[PATCH v8 08/12] mmc: block: add a block request prepare function

Per Forlin
2011-06-28T08:11:53Z

Break out code from mmc_blk_issue_rw_rq to create a
block request prepare function. This doesn't change
any functionallity. This helps when handling more
than one active block request.

Signed-off-by: Per Forlin <per.forlin-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
drivers/mmc/card/block.c | 218 ++++++++++++++++++++++++----------------------
1 files changed, 114 insertions(+), 104 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 88bcc4e..a0a76f4 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -812,12 +812,15 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
R1_CC_ERROR | /* Card controller error */ \
R1_ERROR) /* General/unknown error */

-static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
+static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
+ struct mmc_card *card,
+ int disable_multi,
+ struct mmc_queue *mq)
{
+ u32 readcmd, writecmd;
+ struct mmc_blk_request *brq = &mqrq->brq;
+ struct request *req = mqrq->req;
struct mmc_blk_data *md = mq->data;
- struct mmc_card *card = md->queue.card;
- struct mmc_blk_request *brq = &mq->mqrq_cur->brq;
- int ret = 1, disable_multi = 0, retry = 0;

/*
* Reliable writes are used to implement Forced Unit Access and
@@ -828,119 +831,126 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
(rq_data_dir(req) == WRITE) &&
(md->flags & MMC_BLK_REL_WR);

- do {
- u32 readcmd, writecmd;
-
- memset(brq, 0, sizeof(struct mmc_blk_request));
- brq->mrq.cmd = &brq->cmd;
- brq->mrq.data = &brq->data;
-
- brq->cmd.arg = blk_rq_pos(req);
- if (!mmc_card_blockaddr(card))
- brq->cmd.arg <<= 9;
- brq->cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
- brq->data.blksz = 512;
- brq->stop.opcode = MMC_STOP_TRANSMISSION;
- brq->stop.arg = 0;
- brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
- brq->data.blocks = blk_rq_sectors(req);
-
- /*
- * The block layer doesn't support all sector count
- * restrictions, so we need to be prepared for too big
- * requests.
- */
- if (brq->data.blocks > card->host->max_blk_count)
- brq->data.blocks = card->host->max_blk_count;
+ memset(brq, 0, sizeof(struct mmc_blk_request));
+ brq->mrq.cmd = &brq->cmd;
+ brq->mrq.data = &brq->data;

- /*
- * After a read error, we redo the request one sector at a time
- * in order to accurately determine which sectors can be read
- * successfully.
- */
- if (disable_multi && brq->data.blocks > 1)
- brq->data.blocks = 1;
+ brq->cmd.arg = blk_rq_pos(req);
+ if (!mmc_card_blockaddr(card))
+ brq->cmd.arg <<= 9;
+ brq->cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
+ brq->data.blksz = 512;
+ brq->stop.opcode = MMC_STOP_TRANSMISSION;
+ brq->stop.arg = 0;
+ brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+ brq->data.blocks = blk_rq_sectors(req);

- if (brq->data.blocks > 1 || do_rel_wr) {
- /* SPI multiblock writes terminate using a special
- * token, not a STOP_TRANSMISSION request.
- */
- if (!mmc_host_is_spi(card->host) ||
- rq_data_dir(req) == READ)
- brq->mrq.stop = &brq->stop;
- readcmd = MMC_READ_MULTIPLE_BLOCK;
- writecmd = MMC_WRITE_MULTIPLE_BLOCK;
- } else {
- brq->mrq.stop = NULL;
- readcmd = MMC_READ_SINGLE_BLOCK;
- writecmd = MMC_WRITE_BLOCK;
- }
- if (rq_data_dir(req) == READ) {
- brq->cmd.opcode = readcmd;
- brq->data.flags |= MMC_DATA_READ;
- } else {
- brq->cmd.opcode = writecmd;
- brq->data.flags |= MMC_DATA_WRITE;
- }
+ /*
+ * The block layer doesn't support all sector count
+ * restrictions, so we need to be prepared for too big
+ * requests.
+ */
+ if (brq->data.blocks > card->host->max_blk_count)
+ brq->data.blocks = card->host->max_blk_count;

- if (do_rel_wr)
- mmc_apply_rel_rw(brq, card, req);
+ /*
+ * After a read error, we redo the request one sector at a time
+ * in order to accurately determine which sectors can be read
+ * successfully.
+ */
+ if (disable_multi && brq->data.blocks > 1)
+ brq->data.blocks = 1;

- /*
- * Pre-defined multi-block transfers are preferable to
- * open ended-ones (and necessary for reliable writes).
- * However, it is not sufficient to just send CMD23,
- * and avoid the final CMD12, as on an error condition
- * CMD12 (stop) needs to be sent anyway. This, coupled
- * with Auto-CMD23 enhancements provided by some
- * hosts, means that the complexity of dealing
- * with this is best left to the host. If CMD23 is
- * supported by card and host, we'll fill sbc in and let
- * the host deal with handling it correctly. This means
- * that for hosts that don't expose MMC_CAP_CMD23, no
- * change of behavior will be observed.
- *
- * N.B: Some MMC cards experience perf degradation.
- * We'll avoid using CMD23-bounded multiblock writes for
- * these, while retaining features like reliable writes.
+ if (brq->data.blocks > 1 || do_rel_wr) {
+ /* SPI multiblock writes terminate using a special
+ * token, not a STOP_TRANSMISSION request.
*/
+ if (!mmc_host_is_spi(card->host) ||
+ rq_data_dir(req) == READ)
+ brq->mrq.stop = &brq->stop;
+ readcmd = MMC_READ_MULTIPLE_BLOCK;
+ writecmd = MMC_WRITE_MULTIPLE_BLOCK;
+ } else {
+ brq->mrq.stop = NULL;
+ readcmd = MMC_READ_SINGLE_BLOCK;
+ writecmd = MMC_WRITE_BLOCK;
+ }
+ if (rq_data_dir(req) == READ) {
+ brq->cmd.opcode = readcmd;
+ brq->data.flags |= MMC_DATA_READ;
+ } else {
+ brq->cmd.opcode = writecmd;
+ brq->data.flags |= MMC_DATA_WRITE;
+ }

- if ((md->flags & MMC_BLK_CMD23) &&
- mmc_op_multi(brq->cmd.opcode) &&
- (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) {
- brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
- brq->sbc.arg = brq->data.blocks |
- (do_rel_wr ? (1 << 31) : 0);
- brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
- brq->mrq.sbc = &brq->sbc;
- }
+ if (do_rel_wr)
+ mmc_apply_rel_rw(brq, card, req);

- mmc_set_data_timeout(&brq->data, card);
+ /*
+ * Pre-defined multi-block transfers are preferable to
+ * open ended-ones (and necessary for reliable writes).
+ * However, it is not sufficient to just send CMD23,
+ * and avoid the final CMD12, as on an error condition
+ * CMD12 (stop) needs to be sent anyway. This, coupled
+ * with Auto-CMD23 enhancements provided by some
+ * hosts, means that the complexity of dealing
+ * with this is best left to the host. If CMD23 is
+ * supported by card and host, we'll fill sbc in and let
+ * the host deal with handling it correctly. This means
+ * that for hosts that don't expose MMC_CAP_CMD23, no
+ * change of behavior will be observed.
+ *
+ * N.B: Some MMC cards experience perf degradation.
+ * We'll avoid using CMD23-bounded multiblock writes for
+ * these, while retaining features like reliable writes.
+ */

- brq->data.sg = mq->mqrq_cur->sg;
- brq->data.sg_len = mmc_queue_map_sg(mq, mq->mqrq_cur);
+ if ((md->flags & MMC_BLK_CMD23) &&
+ mmc_op_multi(brq->cmd.opcode) &&
+ (do_rel_wr || !(card->quirks & MMC_QUIRK_BLK_NO_CMD23))) {
+ brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
+ brq->sbc.arg = brq->data.blocks |
+ (do_rel_wr ? (1 << 31) : 0);
+ brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
+ brq->mrq.sbc = &brq->sbc;
+ }

- /*
- * Adjust the sg list so it is the same size as the
- * request.
- */
- if (brq->data.blocks != blk_rq_sectors(req)) {
- int i, data_size = brq->data.blocks << 9;
- struct scatterlist *sg;
-
- for_each_sg(brq->data.sg, sg, brq->data.sg_len, i) {
- data_size -= sg->length;
- if (data_size <= 0) {
- sg->length += data_size;
- i++;
- break;
- }
+ mmc_set_data_timeout(&brq->data, card);
+
+ brq->data.sg = mqrq->sg;
+ brq->data.sg_len = mmc_queue_map_sg(mq, mqrq);
+
+ /*
+ * Adjust the sg list so it is the same size as the
+ * request.
+ */
+ if (brq->data.blocks != blk_rq_sectors(req)) {
+ int i, data_size = brq->data.blocks << 9;
+ struct scatterlist *sg;
+
+ for_each_sg(brq->data.sg, sg, brq->data.sg_len, i) {
+ data_size -= sg->length;
+ if (data_size <= 0) {
+ sg->length += data_size;
+ i++;
+ break;
}
- brq->data.sg_len = i;
}
+ brq->data.sg_len = i;
+ }

- mmc_queue_bounce_pre(mq->mqrq_cur);
+ mmc_queue_bounce_pre(mqrq);
+}

+static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
+{
+ struct mmc_blk_data *md = mq->data;
+ struct mmc_card *card = md->queue.card;
+ struct mmc_blk_request *brq = &mq->mqrq_cur->brq;
+ int ret = 1, disable_multi = 0, retry = 0;
+
+ do {
+ mmc_blk_rw_rq_prep(mq->mqrq_cur, card, disable_multi, mq);
mmc_wait_for_req(card->host, &brq->mrq);

mmc_queue_bounce_post(mq->mqrq_cur);
--
1.7.4.1