This patch adds support for DIX to v3 hw driver.

For this, we build upon support for DIF, most significantly is adding new
DMA map and unmap paths.

Some pre-existing macro precedence issues are also tidied. They were
detected by checkpatch --strict.
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>

This call must have been missed when I reworked the debugfs feature for
upstreaming, so add it back.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Sparse detected some problems in the driver, so tidy them up.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some sizes we allocate for debugfs structure are incorrect, so fix them.
Signed-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>

Hot-plugging SAS wire of direct hard disk backplane may cause disk lost. We
have done this test with several types of SATA disk from different venders,
and only two models from Seagate has this problem, ST4000NM0035-1V4107 and
ST3000VM002-1ET166.

The root cause is that the disk doesn't send D2H frame after OOB finished.
SAS controller will issue phyup interrupt only when D2H frame is received,
otherwise, will be waiting there all the time.

When this issue happen, we can find the disk again with link reset.  To fix
this issue, we setup an timer after OOB finished. If the PHY is not up in
20s, do link reset. Notes: the 20s is an experience value.
Signed-off-by: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The SAS controller cannot support a programmed minimum linkrate of > 1.5G
(it will always negotiate to 1.5G at least), so just reject it.

This solves a strange situation where the PHY negotiated linkrate may be
less than the programmed minimum linkrate.
Signed-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 function hisi_sas_alloc(), parameter shost is not used, so remove it.
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>

When issing a hardreset to a SATA device when running IO, it is possible
that abnormal CQs of the device are returned. Then enter error handler, it
doesn't enter function hisi_sas_abort_task() as there is no timeout IO, and
it doesn't set device as HISI_SAS_DEV_EH. So when hardreset by libata
later, it actually doesn't issue hardreset as there is a check to judge
whether device is in error.

For this situation, actually need to hardreset the device to recover.
So remove the check of sas_dev status in hisi_sas_I_T_nexus_reset().

Before we add the check to avoid the endless loop of reset for
directly-attached SATA device at probe time, actually we flutter it for
it, so it is not necessary to add the check now.
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>

Send primitive NOTIFY to SSP situation only, or it causes underflow issue
when sending IO. Also rename hisi_sas_hw.sl_notify() to hisi_sas_hw.
sl_notify_ssp().
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>

This patch creates debugfs file for ITCT and adds file operations.
Signed-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>

Sparse can detect some type casting issues in the debugfs code, so fix it
up.

Also a missing static qualifier is added to hisi_sas_debugfs_to_reg_name().
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When calling debugfs functions, there is no need to ever check the return
value. The function can work or not, but the code logic should never do
something different based on this.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch create debugfs file for IOST and add file operations.
Signed-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>

This patch create debugfs file for DQ and add file operations
Signed-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>

This patch create debugfs file for CQ and add file operations.
Signed-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>

This patch create debugfs file for port register and add file operations.
Signed-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>

This patch create debugfs file for global register and add file
operations.
Signed-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>

This patch takes snapshot for global regs, port regs, CQ, DQ, IOST, ITCT.

Add code for snapshot trig and generate dump directory.
Signed-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>

This patch allocates snapshot memory for global reg, port regs, CQ, DQ,
IOST, ITCT.

When we fail to allocate memory for some registers, we free the memory
and set hisi_sas_debugfs_enable as 0 to stop loading debugfs from running.
Signed-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>

This patch creates root directory at hisi_sas_init() and generates device
directory when we probe device driver.

And we remove the root directory at hisi_sas_exit(), but recursively
delete device directory when we remove device driver.
Signed-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>

Sht->sg_tablesize is set in the driver, and it will be assigned to
shost->sg_tablesize in SCSI mid-layer. So it is not necessary to assign
shost->sg_table one more time in the driver.

In addition to the change, change each scsi_host_template.sg_tablesize
to HISI_SAS_SGE_PAGE_CNT instead of SG_ALL.
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>

Relocate the codes related to dma_map/unmap in hisi_sas_task_prep() to
reduce complexity, with a view to add DIF/DIX support.
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>

This patchset fixes some warnings detected by the sparse tool, like these:
drivers/scsi/hisi_sas/hisi_sas_main.c:1469:52: warning: incorrect type in assignment (different base types)
drivers/scsi/hisi_sas/hisi_sas_main.c:1469:52:    expected unsigned short [unsigned] [assigned] [usertype] tag_of_task_to_be_managed
drivers/scsi/hisi_sas/hisi_sas_main.c:1469:52:    got restricted __le16 [usertype] <noident>
drivers/scsi/hisi_sas/hisi_sas_main.c:1723:52: warning: incorrect type in assignment (different base types)
drivers/scsi/hisi_sas/hisi_sas_main.c:1723:52:    expected unsigned short [unsigned] [assigned] [usertype] tag_of_task_to_be_managed
drivers/scsi/hisi_sas/hisi_sas_main.c:1723:52:    got restricted __le16 [usertype] <noident>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In function hisi_sas_task_prep(), we check asd_sas_port, but in function
hisi_sas_task_exec(), we already refer to asd_sas_port by using function
dev_to_hisi_hba() implicitly. So to avoid this possible invalid
dereference, relocate the check to function hisi_sas_task_prep().
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>

Currently all the three HBA (v1/v2/v3 HW) share the same host attributes.

To support each HBA having separate attributes in future, create per-HBA
attributes.
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>

There is a NULL pointer dereference in case *slot* happens to be NULL at
lines 1053 and 1878:

struct hisi_sas_cq *cq =
	&hisi_hba->cq[slot->dlvry_queue];

Notice that *slot* is being NULL checked at lines 1057 and 1881:
if (slot), which implies it may be NULL.

Fix this by placing the declaration and definition of variable cq, which
contains the pointer dereference slot->dlvry_queue, after slot has been
properly NULL checked.

Addresses-Coverity-ID: 1474515 ("Dereference before null check")
Addresses-Coverity-ID: 1474520 ("Dereference before null check")
Fixes: 584f53fe ("scsi: hisi_sas: Fix the race between IO completion and timeout for SMP/internal IO")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently we use the IPTT defined in LLDD to identify IOs. Actually for
IOs which are from the block layer, they have tags to identify them. So
for those IOs, use tag of the block layer directly, and for IOs which is
not from the block layer (such as internal IOs from libsas/LLDD), reserve
96 IPTTs for them.
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>

If SMP/internal IO times out, we will possibly free the task immediately.

However if the IO actually completes at the same time, the IO completion
may refer to task which has been freed.

So to solve the issue, flush the tasklet to finish IO completion before
free'ing slot/task.
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 evaluating hisi_hba, the sas_port may be NULL, so for safety relocate
the the check to value possible NULL deference.
Signed-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>

At directly attached situation, if the user modifies the sysfs interface
of maximum_linkrate and minimum_linkrate to renegotiate the linkrate
between SAS controller and target, the value of both files mentioned
above should have change to user setting after renegotiate is over, but
it remains unchanged.

To fix this bug, maximum_linkrate and minimum_linkrate will be directly
fed back to relevant sas_phy structure.
Signed-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>

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: NJason 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: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin 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: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin 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: NXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin 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: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin 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: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The init is missed for hisi_sas_phy spinlock, so add it.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin 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: 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 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: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin 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: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin 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: NXiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>