kernel.git/drivers/mmc/card/queue.c, branch linux-2.6.31.y

block: implement and enforce request peek/start/fetch

2009-05-11T07:52:18Z

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 Cc: Rusty Russell Cc: James Bottomley Cc: Mike Miller Cc: unsik Kim Cc: Paul Clements Cc: Tim Waugh Cc: Geert Uytterhoeven Cc: David S. Miller Cc: Laurent Vivier Cc: Jeff Garzik Cc: Jeremy Fitzhardinge Cc: Grant Likely Cc: Adrian McMenamin Cc: Stephen Rothwell Cc: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: Sergei Shtylyov Cc: Alex Dubov Cc: Pierre Ossman Cc: David Woodhouse Cc: Markus Lidel Cc: Stefan Weinhuber Cc: Martin Schwidefsky Cc: Pete Zaitcev Cc: FUJITA Tomonori Signed-off-by: Jens Axboe

block: convert to dequeueing model (easy ones)

2009-05-11T07:52:17Z

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 Cc: Rusty Russell Cc: Jeremy Fitzhardinge Cc: Stephen Rothwell Cc: Alex Dubov Cc: Markus Lidel Cc: Pierre Ossman Signed-off-by: Jens Axboe

mmc_block: tell block layer there is no seek penalty

2008-10-14T18:04:46Z

Signed-off-by: Pierre Ossman

mmc_block: filter out PC requests

2008-10-12T09:04:32Z

We do not support PC (SCSI) commands, so don't pretend we do by letting them through. Signed-off-by: Pierre Ossman

mmc_block: indicate strict ordering

2008-10-12T09:04:31Z

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

mmc_block: inform block layer about sector count restriction

2008-10-12T09:04:30Z

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

mmc_block: bounce buffer highmem support

2008-07-23T12:42:09Z

Support highmem pages in the bounce buffer code by using the sg_copy_from/to_buffer() functions. Signed-off-by: Pierre Ossman

blk_end_request: changing mmc (take 4)

2008-01-28T09:36:52Z

This patch converts mmc to use blk_end_request interfaces. Related 'uptodate' arguments are converted to 'error'. Cc: Pierre Ossman Signed-off-by: Kiyoshi Ueda Signed-off-by: Jun'ichi Nomura Signed-off-by: Jens Axboe

mmc: Add missing sg_init_table() call

2007-11-27T08:19:40Z

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 Signed-off-by: Jens Axboe

mmc: Fix sg helper copy-and-paste error

2007-11-08T12:50:58Z

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 Tested-by: Romano Giannetti Signed-off-by: Jens Axboe