On Mon, Jun 18, 2012 at 11:13 AM, Seungwon Jeon <tgih.jun@xxxxxxxxxxx> wrote:
> This patch supports packed write command of eMMC4.5 device.
> Several writes can be grouped in packed command and all data
> of the individual commands can be sent in a single transfer
> on the bus.
>
> Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
> ---
> drivers/mmc/card/block.c | 406 +++++++++++++++++++++++++++++++++++++++++---
> drivers/mmc/card/queue.c | 45 +++++-
> drivers/mmc/card/queue.h | 12 ++
> drivers/mmc/core/mmc_ops.c | 1 +
> include/linux/mmc/core.h | 4 +
> 5 files changed, 441 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 7e3f453..eb99e35 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -58,6 +58,12 @@ MODULE_ALIAS("mmc:block");
> #define INAND_CMD38_ARG_SECTRIM1 0x81
> #define INAND_CMD38_ARG_SECTRIM2 0x88
>
> +#define mmc_req_rel_wr(req) (((req->cmd_flags & REQ_FUA) || \
> + (req->cmd_flags & REQ_META)) && \
> + (rq_data_dir(req) == WRITE))
> +#define PACKED_CMD_VER 0x01
> +#define PACKED_CMD_WR 0x02
> +
> static DEFINE_MUTEX(block_mutex);
>
> /*
> @@ -123,9 +129,21 @@ enum mmc_blk_status {
> MMC_BLK_NOMEDIUM,
> };
>
> +enum {
> + MMC_PACKED_N_IDX = -1,
> + MMC_PACKED_N_ZERO,
> + MMC_PACKED_N_SINGLE,
> +};
> +
> module_param(perdev_minors, int, 0444);
> MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
>
> +static inline void mmc_blk_clear_packed(struct mmc_queue_req *mqrq)
> +{
> + mqrq->packed_cmd = MMC_PACKED_NONE;
> + mqrq->packed_num = MMC_PACKED_N_ZERO;
> +}
> +
> static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
> {
> struct mmc_blk_data *md;
> @@ -1081,12 +1099,61 @@ static int mmc_blk_err_check(struct mmc_card *card,
> if (!brq->data.bytes_xfered)
> return MMC_BLK_RETRY;
>
> + if (mq_mrq->packed_cmd != MMC_PACKED_NONE) {
> + if (unlikely(brq->data.blocks << 9 != brq->data.bytes_xfered))
> + return MMC_BLK_PARTIAL;
> + else
> + return MMC_BLK_SUCCESS;
> + }
> +
> if (blk_rq_bytes(req) != brq->data.bytes_xfered)
> return MMC_BLK_PARTIAL;
>
> return MMC_BLK_SUCCESS;
> }
>
> +static int mmc_blk_packed_err_check(struct mmc_card *card,
> + struct mmc_async_req *areq)
> +{
> + struct mmc_queue_req *mq_rq = container_of(areq, struct mmc_queue_req,
> + mmc_active);
> + struct request *req = mq_rq->req;
> + int err, check, status;
> + u8 ext_csd[512];
> +
> + mq_rq->packed_retries--;
> + check = mmc_blk_err_check(card, areq);
> + err = get_card_status(card, &status, 0);
> + if (err) {
> + pr_err("%s: error %d sending status command\n",
> + req->rq_disk->disk_name, err);
> + return MMC_BLK_ABORT;
> + }
> +
> + if (status & R1_EXP_EVENT) {
> + err = mmc_send_ext_csd(card, ext_csd);
> + if (err) {
> + pr_err("%s: error %d sending ext_csd\n",
> + req->rq_disk->disk_name, err);
> + return MMC_BLK_ABORT;
> + }
> +
> + if ((ext_csd[EXT_CSD_EXP_EVENTS_STATUS] &
> + EXT_CSD_PACKED_FAILURE) &&
> + (ext_csd[EXT_CSD_PACKED_CMD_STATUS] &
> + EXT_CSD_PACKED_GENERIC_ERROR)) {
> + if (ext_csd[EXT_CSD_PACKED_CMD_STATUS] &
> + EXT_CSD_PACKED_INDEXED_ERROR) {
> + mq_rq->packed_fail_idx =
> + ext_csd[EXT_CSD_PACKED_FAILURE_INDEX] - 1;
> + return MMC_BLK_PARTIAL;
> + }
> + }
> + }
> +
> + return check;
> +}
> +
> static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
> struct mmc_card *card,
> int disable_multi,
> @@ -1241,10 +1308,197 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
> mmc_queue_bounce_pre(mqrq);
> }
>
> +static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq, struct request *req)
> +{
> + struct request_queue *q = mq->queue;
> + struct mmc_card *card = mq->card;
> + struct request *cur = req, *next = NULL;
> + struct mmc_blk_data *md = mq->data;
> + bool en_rel_wr = card->ext_csd.rel_param & EXT_CSD_WR_REL_PARAM_EN;
> + unsigned int req_sectors = 0, phys_segments = 0;
> + unsigned int max_blk_count, max_phys_segs;
> + u8 put_back = 0;
> + u8 max_packed_rw = 0;
> + u8 reqs = 0;
> +
> + mmc_blk_clear_packed(mq->mqrq_cur);
> +
> + if (!(md->flags & MMC_BLK_CMD23) ||
> + !card->ext_csd.packed_event_en)
> + goto no_packed;
> +
> + if ((rq_data_dir(cur) == WRITE) &&
> + (card->host->caps2 & MMC_CAP2_PACKED_WR))
> + max_packed_rw = card->ext_csd.max_packed_writes;
> +
> + if (max_packed_rw == 0)
> + goto no_packed;
> +
> + if (mmc_req_rel_wr(cur) &&
> + (md->flags & MMC_BLK_REL_WR) &&
> + !en_rel_wr) {
> + goto no_packed;
> + }
> +
> + max_blk_count = min(card->host->max_blk_count,
> + card->host->max_req_size >> 9);
> + if (unlikely(max_blk_count > 0xffff))
> + max_blk_count = 0xffff;
> +
> + max_phys_segs = queue_max_segments(q);
> + req_sectors += blk_rq_sectors(cur);
> + phys_segments += cur->nr_phys_segments;
> +
> + if (rq_data_dir(cur) == WRITE) {
> + req_sectors++;
> + phys_segments++;
> + }
> +
> + while (reqs < max_packed_rw - 1) {
> + spin_lock_irq(q->queue_lock);
> + next = blk_fetch_request(q);
> + spin_unlock_irq(q->queue_lock);
> + if (!next)
> + break;
> +
> + if (next->cmd_flags & REQ_DISCARD ||
> + next->cmd_flags & REQ_FLUSH) {
> + put_back = 1;
> + break;
> + }
> +
> + if (rq_data_dir(cur) != rq_data_dir(next)) {
> + put_back = 1;
> + break;
> + }
> +
> + if (mmc_req_rel_wr(next) &&
> + (md->flags & MMC_BLK_REL_WR) &&
> + !en_rel_wr) {
> + put_back = 1;
> + break;
> + }
> +
> + req_sectors += blk_rq_sectors(next);
> + if (req_sectors > max_blk_count) {
> + put_back = 1;
> + break;
> + }
> +
> + phys_segments += next->nr_phys_segments;
> + if (phys_segments > max_phys_segs) {
> + put_back = 1;
> + break;
> + }
> +
> + list_add_tail(&next->queuelist, &mq->mqrq_cur->packed_list);
> + cur = next;
> + reqs++;
> + }
> +
> + if (put_back) {
> + spin_lock_irq(q->queue_lock);
> + blk_requeue_request(q, next);
> + spin_unlock_irq(q->queue_lock);
> + }
> +
> + if (reqs > 0) {
> + list_add(&req->queuelist, &mq->mqrq_cur->packed_list);
> + mq->mqrq_cur->packed_num = ++reqs;
> + mq->mqrq_cur->packed_retries = reqs;
^^ This means that the number of times the packed command is retried
is equal to the number of requests
it packs ? How are they related ?
> + return reqs;
> + }
> +
> +no_packed:
> + mmc_blk_clear_packed(mq->mqrq_cur);
> + return 0;
> +}
> +
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