mmc: core: Use CMD23 for multiblock transfers when we can.
CMD23-prefixed instead of open-ended multiblock transfers
have a performance advantage on some MMC cards.
Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 126c7f4..a380acc 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -59,10 +59,6 @@
#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);
/*
@@ -90,6 +86,10 @@
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;
@@ -429,6 +429,7 @@
struct mmc_blk_request {
struct mmc_request mrq;
+ struct mmc_command sbc;
struct mmc_command cmd;
struct mmc_command stop;
struct mmc_data data;
@@ -652,13 +653,10 @@
* 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 = {0};
-
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))
@@ -669,15 +667,6 @@
else if (brq->data.blocks < card->ext_csd.rel_sectors)
brq->data.blocks = 1;
}
-
- 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)
@@ -694,7 +683,7 @@
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 = {0};
@@ -732,11 +721,9 @@
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;
@@ -754,8 +741,37 @@
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);
@@ -792,7 +808,8 @@
* 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 "
@@ -803,6 +820,13 @@
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",
@@ -1014,8 +1038,6 @@
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:
@@ -1034,6 +1056,19 @@
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:
@@ -1189,6 +1224,21 @@
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
+ * black list what's bad...
+ * - Certain Toshiba cards.
+ *
+ * N.B. This doesn't affect SD cards.
+ */
+ MMC_FIXUP("MMC08G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
+ MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("MMC16G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
+ MMC_QUIRK_BLK_NO_CMD23),
+ MMC_FIXUP("MMC32G", 0x11, CID_OEMID_ANY, add_quirk_mmc,
+ MMC_QUIRK_BLK_NO_CMD23),
END_FIXUP
};