Re: [PATCH] mmc: core: Add packed command for eMMC4.5 device

Sahitya Tummala
2011-11-16T11:15:10Z

Hi,

On 10/27/2011 4:24 PM, Seungwon Jeon wrote:
>
> +static int mmc_blk_packed_err_check(struct mmc_card *card,
> + struct mmc_async_req *areq)
> +{
> + struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
> + mmc_active);
> + int err, check, status;
> + u8 ext_csd[512];
> +
> + check = mmc_blk_err_check(card, areq);
> +
> + if (check == MMC_BLK_SUCCESS)
> + return check;
> +
> + if (check == MMC_BLK_PARTIAL) {
> + err = get_card_status(card,&status, 0);
> + if (err)
> + return MMC_BLK_ABORT;
> +
> + if (status& R1_EXP_EVENT) {
> + err = mmc_send_ext_csd(card, ext_csd);
> + if (err)
> + return MMC_BLK_ABORT;
> +
> + if ((ext_csd[EXT_CSD_EXP_EVENTS_STATUS + 0]&
> + 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) {
> + /* Make be 0-based */
> + mq_mrq->packed_fail_idx =
> + ext_csd[EXT_CSD_PACKED_FAILURE_INDEX] - 1;
> + return MMC_BLK_PARTIAL;
> + } else {
> + return MMC_BLK_RETRY;
> + }
> + }
> + } else {
> + return MMC_BLK_RETRY;
> + }
> + }
> +
> + if (check != MMC_BLK_ABORT)
> + return MMC_BLK_RETRY;
> + else
> + return MMC_BLK_ABORT;

The current code does not return other errors (MMC_BLK_CMD_ERR,
MMC_BLK_ECC_ERR and MMC_BLK_DATA_ERR) returned by mmc_blk_err_check().
Why not return check here?

> +}
> +
> static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
> struct mmc_card *card,
> int disable_multi,
> @@ -1126,6 +1187,207 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
> mmc_queue_bounce_pre(mqrq);
> }
>
> +static u8 mmc_blk_chk_packable(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 max_packed_rw = 0;
> + u8 reqs = 0;
> +
> + if (!(md->flags& MMC_BLK_CMD23)&&
> + !card->ext_csd.packed_event_en)
> + goto no_packed;
> +
> + if (rq_data_dir(cur) == READ)
> + max_packed_rw = card->ext_csd.max_packed_reads;
> + else
> + 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);
> + max_phys_segs = queue_max_segments(q);
> + req_sectors += blk_rq_sectors(cur);
> + phys_segments += req->nr_phys_segments;
> +
> + if (rq_data_dir(cur) == WRITE) {
> + req_sectors++;
> + phys_segments++;
> + }
> +
> + while (reqs< max_packed_rw - 1) {

What if the number of requests exceeds the packed header size defined?

> + next = blk_fetch_request(q);
> + if (!next)
> + break;
> +
> + if (rq_data_dir(cur) != rq_data_dir(next)) {
> + blk_requeue_request(q, next);
> + break;
> + }
> +
> + if (mmc_req_rel_wr(next)&&
> + (md->flags& MMC_BLK_REL_WR)&&
> + !en_rel_wr) {
> + blk_requeue_request(q, next);
> + break;
> + }
> +
> + req_sectors += blk_rq_sectors(next);
> + if (req_sectors> max_blk_count) {
> + blk_requeue_request(q, next);
> + break;
> + }
> +
> + phys_segments += next->nr_phys_segments;
> + if (phys_segments> max_phys_segs) {
> + blk_requeue_request(q, next);
> + break;
> + }
> +
> + list_add_tail(&next->queuelist,&mq->mqrq_cur->packed_list);
> + cur = next;
> + reqs++;
> + }
> +
> + if (reqs> 0) {
> + list_add(&req->queuelist,&mq->mqrq_cur->packed_list);
> + return (reqs + 1);
> + }
> +
> +no_packed:
> + mq->mqrq_cur->packed_cmd = MMC_PACKED_NONE;
> + return reqs;
> +}
> +
>
> static int mmc_blk_cmd_err(struct mmc_blk_data *md, struct mmc_card *card,
> struct mmc_blk_request *brq, struct request *req,
> int ret)
> @@ -1163,15 +1425,33 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> int ret = 1, disable_multi = 0, retry = 0, type;
> enum mmc_blk_status status;
> struct mmc_queue_req *mq_rq;
> - struct request *req;
> + struct request *req, *prq;
> struct mmc_async_req *areq;
> + u8 reqs = 0;
>
> if (!rqc&& !mq->mqrq_prev->req)
> return 0;
>
> + if (rqc)
> + reqs = mmc_blk_chk_packable(mq, rqc);
> +
> do {
> if (rqc) {
> - mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
> + if (reqs>= 2) {
> + mmc_blk_packed_hdr_wrq_prep(mq->mqrq_cur, card, mq, reqs);
> + if (rq_data_dir(rqc) == READ) {
> + areq =&mq->mqrq_cur->mmc_active;
> + mmc_wait_for_req(card->host, areq->mrq);
> + status = mmc_blk_packed_err_check(card, areq);
> + if (status == MMC_BLK_SUCCESS) {
> + mmc_blk_packed_rrq_prep(mq->mqrq_cur, card, mq);
> + } else {
> + goto check_status;
> + }
> + }
> + } else {
> + mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);

We must use disable_multi variable instead of directly calling this
function with 0 value because there are some cases where disable_multi
is set to 1 (for example, it is set for error case MMC_BLK_ECC_ERR).

> + }
> areq =&mq->mqrq_cur->mmc_active;
> } else
> areq = NULL;
> @@ -1179,6 +1459,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> if (!areq)
> return 0;
>
> +check_status:
> mq_rq = container_of(areq, struct mmc_queue_req, mmc_active);
> brq =&mq_rq->brq;
> req = mq_rq->req;
> @@ -1192,10 +1473,32 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> * A block was successfully transferred.
> */
> mmc_blk_reset_success(md, type);
> - spin_lock_irq(&md->lock);
> - ret = __blk_end_request(req, 0,
> +
> + if (mq_rq->packed_cmd != MMC_PACKED_NONE) {
> + int idx = mq_rq->packed_fail_idx, i = 0;
> + while (!list_empty(&mq_rq->packed_list)) {
> + prq = list_entry_rq(mq_rq->packed_list.next);
> + if (idx == i) {
> + /* retry from error index */
> + reqs -= idx;
> + mq_rq->req = prq;
> + ret = 1;
> + break;
> + }
> + list_del_init(&prq->queuelist);
> + spin_lock_irq(&md->lock);
> + ret = __blk_end_request(prq, 0, blk_rq_bytes(prq));
> + spin_unlock_irq(&md->lock);
> + i++;
> + }
> + break;
> + } else {
> + spin_lock_irq(&md->lock);
> + ret = __blk_end_request(req, 0,
> brq->data.bytes_xfered);
> - spin_unlock_irq(&md->lock);
> + spin_unlock_irq(&md->lock);
> + }
> +
> /*
> * If the blk_end_request function returns non-zero even
> * though all data has been transferred and no errors
> @@ -1254,7 +1557,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> break;
> }
>
> - if (ret) {
> + if (ret&& (mq_rq->packed_cmd == MMC_PACKED_NONE)) {
> /*
> * In case of a incomplete request
> * prepare it again and resend.
> @@ -1267,13 +1570,37 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> return 1;
>
> cmd_abort:
> - spin_lock_irq(&md->lock);
> - while (ret)
> - ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
> - spin_unlock_irq(&md->lock);
> + if (mq_rq->packed_cmd != MMC_PACKED_NONE) {
> + spin_lock_irq(&md->lock);
> + while (ret)
> + ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
> + spin_unlock_irq(&md->lock);
> + } else {
> + while (!list_empty(&mq_rq->packed_list)) {
> + prq = list_entry_rq(mq_rq->packed_list.next);
> + list_del_init(&prq->queuelist);
> + spin_lock_irq(&md->lock);
> + __blk_end_request(prq, -EIO, blk_rq_bytes(prq));
> + spin_unlock_irq(&md->lock);
> + }
> + }
>
> start_new_req:
> if (rqc) {
> + /*
> + * If current request is packed, it need to put back.
> + */
> + if (mq->mqrq_cur->packed_cmd != MMC_PACKED_NONE) {
> + while (!list_empty(&mq->mqrq_cur->packed_list)) {
> + prq = list_entry_rq(mq->mqrq_cur->packed_list.prev);
> + if (prq->queuelist.prev !=&mq->mqrq_cur->packed_list) {
> + list_del_init(&prq->queuelist);
> + blk_requeue_request(mq->queue, prq);
> + } else {
> + list_del_init(&prq->queuelist);
> + }
> + }
> + }
> mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);

We must use disable_multi variable instead of directly calling this
function with 0 value because there are some cases where disable_multi
is set to 1.

> mmc_start_req(card->host,&mq->mqrq_cur->mmc_active, NULL);

I think these two statements must come under else part of above if
condition. Please check.

Thanks,
Sahitya.
--
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