Remove the arbitrary expectation in libsas that all SCSI commands are 16 bytes
or less.  Instead do all copies via cmd->cmd_len (and use a pointer to this in
the libsas task instead of a copy).  Note that this still doesn't enable > 16
byte CDB support in the underlying drivers because their internal format has
to be fixed and the wire format of > 16 byte CDBs according to the SAS spec is
different.  the libsas drivers (isci, aic94xx, mvsas and pm8xxx are all
updated for this change.

Cc: Lukasz Dorau <lukasz.dorau@intel.com>
Cc: Maciej Patelczyk <maciej.patelczyk@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jack Wang <xjtuwjp@gmail.com>
Cc: Lindar Liu <lindar_liu@usish.com>
Cc: Xiangliang Yu <yuxiangl@marvell.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Signed-off-by: James Bottomley <JBottomley@Parallels.com>

These enums have been separate since the dawn of SAS, mainly because the
latter is a procotol only enum and the former includes additional state
for libsas.  The dichotomy causes endless confusion about which one you
should use where and leads to pointless warnings like this:

drivers/scsi/mvsas/mv_sas.c: In function 'mvs_update_phyinfo':
drivers/scsi/mvsas/mv_sas.c:1162:34: warning: comparison between 'enum sas_device_type' and 'enum sas_dev_type' [-Wenum-compare]

Fix by eliminating one of them.  The one kept is effectively the sas.h
one, but call it sas_device_type and make sure the enums are all
properly namespaced with the SAS_ prefix.

Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Pull block core updates from Jens Axboe:

 - Major bit is Kents prep work for immutable bio vecs.

 - Stable candidate fix for a scheduling-while-atomic in the queue
   bypass operation.

 - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging
   discard bios.

 - Tejuns changes to convert the writeback thread pool to the generic
   workqueue mechanism.

 - Runtime PM framework, SCSI patches exists on top of these in James'
   tree.

 - A few random fixes.

* 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits)
  relay: move remove_buf_file inside relay_close_buf
  partitions/efi.c: replace useless kzalloc's by kmalloc's
  fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read()
  block: fix max discard sectors limit
  blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
  Documentation: cfq-iosched: update documentation help for cfq tunables
  writeback: expose the bdi_wq workqueue
  writeback: replace custom worker pool implementation with unbound workqueue
  writeback: remove unused bdi_pending_list
  aoe: Fix unitialized var usage
  bio-integrity: Add explicit field for owner of bip_buf
  block: Add an explicit bio flag for bios that own their bvec
  block: Add bio_alloc_pages()
  block: Convert some code to bio_for_each_segment_all()
  block: Add bio_for_each_segment_all()
  bounce: Refactor __blk_queue_bounce to not use bi_io_vec
  raid1: use bio_copy_data()
  pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage
  pktcdvd: use bio_copy_data()
  block: Add bio_copy_data()
  ...

If a result of the SMP discover function is PHY VACANT,
the content of discover response structure (dr) is not valid.
It sometimes happens that dr->attached_sas_addr can contain
even SAS address of other phy. In such case an invalid phy
is created, what causes NULL pointer dereference during
destruction of expander's phys.

So if a result of SMP function is PHY VACANT, the content of discover
response structure (dr) must not be copied to phy structure.

This patch fixes the following bug:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
IP: [<ffffffff811c9002>] sysfs_find_dirent+0x12/0x90
Call Trace:
  [<ffffffff811c95f5>] sysfs_get_dirent+0x35/0x80
  [<ffffffff811cb55e>] sysfs_unmerge_group+0x1e/0xb0
  [<ffffffff813329f4>] dpm_sysfs_remove+0x24/0x90
  [<ffffffff8132b0f4>] device_del+0x44/0x1d0
  [<ffffffffa016fc59>] sas_rphy_delete+0x9/0x20 [scsi_transport_sas]
  [<ffffffffa01a16f6>] sas_destruct_devices+0xe6/0x110 [libsas]
  [<ffffffff8107ac7c>] process_one_work+0x16c/0x350
  [<ffffffff8107d84a>] worker_thread+0x17a/0x410
  [<ffffffff81081b76>] kthread+0x96/0xa0
  [<ffffffff81464944>] kernel_thread_helper+0x4/0x10

Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

In fact the disc_resp buffer will be overwrite by smp response, so we never
found this typo, correct it by using the right one.

Signed-off-by: John Gong <john_gong@usish.com>
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

More prep work for immutable bvecs/effecient bio splitting - usage of
bi_vcnt has to be auditing, so getting rid of all the unnecessary usage
makes that easier.

Plus, bio_segments() is really what this code wanted, as it respects the
current value of bi_idx.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Eric Moore <Eric.Moore@lsi.com>
CC: "James E.J. Bottomley" <JBottomley@parallels.com>
CC: linux-scsi@vger.kernel.org

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

libsas and ipr pass flags to ata_host_init that are meant for the port.

ata_host flags:
	ATA_HOST_SIMPLEX	= (1 << 0),	/* Host is simplex, one DMA channel per host only */
	ATA_HOST_STARTED	= (1 << 1),	/* Host started */
	ATA_HOST_PARALLEL_SCAN	= (1 << 2),	/* Ports on this host can be scanned in parallel */
	ATA_HOST_IGNORE_ATA	= (1 << 3),	/* Ignore ATA devices on this host. */

flags passed by libsas:
	ATA_FLAG_SATA		= (1 << 1),
	ATA_FLAG_PIO_DMA	= (1 << 7), /* PIO cmds via DMA */
	ATA_FLAG_NCQ		= (1 << 10), /* host supports NCQ */

The only one that aliases is ATA_HOST_STARTED which is a 'don't care' in
the libsas and ipr cases since ata_hosts from these sources are not
registered with libata.

Reported-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Brian King <brking@us.ibm.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

libsas power management routines to suspend and recover the sas domain
based on a model where the lldd is allowed and expected to be
"forgetful".

sas_suspend_ha - disable event processing allowing the lldd to take down
                 links without concern for causing hotplug events.
                 Regardless of whether the lldd actually posts link down
                 messages libsas notifies the lldd that all
                 domain_devices are gone.

sas_prep_resume_ha - on the way back up before the lldd starts link
                     training clean out any spurious events that were
                     generated on the way down, and re-enable event
                     processing

sas_resume_ha - after the lldd has started and decided that all phys
		have posted link-up events this routine is called to let
		libsas start it's own timeout of any phys that did not
		resume.  After the timeout an lldd can cancel the
                phy teardown by posting a link-up event.

Storage for ex_change_count (u16) and phy_change_count (u8) are changed
to int so they can be set to -1 to indicate 'invalidated'.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Tested-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>