virtio_scsi: support multi hw queue of blk-mq

Since virtio_scsi has supported multi virtqueue already,
it is natural to map the virtque to hw-queue of blk-mq.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: remove spin lock around command allocation

It is already using atomic test_and_set_bit to do the
allocation.

There is some microscopic chance of starvation, but it is
so microscopic that it should never happen in reality.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: always call pci_set_master after pci_enable_device

If the kernel is booted with the reset_device parameter, which
is done for kdump, then the driver needs to call pci_set_master
after pci_enable_device to reenable bus mastering (since
the preceding pci_disable_device call disables bus mastering).

Also, place that after pci_request_regions both in the
kdump code and the normal pci_init code.

Remove the comment summarizing what pci_set_master
does, with the incomplete commentary on the impact of
pci_disable_device.

Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: Convert SCSI LLD ->queuecommand() for host_lock less operation

There isn't anything in hpsa that requires the host lock to be held
during queuecommand.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: do not be so noisy about check conditions

We were printing a lot of useless information before ultimately
just passing things up to the SCSI mid layer.  Just let the
midlayer handle it without LLD chatter.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Reviewed-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: use atomics for commands_outstanding

Use atomics for commands_outstanding instead of protecting with spin locks.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: get rid of type/attribute/direction bit field where possible

Using bit fields for hardware command fields isn't portable and
relies on assumptions about how the compiler lays out the bits.
We can fix this in the driver's internal command structure, but the
ioctl interface we can't change because it is part of the
userland ABI.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: fix endianness issue with scatter gather elements

The hardware needs little endian scatter gather addresses and
lengths but we were not bothering to convert from cpu byte
order as we should have been.  On Intel, this is all just
a bunch of no-ops macros, but it makes the code endian-clean(er).

Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: fix allocation sizes for CISS_REPORT_LUNs commands

We were allocating roughly double the amount of memory
we should be due to ReportLUNdata and ExtendedReportLUNdata
containing a non-zero sized array but adding extra memory
to allocate as if the array were zero sized.

Track the logical and physical sizes separately.
Allocate the memory based on the specific data
structure sizes.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: remove 'action required' phrasing

In the case of LUN data changing, the driver will
auto rescan and so it's not even true that "action" is
"required".

Remove "action required" phrases from warning messages and
replace with description phrases.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: correct off-by-one sizing of chained SG block

Correct the size calculation of the chained SG block

Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Webb Scales <webbnh@hp.com>
Reviewed-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: fix a couple pci id table mistakes

Fix a couple of pci id table mistakes:
Subdevice ID 0x3323 missing from product[] table
(another name for HP Smart Storage 1210m)
Bogus 0x1925 subdevice id removed from hpsa_pci_device_id[] (no such thing.)

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: remove dev_warn prints from RAID-1ADM

RAID-1ADM is unusable with dev_warn called on every command.

Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

hpsa: Clean up warnings from sparse.

Clean up issues reported when running sparse.

Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Fix "transfered" typo

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Remove RESET_RUN_DONE macro

There's no need to run the cmd->done callback for aborted commands. Remove
the old EH code and the RESET_RUN_DONE macro.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Move static co-routine variables to host data

Unlike NCR5380.c, the atari_NCR5380.c core driver is limited to a single
instance because co-routine state is stored globally.

Fix this by removing the static scsi host pointer. For the co-routine,
obtain this pointer from the work_struct pointer instead. For the interrupt
handler, obtain it from the dev_id argument.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Move static TagAlloc array to host data

The atari_NCR5380.c core driver keeps some per-host data in a static
variable which limits the driver to a single instance. Fix this by moving
TagAlloc to the hostdata struct.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Introduce FLAG_TAGGED_QUEUING

The static variable setup_use_tagged_queuing is declared in mac_scsi.c,
sun3_scsi.c and atari_scsi.c and doesn't belong in the core driver.
None of the other NCR5380 drivers suffer from this layering issue which
makes merging the core drivers more difficult and will likely hinder plans
for future use of platform data to configure the driver.

Replace the static variable with a host flag. This way it can be reported
along with the other flags.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Merge from NCR5380.c

The NCR5380.c core driver has moved on since the atari_NCR5380.c fork.
Some of those changes are also relevant to atari_NCR5380.c so apply them
there as well.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

sun3_scsi: Adopt atari_NCR5380 core driver and remove sun3_NCR5380.c

Given the preceding changes to atari_NCR5380.c, this patch should not change
behaviour of the sun3_scsi and sun3_scsi_vme modules.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Merge from sun3_NCR5380.c

There is very little difference between the sun3_NCR5380.c core driver
and atari_NCR5380.c. The former is a fork of the latter.

Merge the sun3_NCR5380.c core driver into atari_NCR5380.c so that
sun3_scsi.c can adopt the latter and the former can be deleted.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Refactor Falcon locking

Simplify falcon_release_lock_if_possible() by making callers responsible for
disabling local IRQ's, which they must do anyway to correctly synchronize
the ST DMA "lock" with core driver data structures. Move this
synchronization logic to the core driver with which it is tightly coupled.

Other LLD's like sun3_scsi and mac_scsi that can make use of this core
driver can just stub out the NCR5380_acquire_dma_irq() and
NCR5380_release_dma_irq() calls so the compiler will eliminate the
ST DMA code.

Remove a redundant local_irq_save/restore pair (irq's are disabled for
interrupt handlers these days). Revise the locking for
atari_scsi_bus_reset(): use local_irq_save/restore() instead of
atari_turnoff/turnon_irq(). There is no guarantee that atari_scsi still
holds the ST DMA lock during EH, so atari_turnoff/turnon_irq() could
end up dropping an IDE or floppy interrupt.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_NCR5380: Refactor Falcon special cases

Make the atari_NCR5380.c core driver usable by sun3_scsi, mac_scsi and
others by moving some of the Falcon-specific code out of the core driver:
!IS_A_TT, atari_read_overruns and falcon_dont_release. Replace these with
hostdata variables and flags. FLAG_CHECK_LAST_BYTE_SENT is unused in
atari_NCR5380.c so don't set it.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove ENABLE_IRQ/DISABLE_IRQ macros

atari_NCR5380.c enables its IRQ when it is already enabled. Sun3 doesn't
use the ENABLE_IRQ/DISABLE_IRQ cruft. Remove it.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

sun3_scsi: Move macro definitions

The #defines in sun3_scsi.h are intended to influence subsequent #includes
in sun3_scsi.c. IMHO, that's too convoluted.

Move sun3_scsi.h macro definitions to sun3_scsi.c, consistent with other
NCR5380 drivers.

Omit the unused NCR5380_local_declare() and NCR5380_setup() macros.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

sun3_scsi: Convert to platform device

Convert sun3_scsi to platform device and eliminate scsi_register().

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_scsi: Remove header

The #defines in atari_scsi.h are intended to influence subsequent #includes
in atari_scsi.c. IMHO, that's too convoluted.

Remove atari_scsi.h by moving those macro definitions to atari_scsi.c,
consistent with other NCR5380 drivers.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_scsi: Convert to platform device

Convert atari_scsi to platform device and eliminate scsi_register().

Validate __setup options later on so that module options are checked as well.

Remove the comment about the scsi mid-layer disabling the host irq as it
is no longer true (AFAICT). Also remove the obsolete slow interrupt stuff
(IRQ_TYPE_SLOW == 0 anyway).

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

atari_scsi: Fix atari_scsi deadlocks on Falcon

Don't disable irqs when waiting for the ST DMA "lock"; its release may
require an interrupt.

Introduce stdma_try_lock() for use in soft irq context. atari_scsi now tells
the SCSI mid-layer to defer queueing a command if the ST DMA lock is not
available, as per Michael's patch:
http://marc.info/?l=linux-m68k&m=139095335824863&w=2

The falcon_got_lock variable is race prone: we can't disable IRQs while
waiting to acquire the lock, so after acquiring it there must be some
interval during which falcon_got_lock remains false. Introduce
stdma_is_locked_by() to replace falcon_got_lock.

The falcon_got_lock tests in the EH handlers are incorrect these days. It
can happen that an EH handler is called after a command completes normally.
Remove these checks along with falcon_got_lock.

Also remove the complicated and racy fairness wait queues. If fairness is an
issue (when SCSI competes with IDE for the ST DMA interrupt), the solution
is likely to be a lower value for host->can_queue.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

mac_scsi: Convert to platform device

Convert mac_scsi to platform device and eliminate scsi_register().

Platform resources for chip registers now follow the documentation. This
should fix issues with the Mac IIci (and possibly other models too).

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

mac_scsi: Cleanup PDMA code

Fix whitespace, remove pointless volatile qualifiers and improve code style
by use of INPUT_DATA_REG and OUTPUT_DATA_REG macros.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

mac_scsi: Add module option to Kconfig

Allow mac_scsi to be built as a module. Replace the old validation of
__setup options with code that validates both module and __setup options.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

mac_scsi: Remove header

The #defines in mac_scsi.h are intended to influence subsequent #includes in
mac_scsi.c. IMHO, that's too convoluted.

Remove mac_scsi.h by moving those macro definitions to mac_scsi.c,
consistent with other NCR5380 drivers.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dmx3191d: Use NO_IRQ

Testing shows that the Domex 3191D card never asserts its IRQ. Hence it is
non-functional with Linux (worse, the EH bugs in the core driver are fatal
but that's a problem for another patch). Perhaps the DT-536 chip needs
special setup? I can't find documentation for it. The NetBSD driver uses
polling apparently because of this issue.

Set host->irq = NO_IRQ so the core driver will prevent targets from
disconnecting. Don't request host->irq.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Drop legacy scsi.h include

Convert Scsi_Cmnd to struct scsi_cmnd and drop the #include "scsi.h".
The sun3_NCR5380.c core driver already uses struct scsi_cmnd so converting
the other core drivers reduces the diff which makes them easier to unify.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove *_RELEASE macros

The *_RELEASE macros don't tell me anything. In some cases the version in
the macro contradicts the version in the comments. Anyway, the Linux kernel
version is sufficient information. Remove these macros to improve readability.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove pointless compiler command line override macros

Compile-time override of scsi host defaults is pointless for drivers that
provide module parameters and __setup options for that. Too many macros make
the code hard to read so remove them.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Move static PDMA spin counters to host data

Static variables from dtc.c and pas16.c should not appear in the core
NCR5380.c driver. Aside from being a layering issue this worsens the
divergence between the three core driver variants (atari_NCR5380.c and
sun3_NCR5380.c don't support PSEUDO_DMA) and it can mean multiple hosts
share the same counters.

Fix this by making the pseudo DMA spin counters in the core more generic.
This also avoids the abuse of the {DTC,PAS16}_PUBLIC_RELEASE macros, so
they can be removed.

oak.c doesn't use PDMA and hence it doesn't use the counters and hence it
needs no write_info() method. Remove it.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Cleanup host info() methods

If the host->info() method is not set, then host->name is used by default.
For atari_scsi, that is exactly the same text. So remove the redundant
info() method. Keep sun3_scsi.c in line with atari_scsi.

Some NCR5380 drivers return an empty string from the info() method
(arm/cumana_1.c arm/oak.c mac_scsi.c) while other drivers use the default
(dmx3191d dtc.c g_NCR5380.c pas16.c t128.c).

Implement a common info() method to replace a lot of duplicated code which
the various drivers use to announce the same information.

This replaces most of the (deprecated) show_info() output and all of the
NCR5380_print_info() output. This also eliminates a bunch of code in
g_NCR5380 which just duplicates functionality in the core driver.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove NCR5380_STATS

The NCR5380_STATS option is only enabled by g_NCR5380 yet it adds
clutter to all three core drivers. The atari_NCR5380.c and sun3_NCR5380.c
core drivers have a slightly different implementation of the
NCR5380_STATS option.

Out of all ten NCR5380 drivers, only one of them (g_NCR5380) actually
has the code to report on the collected stats. Aside from being unreadable,
that code seems to be broken because there's no initialization of timebase.
sun3_NCR5380.c and atari_NCR5380.c have the timebase initialization but
lack the code to report the stats.

Remove all of this code to improve readability and reduce divergence
between the three core drivers.

This patch and the next one completely eliminate the PRINTP and ANDP
pre-processor abuse.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Fix SCSI_IRQ_NONE bugs

Oak scsi doesn't use any IRQ, but it sets irq = IRQ_NONE rather than
SCSI_IRQ_NONE. Problem is, the core NCR5380 driver expects SCSI_IRQ_NONE
if it is to issue IDENTIFY commands that prevent target disconnection.
And, as Geert points out, IRQ_NONE is part of enum irqreturn.

Other drivers, when they can't get an IRQ or can't use one, will set
host->irq = SCSI_IRQ_NONE (that is, 255). But when they exit they will
attempt to free IRQ 255 which was never requested.

Fix these bugs by using NO_IRQ in place of SCSI_IRQ_NONE and IRQ_NONE.
That means IRQ 0 is no longer probed by ISA drivers but I don't think
this matters.

Setting IRQ = 255 for these ISA drivers is understood to mean no IRQ.
This remains supported so as to avoid breaking existing ISA setups (which
can be difficult to get working) and because existing documentation
(SANE, TLDP etc) describes this usage for the ISA NCR5380 driver options.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove duplicate comments

The LIMIT_TRANSFERSIZE, PSEUDO_DMA, PARITY and UNSAFE options are all
documented in the core drivers where they are used. The same goes for the
chip databook reference. Remove the duplicate comments.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove redundant AUTOSENSE macro

Every NCR5380 driver sets AUTOSENSE so it need not be optional (and the
mid-layer expects it). Remove this redundant macro to improve readability.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Cleanup TAG_NEXT and TAG_NONE macros

Both atari_NCR5380.c and sun3_NCR5380.c core drivers #undef TAG_NONE and
then redefine it. But the original definition is unused because NCR5380.c
lacks support for tagged queueing. So just define it once.

The TAG_NEXT macro only appears in the arguments to NCR5380_select() calls.
But that routine doesn't use its tag argument as the tag was already
assigned in NCR5380_main(). So remove the unused argument and the macro.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove more useless prototypes

Make use of the host template static initializer instead of assigning
handlers at run-time. Move __maybe_unused qualifiers from declarations
to definitions. Move the atari_scsi_bus_reset() wrapper after the
definition of NCR5380_bus_reset(). All of the host template handler
prototypes are now redundant so remove them.

The write_info() handler is only relevant to drivers using PSEUDO_DMA so
this patch fixes the compiler warning in atari_NCR5380.c and sun3_NCR5380.c:

  CC      drivers/scsi/atari_scsi.o
  drivers/scsi/NCR5380.h:329: warning: 'NCR5380_write_info' declared 'static' but never defined

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove useless prototypes

Add missing static qualifiers and remove the now pointless prototypes. The
NCR5380_* prototypes are all declared in NCR5380.h and renamed using macros.
Further declarations are redundant (some are completely unused). Remove
them.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove unused macros

Some macros are never evaluated (i.e. FOO, USLEEP, SCSI2 and USE_WRAPPER;
and in some drivers, NCR5380_intr and NCR5380_proc_info). DRIVER_SETUP
serves no purpose anymore. Remove these macro definitions.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Fix compiler warnings and __setup options

Some __setup() options mentioned in Documentation/scsi don't work because
a few lines of code went missing sometime since Linux 2.4. Fix the options
and thus fix some compiler warnings for both the non-modular case,

    CC      drivers/scsi/dtc.o
drivers/scsi/dtc.c:176:20: warning: 'dtc_setup' defined but not used [-Wunused-function]

and the modular case,

    CC [M]  drivers/scsi/pas16.o
drivers/scsi/pas16.c:335:20: warning: 'pas16_setup' defined but not used [-Wunused-function]
    CC [M]  drivers/scsi/t128.o
drivers/scsi/t128.c:147:20: warning: 't128_setup' defined but not used [-Wunused-function]

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Remove unused hostdata fields

Remove unused fields from hostdata structs declared with the
NCR5380_implementation_fields macro.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ncr5380: Use printk() not pr_debug()

Having defined NDEBUG, and having set the console log level, I'd like to see
some output. Don't use pr_debug(), it's annoying to have to define DEBUG as
well.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Fnic: Fnic Driver crashed with NULL pointer reference

When issuing I/O request, if the I/O completes before returning from
fnic_queuecommand(), we may be referencing scsi_cmnd structure that may
be freed by interrupt handler. Acquring IO lock would synchronize
fnic_queuecommand and interrupt handler.

- Increment fnic version from 1.6.0.15 to 1.6.0.16

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Anil Chintalapati <achintal@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Fnic: For Standalone C series, "sending VLAN request" message seen even if the link is down

When physical link between standalone C series and switch is down,
the fip timer is not turned off and timer expiration will keep sending
vlan request.

It can be fixed by stopping the fip_timer and
it will be restarted automatically when Link is up.

- Increment fnic version from 1.6.0.14 to 1.6.0.15

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Anil Chintalapati <achintal@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Fnic: Improper resue of exchange Ids

IOs belonging to an rport are aborted with Internal terminate option
when rport goes offline. Any new IO issued to the rport during this
time can reuse the terminated exchange which will cause inconsistent
state of the exchange between local port and remote port.

fc_rport_priv is set to RPORT_ST_DELETE before exchanges are aborted by
libfc. Not issuing amy more I/O requests when RPORT_ST_DELETE is set,
will avoid inconsistent state of the exchange between local port and
remote port.

- Increment fnic version from 1.6.0.13 to 1.6.0.14

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Anil Chintalapati <achintal@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Fnic: Memcopy only mimumum of data or trace buffer

In case of receive path, we do not have eth header or fcoe header available
when we take a trace so we fill the fc trace buffer with 0xff for both
values. We copy only mimimum of received data or trace buffer size -
fc header - eth and fcoe header

- Increment fnic version from 1.6.0.12 to 1.6.0.13

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Anil Chintalapati <achintal@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Fnic: Not probing all the vNICS via fnic_probe on boot

In fnic_dev_wait, Wait for finish to complete at least three times in two
seconds while loop before returning -ETIMEDOUT as sometime
schedule_timeout_uninterruptible takes more than two seconds to wake up.

- Increment fnic version from 1.6.0.11 to 1.6.0.12

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Anil Chintalapati <achintal@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

bnx2fc: fix an error code in _bnx2fc_create()

We should be returning an error code here instead of success.  Either
-ENODEV or -ENOMEM would work.  There is also a failure message in
printk().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

bnx2fc: check IS_ERR() instead of NULL

The bnx2fc_if_create() function returns NULL on failure, it never
returns an error pointer.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Fix a race condition triggered by destroying a queue pair

At least LID reassignment can trigger a race condition in the SRP
initiator driver, namely the receive completion handler trying to
post a request on a QP during or after QP destruction and before
the CQ's have been destroyed. Avoid this race by modifying a QP
into the error state and by waiting until all receive completions
have been processed before destroying a QP.

Reported-by: Max Gurtuvoy <maxg@mellanox.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Add multichannel support

Improve performance by using multiple RDMA/RC channels per SCSI
host for communication with an SRP target. About the
implementation:
- Introduce a loop over all channels in the code that uses
  target->ch.
- Set the SRP_MULTICHAN_MULTI flag during login for the creation
  of the second and subsequent channels.
- RDMA completion vectors are chosen such that RDMA completion
  interrupts are handled by the CPU socket that submitted the I/O
  request. As one can see in this patch it has been assumed if a
  system contains n CPU sockets and m RDMA completion vectors
  have been assigned to an RDMA HCA that IRQ affinity has been
  configured such that completion vectors [i*m/n..(i+1)*m/n) are
  bound to CPU socket i with 0 <= i < n.
- Modify srp_free_ch_ib() and srp_free_req_data() such that it
  becomes safe to invoke these functions after the corresponding
  allocation function failed.
- Add a ch_count sysfs attribute per target port.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Use block layer tags

Since the block layer already contains functionality to assign
a tag to each request, use that functionality instead of
reimplementing that functionality in the SRP initiator driver.
This change makes the free_reqs list superfluous. Hence remove
that list.

[hch: updated to use .use_blk_tags instead scsi_activate_tcq]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Separate target and channel variables

Changes in this patch:
- Move channel variables into a new structure (struct srp_rdma_ch).
- Add an srp_target_port pointer, 'lock' and 'comp_vector' members
  in struct srp_rdma_ch.
- Add code to initialize these three new member variables.
- Many boring "target->" into "ch->" changes.
- The cm_id and completion handler context pointers are now of type
  srp_rdma_ch * instead of srp_target_port *.
- Three kzalloc(a * b, f) calls have been changed into kcalloc(a, b, f)
  to avoid that this patch would trigger a checkpatch warning.
- Two casts from u64 into unsigned long long have been left out
  because these are superfluous. Since considerable time u64 is
  defined as unsigned long long for all architectures supported by
  the Linux kernel.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Introduce two new srp_target_port member variables

Introduce the srp_target_port member variables 'sgid' and 'pkey'.
Change the type of 'orig_dgid' from __be16[8] into union ib_gid.
This patch does not change any functionality but makes the
"Separate target and channel variables" patch easier to verify.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Avoid that I/O hangs due to a cable pull during LUN scanning

If a cable is pulled during LUN scanning it can happen that the
SRP rport and the SCSI host have been created but no LUNs have been
added to the SCSI host. Since multipathd only sends SCSI commands
to a SCSI target if one or more SCSI devices are present and since
there is no keepalive mechanism for IB queue pairs this means that
after a LUN scan failed and after a reconnect has succeeded no
data will be sent over the QP and hence that a subsequent cable
pull will not be detected. Avoid this by not creating an rport or
SCSI host if a cable is pulled during a SCSI LUN scan.

Note: so far the above behavior has only been observed with the
kernel module parameter ch_count set to a value >= 2.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Remove stale connection retry mechanism

Attempting to connect three times may be insufficient after an
initiator system tries to relogin, especially if the relogin
attempt occurs before the SRP target service ID has been
registered. Since the srp_daemon retries a failed login attempt
anyway, remove the stale connection retry mechanism.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

IB/srp: Move ib_destroy_cm_id() call into srp_free_ch_ib()

The patch that adds multichannel support into the SRP initiator
driver introduces an additional call to srp_free_ch_ib(). This
patch helps to keep that later patch simple.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

qla2xxx: remove redundant declaration in 'qla_gbl.h'

Remove 2 redundant extern inline functions: qla8044_set_qsnt_ready() and
qla8044_need_reset_handler(). At present, within upstream next kernel
source code, they are only used within "drivers/scsi/qla2xxx/qla_nx2.c".

The related error and warnings (with allmodconfig under tile):

    CC [M]  drivers/scsi/qla2xxx/qla_nx2.o
  drivers/scsi/qla2xxx/qla_nx2.c:1633:1: error: static declaration of 'qla8044_need_reset_handler' follows non-static declaration
   qla8044_need_reset_handler(struct scsi_qla_host *vha)
   ^
  In file included from drivers/scsi/qla2xxx/qla_def.h:3706:0,
                   from drivers/scsi/qla2xxx/qla_nx2.c:11:
  drivers/scsi/qla2xxx/qla_gbl.h:756:20: note: previous declaration of 'qla8044_need_reset_handler' was here
   extern inline void qla8044_need_reset_handler(struct scsi_qla_host *vha);
                      ^
  drivers/scsi/qla2xxx/qla_gbl.h:756:20: warning: inline function 'qla8044_need_reset_handler' declared but never defined
  make[3]: *** [drivers/scsi/qla2xxx/qla_nx2.o] Error 1
  make[2]: *** [drivers/scsi/qla2xxx] Error 2
  make[1]: *** [drivers/scsi] Error 2
  make: *** [drivers] Error 2

    CC [M]  drivers/scsi/qla2xxx/qla_tmpl.o
  In file included from drivers/scsi/qla2xxx/qla_def.h:3706:0,
                   from drivers/scsi/qla2xxx/qla_tmpl.c:7:
  drivers/scsi/qla2xxx/qla_gbl.h:755:20: warning: inline function 'qla8044_set_qsnt_ready' declared but never defined
   extern inline void qla8044_set_qsnt_ready(struct scsi_qla_host *vha);
                    ^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ipr: set coherent DMA mask

Use dma_set_mask_and_coherent() to set both the DMA and coherent
DMA mask.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ipr: convert to generic DMA API

Even though the ipr driver is only used on PCI, convert it
to use the generic DMA API.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

vmw_pvscsi: fixup tagging

The request (and SCSI command) tag is the tag number assigned
by the generic block-tagging code, not the SCSI-II tag messages.
Those are represented by the device flags 'tagged_supported',
'simple_tags', and 'ordered_tags'.
(The SCSI midlayer doesn't use HEAD_OF_QUEUE tags).
So fixup vmw_pvscsi to assign the correct tag type.

[hch: fixed up to never set MSG_ORDERED_TAG]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Arvind Kumar <arvindkumar@vmware.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi_debug: error message should say scsi_host_alloc not scsi_register

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

tmscim: remove unused SCSI_IRQ_NONE macro definition

This macro is only used in the NCR5380 drivers and they don't include
this header.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ufs: remove spurious scsi_set_tag_type call

ufs never looks at the tag type, so there is no need to set it either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't force tagged_supported in drivers

Now that we also get proper values in cmd->request->tag for untagged
commands, there is no need to force tagged_supported to on in drivers
that need host-wide tags.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove use_blk_tcq Scsi_Host field

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

mptfusion: don't change queue type in ->change_queue_depth

This function shouldn't change the queue type, just the depth.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove abuses of scsi_populate_tag

Unless we want to build a SPI tag message we should just check SCMD_TAGGED
instead of reverse engineering a tag type through the use of
scsi_populate_tag_msg.

Also rename the function to spi_populate_tag_msg, make it behave like the
other spi message helpers, and move it to the spi transport class.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove ordered_tag host template field

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove ordered_tags scsi_device field

Remove the ordered_tags field, we haven't been issuing ordered tags based
on it since the big barrier rework in 2010.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: add new scsi-command flag for tagged commands

Currently scsi piggy backs on the block layer to define the concept
of a tagged command.  But we want to be able to have block-level host-wide
tags assigned even for untagged commands like the initial INQUIRY, so add
a new SCSI-level flag for commands that are tagged at the scsi level, so
that even commands without that set can have tags assigned to them.  Note
that this alredy is the case for the blk-mq code path, and this just lets
the old path catch up with it.

We also set this flag based upon sdev->simple_tags instead of the block
queue flag, so that it is entirely independent of the block layer tagging,
and thus always correct even if a driver doesn't use block level tagging
yet.

Also remove the old blk_rq_tagged; it was only used by SCSI drivers, and
removing it forces them to look for the proper replacement.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: provide a generic change_queue_type method

Most drivers use exactly the same implementation, so provide it as a
library function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: handle more device handler setup/teardown in common code

Move all code to set up and tear down sdev->scsi_dh_data to common code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: device handlers must have attach and detach methods

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove struct scsi_dh_devlist

All drivers now do their own matching, so there is no more need to expose
a device list as part of the interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: use container_of to get at device handler private data

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi_dh: get module reference outside of device handler

We need to grab a reference to the module before calling the attach
routines to avoid a small race vs module removal.  It also cleans up
the code significantly as a side effect.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi_dh_hp_sw: fix return value on failed allocation

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

sd: disable discard_zeroes_data for UNMAP

The T10 SBC UNMAP command does not provide any hard guarantees that
blocks will return zeroes on a subsequent READ. This is due to the fact
that the device server is free to silently ignore all or parts of the
request.

The only way to ensure that a block consistently returns zeroes after
being unmapped is to use WRITE SAME with the UNMAP bit set. Should the
device be unable to unmap one or more blocks described by the command it
is required to manually write zeroes to them.

Until now we have preferred UNMAP over the WRITE SAME variants to
accommodate thinly provisioned devices that predated the final SBC-3
spec. This patch changes the heuristic so that we favor WRITE SAME(16)
or (10) over UNMAP if these commands are marked as supported in the
Logical Block Provisioning VPD page.

The patch also disables discard_zeroes_data for devices operating in
UNMAP mode.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: return EAGAIN when resetting a device under EH

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

osst: call scsi_set_medium_removal directly

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

st: call scsi_set_medium_removal directly

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

sd: fix up ->compat_ioctl

No need to verify the passthrough ioctls, the real handler will
take care of that.  Also make sure not to block for resets on
O_NONBLOCK fds.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: split scsi_nonblockable_ioctl

The calling conventions for this function are bad as it could return
-ENODEV both for a device not currently online and a not recognized ioctl.

Add a new scsi_ioctl_block_when_processing_errors function that wraps
scsi_block_when_processing_errors with the a special case for the
SG_SCSI_RESET ioctl command, and handle the SG_SCSI_RESET case itself
in scsi_ioctl.  All callers of scsi_ioctl now must call the above helper
to check for the EH state, so that the ioctl handler itself doesn't
have to.

Reported-by: Robert Elliott <Elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: refactor scsi_reset_provider handling

Pull the common code from the two callers into the function,
and rename it to scsi_ioctl_reset.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: add support for multiple hardware queues in scsi_(host_)find_tag

Modify scsi_find_tag() and scsi_host_find_tag() such that these
functions can translate a tag generated by blk_mq_unique_tag().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: add support for multiple hardware queues

Allow a SCSI LLD to declare how many hardware queues it supports
by setting Scsi_Host.nr_hw_queues before calling scsi_add_host().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

blk-mq: add blk_mq_unique_tag()

The queuecommand() callback functions in SCSI low-level drivers
need to know which hardware context has been selected by the
block layer. Since this information is not available in the
request structure, and since passing the hctx pointer directly to
the queuecommand callback function would require modification of
all SCSI LLDs, add a function to the block layer that allows to
query the hardware context index.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: ratelimit I/O error messages

There can be quite a lot of I/O error messages, even on smaller
machines. So we need to ratelimit them to not overwhelm logging.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>