Some UFS devices may expose bLUQueueDepth field as zero indicating
that the queue depth depends on the number of resources available
for LUN at a particular instant to handle the outstanding transfer
requests. Currently, when response for SCSI command is TASK_FULL
the LLD decrements the queue depth but fails to increment when the
resources are available. The scsi mid-layer handles the change in
queue depth heuristically and offers simple interface with
->change_queue_depth.
Signed-off-by: NSujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: NDolev Raviv <draviv@codeaurora.org>
Acked-by: NSantosh Y <santoshsy@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Some of the UFS devices may support different number of commands
that can be queued per LU. At the current implementation,
SW configure each of the UFS devices LU's according to the
controller capability.

In this patch the queue depth available per LU is read and updated in
the LU's SW structure.
Signed-off-by: NDolev Raviv <draviv@codeaurora.org>
Signed-off-by: NRaviv Shvili <rshvili@codeaurora.org>
Acked-by: NSantosh Y <santoshsy@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Check query response status before copying the response.
Add descriptor query response size check, before copying it to buffer.
Signed-off-by: NDolev Raviv <draviv@codeaurora.org>
Signed-off-by: NRaviv Shvili <rshvili@codeaurora.org>
Acked-by: NSantosh Y <santoshsy@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Introduces the API for sending queries with descriptors.
A descriptor is a block or page of parameters that describe the device.
The descriptors are classified into types and can range in size
from 2 bytes through 255 bytes.
All descriptors have a length value as their first element, and a type
identification element as their second byte.
All descriptors are readable and some may be write once.
They are accessed using their type, index and selector.
Signed-off-by: NDolev Raviv <draviv@codeaurora.org>
Signed-off-by: NRaviv Shvili <rshvili@codeaurora.org>
Acked-by: NSantosh Y <santoshsy@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The if_info pointer is not released by the mgmt_set_ip() function
Signed-off-by: NMaurizio Lombardi <mlombard@redhat.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

change_queue_depth allows changing per-target queue depth via sysfs.

It also allows the SCSI midlayer to ramp down the number of concurrent
inflight requests in response to a SCSI BUSY status response and allows
the midlayer to ramp the count back up to the device maximum when the
BUSY condition has resolved.
Signed-off-by: NVenkatesh Srinivas <venkateshs@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The spinlock of tgt_lock is only for serializing read and write
req_vq, one lockless seqcount is enough for the purpose.

On one 16core VM with vhost-scsi backend, the patch can improve
IOPS with 3% on random read test.
Signed-off-by: NMing Lei <ming.lei@canonical.com>
[Add initialization in virtscsi_target_alloc. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

When copy_from_user fails, return -EFAULT, not -ENOMEM
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-by: NRobert Elliott <elliott@hp.com>
Reviewed-by: NJoe Handzik <joseph.t.handzik@hp.com>
Reviewed-by: NScott Teel <scott.teel@hp.com>
Reviewed by: Mike MIller <michael.miller@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

When devices come on line, they should be removed from the list of
offline devices that are monitored.
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: NScott Teel <scott.teel@hp.com>
Reviewed-by: NJoe Handzik <joseph.t.handzik@hp.com>
Reviewed by: Mike MIller <michael.miller@canonical.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

commit 28e13446 "[SCSI] hpsa: enable unit attention reporting"
turns on unit attention notifications, but got the change wrong for
all architectures other than x86, which now store an uninitialized
value into the device register.

Gcc helpfully warns about this:

../drivers/scsi/hpsa.c: In function 'hpsa_set_driver_support_bits':
../drivers/scsi/hpsa.c:6373:17: warning: 'driver_support' is used uninitialized in this function [-Wuninitialized]
  driver_support |= ENABLE_UNIT_ATTN;
                 ^

This moves the #ifdef so only the prefetch-enable is conditional
on x86, not also reading the initial register contents.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 28e13446 "[SCSI] hpsa: enable unit attention reporting"
Cc: stable@vger.kernel.org # v3.14+
Acked-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NRobert Elliott <elliott@hp.com>
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

a 6-byte READ/WRITE CDB with a 0 block data transfer really
means a 256 block data transfer.  The RAID mapping code failed
to handle this case.  For 10/12/16 byte READ/WRITEs, 0 just means
no data should be transferred, and should not trigger BUG_ON.
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-by: NRobert Elliott <elliott@hp.com>
Reviewed-by: NRobert Elliott <elliott@hp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: NJoe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Acked-by: NEddie Wai <eddie.wai@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

QLogic has acquired the NetXtremeII products and drivers from Broadcom.
This patch re-brands bnx2fc driver as a QLogic driver
Signed-off-by: NSaurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Acked-by: NEddie Wai <eddie.wai@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

QLogic has acquired the NetXtremeII products and drivers from Broadcom.
This patch re-brands bnx2i driver as a QLogic driver
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Acked-by: NEddie Wai <eddie.wai@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

On systems with a non power-of-two CPU count the existing MSI-X grouping
code failed to distribute interrupts correctly. Rework the code to
handle arbitrary processor counts.

Also remove the hardcoded upper limit on the number of processors so we
can boot on large systems.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Acked-by: NSreekanth Reddy <Sreekanth.reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

On systems with a non power-of-two CPU count the existing MSI-X grouping
code failed to distribute interrupts correctly. Rework the code to
handle arbitrary processor counts.

Also remove the hardcoded upper limit on the number of processors so we
can boot on large systems.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Acked-by: NSreekanth Reddy <Sreekanth.reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fixes the following smatch warnings:

  drivers/message/fusion/mptbase.c:652 mptbase_reply() warn: variable
    dereferenced before check 'reply' (see line 639)

      [JL: No-brainer, the enclosing switch statement dereferences
       reply, so we can't get here unless reply is valid.]

  drivers/message/fusion/mptsas.c:1255 mptsas_taskmgmt_complete() error:
    we previously assumed 'pScsiTmReply' could be null (see line 1227)

      [HCH: Reading the code in mptsas_taskmgmt_complete it's pretty
       obvious that it can't do anything useful if mr/pScsiTmReply are
       NULL, so I suspect it would be best to just return at the
       beginning of the function.

       I'd love to understand if it actually could ever be zero, which I
       doubt.  Maybe the LSI people can shed some light on that?]

  drivers/message/fusion/mptsas.c:3888 mptsas_not_responding_devices()
    error: we previously assumed 'port_info->phy_info' could be null
    (see line 3875)

      [HCH: It's pretty obvious from reading mptsas_sas_io_unit_pg0 that
       we never register a port_info with a NULL phy_info in the lists,
       so all NULL checks on it could be deleted.]

  drivers/message/fusion/mptscsih.c:1284 mptscsih_info() error:
    we previously assumed 'h' could be null (see line 1274)

      [HCH: shost_priv can't return NULL, so the if (h) should be
       removed.]

  drivers/message/fusion/mptscsih.c:1388 mptscsih_qcmd() error: we
    previously assumed 'vdevice' could be null (see line 1373)

      [HCH: vdevice can't ever be NULL here, it's allocated in
       ->slave_alloc and thus guaranteed to be around when
       ->queuecommand is called.]
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Tack the firmware reply event_data payload to the end of its
corresponding struct fw_event_work allocation.  Rework fw_event_work
allocation calculations to include the event_data size where
appropriate.

This clarifies the code a bit and avoids the following smatch warnings:

  drivers/message/fusion/mptsas.c:1003 mptsas_queue_device_delete()
    error: memcpy() 'fw_event->event_data' too small (29 vs 36)

  drivers/message/fusion/mptsas.c:1017 mptsas_queue_rescan() error: not
    allocating enough data 168 vs 160
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The struct _MPT_ADAPTER doesn't need a full copy of the product string,
so prod_name can point to the string literal storage that the driver
already provides.

Avoids the following smatch warning:

  drivers/message/fusion/mptbase.c:2858 MptDisplayIocCapabilities()
    warn: this array is probably non-NULL. 'ioc->prod_name'
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Let memdup_user handle the kmalloc, copy_from_user and error checking
kfree code.

Spotted by the following smatch (false positive) warning:

  drivers/message/fusion/mptctl.c:1369 mptctl_getiocinfo() warn:
    possible info leak 'karg'
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fixes the following smatch warnings:

  drivers/message/fusion/mptfc.c:529 mptfc_target_destroy() info:
    redundant null check on starget->hostdata calling kfree()

  drivers/message/fusion/mptspi.c:465 mptspi_target_destroy() info:
    redundant null check on starget->hostdata calling kfree()
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fixes the following sparse warnings:

  drivers/message/fusion/mptbase.c:7011:1: warning: symbol
    'mpt_SoftResetHandler' was not declared. Should it be static?

  drivers/message/fusion/mptsas.c:1578:23: warning: symbol
    'mptsas_refreshing_device_handles' was not declared. Should it be
    static?

  drivers/message/fusion/mptsas.c:3653:24: warning: symbol
    'mptsas_expander_add' was not declared. Should it be static?

  drivers/message/fusion/mptsas.c:5327:1: warning: symbol
    'mptsas_shutdown' was not declared. Should it be static?

  drivers/message/fusion/mptspi.c:624:1: warning: symbol
    'mptscsih_quiesce_raid' was not declared. Should it be static?
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Tack the firmware reply event_data payload to the end of its
corresponding struct fw_event_work allocation.  This matches the
convention in the mptfusion driver and simplifies the code.

This avoids the following smatch warning:

  drivers/scsi/mpt3sas/mpt3sas_scsih.c:2519
    mpt3sas_send_trigger_data_event() warn: possible memory leak of
    'fw_event'
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

In _scsih_{slave,target}_alloc, an incorrect structure type is passed
to sizeof() when allocating storage for hostdata.  Luckily larger
structure types were used, so at least the wrong sizes were safe:

  struct scsi_device (1784 bytes) > struct MPT3SAS_DEVICE (24 bytes)
  struct scsi_target (760 bytes)  > struct MPT3SAS_TARGET (32 bytes)

This fixes the following smatch warnings:

  drivers/scsi/mpt3sas/mpt3sas_scsih.c:1166 _scsih_target_alloc()
    warn: struct type mismatch 'MPT3SAS_TARGET vs scsi_target'

  drivers/scsi/mpt3sas/mpt3sas_scsih.c:1280 _scsih_slave_alloc()
    warn: struct type mismatch 'MPT3SAS_DEVICE vs scsi_device'
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The MPT2SAS_ADAPTER reply_post_host_index[] holds calculated addresses
in memory mapped register space.  Add an "__iomem" annotation to silence
the following sparse warnings:

  drivers/scsi/mpt2sas/mpt2sas_base.c:1006:43:
    warning: incorrect type in argument 2 (different address spaces)
       expected void volatile [noderef] <asn:2>*addr
       got unsigned long long [usertype] *<noident>

  drivers/scsi/mpt2sas/mpt2sas_base.c:4299:22:
    warning: cast removes address space of expression
  drivers/scsi/mpt2sas/mpt2sas_base.c:4303:27:
    warning: cast removes address space of expression
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Tack the firmware reply event_data payload to the end of its
corresponding struct fw_event_work allocation.  This matches the
convention in the mptfusion driver and simplifies the code.
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

In _scsih_{slave,target}_alloc, an incorrect structure type is passed
to sizeof() when allocating storage for hostdata.  Luckily larger
structure types were used, so at least the wrong sizes were safe:

  struct scsi_device (1784 bytes) > struct MPT2SAS_DEVICE (24 bytes)
  struct scsi_target (760 bytes)  > struct MPT2SAS_TARGET (40 bytes)

This fixes the following smatch warnings:

  drivers/scsi/mpt2sas/mpt2sas_scsih.c:1295 _scsih_target_alloc()
    warn: struct type mismatch 'MPT2SAS_TARGET vs scsi_target'

  drivers/scsi/mpt2sas/mpt2sas_scsih.c:1409 _scsih_slave_alloc()
    warn: struct type mismatch 'MPT2SAS_DEVICE vs scsi_device'
Signed-off-by: NJoe Lawrence <joe.lawrence@stratus.com>
Acked-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Building an allmodconfig ARM kernel, I get multiple such
warnings because of a spinlock contained in packed structure
in the 3w-xxxx driver:

../drivers/scsi/3w-xxxx.c: In function 'tw_chrdev_ioctl':
../drivers/scsi/3w-xxxx.c:1001:68: warning: mis-aligned access used for structure member [-fstrict-volatile-bitfields]
    timeout = wait_event_timeout(tw_dev->ioctl_wqueue, tw_dev->chrdev_request_id == TW_IOCTL_CHRDEV_FREE, timeout);
                                                                    ^
../drivers/scsi/3w-xxxx.c:1001:68: note: when a volatile object spans multiple type-sized locations, the compiler must choose between using a single mis-aligned access to preserve the volatility, or using multiple aligned accesses to avoid runtime faults; this code may fail at runtime if the hardware does not allow this access

The same bug apparently was present in 3w-sas and 3w-9xxx, but has been
fixed in the past. This patch uses the same fix by moving the pragma
in front of the TW_Device_Extension definition, so it only covers
hardware structures.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NAdam Radford <aradford@gmail.com>
Cc: Adam Radford <linuxraid@lsi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The NCR53c406a scsi driver normally does not use DMA, unless
the USE_PIO macro is disabled by modifying the source code.

The call to free_dma() for some reason uses #ifdef USE_DMA,
which does not do the right thing, since USE_DMA is defined
as a boolean that is either 0 or 1, but always present.

One case where it gets in the way is randconfig builds on ARM,
which depending on the configuration does not provide a free_dma()
function, causing this build error:

drivers/scsi/NCR53c406a.c: In function 'NCR53c406a_release':
drivers/scsi/NCR53c406a.c:600:3: error: implicit declaration of function 'free_dma' [-Werror=implicit-function-declaration]
   free_dma(shost->dma_channel);
   ^

This changes the code to use #if USE_DMA, to match the
rest of the file, which seems to be what the author intended.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The qlogicfas scsi driver does not use DMA, and the call to free_dma()
in its exit function seems to have been copied incorrectly from
another driver but never caused trouble.

One case where it gets in the way is randconfig builds on ARM,
which depending on the configuration does not provide a free_dma()
function, causing this build error:

drivers/scsi/qlogicfas.c: In function 'qlogicfas_release':
drivers/scsi/qlogicfas.c:175:3: error: implicit declaration of function 'free_dma' [-Werror=implicit-function-declaration]
   free_dma(shost->dma_channel);
   ^

Removing the incorrect function calls should be the obvious
fix for this, with no downsides.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The pas16 scsi driver does not use DMA, and the call to free_dma()
in its exit function seems to have been copied incorrectly from
another driver but never caused trouble.

One case where it gets in the way is randconfig builds on ARM,
which depending on the configuration does not provide a free_dma()
function, causing this build error:

drivers/scsi/pas16.c: In function 'pas16_release':
drivers/scsi/pas16.c:611:3: error: implicit declaration of function 'free_dma' [-Werror=implicit-function-declaration]
   free_dma(shost->dma_channel);

Removing the incorrect function calls should be the obvious
fix for this, with no downsides.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The advansys SCSI driver uses the dma_cache_sync function, which is
not available on the ARM architecture, and cannot be implemented
correctly, so we always get this build error:

drivers/scsi/advansys.c: In function 'advansys_get_sense_buffer_dma':
drivers/scsi/advansys.c:7882:2: error: implicit declaration of function 'dma_cache_sync' [-Werror=implicit-function-declaration]
  dma_cache_sync(board->dev, scp->sense_buffer,
  ^

It seems nobody has missed this driver so far, so let's just
disable it for ARM to help randconfig builds.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Added big endian annotations to relevant data structure fields, and necessary
byte swappings to support little endian builds.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use the zeroing function instead of dma_alloc_coherent & memset(,0,)
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NSaurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use macro definition
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Acked-by: NAnil Gurumurthy <anil.gurumurthy@qlogic.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This patch remove variables that are initialized with a constant,
are never updated, and are only used as parameter of return.
Return the constant instead of using a variable.

Verified by compilation only.

The coccinelle script that find and fixes this issue is:
// <smpl>
@@
type T;
constant C;
identifier ret;
@@
- T ret = C;
... when != ret
    when strict
return
- ret
+ C
;
// </smpl>
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Acked-by: NSudarsana Kalluru <Sudarsana.Kalluru@qlogic.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

bfa_swap_words() shifts its argument (assumed to be 64-bit) by 32 bits
each way.  In two places the argument type is dma_addr_t, which may be
32-bit, in which case the effect of the bit shift is undefined:

drivers/scsi/bfa/bfa_fcpim.c: In function 'bfa_ioim_send_ioreq':
drivers/scsi/bfa/bfa_fcpim.c:2497:4: warning: left shift count >= width of type [enabled by default]
    addr = bfa_sgaddr_le(sg_dma_address(sg));
    ^
drivers/scsi/bfa/bfa_fcpim.c:2497:4: warning: right shift count >= width of type [enabled by default]
drivers/scsi/bfa/bfa_fcpim.c:2509:4: warning: left shift count >= width of type [enabled by default]
    addr = bfa_sgaddr_le(sg_dma_address(sg));
    ^
drivers/scsi/bfa/bfa_fcpim.c:2509:4: warning: right shift count >= width of type [enabled by default]

Avoid this by adding casts to u64 in bfa_swap_words().

Compile-tested only.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Acked-by: NAnil Gurumurthy <anil.gurumurthy@qlogic.com>
Cc: stable@vger.kernel.org
Fixes: f16a1750 ('[SCSI] bfa: remove all OS wrappers')
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use the zeroing function instead of dma_alloc_coherent & memset(,0,)
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NAnil Gurumurthy <anil.gurumurthy@qlogic.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>