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authorPierre Ossman <drzeus@drzeus.cx>2006-10-06 00:44:03 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-06 08:53:41 -0700
commitec5a19dd935eb3793e1f6ed491e8035b3d7b1df9 (patch)
tree931d2ffce2fe444f26b51b076c3472110a3e5a8a /drivers
parent45e02b5b52e43aa7a674f64ca3470b9ee51fc9fd (diff)
downloadblackbird-op-linux-ec5a19dd935eb3793e1f6ed491e8035b3d7b1df9.tar.gz
blackbird-op-linux-ec5a19dd935eb3793e1f6ed491e8035b3d7b1df9.zip
[PATCH] mmc: multi sector write transfers
SD cards extend the protocol by allowing the host to query a card how many blocks were successfully stored on the medium. This allows us to safely write chunks of blocks at once. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/mmc_block.c104
1 files changed, 95 insertions, 9 deletions
diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index c1293f1bda87..f9027c8db792 100644
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -28,6 +28,7 @@
#include <linux/kdev_t.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
+#include <linux/scatterlist.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -154,6 +155,71 @@ static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
return stat;
}
+static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
+{
+ int err;
+ u32 blocks;
+
+ struct mmc_request mrq;
+ struct mmc_command cmd;
+ struct mmc_data data;
+ unsigned int timeout_us;
+
+ struct scatterlist sg;
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+
+ cmd.opcode = MMC_APP_CMD;
+ cmd.arg = card->rca << 16;
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+ err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD))
+ return (u32)-1;
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+
+ cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
+ cmd.arg = 0;
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+ memset(&data, 0, sizeof(struct mmc_data));
+
+ data.timeout_ns = card->csd.tacc_ns * 100;
+ data.timeout_clks = card->csd.tacc_clks * 100;
+
+ timeout_us = data.timeout_ns / 1000;
+ timeout_us += data.timeout_clks * 1000 /
+ (card->host->ios.clock / 1000);
+
+ if (timeout_us > 100000) {
+ data.timeout_ns = 100000000;
+ data.timeout_clks = 0;
+ }
+
+ data.blksz = 4;
+ data.blocks = 1;
+ data.flags = MMC_DATA_READ;
+ data.sg = &sg;
+ data.sg_len = 1;
+
+ memset(&mrq, 0, sizeof(struct mmc_request));
+
+ mrq.cmd = &cmd;
+ mrq.data = &data;
+
+ sg_init_one(&sg, &blocks, 4);
+
+ mmc_wait_for_req(card->host, &mrq);
+
+ if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE)
+ return (u32)-1;
+
+ blocks = ntohl(blocks);
+
+ return blocks;
+}
+
static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->data;
@@ -184,10 +250,13 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
/*
* If the host doesn't support multiple block writes, force
- * block writes to single block.
+ * block writes to single block. SD cards are excepted from
+ * this rule as they support querying the number of
+ * successfully written sectors.
*/
if (rq_data_dir(req) != READ &&
- !(card->host->caps & MMC_CAP_MULTIWRITE))
+ !(card->host->caps & MMC_CAP_MULTIWRITE) &&
+ !mmc_card_sd(card))
brq.data.blocks = 1;
if (brq.data.blocks > 1) {
@@ -276,24 +345,41 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
return 1;
cmd_err:
- mmc_card_release_host(card);
-
ret = 1;
- /*
- * For writes and where the host claims to support proper
- * error reporting, we first ok the successful blocks.
+ /*
+ * If this is an SD card and we're writing, we can first
+ * mark the known good sectors as ok.
+ *
+ * If the card is not SD, we can still ok written sectors
+ * if the controller can do proper error reporting.
*
* For reads we just fail the entire chunk as that should
* be safe in all cases.
*/
- if (rq_data_dir(req) != READ &&
- (card->host->caps & MMC_CAP_MULTIWRITE)) {
+ if (rq_data_dir(req) != READ && mmc_card_sd(card)) {
+ u32 blocks;
+ unsigned int bytes;
+
+ blocks = mmc_sd_num_wr_blocks(card);
+ if (blocks != (u32)-1) {
+ if (card->csd.write_partial)
+ bytes = blocks << md->block_bits;
+ else
+ bytes = blocks << 9;
+ spin_lock_irq(&md->lock);
+ ret = end_that_request_chunk(req, 1, bytes);
+ spin_unlock_irq(&md->lock);
+ }
+ } else if (rq_data_dir(req) != READ &&
+ (card->host->caps & MMC_CAP_MULTIWRITE)) {
spin_lock_irq(&md->lock);
ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
spin_unlock_irq(&md->lock);
}
+ mmc_card_release_host(card);
+
spin_lock_irq(&md->lock);
while (ret) {
ret = end_that_request_chunk(req, 0,
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