_sas_port->phy_list_lock. However, there are still a few places
which miss the lock. Add it in those places.

Link: https://lore.kernel.org/r/1639999298-244569-5-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>

show more ...

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://

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>

show more ...

scsi: libsas: Switch back to original event notifiers API

libsas event notifiers required an extension where gfp_t flags must be
explicitly passed. For bisectability, a temporary _gfp() variant of s

scsi: libsas: Switch back to original event notifiers API

libsas event notifiers required an extension where gfp_t flags must be
explicitly passed. For bisectability, a temporary _gfp() variant of such
functions were added. All call sites then got converted use the _gfp()
variants and explicitly pass GFP context. Having no callers left, the
original libsas notifiers were then modified to accept gfp_t flags by
default.

Switch back to the original event notifiers API, while still passing GFP
context. The _gfp() notifier variants will be removed afterwards.

Link: https://lore.kernel.org/r/20210118100955.1761652-17-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>

show more ...

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

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>

show more ...

scsi: libsas: Pass gfp_t flags to event notifiers

Use the new libsas event notifiers API, which requires callers to
explicitly pass the gfp_t memory allocation flags.

Context analysis:

- sas_ena

scsi: libsas: Pass gfp_t flags to event notifiers

Use the new libsas event notifiers API, which requires callers to
explicitly pass the gfp_t memory allocation flags.

Context analysis:

- sas_enable_revalidation(): process, acquires mutex
- sas_resume_ha(): process, calls wait_event_timeout()

Link: https://lore.kernel.org/r/20210118100955.1761652-9-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>

show more ...

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

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>

show more ...

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 function

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>

show more ...

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

[ Upstream commit c2d0f1a65ab9fbabebb463bf36f50ea8f4633386 ]

sas_alloc_event() uses in_interrupt() to decide which allocation should be
u

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

[ Upstream commit c2d0f1a65ab9fbabebb463bf36f50ea8f4633386 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

scsi: libsas: Remove notifier indirection

[ Upstream commit 121181f3f839c29d8dd9fdc3cc9babbdc74227f8 ]

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

These

scsi: libsas: Remove notifier indirection

[ Upstream commit 121181f3f839c29d8dd9fdc3cc9babbdc74227f8 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

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@su

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>

show more ...

scsi: libsas: Delete sas_dump.{c, h}

The code in these files is not longer referenced, so delete them.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.pe

scsi: libsas: Delete sas_dump.{c, h}

The code in these files is not longer referenced, so delete them.

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

show more ...

scsi: libsas: notify event PORTE_BROADCAST_RCVD in sas_enable_revalidation()

There are two places queuing the disco event DISCE_REVALIDATE_DOMAIN.
One is in sas_porte_broadcast_rcvd() and uses sas_c

scsi: libsas: notify event PORTE_BROADCAST_RCVD in sas_enable_revalidation()

There are two places queuing the disco event DISCE_REVALIDATE_DOMAIN.
One is in sas_porte_broadcast_rcvd() and uses sas_chain_event() to queue
the event. The other is in sas_enable_revalidation() and uses
sas_queue_event() to queue the event. We have diffrent work queues for
event and discovery now, so the DISCE_REVALIDATE_DOMAIN event may be
processed in both event queue and discovery queue.

Now since we do synchronous event handling, we cannot do it in discovery
queue, so have to trigger a fake broadcast event to re-trigger the
revalidation from event queue.

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>

show more ...

scsi: libsas: Use new workqueue to run sas event and disco event

Now all libsas works are queued to scsi host workqueue, include sas
event work post by LLDD and sas discovery work, and a sas hotplug

scsi: libsas: Use new workqueue to run sas event and disco event

Now all libsas works are queued to scsi host workqueue, include sas
event work post by LLDD and sas discovery work, and a sas hotplug flow
may be divided into several works, e.g libsas receive a
PORTE_BYTES_DMAED event, currently we process it as following steps:

sas_form_port --- run in work in shost workq
sas_discover_domain --- run in another work in shost workq
...
sas_probe_devices --- run in new work in shost workq
We found during hot-add a device, libsas may need run several
works in same workqueue to add device in system, the process is
not atomic, it may interrupt by other sas event works, like
PHYE_LOSS_OF_SIGNAL.

This patch is preparation of execute libsas sas event in sync. We need
to use different workqueue to run sas event and disco event. Otherwise
the work will be blocked for waiting another chained work in the same
workqueue.

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>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

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

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>

show more ...

scsi: libsas: add event to defer list tail instead of head when draining

Events will be added to defer_q list when setting ha->status to
SAS_HA_DRAINING. Events will be called after drain workqueue.

scsi: libsas: add event to defer list tail instead of head when draining

Events will be added to defer_q list when setting ha->status to
SAS_HA_DRAINING. Events will be called after drain workqueue.

Those events are added to the head of list, but they are scanned one by
one from the head to the tail, which will cause those events be called
in the reverse order of being added. So change list_add to list_add_tail
in function sas_queue_work.

Signed-off-by: chenxiang <chenxiang66@hisilicon.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>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: libsas: rename notify_port_event() for consistency

Rename function notify_port_event() to sas_notify_port_event(), which
will be consistent with sas_notify_phy_event().

Signed-off-by: Jason Y

scsi: libsas: rename notify_port_event() for consistency

Rename function notify_port_event() to sas_notify_port_event(), which
will be consistent with sas_notify_phy_event().

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

show more ...

scsi: libsas: kill useless ha_event and do some cleanup

The ha_event now has only one event HAE_RESET, and this event does
nothing. Kill it and do some cleanup.

This is a preparation for enhance li

scsi: libsas: kill useless ha_event and do some cleanup

The ha_event now has only one event HAE_RESET, and this event does
nothing. Kill it and do some cleanup.

This is a preparation for enhance libsas hotplug feature in the next
patches.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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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 exi

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>

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[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

[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>

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[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship. libsas creates a 1:N relation

[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship. libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time. Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.

Reviewed-by: Jacek Danecki <jacek.danecki@intel.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>

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