Now LLDDs have to implement lldd_port_deformed method otherwise NULL
dereference will happen. Make it optional and remove the dummy implementation
in hisi_sas.
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>
Acked-by: John Garry <john.garry@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.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>
Add a check ERR bit of status to decide whether there is something wrong
with initial register-D2H FIS. If error exist, PHY link reset the channel
to restart OOB.
Directly call work HISI_PHYE_LINK_RESET replacing disable_phy_vx_hw() and
enable_phy_vx_hw().
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In task start delivery function, we need to add a memory barrier to prevent
re-ordering of reading memory by hardware. Because the slot data is set in
task prepare function and it could be running in another CPU.
This patch adds an memory barrier after s->ready is read in the task start
delivery function, and uses WRITE_ONCE() in the places where s->ready is
set to ensure that the compiler does not re-order.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
To decrease the usage of spinlock during delivery IO, relocate some code in
hisi_sas_task_prep().
Also an invalid comment is removed.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch implements handlers of PCIe FLR for v3 hw, reset_prepare() and
reset_done().
User can issue FLR through sysfs interface, as v3 hw support PCIe FLR.
Then if we don't implement these two handlers, our SAS controller will not
work after executing FLR.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Much code of PM suspend function also exists in soft reset function. This
is not concise. So, this patch relocates the common code of these two
functions to a separate function.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch tidies host controller reset function by putting some code to
two new functions, and exports these two functions out, so that they could
be used by FLR feature to be realised.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is an issue that link reset can't recover PHY when STP link timeout.
Because current process of enabling PHY for v3 hw will wait last
transmission done. The time of one transmission depends IO size, disk model
and so on. Normally, it should be shorter than 50ms. But the last
transmission could be never done for some abnormal scenarios, such as STP
link timeout.
This patch is to fix the issue. Check PHY status after starting process of
enabling PHY for 50ms. If the PHY is still active, we disable it forcibly
by PHY reset. Of course, we need to clear the PHY reset bit when enable
PHY.
Besides, the function disable_phy_v3_hw() should not be suitable to call in
interrupts for hilink bug for this 50ms delay. Then, we do link reset for
hilink bug directly. The change is that we don't clear the invalid dword
count register. This is better. Because we should not clear such error
count while not saved.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The ISR of channel interrupt of v3 hw is a little long and messy. This
patch tidies it by relocating CHL_INT1 and CHL_INT2 handling to new
function separately.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
For some time now we have not used hisi_sas_slot_abort() to handle erroring
slots, apart from in archaic v1 hw.
As such, remove this function and associated code. For v1 hw, move error
handling to same scheme as other hw revisions, where we allow erroring
commands to timeout.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Update CFG_1US_TIMER_TRSH and CON_CFG_DRIVER settings.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The init is missed for hisi_sas_phy spinlock, so add it.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently the driver spends much time allocating and freeing the slot DMA
buffer for command delivery/completion. To boost the performance,
pre-allocate the buffers for all IPTT. The downside of this approach is
that we are reallocating all buffer memory upfront, so hog memory which we
may not need.
However, the current method - DMA buffer pool - also caches all buffers and
does not free them until the pool is destroyed, so is not exactly efficient
either.
On top of this, since the slot DMA buffer is slightly bigger than a 4K
page, we need to allocate 2x4K pages per buffer (for 4K page kernel), which
is quite wasteful. For 64K page size this is not such an issue.
So, for the 4K page case, in order to make memory usage more efficient,
pre-allocating larger blocks of DMA memory for the buffers can be more
efficient.
To make DMA memory usage most efficient, we would choose a single
contiguous DMA memory block, but this could use up all the DMA memory in
the system (when CMA enabled and no IOMMU), or we may just not be able to
allocate a DMA buffer large enough when no CMA or IOMMU.
To decide the block size we use the LCM (least common multiple) of the
buffer size and the page size. We roundup(64) to ensure the LCM is not too
large, even though a little memory may be wasted per block.
So, with this, the total memory requirement is about is about 17MB for 4096
max IPTT.
Previously (for 4K pages case), it would be 32MB (for all slots
allocated).
With this change, the relative increase of IOPS for bs=4K read when
PAGE_SIZE=4K and PAGE_SIZE=64K is as follows:
IODEPTH 4K PAGE_SIZE 64K PAGE_SIZE
32 56% 47%
64 53% 44%
128 64% 43%
256 67% 45%
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In host reset, we use TMF or soft-reset to re-init device, and if success,
we will release all LLDD resources of this device. If the init fails -
maybe because the device was removed or link has not come up - then do not
release the LLDD resources, but rather rely on SCSI EH to handle the
timeout for these resources later on.
But if clear nexus ha calls host reset, which is the last effort of SCSI
EH, we should release all LLDD remain resources. Because SCSI EH will
release all tasks after clear nexus ha.
Before release, we do I_T nexus reset to try to clear target remain IOs.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
During reset, we don't want PHY events reported to libsas for PHYs which
were previously attached prior to reset.
So check hisi_hba->flags for HISI_SAS_RESET_BIT to filter PHY events during
reset.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
After soft_reset() for host reset, we should not be allowed to send
commands to the HW before the PHYs have come up and the port ids have been
refreshed.
Prior to this point, any commands cannot be successfully completed.
This exclusion is achieved by grabbing the host reset semaphore.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is a possible conflict when a device is removed and host reset occurs
concurrently.
The reason is that then the device is notified as gone, we try to clear the
ITCT, which is notified via an interrupt. The dev gone function pends on
this event with a completion, which is completed when the ITCT interrupt
occurs.
But host reset will disable all interrupts, the wait_for_completion() may
wait indefinitely.
This patch adds an semaphore to synchronise this two processes. The
semaphore is taken by the host reset as the basis of synchronising.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There are many BROADCAST primitives generated by the host. We are only
interested in BROADCAST (CHANGE) primitives currently, so only process
this.
We have applied this processing for v2 hw before, and it is also needed for
v3 hw.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch replaces the usage of dma_alloc_coherent() with the managed
version, dmam_alloc_coherent(), hereby reducing replicated code.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by; John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When issuing a nexus reset for directly attached device, we want to ignore
the PHY down events so libsas will not deform and reform the port.
In the case that the attached SAS changes for the reset, libsas will deform
and form a port.
For scenario that the PHY does not come up after a timeout period, then
report the PHY down to libsas.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It is an step of executing task to get free slot. If the step fails, we
will cleanup LLDD resources and should return failure to upper layer or
internal caller to abort task execution of this time.
But in the current code, the caller of get_free_slot() doesn't return
failure when get_free_slot() failed. This patch is to fix it.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
For v2 hw, STP link from target is rejected after host reset because of a
SoC bug. The STP reject will be terminated after we have sent IO from each
PHY of a port.
This is not an problem before, as we don't need to setup STP link from
target immediately after host reset. But now, it is. Because we want to
send soft-reset immediately after host reset.
In order to terminate STP reject quickly, this patch send ATA reset command
through each PHY of a port. Notes: ATA reset command don't need target's
response.
Besides, we do abort dev for each device before terminating STP reject.
This is a quirk of v2 hw.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch adds a force PHY function for internal ATA command for v2 hw.
Because there is an SoC bug in v2 hw, and need send an IO through each PHY
of a port to work around a bug which occurs after a controller reset.
This force PHY function will be used in the later patch.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In future scenarios we will want to use the TMF struct for more task types
than SSP.
As such, we can add struct hisi_sas_tmf_task directly into struct
hisi_sas_slot, and this will mean we can remove the TMF parameters from the
task prep functions.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
We may reset the controller in many scenarios, such as SCSI EH and HW
errors. There should be no IO which returns from target when SCSI EH is
active. But for other scenarios, there may be. It is not necessary to make
such IOs fail.
This patch adds an function of trying to wait for any commands, or IO, to
complete before host reset. If no more CQ returned from host controller in
100ms, we assume no more IO can return, and then stop waiting. We wait 5s
at most.
The HW has a register CQE_SEND_CNT to indicate the total number of CQs that
has been reported to driver. We can use this register and it is reliable to
resd this register in such scenarios that require host reset.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
After the controller is reset, it is possible that the disks attached still
have outstanding IO to complete.
Thus, when the PHYs come back up after controller reset, it is possible
that these IOs complete at some unknown point later.
We want to ensure that all IOs are complete after the controller reset so
that all associated IPTT and other resources can be recycled safely.
To achieve this, re-init the disks by TMF or softreset (in case of ATA
devices).
If the init fails - maybe because the device was removed or link has not
come up - then do not release the device resources, but rather rely on SCSI
EH to handle the timeout for these resources later on.
This patch also does some cleanup to hisi_sas_init_disk(), including
removing superfluous cases in the switch statement.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When a SCSI host is registered, the SCSI mid-layer takes a reference to a
module in Scsi_host.hostt.module. In doing this, we are prevented from
removing the driver module for the host in dangerous scenario, like when a
disk is mounted.
Currently there is only one scsi_host_template (sht) for all HW versions,
and this is the main.c module. So this means that we can possibly remove
the HW module in this dangerous scenario, as SCSI mid-layer is only
referencing the main.c module.
To fix this, create a sht per module, referencing that same module to
create the Scsi host.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When a disk is discovered, it may be in an error state, or there may be
residual commands remaining in the disk.
To ensure any disk is in good state after discovery, reset via TMF (for SAS
disk) or softreset (for a SATA disk).
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch implements LED feature of directly attached disk for v3 hw.
In fact, this hw has created an SGPIO component for LED feature, and we can
control LEDs just by internal registers.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
To reduce possibility of hitting unknown SoC bugs and aid debugging and
test, change allocation mode of device id from last used device id instead
of lowest available index.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently we find the lowest available empty bit in the IPTT bitmap to
allocate the IPTT for a command.
To reduce possibility of hitting unknown SoC bugs and also aid in the
debugging of those same bugs, change the allocation mode.
The next allocation method is to use the next free slot adjacent to the
most recently allocated slot, in a round-robin fashion.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is much common code and functionality between the HW versions to set
the PHY linkrate.
As such, this patch factors out the common code into a generic function
hisi_sas_phy_set_linkrate().
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently we don't check that device is not gone before dereferencing
its elements in the function hisi_sas_task_exec() (specifically, the DQ
pointer).
This patch fixes this issue by filling in the DQ pointer in
hisi_sas_task_prep() after we check that the device pointer is still
safe to reference.
[mkp: typo]
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The IPTT of a slot is unique, and we currently use hisi_hba lock to
protect it.
Now slot is managed on hisi_sas_device.list, so use DQ lock to protect
for allocating and freeing the slot.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently we lock the DQ to protect whole delivery process. So this
stops us building slots for the same queue in parallel, and can affect
performance.
To optimise it, only lock the DQ during special periods, specifically
when allocating a slot from the DQ and when delivering a slot to the HW.
This approach is now safe, thanks to the previous patches to ensure that
we always deliver a slot to the HW once allocated.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently we allocate the slot's memory buffer after allocating the DQ
slot.
To aid DQ lockout reduction, and allow slots to be built in parallel,
move this step (which can fail) prior to allocating the slot.
Also a stray spin_unlock_irqrestore() is removed from internal task exec
function.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Since the task prep functions now should not fail, adjust the return
types to void.
In addition, some checks in the task prep functions are relocated to the
main module; this is specifically the check for the number of elements
in an sg list exceeded the HW SGE limit.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently we use DQ lock to protect delivery of DQ entry one by one.
To optimise to allow more than one slot to be built for a single DQ in
parallel, we need to remove the DQ lock when preparing slots, prior to
delivery.
To achieve this, we rearrange the slot build order to ensure that once
we allocate a slot for a task, we do cannot fail to deliver the task.
In this patch, we rearrange the slot building for SMP tasks to ensure
that sg mapping part (which can fail) happens before we allocate the
slot in the DQ.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There is an SoC bug of v3 hw development version. When hot- unplugging a
directly attached disk, the PHY down interrupt may not happen. It is
very easy to appear on some boards.
When this issue occurs, the controller will receive many invalid dword
frames, and the "alos" fields of register HILINK_ERR_DFX can indicate
that disk was unplugged.
As an workaround solution, this patch detects this issue in the channel
interrupt, and workaround it by following steps:
- Disable the PHY
- Clear error code and interrupt
- Enable the PHY
Then the HW will reissue PHY down interrupt.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It is common to use readl poll timeout helpers in the driver, so create
custom wrappers.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Event95 is used for DFX purpose. The relevant bit for this interrupt in
the ENT_INT_SRC_MSK3 register has been disabled, so remove the
processing.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
As a unconstrained command, a command can be sent to SATA disk even if
SATA disk status is BUSY, ERR or DRQ.
If an ATA reset assert is successful but ATA reset de-assert fails, then
it will retry the reset de-assert. If reset de- assert retry is
successful, we think it is okay to probe the device but actually it
still has Err status.
Apparently we need to retry the ATA reset assertion and de- assertion
instead for this mentioned scenario.
As such, we config ATA reset assert as a constrained command, if ATA
reset de-assert fails, then ATA reset de-assert retry will also
fail. Then we will retry the proper process of ATA reset assert and
de-assert again.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
After the controller is reset, we currently may not honour the PHY max
linkrate set via sysfs, in that after a reset we always revert to max
linkrate of 12Gbps, ignoring the value set via sysfs.
This patch modifies to policy to set the programmed PHY linkrate,
honouring the max linkrate programmed via sysfs.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
We should only have the timer enabled after PHY up after controller
reset, so disable prior to reset.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
It is possible to dereference a NULL-pointer in hisi_sas_abort_task() in
special scenario when the device has been removed.
If an SMP task times-out, it will call hisi_sas_abort_task() to
recover. And currently there is a check in hisi_sas_abort_task() to
avoid the situation of processing the abort for the removed device.
However we have an ordering problem, in that we may reference a task for
the removed device before checking if the device has been removed.
Fix this by only referencing the sas_dev after we know it is still
present.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There are 28 bytes of protection information record of SSP for v3 hw, 16
bytes for v2 hw, and probably 24 for v1 hw (forgotten now).
So use a value big enough in hisi_sas_command_table_ssp.prot to cover
all cases.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When the host is frozen in SCSI EH state, at any point after the LLDD
sets SAS_TASK_STATE_DONE for the sas_task task state, libsas may free
the task; see sas_scsi_find_task().
This puts the LLDD in a difficult position, in that once it sets
SAS_TASK_STATE_DONE for the task state it should not reference the
sas_task again. But the LLDD needs will check the sas_task indirectly in
calling task->task_done()->sas_scsi_task_done() or sas_ata_task_done()
(to check if the host is frozen state actually).
And the LLDD cannot set SAS_TASK_STATE_DONE for the task state after
task->task_done() is called (as the sas_task is free'd at this point).
This situation would seem to be a problem made by libsas.
To work around, check in the LLDD whether the host is in frozen state to
ensure it is ok to call task->task_done() function. If in the frozen
state, we rely on SCSI EH and libsas to free the sas_task directly.
We do not do this for the following IO types:
- SMP - they are managed in libsas directly, outside SCSI EH
- Any internally originated IO, for similar reason
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
If the SCSI host enters EH, any pending IO will be processed by SCSI
EH. However it is possible that SCSI EH will try to abort the IO and
also at the same time the IO completes in the driver. In this situation
there is a small chance of freeing the sas_task twice.
Then if another IO re-uses freed sas_task before the second time of
free'ing sas_task, it is possible to free incorrect sas_task.
To avoid this situation, add some checks to increase reliability. The
sas_task task state flag SAS_TASK_STATE_ABORTED is used to mutually
protect the LLDD and libsas freeing the task.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In the DQ tasklet processing it is not necessary to take the DQ lock, as
there is no contention between adding slots to the CQ and removing slots
from the matching DQ.
In addition, since we run each DQ in a separate tasklet context, there
would be no possible contention between DQ processing running for the
same queue in parallel.
It is still necessary to take hisi_hba lock when free'ing slots.
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
