Commit graph

8 commits

Author SHA1 Message Date
Simon Glass
cd0fb55b64 dm: blk: Add functions to select a hardware partition
The block device uclass does not currently support selecting a particular
hardware partition but this is needed for MMC. Add it so that the blk API
can support MMC properly.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-05-17 09:54:43 -06:00
Simon Glass
d0773524e1 dm: blk: Free the block device name when unbound
Mark the device name as allocated so that it will be freed correctly when the
device is unbound.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-05-17 09:54:43 -06:00
Simon Glass
72a85c0d2d dm: blk: Fix allocation of block-device numbering
Due to code ordering the block devices are not numbered sequentially. Fix
this.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-05-17 09:54:43 -06:00
Simon Glass
9107c973d3 dm: blk: Add a easier way to create a named block device
Add a function that automatically builds the device name given the parent
and a supplied string. Most callers will want to do this, so putting this
functionality in one place makes more sense.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-05-17 09:54:43 -06:00
Simon Glass
52138fd407 dm: blk: Allow blk_create_device() to allocate the device number
Allow a devnum parameter of -1 to indicate that the device number should be
alocated automatically. The next highest available device number for that
interface type is used.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-05-17 09:54:43 -06:00
Simon Glass
d508c82ba9 dm: mmc: Add an implementation of the 'devnum' functions
Now that the MMC code accesses devices by number, we can implement this same
interface for driver model, allowing MMC to support using driver model for
block devices.

Add the required functions to the uclass.

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