Except for SCSI no device drivers distinguish between physical and
hardware segment limits.  Consolidate the two into a single segment
limit.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

The block layer calling convention is blk_queue_<limit name>.
blk_queue_max_sectors predates this practice, leading to some confusion.
Rename the function to appropriately reflect that its intended use is to
set max_hw_sectors.

Also introduce a temporary wrapper for backwards compability.  This can
be removed after the merge window is closed.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

The main bug was that 'blk_cleanup_queue()' was called while the block
device could still be in use, for example, because the card was removed
while files were still open.

In addition, to be sure that 'mmc_request()' will get called for all new
requests (so it can error them out), the queue is emptied during cleanup.
This is done after the worker thread is stopped to avoid racing with it.

Finally, it is not a device error for this to be happening, so quiet the
(sometimes very many) error messages.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Till now block layer allowed two separate modes of request execution.
A request is always acquired from the request queue via
elv_next_request().  After that, drivers are free to either dequeue it
or process it without dequeueing.  Dequeue allows elv_next_request()
to return the next request so that multiple requests can be in flight.

Executing requests without dequeueing has its merits mostly in
allowing drivers for simpler devices which can't do sg to deal with
segments only without considering request boundary.  However, the
benefit this brings is dubious and declining while the cost of the API
ambiguity is increasing.  Segment based drivers are usually for very
old or limited devices and as converting to dequeueing model isn't
difficult, it doesn't justify the API overhead it puts on block layer
and its more modern users.

Previous patches converted all block low level drivers to dequeueing
model.  This patch completes the API transition by...

* renaming elv_next_request() to blk_peek_request()

* renaming blkdev_dequeue_request() to blk_start_request()

* adding blk_fetch_request() which is combination of peek and start

* disallowing completion of queued (not started) requests

* applying new API to all LLDs

Renamings are for consistency and to break out of tree code so that
it's apparent that out of tree drivers need updating.

[ Impact: block request issue API cleanup, no functional change ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: unsik Kim <donari75@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Laurent Vivier <Laurent@lvivier.info>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

plat-omap/mailbox, floppy, viocd, mspro_block, i2o_block and
mmc/card/queue are already pretty close to dequeueing model and can be
converted with simple changes.  Convert them.

While at it,

* xen-blkfront: !fs check moved downwards to share dequeue call with
  normal path.

* mspro_block: __blk_end_request(..., blk_rq_cur_byte()) converted to
  __blk_end_request_cur()

* mmc/card/queue: loop of __blk_end_request() converted to
  __blk_end_request_all()

[ Impact: dequeue in-flight request ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

We do not support PC (SCSI) commands, so don't pretend we do by
letting them through.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

The MMC block driver services requests one at a time and in strict
order. Indicate this to the block layer so that it can handle barriers
in an efficient manner.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Make sure we consider the maximum block count when we tell the block
layer about the maximum sector count. That way we don't have to chop
up the request ourselves.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Support highmem pages in the bounce buffer code by using the
sg_copy_from/to_buffer() functions.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

This patch converts mmc to use blk_end_request interfaces.
Related 'uptodate' arguments are converted to 'error'.

Cc: Pierre Ossman <drzeus-mmc@drzeus.cx>
Signed-off-by: NKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

mmc_init_queue only initializes the scatterlists with sg_init_table()
when using a bounce buffer. This leads to a BUG() when CONFIG_DEBUG_SG
is set.
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Commit 45711f1a ("[SG] Update drivers to use sg helpers") had the
following bogus change in drivers/mmc/card/queue.c:

    > -			src_buf = page_address(src->page) + src->offset;
    > +			src_buf = sg_virt(dst);

(Notice that "src" is converted to "dst").  Turn this "dst" back into
the intended "src".
Signed-off-by: NRoland Dreier <roland@digitalvampire.org>
Tested-by: NRomano Giannetti <romano.giannetti@gmail.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Otherwise we could have junk in the sg fields, fooling
the sg chaining into thinking ->page is valid.
Acked-by: NPierre Ossman <drzeus@drzeus.cx>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Reorganize the code that initializes mmc_block's bounce buffer in
order to avoid warnings when MMC_BLOCK_BOUNCE isn't used.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Make sure all headers in the files reflect their true position
in the tree.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

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>

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some hosts cannot do scatter/gather in hardware. Since not doing sg
is such a big performance hit, we (optionally) bounce the requests
to a simple linear buffer that we hand over to the driver.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Remove dead code and unused structs from the block driver.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Make sure we don't deadlock when removing a suspended block
queue, something that might happen if the card is removed during
suspend.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Clean up the drivers/mmc directory by moving card and host drivers
into subdirectories.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

The mmc block queue functions are tailored for the mmc_block
driver, so move those functions into that module.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Many controllers have an upper limit on the number of blocks that can be
transferred in one request. Allow the host drivers to specify this and make
sure we avoid hitting this limit.

Also change the max_sectors field to avoid confusion. This makes it map
less directly to the block layer limits, but as they didn't apply directly
on MMC cards anyway, this isn't a great loss.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Currently on SD/MMC card removal the system exhibits the following message (the platform is ARM Versatile):

    prev->state: 2 != TASK_RUNNING??
    mmcqd/762[CPU#0]: BUG in __schedule at linux-2.6/kernel/sched.c:3826

(akpm: someone tried to fix this, but it's still wrong)
Signed-off-by: NVitaly Wool <vitalywool@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Converts from using struct "class_device" to "struct device" making
everything show up properly in /sys/devices/ with symlinks from the
/sys/class directory.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

After mmc_block's remove function has exited, we must not
touch the card structure in any way. This means we not only
must remove the gendisk, we must also flush out any
remaning requests already queued up.

We previously removed the disk, but didn't flush it,
causing oops:es when removing a card in the middle of a
transfer.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

Replace kernel_thread() with kthread_run()/kthread_stop().
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

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>

Patch from Juha [l

When the block queue is plugged, mq->req must be set to NULL.
Otherwise mq->req might be left non-NULL, even though mmcqd is
not processing a request, thus preventing the MMC queue thread from
being woken up when new requests do arrive.
Signed-off-by: NJuha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!