[U-Boot] [PATCH v2 5/7] ext2: Cache line aligned partial sector bounce buffer

Anton Staaf robotboy at chromium.org
Tue Oct 4 23:24:49 CEST 2011


Currently, if a device read request is done that does not begin or end
on a sector boundary a stack allocated bounce buffer is used to perform
the read, and then just the part of the sector that is needed is copied
into the users buffer.  This stack allocation can mean that the bounce
buffer will not be aligned to the dcache line size.  This is a problem
when caches are enabled because unaligned cache invalidates are not
safe.

This patch uses ALLOC_CACHE_ALIGN_BUFFER to create a stack allocated
cache line size aligned bounce buffer.

Signed-off-by: Anton Staaf <robotboy at chromium.org>
Acked-by: Mike Frysinger <vapier at gentoo.org>
Cc: Lukasz Majewski <l.majewski at samsung.com>
Cc: Mike Frysinger <vapier at gentoo.org>
Cc: Dave Liu <r63238 at freescale.com>
Cc: Andy Fleming <afleming at gmail.com>
Cc: Albert ARIBAUD <albert.u.boot at aribaud.net>

---
 fs/ext2/dev.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c
index 78851d0..874e211 100644
--- a/fs/ext2/dev.c
+++ b/fs/ext2/dev.c
@@ -52,7 +52,7 @@ int ext2fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
 
 int ext2fs_devread(int sector, int byte_offset, int byte_len, char *buf)
 {
-	char sec_buf[SECTOR_SIZE];
+	ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, SECTOR_SIZE);
 	unsigned sectors;
 
 	/*
-- 
1.7.3.1



More information about the U-Boot mailing list