We used only single sg entry for SDIO transfer.
This chagne is to use multiple sg entry.
In case of dwmci, it support only up to 4KB size per single sg entry.
So if we want to transfer more than 4KB, we should send more than 1 command.
This makes performance degradation for large data transfer.
Signed-off-by: Kyoungil Kim <ki0351....@samsung.com>
---
drivers/mmc/core/sdio_io.c | 10 +++-------
drivers/mmc/core/sdio_ops.c | 33 +++++++++++++++++++++++++++++----
2 files changed, 32 insertions(+), 11 deletions(-)
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 8f6f5ac..78cb4d5 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -188,8 +188,7 @@ EXPORT_SYMBOL_GPL(sdio_set_block_size);
*/
static inline unsigned int sdio_max_byte_size(struct sdio_func *func)
{
- unsigned mval = min(func->card->host->max_seg_size,
- func->card->host->max_blk_size);
+ unsigned mval = func->card->host->max_blk_size;
if (mmc_blksz_for_byte_mode(func->card))
mval = min(mval, func->cur_blksize);
@@ -311,11 +310,8 @@ static int sdio_io_rw_ext_helper(struct sdio_func *func,
int write,
/* Do the bulk of the transfer using block mode (if supported). */
if (func->card->cccr.multi_block && (size > sdio_max_byte_size(func))) {
/* Blocks per command is limited by host count, host transfer
- * size (we only use a single sg entry) and the maximum for
- * IO_RW_EXTENDED of 511 blocks. */
- max_blocks = min(func->card->host->max_blk_count,
- func->card->host->max_seg_size / func->cur_blksize);
- max_blocks = min(max_blocks, 511u);
+ * size and the maximum for IO_RW_EXTENDED of 511 blocks. */
+ max_blocks = min(func->card->host->max_blk_count, 511u);
while (remainder >= func->cur_blksize) {
unsigned blocks;
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index d29e206..ac01352 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -124,7 +124,10 @@ int mmc_io_rw_extended(struct mmc_card *card, int write,
unsigned fn,
struct mmc_request mrq = {NULL};
struct mmc_command cmd = {0};
struct mmc_data data = {0};
- struct scatterlist sg;
+ struct scatterlist sg, *sg_ptr;
+ struct sg_table sgtable;
+ unsigned int nents, left_size, i;
+ unsigned int seg_size = card->host->max_seg_size;
BUG_ON(!card);
BUG_ON(fn > 7);
@@ -152,15 +155,37 @@ int mmc_io_rw_extended(struct mmc_card *card, int write,
unsigned fn,
/* Code in host drivers/fwk assumes that "blocks" always is >=1 */
data.blocks = blocks ? blocks : 1;
data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
- data.sg = &sg;
- data.sg_len = 1;
- sg_init_one(&sg, buf, data.blksz * data.blocks);
+ left_size = data.blksz * data.blocks;
+ nents = (left_size - 1) / seg_size + 1;
+ if (nents > 1) {
+ if (sg_alloc_table(&sgtable, nents, GFP_KERNEL))
+ return -ENOMEM;
+
+ data.sg = sgtable.sgl;
+ data.sg_len = nents;
+
+ for_each_sg(data.sg, sg_ptr, data.sg_len, i) {
+ sg_set_page(sg_ptr, virt_to_page(buf + (i * seg_size)),
+ min(seg_size, left_size),
+ offset_in_page(buf + (i * seg_size)));
+ left_size = left_size - seg_size;
+ }
+ } else {
+ data.sg = &sg;
+ data.sg_len = 1;
+
+ sg_init_one(&sg, buf, left_size);
+ }
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
+ if (nents > 1)
+ sg_free_table(&sgtable);
+
+
if (cmd.error)
return cmd.error;
if (data.error)
--
1.7.4.1
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
