linux-stable.git/drivers/firewire/sbp2.c, branch linux-3.8.y

firewire: sbp2: allow WRITE SAME and REPORT SUPPORTED OPERATION CODES

2012-12-02T19:10:18+00:00

The commits
    3c6bdaeab4fd "[SCSI] Add a report opcode helper"
    5db44863b6eb "[SCSI] sd: Implement support for WRITE SAME"
introduced in-kernel uses of the mentioned commands but cautiously
blacklisted them for any IEEE 1394 (SBP-2/3) targets and some other
transports.

I looked through a range of SBP devices and found that the blacklist
flags can be removed:

The kernel never attempts these commands if the device's INQUIRY
data claim a SCSI revision of less than 0x05.  This is the case with
all SBP devices that I checked, except for three more recent devices
which claimed a revision of 0x05 i.e. conformance with SPC-3 (two
devices based on the OXUF936QSE chip but having different firmwares,
one based on OXUF934DSB.)

I tried "sg_opcodes" from sg3_utils on several older and newer devices
and did not encounter any apparent firmware bugs with it.  All devices
returned Illegal Request/ Invalid command operation code and carried on.
I furthermore tried "sg_write_same -U" on the OXUF934DSB device with the
same result.  Alas I did not have a TRIM enabled SSD available for these
tests.  All of the bridges were correctly identified by the kernel as
"fully provisioned", CD-ROM devices aside.

The kernel won't issue WRITE SAME to fully provisioned devices, nor
would it attempt REPORT SUPPORTED OPERATION CODES or WRITE SAME with
UNMAP bit on devices which do not claim conformance to SPC-3 or later.

Hence let's remove the no_report_opcodes and no_write_same blacklist
flags so that these commands can be used on newer targets with
respective capabilities.  I guess the Linux sbp-target could be such a
target.

Signed-off-by: Stefan Richter

[SCSI] sd: Implement support for WRITE SAME

2012-11-14T06:45:42+00:00

Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk
driver.

 - We set the default maximum to 0xFFFF because there are several
   devices out there that only support two-byte block counts even with
   WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the
   device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK
   LIMITS VPD.

 - max_write_same_blocks can be overriden per-device basis in sysfs.

 - The UNMAP discovery heuristics remain unchanged but the discard
   limits are tweaked to match the "real" WRITE SAME commands.

 - In the error handling logic we now distinguish between WRITE SAME
   with and without UNMAP set.

The discovery process heuristics are:

 - If the device reports a SCSI level of SPC-3 or greater we'll issue
   READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is
   supported. If that's the case we will use it.

 - If the device supports the block limits VPD and reports a MAXIMUM
   WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16).

 - Otherwise we will use WRITE SAME(10) unless the target LBA is beyond
   0xFFFFFFFF or the block count exceeds 0xFFFF.

 - no_write_same is set for ATA, FireWire and USB.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Mike Snitzer 
Reviewed-by: Jeff Garzik 
Signed-off-by: James Bottomley

[SCSI] Add a report opcode helper

2012-11-14T05:11:31+00:00

The REPORT SUPPORTED OPERATION CODES command can be used to query
whether a given opcode is supported by a device. Add a helper function
that allows us to look up commands.

We only issue RSOC if the device reports compliance with SPC-3 or
later. But to err on the side of caution we disable the command for ATA,
FireWire and USB.

Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Signed-off-by: James Bottomley

firewire: sbp2: document the absence of alignment requirements

2012-05-21T19:49:44+00:00

The SBP-2/3 specifications do not require any alignment of data
buffers; only their own data structures need to be quadlet-aligned
[SR: or octlet-aligned].

Fix the comments to reflect this, but leave the actual alignment at
32 bits to avoid theoretical problems with target implementations
that might handle this incorrectly.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter

firewire: sbp2: remove superfluous blk_queue_max_segment_size() call

2012-05-21T19:42:51+00:00

The SCSI framework automatically initializes the block queue's segment
size with the DMA device's segment size.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter

firewire: sbp2: use scsi_dma_(un)map

2012-05-21T19:42:51+00:00

Use the scsi_dma_map/scsi_dma_unmap helper to simplify the code
a little.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter

firewire: sbp2: give correct DMA device to scsi framework

2012-05-21T19:42:51+00:00

The sbp2 driver does DMA not on the unit but on the card device.

The driver worked even with the wrong device because at the moment, it
happens to reimplement the DMA functions of the SCSI framework.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter

Remove all #inclusions of asm/system.h

2012-03-28T17:30:03+00:00

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*.*\n!!' `grep -Irl '^#\s*include\s*' *`

Signed-off-by: David Howells

Merge tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

2012-03-23T03:31:15+00:00

Pull IEEE 1394 (FireWire) subsystem updates post v3.3 from Stefan Richter:

 - Some SBP-2 initiator fixes, side product from ongoing work on a target.

 - Reintroduction of an isochronous I/O feature of the older ieee1394 driver
   stack (flush buffer completions); it was evidently rarely used but not
   actually unused.  Matching libraw1394 code is already available.

 - Be sure to prefix all kernel log messages with device name or card name,
   and other logging related cleanups.

 - Misc other small cleanups, among them a small API change that affects
   sound/firewire/ too. Clemens Ladisch is aware of it.

* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: (26 commits)
  firewire: allow explicit flushing of iso packet completions
  firewire: prevent dropping of completed iso packet header data
  firewire: ohci: factor out iso completion flushing code
  firewire: ohci: simplify iso header pointer arithmetic
  firewire: ohci: optimize control bit checks
  firewire: ohci: remove unused excess_bytes field
  firewire: ohci: copy_iso_headers(): make comment match the code
  firewire: cdev: fix IR multichannel event documentation
  firewire: ohci: fix too-early completion of IR multichannel buffers
  firewire: ohci: move runtime debug facility out of #ifdef
  firewire: tone down some diagnostic log messages
  firewire: sbp2: replace a GFP_ATOMIC allocation
  firewire: sbp2: Fix SCSI sense data mangling
  firewire: sbp2: Ignore SBP-2 targets on the local node
  firewire: sbp2: Take into account Unit_Unique_ID
  firewire: nosy: Use the macro DMA_BIT_MASK().
  firewire: core: convert AR-req handler lock from _irqsave to _bh
  firewire: core: fix race at address_handler unregistration
  firewire: core: remove obsolete comment
  firewire: core: prefix log messages with card name
  ...

firewire: sbp2: replace a GFP_ATOMIC allocation

2012-03-10T16:41:19+00:00

sbp2_send_management_orb() is called by sbp2_login, sbp2_reconnect, and
sbp2_remove, all which are able to sleep during memory allocations.
Actually, sbp2_send_management_orb() itself is a sleeping function.

Login and remove could allocate with GFP_KERNEL but reconnect needs
GFP_NOIO to ensure progress in low memory situations.

Signed-off-by: Stefan Richter