CMD23-prefixed instead of open-ended multiblock transfers
have a performance advantage on some MMC cards.
Cc: arindam.nath@xxxxxxx
Cc: cjb@xxxxxxxxxx
Cc: arnd@xxxxxxxx
Signed-off-by: Andrei Warkentin <andreiw@xxxxxxxxxxxx>
---
drivers/mmc/card/block.c | 112 +++++++++++++++++++++++++++++++++------------
include/linux/mmc/card.h | 1 +
include/linux/mmc/core.h | 1 +
include/linux/mmc/host.h | 6 +++
include/linux/mmc/mmc.h | 6 +++
5 files changed, 96 insertions(+), 30 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index c209953..bba0888 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -55,10 +55,6 @@ MODULE_ALIAS("mmc:block");
#define INAND_CMD38_ARG_SECTRIM1 0x81
#define INAND_CMD38_ARG_SECTRIM2 0x88
-#define REL_WRITES_SUPPORTED(card) (mmc_card_mmc((card)) && \
- (((card)->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) || \
- ((card)->ext_csd.rel_sectors)))
-
static DEFINE_MUTEX(block_mutex);
/*
@@ -85,6 +81,10 @@ struct mmc_blk_data {
struct mmc_queue queue;
struct list_head part;
+ unsigned int flags;
+#define MMC_BLK_CMD23 (1 << 0) /* Can do SET_BLOCK_COUNT for multiblock */
+#define MMC_BLK_REL_WR (1 << 1) /* MMC Reliable write support */
+
unsigned int usage;
unsigned int read_only;
unsigned int part_type;
@@ -225,6 +225,7 @@ static const struct block_device_operations mmc_bdops = {
struct mmc_blk_request {
struct mmc_request mrq;
+ struct mmc_command sbc;
struct mmc_command cmd;
struct mmc_command stop;
struct mmc_data data;
@@ -455,13 +456,10 @@ static int mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)
* reliable write can handle, thus finish the request in
* partial completions.
*/
-static inline int mmc_apply_rel_rw(struct mmc_blk_request *brq,
- struct mmc_card *card,
- struct request *req)
+static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
+ struct mmc_card *card,
+ struct request *req)
{
- int err;
- struct mmc_command set_count;
-
if (!(card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN)) {
/* Legacy mode imposes restrictions on transfers. */
if (!IS_ALIGNED(brq->cmd.arg, card->ext_csd.rel_sectors))
@@ -472,16 +470,6 @@ static inline int mmc_apply_rel_rw(struct mmc_blk_request *brq,
else if (brq->data.blocks < card->ext_csd.rel_sectors)
brq->data.blocks = 1;
}
-
- memset(&set_count, 0, sizeof(struct mmc_command));
- set_count.opcode = MMC_SET_BLOCK_COUNT;
- set_count.arg = brq->data.blocks | (1 << 31);
- set_count.flags = MMC_RSP_R1 | MMC_CMD_AC;
- err = mmc_wait_for_cmd(card->host, &set_count, 0);
- if (err)
- printk(KERN_ERR "%s: error %d SET_BLOCK_COUNT\n",
- req->rq_disk->disk_name, err);
- return err;
}
static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
@@ -498,7 +486,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
(req->cmd_flags & REQ_META)) &&
(rq_data_dir(req) == WRITE) &&
- REL_WRITES_SUPPORTED(card);
+ (md->flags & MMC_BLK_REL_WR);
do {
struct mmc_command cmd;
@@ -536,11 +524,9 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
if (brq.data.blocks > 1 || do_rel_wr) {
/* SPI multiblock writes terminate using a special
- * token, not a STOP_TRANSMISSION request. Reliable
- * writes use SET_BLOCK_COUNT and do not use a
- * STOP_TRANSMISSION request either.
+ * token, not a STOP_TRANSMISSION request.
*/
- if ((!mmc_host_is_spi(card->host) && !do_rel_wr) ||
+ if (!mmc_host_is_spi(card->host) ||
rq_data_dir(req) == READ)
brq.mrq.stop = &brq.stop;
readcmd = MMC_READ_MULTIPLE_BLOCK;
@@ -558,8 +544,37 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
brq.data.flags |= MMC_DATA_WRITE;
}
- if (do_rel_wr && mmc_apply_rel_rw(&brq, card, req))
- goto cmd_err;
+ if (do_rel_wr)
+ mmc_apply_rel_rw(&brq, card, req);
+
+ /*
+ * 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 ((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;
+ }
mmc_set_data_timeout(&brq.data, card);
@@ -596,7 +611,8 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
* until later as we need to wait for the card to leave
* programming mode even when things go wrong.
*/
- if (brq.cmd.error || brq.data.error || brq.stop.error) {
+ if (brq.sbc.error || brq.cmd.error ||
+ brq.data.error || brq.stop.error) {
if (brq.data.blocks > 1 && rq_data_dir(req) == READ) {
/* Redo read one sector at a time */
printk(KERN_WARNING "%s: retrying using single "
@@ -607,6 +623,13 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
status = get_card_status(card, req);
}
+ if (brq.sbc.error) {
+ printk(KERN_ERR "%s: error %d sending SET_BLOCK_COUNT "
+ "command, response %#x, card status %#x\n",
+ req->rq_disk->disk_name, brq.sbc.error,
+ brq.sbc.resp[0], status);
+ }
+
if (brq.cmd.error) {
printk(KERN_ERR "%s: error %d sending read/write "
"command, response %#x, card status %#x\n",
@@ -804,8 +827,6 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
md->disk->queue = md->queue.queue;
md->disk->driverfs_dev = parent;
set_disk_ro(md->disk, md->read_only || default_ro);
- if (REL_WRITES_SUPPORTED(card))
- blk_queue_flush(md->queue.queue, REQ_FLUSH | REQ_FUA);
/*
* As discussed on lkml, GENHD_FL_REMOVABLE should:
@@ -829,6 +850,19 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
blk_queue_logical_block_size(md->queue.queue, 512);
set_capacity(md->disk, size);
+
+ if (mmc_host_cmd23(card->host) &&
+ mmc_card_mmc(card))
+ md->flags |= MMC_BLK_CMD23;
+
+ if (mmc_card_mmc(card) &&
+ md->flags & MMC_BLK_CMD23 &&
+ ((card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN) ||
+ card->ext_csd.rel_sectors)) {
+ md->flags |= MMC_BLK_REL_WR;
+ blk_queue_flush(md->queue.queue, REQ_FLUSH | REQ_FUA);
+ }
+
return md;
err_putdisk:
@@ -982,6 +1016,24 @@ static const struct mmc_fixup blk_fixups[] =
MMC_FIXUP("SEM08G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
MMC_FIXUP("SEM16G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
MMC_FIXUP("SEM32G", 0x2, 0x100, add_quirk, MMC_QUIRK_INAND_CMD38),
+
+ /*
+ * Some MMC cards experience performance degradation with CMD23
+ * instead of CMD12-bounded multiblock transfers. For now we'll
+ * white list what's good.
+ */
+ MMC_FIXUP(CID_NAME_ANY, CID_MANFID_ANY, CID_OEMID_ANY, add_quirk,
+ MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM02G", 0x2, 0x100, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM04G", 0x2, 0x100, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM08G", 0x2, 0x100, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM16G", 0x2, 0x100, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM32G", 0x2, 0x100, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM02G", 0x45, 0x0, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM04G", 0x45, 0x0, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM08G", 0x45, 0x0, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM16G", 0x45, 0x0, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("SEM32G", 0x45, 0x0, remove_quirk, MMC_QUIRK_BLK_NO_CMD23),
END_FIXUP
};
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 72a9868..1e6bd6c 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -134,6 +134,7 @@ struct mmc_card {
#define MMC_QUIRK_NONSTD_FUNC_IF (1<<4) /* SDIO card has nonstd function interfaces */
#define MMC_QUIRK_DISABLE_CD (1<<5) /* disconnect CD/DAT[3] resistor */
#define MMC_QUIRK_INAND_CMD38 (1<<6) /* iNAND devices have broken CMD38 */
+#define MMC_QUIRK_BLK_NO_CMD23 (1<<7) /* Avoid CMD23 for regular multiblock */
unsigned int erase_size; /* erase size in sectors */
unsigned int erase_shift; /* if erase unit is power 2 */
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index f8e4bcb..55d7fde 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -120,6 +120,7 @@ struct mmc_data {
};
struct mmc_request {
+ struct mmc_command *sbc; /* SET_BLOCK_COUNT for multiblock */
struct mmc_command *cmd;
struct mmc_data *data;
struct mmc_command *stop;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 4f705eb..ba34fc5 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -173,6 +173,7 @@ struct mmc_host {
/* DDR mode at 1.2V */
#define MMC_CAP_POWER_OFF_CARD (1 << 13) /* Can power off after boot */
#define MMC_CAP_BUS_WIDTH_TEST (1 << 14) /* CMD14/CMD19 bus width ok */
+#define MMC_CAP_CMD23 (1 << 15) /* CMD23 supported */
mmc_pm_flag_t pm_caps; /* supported pm features */
@@ -330,5 +331,10 @@ static inline int mmc_card_wake_sdio_irq(struct mmc_host *host)
{
return host->pm_flags & MMC_PM_WAKE_SDIO_IRQ;
}
+
+static inline int mmc_host_cmd23(struct mmc_host *host)
+{
+ return host->caps & MMC_CAP_CMD23;
+}
#endif
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 373b2bf..ea74168 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -82,6 +82,12 @@
#define MMC_APP_CMD 55 /* ac [31:16] RCA R1 */
#define MMC_GEN_CMD 56 /* adtc [0] RD/WR R1 */
+static inline bool mmc_op_multi(u32 opcode)
+{
+ return opcode == MMC_WRITE_MULTIPLE_BLOCK ||
+ opcode == MMC_READ_MULTIPLE_BLOCK;
+}
+
/*
* MMC_SWITCH argument format:
*
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
