Add a buffer bouncing mechanism to get_cluster. This can be useful for misaligned applicative buffers passed through get_contents. This is required for the following patches in the case of data aligned differently relatively to buffers and clusters.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau@advansee.com Cc: Wolfgang Denk wd@denx.de --- .../fs/fat/fat.c | 42 ++++++++++++++------ 1 file changed, 30 insertions(+), 12 deletions(-)
diff --git u-boot-66714b1.orig/fs/fat/fat.c u-boot-66714b1/fs/fat/fat.c index 943cdb6..4c80820 100644 --- u-boot-66714b1.orig/fs/fat/fat.c +++ u-boot-66714b1/fs/fat/fat.c @@ -274,7 +274,6 @@ get_cluster (fsdata *mydata, __u32 clustnum, __u8 *buffer, { __u32 idx = 0; __u32 startsect; - __u32 nr_sect; int ret;
if (clustnum > 0) { @@ -286,25 +285,44 @@ get_cluster (fsdata *mydata, __u32 clustnum, __u8 *buffer,
debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
- nr_sect = size / mydata->sect_size; - ret = disk_read(startsect, nr_sect, buffer); - if (ret != nr_sect) { - debug("Error reading data (got %d)\n", ret); - return -1; - } - if (size % mydata->sect_size) { + if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) { ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
+ debug("FAT: Misaligned buffer address (%p)\n", buffer); + + while (size >= mydata->sect_size) { + ret = disk_read(startsect++, 1, tmpbuf); + if (ret != 1) { + debug("Error reading data (got %d)\n", ret); + return -1; + } + + memcpy(buffer, tmpbuf, mydata->sect_size); + buffer += mydata->sect_size; + size -= mydata->sect_size; + } + } else { idx = size / mydata->sect_size; - ret = disk_read(startsect + idx, 1, tmpbuf); + ret = disk_read(startsect, idx, buffer); + if (ret != idx) { + debug("Error reading data (got %d)\n", ret); + return -1; + } + startsect += idx; + idx *= mydata->sect_size; + buffer += idx; + size -= idx; + } + if (size) { + ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size); + + ret = disk_read(startsect, 1, tmpbuf); if (ret != 1) { debug("Error reading data (got %d)\n", ret); return -1; } - buffer += idx * mydata->sect_size;
- memcpy(buffer, tmpbuf, size % mydata->sect_size); - return 0; + memcpy(buffer, tmpbuf, size); }
return 0;