Commit graph

21 commits

Author SHA1 Message Date
Tejun Heo
9934c8c045 block: implement and enforce request peek/start/fetch
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: Tejun 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: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:18 +02:00
Tejun Heo
296b2f6ae6 block: convert to dequeueing model (easy ones)
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: Tejun 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: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:17 +02:00
Pierre Ossman
8dddfe1926 mmc_block: tell block layer there is no seek penalty
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-10-14 20:04:46 +02:00
Pierre Ossman
d6d8de3341 mmc_block: filter out PC requests
We do not support PC (SCSI) commands, so don't pretend we do by
letting them through.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-10-12 11:04:32 +02:00
Pierre Ossman
9102895411 mmc_block: indicate strict ordering
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: Pierre Ossman <drzeus@drzeus.cx>
2008-10-12 11:04:31 +02:00
Pierre Ossman
f3eb0aaa02 mmc_block: inform block layer about sector count restriction
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: Pierre Ossman <drzeus@drzeus.cx>
2008-10-12 11:04:30 +02:00
Pierre Ossman
2ff1fa6791 mmc_block: bounce buffer highmem support
Support highmem pages in the bounce buffer code by using the
sg_copy_from/to_buffer() functions.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2008-07-23 14:42:09 +02:00
Kiyoshi Ueda
fd539832c7 blk_end_request: changing mmc (take 4)
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: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28 10:36:52 +01:00
Haavard Skinnemoen
05e5b13645 mmc: Add missing sg_init_table() call
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: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-27 09:19:40 +01:00
Roland Dreier
8578007065 mmc: Fix sg helper copy-and-paste error
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: Roland Dreier <roland@digitalvampire.org>
Tested-by: Romano Giannetti <romano.giannetti@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-08 13:50:58 +01:00
Jens Axboe
45711f1af6 [SG] Update drivers to use sg helpers
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-22 21:19:53 +02:00
Jens Axboe
d3ad0aa424 mmc: need to zero sglist on init
Otherwise we could have junk in the sg fields, fooling
the sg chaining into thinking ->page is valid.

Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-16 11:24:45 +02:00
Pierre Ossman
aafabfab26 mmc: reorganize bounce buffer init
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: Pierre Ossman <drzeus@drzeus.cx>
2007-08-09 14:37:17 +02:00
Linus Torvalds
d941cf5e37 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
  drivers/mmc/core/: make 3 functions static
  mmc: add missing printk levels
  mmc: remove redundant debug information from sdhci and wbsd
  mmc: proper debugging output in core
  mmc: be more verbose about card insertions/removal
  mmc: Don't hold lock when releasing an added card
  mmc: add a might_sleep() to mmc_claim_host()
  mmc: update kerneldoc
  mmc: update header file paths
  sdhci: add support to ENE-CB714
  mmc: check error bits before command completion
2007-07-26 14:00:56 -07:00
Pierre Ossman
70f10482c6 mmc: update header file paths
Make sure all headers in the files reflect their true position
in the tree.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-07-26 01:53:31 +02:00
Jens Axboe
165125e1e4 [BLOCK] Get rid of request_queue_t typedef
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: Jens Axboe <jens.axboe@oracle.com>
2007-07-24 09:28:11 +02:00
Rafael J. Wysocki
8314418629 Freezer: make kernel threads nonfreezable by default
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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Pierre Ossman
98ccf14909 mmc: bounce requests for simple hosts
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: Pierre Ossman <drzeus@drzeus.cx>
2007-07-09 21:22:53 +02:00
Pierre Ossman
9c9f2d63a7 mmc: clean up unused parts of block driver
Remove dead code and unused structs from the block driver.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-24 06:51:02 +02:00
Pierre Ossman
d2b46f66b4 mmc: allow suspended block driver to be removed
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: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 13:04:17 +02:00
Pierre Ossman
1c6a0718f0 mmc: Move host and card drivers to subdirs
Clean up the drivers/mmc directory by moving card and host drivers
into subdirectories.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 13:04:17 +02:00
Renamed from drivers/mmc/queue.c (Browse further)