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

S, Venkatraman
2011-10-27T13:22:59Z

On Thu, Oct 27, 2011 at 4:24 PM, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> This patch supports packed command feature of eMMC4.5 Spec.
> Several reads(or writes) can be grouped in packed command
> and all data of the individual commands can be sent in one
> transfer on the bus.
>
> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
> ---
>  drivers/mmc/card/block.c |  349 ++++++++++++++++++++++++++++++++++++++++++++--
>  drivers/mmc/card/queue.c |   48 ++++++-
>  drivers/mmc/card/queue.h |   12 ++
>  drivers/mmc/core/mmc.c   |   20 +++
>  include/linux/mmc/card.h |    3 +
>  include/linux/mmc/host.h |    1 +
>  include/linux/mmc/mmc.h  |   15 ++
>  7 files changed, 434 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 4fd5723..0258a81 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -45,6 +45,7 @@
>  #include <asm/uaccess.h>
>
>  #include "queue.h"
> +#include "../core/mmc_ops.h"

I don't think this is the right way to include files. The core
directory should be in the include path already.

>
>  MODULE_ALIAS("mmc:block");
>  #ifdef MODULE_PARAM_PREFIX
> @@ -59,6 +60,10 @@ 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))
> +
>  static DEFINE_MUTEX(block_mutex);
>
>  /*
> @@ -943,7 +948,8 @@ static int mmc_blk_err_check(struct mmc_card *card,
>         * kind.  If it was a write, we may have transitioned to
>         * program mode, which we have to wait for it to complete.
>         */
> -       if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
> +       if ((!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) ||
> +                       (mq_mrq->packed_cmd == MMC_PACKED_WR_HDR)) {
>                u32 status;
>                do {
>                        int err = get_card_status(card, &status, 5);
> @@ -980,12 +986,67 @@ 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_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;
> +}
> +
>  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) {
> +               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++;
> +       }

IIRC, blk_fetch_request gets it from the top of the request_queue and
blk_requeue_request puts it back to the top of the queue
(request_queue->queue_head). Hence, possibly, this loop will keep
fetching and requeing the same request repeatedly ?

> +
> +       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 void mmc_blk_packed_hdr_wrq_prep(struct mmc_queue_req *mqrq,
> +                              struct mmc_card *card,
> +                              struct mmc_queue *mq,
> +                              u8 reqs)
> +{
> +       struct mmc_blk_request *brq = &mqrq->brq;
> +       struct request *req = mqrq->req;
> +       struct request *prq;
> +       struct mmc_blk_data *md = mq->data;
> +       bool do_rel_wr;
> +       u32 *packed_cmd_hdr = mqrq->packed_cmd_hdr;
> +       u8 i =1;
> +
> +       mqrq->packed_cmd = (rq_data_dir(req) == READ) ?
> +               MMC_PACKED_WR_HDR : MMC_PACKED_WRITE;
> +       mqrq->packed_blocks = 0;
> +       mqrq->packed_fail_idx = -1;
> +
> +       memset(packed_cmd_hdr, 0, sizeof(mqrq->packed_cmd_hdr));
> +       packed_cmd_hdr[0] = (reqs << 16) |
> +               (((rq_data_dir(req) == READ) ? 0x01 : 0x02) << 8) | (0x01 << 0);
> +
Too many magic numbers here.

> +       /*
> +        * Argument for each entry of packed group
> +        */
> +       list_for_each_entry(prq, &mqrq->packed_list, queuelist) {
> +               do_rel_wr = mmc_req_rel_wr(prq) && (md->flags & MMC_BLK_REL_WR);
> +               /* Argument of CMD23*/
> +               packed_cmd_hdr[(i * 2)] = (do_rel_wr ? (1 << 31) : 0) |
> +                       blk_rq_sectors(prq);
> +               /* Argument of CMD18 or CMD25 */
> +               packed_cmd_hdr[((i * 2)) + 1] = mmc_card_blockaddr(card) ?
> +                       blk_rq_pos(prq) : blk_rq_pos(prq) << 9;
> +               mqrq->packed_blocks += blk_rq_sectors(prq);
> +               i++;
> +       }
> +
> +       memset(brq, 0, sizeof(struct mmc_blk_request));
> +       brq->mrq.cmd = &brq->cmd;
> +       brq->mrq.data = &brq->data;
> +       brq->mrq.sbc = &brq->sbc;
> +       brq->mrq.stop = &brq->stop;
> +
> +       brq->sbc.opcode = MMC_SET_BLOCK_COUNT;
> +       brq->sbc.arg = (0 << 31) | (1 << 30) |
> +               ((rq_data_dir(req) == READ) ? 1 : mqrq->packed_blocks + 1);

.. and here ^^..

> +       brq->sbc.flags = MMC_RSP_R1 | MMC_CMD_AC;
> +
> +       brq->cmd.opcode = MMC_WRITE_MULTIPLE_BLOCK;
> +       brq->cmd.arg = blk_rq_pos(req);
> +       if (!mmc_card_blockaddr(card))
> +               brq->cmd.arg <<= 9;
> +       brq->cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
> +
> +       brq->data.blksz = 512;
> +       /*
> +        * Write separately the packd command header only for packed read.
> +        * In case of packed write, header is sent with blocks of data.
> +        */
> +       brq->data.blocks = (rq_data_dir(req) == READ) ?
> +               1 : mqrq->packed_blocks + 1;
> +       brq->data.flags |= MMC_DATA_WRITE;
> +
> +       brq->stop.opcode = MMC_STOP_TRANSMISSION;
> +       brq->stop.arg = 0;
> +       brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
> +
> +       mmc_set_data_timeout(&brq->data, card);
> +
> +       brq->data.sg = mqrq->sg;
> +       brq->data.sg_len = mmc_queue_map_sg(mq, mqrq);
> +
> +       mqrq->mmc_active.mrq = &brq->mrq;
> +       mqrq->mmc_active.err_check = mmc_blk_packed_err_check;
> +
> +       mmc_queue_bounce_pre(mqrq);
> +}
> +
> +static void mmc_blk_packed_rrq_prep(struct mmc_queue_req *mqrq,
> +                              struct mmc_card *card,
> +                              struct mmc_queue *mq)
> +{
> +       struct mmc_blk_request *brq = &mqrq->brq;
> +       struct request *req = mqrq->req;
> +
> +       mqrq->packed_cmd = MMC_PACKED_READ;
> +
> +       memset(brq, 0, sizeof(struct mmc_blk_request));
> +       brq->mrq.cmd = &brq->cmd;
> +       brq->mrq.data = &brq->data;
> +       brq->mrq.stop = &brq->stop;
> +
> +       brq->cmd.opcode = MMC_READ_MULTIPLE_BLOCK;
> +       brq->cmd.arg = blk_rq_pos(req);
> +       if (!mmc_card_blockaddr(card))
> +               brq->cmd.arg <<= 9;
> +       brq->cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
> +       brq->data.blksz = 512;
> +       brq->data.blocks = mqrq->packed_blocks;
> +       brq->data.flags |= MMC_DATA_READ;
> +
> +       brq->stop.opcode = MMC_STOP_TRANSMISSION;
> +       brq->stop.arg = 0;
> +       brq->stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
> +
> +       mmc_set_data_timeout(&brq->data, card);
> +
> +       brq->data.sg = mqrq->sg;
> +       brq->data.sg_len = mmc_queue_map_sg(mq, mqrq);
> +
> +       mqrq->mmc_active.mrq = &brq->mrq;
> +       mqrq->mmc_active.err_check = mmc_blk_packed_err_check;
> +
> +       mmc_queue_bounce_pre(mqrq);
> +}
> +
>  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);
> +                       }
>                        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);
>                mmc_start_req(card->host, &mq->mqrq_cur->mmc_active, NULL);
>        }
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index dcad59c..3a4542e 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -172,6 +172,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
>
>        memset(&mq->mqrq_cur, 0, sizeof(mq->mqrq_cur));
>        memset(&mq->mqrq_prev, 0, sizeof(mq->mqrq_prev));
> +       INIT_LIST_HEAD(&mqrq_cur->packed_list);
> +       INIT_LIST_HEAD(&mqrq_prev->packed_list);
>        mq->mqrq_cur = mqrq_cur;
>        mq->mqrq_prev = mqrq_prev;
>        mq->queue->queuedata = mq;
> @@ -372,6 +374,39 @@ void mmc_queue_resume(struct mmc_queue *mq)
>        }
>  }
>
> +static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
> +                               struct mmc_queue_req *mqrq,
> +                               struct scatterlist *sg)
> +{
> +       struct scatterlist *__sg;
> +       unsigned int sg_len = 0;
> +       struct request *req;
> +       enum mmc_packed_cmd cmd;
> +
> +       cmd = mqrq->packed_cmd;
> +
> +       if (cmd == MMC_PACKED_WR_HDR || cmd == MMC_PACKED_WRITE) {
> +               __sg =sg;
> +               sg_set_buf(__sg, mqrq->packed_cmd_hdr,
> +                               sizeof(mqrq->packed_cmd_hdr));
> +               sg_len++;
> +               if (cmd == MMC_PACKED_WR_HDR) {
> +                       sg_mark_end(__sg);
> +                       return sg_len;
> +               }
> +               __sg->page_link &= ~0x02;
> +       }
> +
> +       __sg = sg + sg_len;
> +       list_for_each_entry(req, &mqrq->packed_list, queuelist) {
> +               sg_len += blk_rq_map_sg(mq->queue, req, __sg);
> +               __sg = sg + (sg_len - 1);
> +               (__sg++)->page_link &= ~0x02;
> +       }
> +       sg_mark_end(sg + (sg_len - 1));
> +       return sg_len;
> +}
> +
>  /*
>  * Prepare the sg list(s) to be handed of to the host driver
>  */
> @@ -382,12 +417,19 @@ unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
>        struct scatterlist *sg;
>        int i;
>
> -       if (!mqrq->bounce_buf)
> -               return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
> +       if (!mqrq->bounce_buf) {
> +               if (!list_empty(&mqrq->packed_list))
> +                       return mmc_queue_packed_map_sg(mq, mqrq, mqrq->sg);
> +               else
> +                       return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
> +       }
>
>        BUG_ON(!mqrq->bounce_sg);
>
> -       sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
> +       if (!list_empty(&mqrq->packed_list))
> +               sg_len = mmc_queue_packed_map_sg(mq, mqrq, mqrq->bounce_sg);
> +       else
> +               sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
>
>        mqrq->bounce_sg_len = sg_len;
>
> diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
> index d2a1eb4..5d0131e 100644
> --- a/drivers/mmc/card/queue.h
> +++ b/drivers/mmc/card/queue.h
> @@ -12,6 +12,13 @@ struct mmc_blk_request {
>        struct mmc_data         data;
>  };
>
> +enum mmc_packed_cmd {
> +       MMC_PACKED_NONE = 0,
> +       MMC_PACKED_WR_HDR,
> +       MMC_PACKED_WRITE,
> +       MMC_PACKED_READ,
> +};
> +
>  struct mmc_queue_req {
>        struct request          *req;
>        struct mmc_blk_request  brq;
> @@ -20,6 +27,11 @@ struct mmc_queue_req {
>        struct scatterlist      *bounce_sg;
>        unsigned int            bounce_sg_len;
>        struct mmc_async_req    mmc_active;
> +       struct list_head        packed_list;
> +       u32                     packed_cmd_hdr[128];
> +       unsigned int            packed_blocks;
> +       enum mmc_packed_cmd     packed_cmd;
> +       int             packed_fail_idx;
>  };
>
>  struct mmc_queue {
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 3627044..eab01c1 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -487,6 +487,9 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
>                        ext_csd[EXT_CSD_CACHE_SIZE + 1] << 8 |
>                        ext_csd[EXT_CSD_CACHE_SIZE + 2] << 16 |
>                        ext_csd[EXT_CSD_CACHE_SIZE + 3] << 24;
> +
> +               card->ext_csd.max_packed_writes = ext_csd[EXT_CSD_MAX_PACKED_WRITES];
> +               card->ext_csd.max_packed_reads = ext_csd[EXT_CSD_MAX_PACKED_READS];
>        }
>
>  out:
> @@ -1072,6 +1075,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>                card->ext_csd.cache_ctrl = err ? 0 : 1;
>        }
>
> +       if ((host->caps2 & MMC_CAP2_PACKED_CMD) &&
> +                       (card->ext_csd.max_packed_writes > 0) &&
> +                       (card->ext_csd.max_packed_reads > 0)) {
> +               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> +                               EXT_CSD_EXP_EVENTS_CTRL,
> +                               EXT_CSD_PACKED_EVENT_EN,
> +                               card->ext_csd.generic_cmd6_time);
> +               if (err && err != -EBADMSG)
> +                       goto free_card;
> +               if (err) {
> +                       pr_warning("%s: Enabling packed event failed\n",
> +                                       mmc_hostname(card->host));
> +                       err = 0;
> +               } else
> +                       card->ext_csd.packed_event_en = 1;
> +       }
> +
>        if (!oldcard)
>                host->card = card;
>
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 6e04e10..3ffd93f 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -52,6 +52,9 @@ struct mmc_ext_csd {
>        u8                      part_config;
>        u8                      cache_ctrl;
>        u8                      rst_n_function;
> +       u8                      max_packed_writes;
> +       u8                      max_packed_reads;
> +       u8                      packed_event_en;
>        unsigned int            part_time;              /* Units: ms */
>        unsigned int            sa_timeout;             /* Units: 100ns */
>        unsigned int            generic_cmd6_time;      /* Units: 10ms */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index a3ac9c4..d2e4210 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -242,6 +242,7 @@ struct mmc_host {
>  #define MMC_CAP2_CACHE_CTRL    (1 << 1)        /* Allow cache control */
>  #define MMC_CAP2_POWEROFF_NOTIFY (1 << 2)      /* Notify poweroff supported */
>  #define MMC_CAP2_NO_MULTI_READ (1 << 3)        /* Multiblock reads don't work */
> +#define MMC_CAP2_PACKED_CMD    (1 << 4)        /* Allow packed command */
>
>        mmc_pm_flag_t           pm_caps;        /* supported pm features */
>        unsigned int        power_notify_type;
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index 0e71356..1988780 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -138,6 +138,7 @@ static inline bool mmc_op_multi(u32 opcode)
>  #define R1_CURRENT_STATE(x)    ((x & 0x00001E00) >> 9) /* sx, b (4 bits) */
>  #define R1_READY_FOR_DATA      (1 << 8)        /* sx, a */
>  #define R1_SWITCH_ERROR                (1 << 7)        /* sx, c */
> +#define R1_EXP_EVENT           (1 << 6)        /* sr, a */
>  #define R1_APP_CMD             (1 << 5)        /* sr, c */
>
>  #define R1_STATE_IDLE  0
> @@ -273,6 +274,10 @@ struct _mmc_csd {
>  #define EXT_CSD_FLUSH_CACHE            32      /* W */
>  #define EXT_CSD_CACHE_CTRL             33      /* R/W */
>  #define EXT_CSD_POWER_OFF_NOTIFICATION 34      /* R/W */
> +#define EXT_CSD_PACKED_FAILURE_INDEX   35      /* RO */
> +#define EXT_CSD_PACKED_CMD_STATUS      36      /* RO */
> +#define EXT_CSD_EXP_EVENTS_STATUS      54      /* RO, 2 bytes */
> +#define EXT_CSD_EXP_EVENTS_CTRL        56      /* R/W, 2 bytes */
>  #define EXT_CSD_GP_SIZE_MULT           143     /* R/W */
>  #define EXT_CSD_PARTITION_ATTRIBUTE    156     /* R/W */
>  #define EXT_CSD_PARTITION_SUPPORT      160     /* RO */
> @@ -313,6 +318,8 @@ struct _mmc_csd {
>  #define EXT_CSD_POWER_OFF_LONG_TIME    247     /* RO */
>  #define EXT_CSD_GENERIC_CMD6_TIME      248     /* RO */
>  #define EXT_CSD_CACHE_SIZE             249     /* RO, 4 bytes */
> +#define EXT_CSD_MAX_PACKED_WRITES      500     /* RO */
> +#define EXT_CSD_MAX_PACKED_READS       501     /* RO */
>  #define EXT_CSD_HPI_FEATURES           503     /* RO */
>
>  /*
> @@ -364,6 +371,14 @@ struct _mmc_csd {
>  #define EXT_CSD_PWR_CL_4BIT_MASK       0x0F    /* 8 bit PWR CLS */
>  #define EXT_CSD_PWR_CL_8BIT_SHIFT      4
>  #define EXT_CSD_PWR_CL_4BIT_SHIFT      0
> +
> +#define EXT_CSD_PACKED_EVENT_EN        (1<<3)
> +
> +#define EXT_CSD_PACKED_FAILURE (1<<3)
> +
> +#define EXT_CSD_PACKED_GENERIC_ERROR   (1<<0)
> +#define EXT_CSD_PACKED_INDEXED_ERROR   (1<<1)
> +
>  /*
>  * MMC_SWITCH access modes
>  */
> --
> 1.7.2.3
>

It'd be helpful if you split this patch into several smaller ones for
easier review.
Also please copy linux-kernel mailing list for wider review.