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mmc: block: add a block request prepare function
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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@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Per Forlin authored and Chris Ball committed Jul 20, 2011
1 parent 97868a2 commit 54d49d7
Showing 1 changed file with 114 additions and 104 deletions.
218 changes: 114 additions & 104 deletions drivers/mmc/card/block.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand All @@ -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);
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