For when managed interrupts are used (and shost->nr_hw_queues is set), a
fixed queue - set per-device - is still used for internal I/Os.

If all the CPUs mapped to that queue are offlined, then the completions for
that queue are not serviced and any internal I/Os will time out.

Fix by selecting a queue for internal I/Os from the queue mapped from the
current CPU in this scenario.

This is still not ideal as it does not deal with CPU hotplug for inflight
internal I/Os, and needs proper support from [0].

[0] https://lore.kernel.org/linux-scsi/20200703130122.111448-1-hare@suse.de/T/#m7d77d049b18f33a24ef206af69ebb66d07440556

Link: https://lore.kernel.org/r/1607347855-59091-1-git-send-email-john.garry@huawei.com
Fixes: 8d98416a ("scsi: hisi_sas: Switch v3 hw to MQ")
Signed-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In commit 8d98416a ("scsi: hisi_sas: Switch v3 hw to MQ"), the dispatch
function was changed to choose the delivery queue based on the request tag
HW queue index.

This heavily degrades performance for v2 hw, since the HW queues are not
exposed there, and, as such, HW queue #0 is used for every command.

Revert to previous behaviour for when nr_hw_queues is not set, that being
to choose the HW queue based on target device index.

Link: https://lore.kernel.org/r/1602750425-240341-1-git-send-email-john.garry@huawei.com
Fixes: 8d98416a ("scsi: hisi_sas: Switch v3 hw to MQ")
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently the PHY state is set according to the state of the PHYs after
reset. This is invalid as the PHYs are already re-initialized.

Set PHY state according to the state before the reset instead of after.

Link: https://lore.kernel.org/r/1601649038-25534-8-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently sas_resume_ha() is called while resuming the controller to wait
for all suspended PHYs to come up and all the libsas events to be
completed.

There is a scenario which will cause task hung: For direct attach with two
disks connected with two PHYs, disable phy0 before suspending the disk on
phy1 and the controller, then enable phy0 and resume the controller, and
task hung occurs as follows:

[  591.901463] hisi_sas_v3_hw 0000:b4:02.0: resuming from operating state [D0]
[  593.113525] hisi_sas_v3_hw 0000:b4:02.0: neither _PS0 nor _PR0 is defined
[  593.120301] hisi_sas_v3_hw 0000:b4:02.0: waiting up to 25 seconds for 1 phy to resume
[  593.120836] hisi_sas_v3_hw 0000:b4:02.0: phyup: phy0 link_rate=10(sata)
[  593.134680] hisi_sas_v3_hw 0000:b4:02.0: phyup: phy1 link_rate=10(sata)
[  593.134733] sas: phy-2:0 added to port-2:0, phy_mask:0x1 (5000000000000200)
[  593.148350] sas: DOING DISCOVERY on port 0, pid:948
[  593.153227] hisi_sas_v3_hw 0000:b4:02.0: dev[3:5] found
[  593.159840] sas: Enter sas_scsi_recover_host busy: 0 failed: 0
[  593.165663] sas: ata7: end_device-2:0: dev error handler
[  593.165730] sas: ata2: end_device-2:1: dev error handler
[  593.172532] hisi_sas_v3_hw 0000:b4:02.0: phydown: phy0 phy_state=0x2
[  593.182570] hisi_sas_v3_hw 0000:b4:02.0: ignore flutter phy0 down
[  593.331277] hisi_sas_v3_hw 0000:b4:02.0: phyup: phy0 link_rate=10(sata)
[  593.498956] ata7.00: ATA-11: SAMSUNG MZ7LH960HAJR-00005, HXT7404Q, max UDMA/133
[  593.506235] ata7.00: 1875385008 sectors, multi 16: LBA48 NCQ (depth 32)
[  593.514295] ata7.00: configured for UDMA/133
[  593.518557] sas: --- Exit sas_scsi_recover_host: busy: 0 failed: 0 tries: 1
[  593.528613] sas: ata7: end_device-2:0: model:SAMSUNG MZ7LH960HAJR-00005
serial:S45NNA0M712225
[  593.537520] device_link_add 316: dev=2:0:2:0 supplier:2 consumer:0
[  593.543674] device_link_add 324
[  593.546801] device_link_add 352
[  593.549930] device_link_add 406
[  593.553058] device_link_add 440: dev=2:0:2:0 supplier:2 consumer:0
[  593.559208] device_link_add 444
[  593.562335] device_link_add 455
[  593.565517] scsi 2:0:2:0: Direct-Access     ATA      SAMSUNG MZ7LH960 404Q PQ: 0
ANSI: 5
[  620.057464]  phy-2:1: resume timeout
[  738.841445] INFO: task kworker/u256:0:8 blocked for more than 120 seconds.
[  738.848295]       Not tainted 5.8.0-rc1-76154-g0d52b59-dirty #744
[  738.854361] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  738.862155] kworker/u256:0  D    0     8      2 0x00000028
[  738.867626] Workqueue: 0000:b4:02.0_event_q sas_port_event_worker
[  738.873693] Call trace:
[  738.876133]  __switch_to+0xf4/0x148
[  738.879613]  __schedule+0x270/0x5d8
[  738.883091]  schedule+0x78/0x110
[  738.886307]  schedule_timeout+0x1ac/0x280
[  738.890299]  wait_for_completion+0x94/0x138
[  738.894472]  flush_workqueue+0x114/0x438
[  738.898377]  sas_porte_bytes_dmaed+0x400/0x500
[  738.902801]  sas_port_event_worker+0x28/0x40
[  738.907053]  process_one_work+0x1e8/0x360
[  738.911046]  worker_thread+0x44/0x478
[  738.914698]  kthread+0x150/0x158
[  738.917915]  ret_from_fork+0x10/0x1c
[  738.921534] INFO: task kworker/u256:1:948 blocked for more than 120 seconds.
[  738.928550]       Not tainted 5.8.0-rc1-76154-g0d52b59-dirty #744
[  738.934614] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  738.942408] kworker/u256:1  D    0   948      2 0x00000028
[  738.947873] Workqueue: 0000:b4:02.0_disco_q sas_discover_domain
[  738.953766] Call trace:
[  738.956203]  __switch_to+0xf4/0x148
[  738.959678]  __schedule+0x270/0x5d8
[  738.963152]  schedule+0x78/0x110
[  738.966368]  rpm_resume+0xcc/0x550
[  738.969757]  __pm_runtime_resume+0x3c/0x88
[  738.973836]  rpm_get_suppliers+0x50/0x148
[  738.977829]  __pm_runtime_set_status+0x124/0x2f0
[  738.982427]  scsi_sysfs_add_sdev+0x1a0/0x2a8
[  738.986679]  scsi_probe_and_add_lun+0x888/0xab0
[  738.991190]  __scsi_scan_target+0xec/0x520
[  738.995268]  scsi_scan_target+0x11c/0x128
[  738.999261]  sas_rphy_add+0x15c/0x1e8
[  739.002907]  sas_probe_devices+0xe4/0x150
[  739.006899]  sas_discover_domain+0x33c/0x588
[  739.011150]  process_one_work+0x1e8/0x360
[  739.015143]  worker_thread+0x44/0x478
[  739.018789]  kthread+0x150/0x158
[  739.022003]  ret_from_fork+0x10/0x1c
...

If an extra phy0 up happens during resume of the SAS controller, it will
emit a new libsas event (event PORTE_BYTES_DMAED and event
DISCE_DISCOVER_DOMAIN). We will call function scsi_sysfs_add_sdev() in
event DISCE_DISCOVER_DOMAIN, which will call __pm_runtime_set_status() to
resume supplier (host controller). For runtime PM core, if device is in the
resuming state, the later resume request of the device will wait for
previous resume request to complete synchronously. At that point in time
the state of the controller is still resuming as it waits for all libsas
events to be completed, while libsas event DISCE_DISCOVER_DOMAIN is blocked
as the state of the controller is resuming which causes a deadlock.

To avoid the issue, filter out new PHY up events while the controller is
suspended.

Link: https://lore.kernel.org/r/1601649038-25534-7-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Now that the block layer provides a shared tag, we can switch the driver
to expose all HW queues.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove extra blank lines and add spaces around operators.

Link: https://lore.kernel.org/r/1598958790-232272-9-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Newline is missing from some printk() statements. Add them.

Link: https://lore.kernel.org/r/1598958790-232272-8-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Through the new debugfs interface the user can select fixed code
patterns. Add two new interfaces fixed_code and fixed_code1.

Link: https://lore.kernel.org/r/1598958790-232272-7-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add BIST support for phy FFE (Feed forward equalizer) setting. The user can
configure FFE through the new debugfs interface.

FFE is a parameter used for link layer control. It will affect the link
quality between the SAS controller and the backplane. In the BIST test, the
FFE interface is provided to assist board testers in optimizing link
parameters.

The modification of the FFE parameter will affect the test after BIST or
the normal running of the board. The user should save the initial FFE
values and restore them after BIST test is complete.

Link: https://lore.kernel.org/r/1598958790-232272-6-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

hisi_sas_slot_task_free() attempts to dereference SSP task for non-ATA
tasks. If the task is SMP, the code may reference the wrong structure
although this may not cause any problems.

To avoid this, only access to SSP task when slot->n_elem_dif is not 0 which
indicates this is an SSP task.

Link: https://lore.kernel.org/r/1598958790-232272-2-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

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-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

We found out that after phy up, the hardware reports another oob interrupt
but did not follow a phy up interrupt:

oob ready -> phy up -> DEV found -> oob read -> wait phy up -> timeout

We run link reset when wait phy up timeout, and it send a normal disk into
reset processing. So we made some circumvention action in the code, so that
this abnormal oob interrupt will not start the timer to wait for phy up.

Link: https://lore.kernel.org/r/1589552025-165012-2-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In future we will want to use hisi_sas_cq.pci_irq_mask for non-pci
interrupt masks, so rename to be more general.

Link: https://lore.kernel.org/r/1579522957-4393-7-git-send-email-john.garry@huawei.comSigned-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The trigger_dump file is only used to manually trigger the dump, and did
not provide a read callback function for it, so its file permission
setting to 600 is wrong,and should be changed to 200.

Link: https://lore.kernel.org/r/1579522957-4393-5-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

After changing tasklet to workqueue or threaded irq, some critical
resources are only used on threads (not in interrupt or bottom half of
interrupt), so replace spin_lock_irqsave/spin_unlock_restore with
spin_lock/spin_unlock to protect those critical resources.

Link: https://lore.kernel.org/r/1579522957-4393-3-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently IRQ_EFFECTIVE_AFF_MASK is enabled for ARM_GIC and ARM_GIC3, so it
only allows a single target CPU in the affinity mask to process interrupts
and also interrupt thread, and the performance of using threaded irq is
almost the same as tasklet. But if the config is not enabled, the interrupt
thread will be allowed all the CPUs in the affinity mask. At that situation
it improves the performance (about 20%).

Note: IRQ_EFFECTIVE_AFF_MASK is configured differently for different
architecture chip, and it seems to be better to make it be configured
easily.

Link: https://lore.kernel.org/r/1579522957-4393-2-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The !! operator on a bool is pointless, so remove an example in
hisi_sas_rescan_topology().

Link: https://lore.kernel.org/r/1573551059-107873-5-git-send-email-john.garry@huawei.comSigned-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Need to check the structure sas_port before using it.

Link: https://lore.kernel.org/r/1573551059-107873-2-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The number of phy down reflects the quality of the link between SAS
controller and disk. In order to allow the user to confirm the link quality
of the system, we record the number of phy down for each phy.

The user can check the current phy down count by reading the debugfs file
corresponding to the specific phy, or clear the phy down count by writing 0
to the debugfs file.

Link: https://lore.kernel.org/r/1571926105-74636-19-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Although if the debugfs initialization fails, we will delete the debugfs
folder of hisi_sas, but we did not consider the scenario where debugfs was
successfully initialized, but the probe failed for other reasons. We found
out that hisi_sas folder is still remain after the probe failed.

When probe fail, we should delete debugfs folder to avoid the above issue.

Link: https://lore.kernel.org/r/1571926105-74636-18-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

We use the module parameter debugfs_dump_count to manage the upper limit of
the memory block for multiple dumps.

Link: https://lore.kernel.org/r/1571926105-74636-17-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

We still only use dump index #0 however.

Link: https://lore.kernel.org/r/1571926105-74636-16-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

We add multiple dumps for debugfs, but only allocate memory this time and
only dump #0.

Link: https://lore.kernel.org/r/1571926105-74636-15-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address for
ITCT cache at debugfs. This structure is bound to the corresponding debugfs
file, it can help callback function of debugfs file to get what it needs.

Link: https://lore.kernel.org/r/1571926105-74636-14-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address for IOST
cache at debugfs. This structure is bound to the corresponding debugfs
file, it can help callback function of debugfs file to get what it needs.

Link: https://lore.kernel.org/r/1571926105-74636-13-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address for ITCT
at debugfs. This structure is bound to the corresponding debugfs file, it
can help callback function of debugfs file to get what it needs.

Link: https://lore.kernel.org/r/1571926105-74636-12-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address for IOST
at debugfs. This structure is bound to the corresponding debugfs file, it
can help callback function of debugfs file to get what it needs.

Link: https://lore.kernel.org/r/1571926105-74636-11-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address and phy
pointer for port at debugfs. This structure is bound to the corresponding
debugfs file, it can help callback function of debugfs file to get what it
need.

Link: https://lore.kernel.org/r/1571926105-74636-10-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address and
hisi_hba pointer for REGS at debugfs. This structure is bound to the
corresponding debugfs file, it can help callback function of debugfs file
to get what it need.

Link: https://lore.kernel.org/r/1571926105-74636-9-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address and DQ
pointer for DQ at debugfs. This structure is bound to the corresponding
debugfs file, it can help callback function of debugfs file to get what it
need.

Link: https://lore.kernel.org/r/1571926105-74636-8-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Create a file structure which was used to save the memory address and CQ
pointer for CQ at debugfs. This structure is bound to the corresponding
debugfs file, it can help callback function of debugfs file to get what it
need.

Link: https://lore.kernel.org/r/1571926105-74636-7-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

It's useful to know when the dump occurred, so add a timestamp file for
this.

Link: https://lore.kernel.org/r/1571926105-74636-6-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For IOs from upper layer, preemption may be disabled as it may be called by
function __blk_mq_delay_run_hw_queue which will call get_cpu() (it disables
preemption). So if flags HISI_SAS_REJECT_CMD_BIT is set in function
hisi_sas_task_exec(), it may disable preempt twice after down() and up()
which will cause following call trace:

BUG: scheduling while atomic: fio/60373/0x00000002
Call trace:
dump_backtrace+0x0/0x150
show_stack+0x24/0x30
dump_stack+0xa0/0xc4
__schedule_bug+0x68/0x88
__schedule+0x4b8/0x548
schedule+0x40/0xd0
schedule_timeout+0x200/0x378
__down+0x78/0xc8
down+0x54/0x70
hisi_sas_task_exec.isra.10+0x598/0x8d8 [hisi_sas_main]
hisi_sas_queue_command+0x28/0x38 [hisi_sas_main]
sas_queuecommand+0x168/0x1b0 [libsas]
scsi_queue_rq+0x2ac/0x980
blk_mq_dispatch_rq_list+0xb0/0x550
blk_mq_do_dispatch_sched+0x6c/0x110
blk_mq_sched_dispatch_requests+0x114/0x1d8
__blk_mq_run_hw_queue+0xb8/0x130
__blk_mq_delay_run_hw_queue+0x1c0/0x220
blk_mq_run_hw_queue+0xb0/0x128
blk_mq_sched_insert_requests+0xdc/0x208
blk_mq_flush_plug_list+0x1b4/0x3a0
blk_flush_plug_list+0xdc/0x110
blk_finish_plug+0x3c/0x50
blkdev_direct_IO+0x404/0x550
generic_file_read_iter+0x9c/0x848
blkdev_read_iter+0x50/0x78
aio_read+0xc8/0x170
io_submit_one+0x1fc/0x8d8
__arm64_sys_io_submit+0xdc/0x280
el0_svc_common.constprop.0+0xe0/0x1e0
el0_svc_handler+0x34/0x90
el0_svc+0x10/0x14
...

To solve the issue, check preemptible() to avoid disabling preempt multiple
when flag HISI_SAS_REJECT_CMD_BIT is set.

Link: https://lore.kernel.org/r/1571926105-74636-5-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When injecting 2bit ecc errors, it will cause confusion inside SAS
controller which needs host reset to recover it. If a device is gone at the
same times inject 2bit ecc errors, we may not receive the ITCT interrupt so
it will wait for completion in clear_itct_v3_hw() all the time. And host
reset will also not occur because it can't require hisi_hba->sem, so the
system will be suspended.

To solve the issue, use wait_for_completion_timeout() instead of
wait_for_completion(), and also don't mark the gone device as
SAS_PHY_UNUSED when device gone.

Link: https://lore.kernel.org/r/1571926105-74636-4-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Due to a merge error, we attempt to create 2x debugfs dump folders, which
fails:
[  861.101914] debugfs: Directory 'dump' with parent '0000:74:02.0'
already present!

This breaks the dump function.

To fix, remove the superfluous attempt to create the folder.

Fixes: 7ec7082c ("scsi: hisi_sas: Add hisi_sas_debugfs_alloc() to centralise allocation")
Link: https://lore.kernel.org/r/1571926105-74636-2-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

There is a spelling mistake in literal string. Fix it.

Link: https://lore.kernel.org/r/20190916091706.32268-1-colin.king@canonical.comSigned-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Fix sparse warnings:

drivers/scsi/hisi_sas/hisi_sas_main.c:3686:6:
 warning: symbol 'hisi_sas_debugfs_release' was not declared. Should it be static?
drivers/scsi/hisi_sas/hisi_sas_main.c:3708:5:
 warning: symbol 'hisi_sas_debugfs_alloc' was not declared. Should it be static?
drivers/scsi/hisi_sas/hisi_sas_main.c:3799:6:
 warning: symbol 'hisi_sas_debugfs_bist_init' was not declared. Should it be static?

Link: https://lore.kernel.org/r/20190923054035.19036-1-yuehaibing@huawei.comReported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When device gone, it will check whether it is during reset, if not, it will
send internal task abort. Before internal task abort returned, reset
begins, and it will check whether SAS_PHY_UNUSED is set, if not, it will
call hisi_sas_init_device(), but at that time domain_device may already be
freed or part of it is freed, so it may referenece null pointer in
hisi_sas_init_device(). It may occur as follows:

    thread0				thread1
hisi_sas_dev_gone()
    check whether in RESET(no)
    internal task abort
				    reset prep
				    soft_reset
				    ... (part of reset_done)
    internal task abort failed
    release resource anyway
    clear_itct
    device->lldd_dev=NULL
				    hisi_sas_reset_init_all_device
					check sas_dev->dev_type is SAS_PHY_UNUSED and
					!device
    set dev_type SAS_PHY_UNUSED
    sas_free_device
					hisi_sas_init_device
					...

Semaphore hisi_hba.sema is used to sync the processes of device gone and
host reset.

To solve the issue, expand the scope that semaphore protects and let them
never occur together.

And also some places will check whether domain_device is NULL to judge
whether the device is gone. So when device gone, need to clear
sas_dev->sas_device.

Link: https://lore.kernel.org/r/1567774537-20003-14-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add BIST (built in self test) support for phy loopback.

Through the new debugfs interface, the user can configure loopback
mode/linkrate/phy id/code mode before enabling it. And also user can
enable/disable BIST function.

Link: https://lore.kernel.org/r/1567774537-20003-13-git-send-email-john.garry@huawei.comSigned-off-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

We extract the code of memory allocate and construct an new function for
it. We think it's convenient for subsequent optimization.

Link: https://lore.kernel.org/r/1567774537-20003-12-git-send-email-john.garry@huawei.comSigned-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>