diff options
author | Andrei Warkentin <andreiw@motorola.com> | 2011-05-23 15:06:36 -0500 |
---|---|---|
committer | Chris Ball <cjb@laptop.org> | 2011-05-25 16:48:46 -0400 |
commit | d0c97cfb81ebc5b416c0f92fa2fc18d2773e3023 (patch) | |
tree | dbf0fa49bdad896d283a7f392c156483d9687d4b /drivers/mmc | |
parent | c59de9287993b5c36f9005f745a3ce0b1008131d (diff) | |
download | kernel_samsung_smdk4412-d0c97cfb81ebc5b416c0f92fa2fc18d2773e3023.zip kernel_samsung_smdk4412-d0c97cfb81ebc5b416c0f92fa2fc18d2773e3023.tar.gz kernel_samsung_smdk4412-d0c97cfb81ebc5b416c0f92fa2fc18d2773e3023.tar.bz2 |
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>
Diffstat (limited to 'drivers/mmc')
-rw-r--r-- | drivers/mmc/card/block.c | 108 |
1 files changed, 79 insertions, 29 deletions
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 @@ 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); /* @@ -90,6 +86,10 @@ 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; @@ -429,6 +429,7 @@ 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; @@ -652,13 +653,10 @@ 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 = {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 @@ 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; } - - 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 @@ 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 = {0}; @@ -732,11 +721,9 @@ 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; @@ -754,8 +741,37 @@ 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); @@ -792,7 +808,8 @@ 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 " @@ -803,6 +820,13 @@ 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", @@ -1014,8 +1038,6 @@ 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: @@ -1034,6 +1056,19 @@ 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: @@ -1189,6 +1224,21 @@ 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 + * 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 }; |