* Add IDE_TFLAG_OUT_DEVICE taskfile flag to indicate the need of writing
  the Device register and handle it in ide_tf_load().

  Update ide_tf_load() and {do_rw,flagged}_taskfile() users accordingly.

* Use struct ide_taskfile and ide_tf_load() in execute_drive_cmd().

* Make the debugging code dump all taskfile registers for both
  REQ_ATA_TYPE_{CMD,TASK} requests and move it to ide_tf_load()
  so it also covers REQ_ATA_TYPE_TASKFILE requests.

There should be no functionality changes caused by this patch
(unless DEBUG is defined).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Remove ide_cmd() helper.

* Clear nIEN and call SELECT_MASK() before writing taskfile registers.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Rename 'args' variable in 'if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)'
  block to 'task'.

* execute_drive_cmd() is used only for REQ_TYPE_ATA_{CMD,TASK,TASKFILE} so
  we can move the common code out from 'if (rq->cmd_type == REQ_TYPE_ATA_CMD)'
  and 'if (rq->cmd_type == REQ_TYPE_ATA_TASK)' blocks.

There should be no functionality changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move loading of IDE_NSECTOR_REG from ide_cmd() to execute_drive_cmd()
(load the IDE_NSECTOR_REG just after IDE_FEATURE_REG).

This also allows us to drop 'nsect' argument from ide_cmd() and simplify
execute_drive_cmd() code for REQ_TYPE_ATA_CMD case a bit.

It shouldn't affect anything (just a usual paranoia to separate changes
which change the way in which hardware is accessed from code cleanups).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Fix registers loading order for REQ_TYPE_ATA_CMD request with WIN_SMART
command in execute_drive_cmd() (load IDE_FEATURE_REG and IDE_SECTOR_REG
before loading IDE_LCYL_REG and IDE_HCYL_REG).

It shouldn't affect anything (just a usual paranoia to separate changes
which change the way in which hardware is accessed from code cleanups).
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Remove stale ide.h "configuration options":

* INITIAL_MULT_COUNT - always defined to 0

* SUPPORT_SLOW_DATA_PORTS - unused

* OK_TO_RESET_CONTROLLER - always defined to 1

* DISABLE_IRQ_NOSYNC - always defined to 0

Leave SUPPORT_VLB_SYNC (defined to 0 for CRIS and FRV, otherwise to 1)
for now but disallow overriding it by <asm/ide.h>.

There should be no functionality changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on the earlier work by Tejun Heo.

* Move setting IDE_TFLAG_LBA48 taskfile flag from do_rw_taskfile()
  function to the callers.

* Add IDE_TFLAG_FLAGGED taskfile flag for flagged taskfiles coming
  from ide_taskfile_ioctl().  Check it instead of ->tf_out_flags.all.

* Add IDE_TFLAG_OUT_DATA taskfile flag to indicate the need to load
  IDE data register in ide_tf_load().

* Add IDE_TFLAG_OUT_* taskfile flags to indicate the need to load
  particular IDE taskfile registers in ide_tf_load().

* Update do_rw_taskfile() and ide_tf_load() users to set respective
  IDE_TFLAG_OUT_* taksfile flags.

* Add task_dma_ok() helper.

* Use IDE_TFLAG_FLAGGED taskfile flag to select HIHI mask in ide_tf_load().

* Use do_rw_taskfile() in flagged_taskfile().

* Remove no longer needed 'tf_out_flags' field from ide_task_t.

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Don't set write-only ide_task_t.hobRegister[6] and ide_task_t.hobRegister[7]
  in idedisk_set_max_address_ext().

* Add struct ide_taskfile and use it in ide_task_t instead of tfRegister[]
  and hobRegister[].

* Remove no longer needed IDE_CONTROL_OFFSET_HOB define.

* Add #ifndef/#endif __KERNEL__ around definitions of {task,hob}_struct_t.

While at it:

* Use ATA_LBA define for LBA bit (0x40) as suggested by Tejun Heo.

v2:
* Add missing newlines. (Noticed by Sergei)

* Use ~ATA_LBA instead of 0xBF. (Noticed by Sergei)

* Use unnamed unions for error/feature and status/command.
  (Suggested by Sergei).

There should be no functionality changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Currently it's possible to ide-cd to set an incorrect blocksize by
reading garbage if the drive is dead:

ide_cd_probe()
 -> cdrom_read_toc()
     -> cdrom_read_capacity()
         -> cdrom_queue_packet_command()
             -> ide_do_drive_cmd()
                 -> ide_do_request()
                     -> start_request()

on start_request():

        /* bail early if we've exceeded max_failures */
        if (drive->max_failures && (drive->failures > drive->max_failures)) {
                goto kill_rq;
        }
(...)
kill_rq:
        ide_kill_rq(drive, rq);
        return ide_stopped;

ide_kill_rq() and the next calls won't set REQ_FAILED on rq->cmd_flags and thus
cdrom_queue_packet_command() won't return an error. then:

        stat = cdrom_queue_packet_command(drive, &req);
        if (stat == 0) {
                *capacity = 1 + be32_to_cpu(capbuf.lba);
                *sectors_per_frame =
                        be32_to_cpu(capbuf.blocklen) >> SECTOR_BITS;
        }

cdrom_read_capacity() ends believing capbuf is valid but in fact it's just
uninitialized data. back to cdrom_read_toc():

        /* Try to get the total cdrom capacity and sector size. */
        stat = cdrom_read_capacity(drive, &toc->capacity, &sectors_per_frame,
                                   sense);
        if (stat)
                toc->capacity = 0x1fffff;

        set_capacity(info->disk, toc->capacity * sectors_per_frame);
        /* Save a private copy of te TOC capacity for error handling */
        drive->probed_capacity = toc->capacity * sectors_per_frame;

        blk_queue_hardsect_size(drive->queue,
                                sectors_per_frame << SECTOR_BITS);

that will set drive->queue->hardsect_size to be the random value.
hardsect_size is used to calculate inode->i_blkbits. later on, on a read
path:

void create_empty_buffers(struct page *page,
                        unsigned long blocksize, unsigned long b_state)
{       
        struct buffer_head *bh, *head, *tail;

        head = alloc_page_buffers(page, blocksize, 1);
        bh = head;
        do {    
                bh->b_state |= b_state;
                tail = bh;
                bh = bh->b_this_page;
        } while (bh);
        tail->b_this_page = head;

alloc_page_buffers() will return NULL if blocksize > 4096. blocksize is
calculed based on inode->i_blkbits. that will trigger a null
dereference on create_empty_buffers().
Signed-off-by: NAristeu Rozanski <arozansk@redhat.com>
Cc: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add missing checks for control register existence (some legacy m68k specific
IDE controllers don't have it).  Also use drive->ctl while at it.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Use drive->select.all for REQ_TYPE_ATA_TASK requests in execute_drive_cmd()
(the obsolete bits 7 and 5 of the Device register need to be set).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide_dump_ata_status() may set HOB bit before ide_end_drive_cmd() is called.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drive_cmd_intr() is used by both REQ_TYPE_ATA_CMD and REQ_TYPE_ATA_TASK
but commands using PIO-in protocol are valid only for REQ_TYPE_ATA_CMD
(&args[4] in case of REQ_TYPE_ATA_TASK points to a value for IDE_LCYL_REG
register instead of the data buffer).  This fix allows REQ_TYPE_ATA_TASK
commands to use non-zero values for IDE_SECTOR_REG (args[3]).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Remove dead code for handling IDE TCQ from ide_end_dequeued_request().

* Add 'dequeue' parameter to __ide_end_request().

* Use __ide_end_request() in ide_end_dequeued_request().
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Take ide_lock for prefetch disable/enable in do_special(),
then cleanup cmd640 and ht6560b host drivers.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

remove asm/bitops.h includes

including asm/bitops directly may cause compile errors. don't include it
and include linux/bitops instead. next patch will deny including asm header
directly.

Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add IDE_HFLAG_ERROR_STOPS_FIFO host flag and use it instead
of hwif->err_stops_fifo.  As a side-effect this change fixes
hwif->err_stops_fifo not being restored by ide_hwif_restore().
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add IDE_HFLAG_TRUST_BIOS_FOR_DMA host flag for host drivers that depend
  on BIOS for programming device/controller for DMA.  Set it in cy82c693,
  generic, ns87415, opti621 and trm290 host drivers.

* Add IDE_HFLAG_VDMA host flag for host drivers using VDMA.  Set it in cs5520
  host driver.

* Teach ide_tune_dma() about IDE_HFLAG_TRUST_BIOS_FOR_DMA flag.

* Add generic ide_dma_check() helper and remove all open coded ->ide_dma_check
  implementations.  Fix all places checking for presence of ->ide_dma_check
  hook to check for ->ide_dma_on instead.

* Remove no longer needed code from config_drive_for_dma().

* Make ide_tune_dma() static.

v2:
* Fix config_drive_for_dma() return values.

* Fix ide-dma.c build for CONFIG_BLK_DEV_IDEDMA_PCI=n by adding
  dummy config_drive_for_dma() inline.

* Fix IDE_HFLAG_TRUST_BIOS_FOR_DMA handling in ide_dma_check().

* Fix init_hwif_it8213() comment.

There should be no functionality changes caused by this patch.

Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Acked-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Use ide_config_drive_speed() instead of pmac_ide_do_setfeature() and remove
the latter, also  ide-iops.c::__ide_wait_stat() could be static again.

Since for IDE PMAC host driver IDE_CONTROL_REG is always true, device's
->quirk_list is always zero and ->ide_dma_host_{on,off} are nops than
the only changes in behavior are:

* if PIO mode is set then ->dma_off_queitly is called to disable DMA

* if setting transfer mode fails ide_dump_status() is called to dump status

v2:
* IDE PMAC controllers allow separate PIO and DMA timings and PPC userland
  depends on this fact, and calls "hdparm -p" without calling "hdparm -d".

  Therefore to compensate for DMA being disabled by ide_config_drive_speed()
  for PIO modes:

  - add IDE_HFLAG_SET_PIO_MODE_KEEP_DMA flag and set it in PMAC host driver

  - add handling of the new flag to ide-io.c::do_special()

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add IDE_HFLAG_ABUSE_{PREFETCH,FAST_DEVSEL,DMA_MODES} flags
  and set them in ht6560, cmd640, cmd64x and sc1200 host drivers.

* Add set_pio_mode_abuse() for checking if host driver has a non-standard
  ->tuneproc() implementation and use it in do_special().

* Add ide_set_pio() for setting PIO mode (it uses hwif->pio_mask to find
  the maximum PIO mode supported by the host), also add ide_set_max_pio()
  wrapper for ide_set_pio() to use for auto-tuning.  Convert users of
  ->tuneproc to use ide_set{_max}_pio() where possible.  This leaves only
  do_special(), set_using_pio(), ide_hwif_restore() and ide_set_pio() as
  a direct users of ->tuneproc.

* Remove no longer needed ide_get_best_pio_mode() calls and printk-s
  reporting PIO mode selected from ->tuneproc implementations.

* Rename ->tuneproc hook to ->set_pio_mode and make 'pio' argument const.

* Remove stale comment from ide_config_drive_speed().

v2:
* Fix "ata_" prefix (Noticed by Jeff).

v3:
* Minor cleanups/fixups per Sergei's suggestions.

v4:
* Fix compile problem in drivers/ide/pci/cmd640.c
  (Noticed by Andrew Morton).

* Improve some ->set_pio_mode comments.
Reviewed-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

* Do the same thing as probe_hwif() and always disable DMA so chipset DMA
  enabled bit gets cleared (if the drive doesn't support DMA ide_set_dma()
  won't try to tune it anyway).

* Add TODO comment about respecting ->using_dma setting.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide-disk calls

        ide_end_request(drive, 0, 0);

to finish an unknown request, but this doesn't work so well for non-fs
requests, since ide_end_request() internally looks at ->hard_cur_sectors
to see how much data to end. Only file system requests store a transfer
value in there, pc requests fill out ->data_len as a byte based transfer
value instead.

Since we ask to end 0 bytes of that request, it will never be terminated
and ide-disk gets stuck in a loop "handling" that same request over and
over.

Switch __ide_end_request() to take a byte based transfer count, and
adjust ide_end_request() to look at the right field to determine how
much IO to end when it's being passed in 0.
Acked-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Tested-By: NGiacomo Catenazzi <cate@debian.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since ide_dma_timeout() method's result is discarded, make it return 'void'.
While at it, drop 'ide_' from the method's name, drop the '__' prefix from
the default method's name, and do some cleanups in this method driver-wise:

- in ide-dma.c, au1xxx-ide.c, and pdc202xx_old.c, define/use 'hwif' variable;

- in au1xxx-ide.c, get rid of commented out printk();

- in sl82c105.c, get rid of unnecessary variables.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Since ide_dma_lostirq() method's result is discarded, make it return 'void'.
While at it, rename the method to dma_lost_irq(), drop the '__' prefix from the
default method's name, and do some cleanups in this method driver-wise:

- in aec62xx.c, rename the method in accordance with other drivers, and get rid
  of unnecessary variables there;

- in pdc202xx_old.c, define/use 'hwif' variable;

- in sgiioc4.c, rearrange the code to call the resetproc() method directly.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide_start_power_step() and set_using_dma() were missing ->dma_off_quietly
call (comment in probe_hwif() states that DMA should be always cleared before
tuning is attempted).  Fix it.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

PIO should be restored also for ATAPI devices during resume, fix it.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

It is possible for the timer expiry function to run even though the
request has already been handled: ide_timer_expiry() only checks that
the handler is not NULL, but it is possible that we have handled a
request (thus clearing the handler) and then started a new request
(thus starting the timer again, and setting a handler). 

A simple way to exhibit this is to set the DMA timeout to 1 jiffy and
run dd: The kernel will panic after a few minutes because
ide_timer_expiry() tries to add a timer when it's already active.

To fix this, we simply add a request generation count that gets
incremented at every interrupt, and check in ide_timer_expiry() that
we have not already handled a new interrupt before running the expiry
function.
Signed-off-by: NSuleiman Souhlal <suleiman@google.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

IDE error recovery is using IDLE IMMEDIATE if the drive is busy or has DRQ set.
This violates the ATA spec (can only send IDLE IMMEDIATE when drive is not
busy) and really hoses up some drives (modern drives will not be able to
recover using this error handling).  The correct thing to do is issue a SRST
followed by a SET FEATURES command.  This is what Western Digital recommends
for error recovery and what Western Digital says Windows does.  It also does
not violate the ATA spec as far as I can tell.

Bart:
* port the patch over the current tree
* undo the recalibration code removal
* send SET FEATURES command after checking for good drive status
* don't check whether the current request is of REQ_TYPE_ATA_{CMD,TASK}
  type because we need to send SET FEATURES before handling any requests
* some pre-ATA4 drives require INITIALIZE DEVICE PARAMETERS command before
  other commands (except IDENTIFY) so send SET FEATURES only if there are
  no pending drive->special requests
* update comments and patch description
* any bugs introduced by this patch are mine and not Suleiman's :-)
Signed-off-by: NSuleiman Souhlal <suleiman@google.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* since ide_hwif_t.ide_dma_{host_off,off_quietly} always return '0'
  make these functions void and while at it drop "ide_" prefix
* fix comment for __ide_dma_off_quietly()
* make __ide_dma_{host_off,off_quietly,off}() void and drop "__" prefix

v2:
* while at it rename atiixp_ide_dma_host_off() to atiixp_dma_host_off(),
  sgiioc4_ide_dma_{host_off,off_quietly}() to sgiioc4_dma_{host_off,off_quietly}()
  and sl82c105_ide_dma_off_quietly() to sl82c105_dma_off_quietly()
  [ Noticed by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* add ide_set_dma() helper and make ide_hwif_t.ide_dma_check return
  -1 when DMA needs to be disabled (== need to call ->ide_dma_off_quietly)
   0 when DMA needs to be enabled  (== need to call ->ide_dma_on)
   1 when DMA setting shouldn't be changed
* fix IDE code to use ide_set_dma() instead if using ->ide_dma_check directly

v2:
* updated for scc_pata
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

patch 1/2 (revised):
- Fix drive->waiting_for_dma to work with CDB-intr devices.
- Do the dma status clearing in ide_intr() and add a new
  hwif->ide_dma_clear_irq for Intel ICHx controllers.

Revised per Alan, Sergei and Bart's advice.

Patch against 2.6.20-rc6. Tested ok on my ICH4 and pdc20275 adapters.
Please review/apply, thanks.
Signed-off-by: NAlbert Lee <albertcc@tw.ibm.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Adam W. Hawks" <awhawks@us.ibm.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

Add a step to the IDE PM state machine that reprograms disk PIO timings
as the first step on resume. This prevents ide deadlock on
resume-from-ram on my nforce3-based laptop.

An earlier implementation was written entirely within the amd74xx ide
driver, but Alan helpfully pointed out that this is the correct thing to
do globally. Still, I'm only calling hwif->tuneproc() for disks, based
on two things:

 - The existing state machine is already passed over for non-disk drives
 - Previous testing on my laptop shows that the hangs are related only
   to the disk - suspend/resume from a livecd showed that there's no
   need for this on the cdrom.
Signed-off-by: NJason Lunz <lunz@falooley.org>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Brad Campbell <brad@wasp.net.au>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In 2.6.15.1 I encountered some IDE crashes when unplugging IDE cables to
emulate disk errors.  Below is a patch against 2.6.16 which I think still
applies.

1.  The first BUG_ON could trigger when a PREFLUSH IO fails (it would
   fail the original barrier request which hasn't been marked REQ_STARTED
   yet).

2. the rq could have been dequeued already (same as 1).

3.  HWGROUP(drive)->rq could be NULL because of the ide_error() several
   lines earlier.
Signed-off-by: NHua Zhong <hzhong@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.

So kill/clean the remaining users, straight forward.
Signed-off-by: NJens Axboe <axboe@suse.de>

As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: NJens Axboe <axboe@suse.de>