Commit graph

5 commits

Author SHA1 Message Date
Simon Glass
a219639d42 dm: Rename disk uclass to ahci
This started as 'ahci' and was renamed to 'disk' during code review. But it
seems that this is too generic. Now that we have a 'blk' uclass, we can use
that as the generic piece, and revert to ahci for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-05-17 09:54:43 -06:00
Eric Nelson
e40cf34a29 drivers: block: add block device cache
Add a block device cache to speed up repeated reads of block devices by
various filesystems.

This small amount of cache can dramatically speed up filesystem
operations by skipping repeated reads of common areas of a block
device (typically directory structures).

This has shown to have some benefit on FAT filesystem operations of
loading a kernel and RAM disk, but more dramatic benefits on ext4
filesystems when the kernel and/or RAM disk are spread across
multiple extent header structures as described in commit fc0fc50.

The cache is implemented through a minimal list (block_cache) maintained
in most-recently-used order and count of the current number of entries
(cache_count). It uses a maximum block count setting to prevent copies
of large block reads and an upper bound on the number of cached areas.

The maximum number of entries in the cache defaults to 32 and the maximum
number of blocks per cache entry has a default of 2, which has shown to
produce the best results on testing of ext4 and FAT filesystems.

The 'blkcache' command (enabled through CONFIG_CMD_BLOCK_CACHE) allows
changing these values and can be used to tune for a particular filesystem
layout.

Signed-off-by: Eric Nelson <eric@nelint.com>
2016-04-01 17:18:27 -04:00
Simon Glass
09d71aac7b dm: blk: Add a block-device uclass
Add a uclass for block devices. These provide block-oriented data access,
supporting reading, writing and erasing of whole blocks.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
2016-03-14 15:34:50 -06:00
Simon Glass
e3b5f04143 ahci: Add a disk-controller uclass
Add a uclass ID for a disk controller. This can be used by AHCI/SATA or
other controller types. There are no operations and no interface so far,
but it is possible to probe a SATA device.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2016-01-24 12:09:39 +08:00
Masahiro Yamada
ed36323f6d kconfig: add blank Kconfig files
This would be useful to start moving various config options.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
2014-09-24 18:30:28 -04:00