From cdf8a6fb48882651049e468e6b16956fb83db86c Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 13 Mar 2017 14:36:35 +0200 Subject: [PATCH] mmc: block: Introduce queue semantics Change from viewing the requests in progress as 'current' and 'previous', to viewing them as a queue. The current request is allocated to the first free slot. The presence of incomplete requests is determined from the count (mq->qcnt) of entries in the queue. Non-read-write requests (i.e. discards and flushes) are not added to the queue at all and require no special handling. Also no special handling is needed for the MMC_BLK_NEW_REQUEST case. As well as allowing an arbitrarily sized queue, the queue thread function is significantly simpler. Signed-off-by: Adrian Hunter Reviewed-by: Linus Walleij Signed-off-by: Ulf Hansson --- drivers/mmc/core/block.c | 66 +++++++++++++++++++++-------------- drivers/mmc/core/queue.c | 75 +++++++++++++++++++++++++--------------- drivers/mmc/core/queue.h | 10 ++++-- 3 files changed, 95 insertions(+), 56 deletions(-) diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index d317e5e9b79a..16c313a62129 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -129,6 +129,13 @@ static inline int mmc_blk_part_switch(struct mmc_card *card, struct mmc_blk_data *md); static int get_card_status(struct mmc_card *card, u32 *status, int retries); +static void mmc_blk_requeue(struct request_queue *q, struct request *req) +{ + spin_lock_irq(q->queue_lock); + blk_requeue_request(q, req); + spin_unlock_irq(q->queue_lock); +} + static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk) { struct mmc_blk_data *md; @@ -1585,11 +1592,14 @@ static bool mmc_blk_rw_cmd_err(struct mmc_blk_data *md, struct mmc_card *card, return req_pending; } -static void mmc_blk_rw_cmd_abort(struct mmc_card *card, struct request *req) +static void mmc_blk_rw_cmd_abort(struct mmc_queue *mq, struct mmc_card *card, + struct request *req, + struct mmc_queue_req *mqrq) { if (mmc_card_removed(card)) req->rq_flags |= RQF_QUIET; while (blk_end_request(req, -EIO, blk_rq_cur_bytes(req))); + mmc_queue_req_free(mq, mqrq); } /** @@ -1609,6 +1619,7 @@ static void mmc_blk_rw_try_restart(struct mmc_queue *mq, struct request *req, if (mmc_card_removed(mq->card)) { req->rq_flags |= RQF_QUIET; blk_end_request_all(req, -EIO); + mmc_queue_req_free(mq, mqrq); return; } /* Else proceed and try to restart the current async request */ @@ -1623,14 +1634,23 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) struct mmc_blk_request *brq; int disable_multi = 0, retry = 0, type, retune_retry_done = 0; enum mmc_blk_status status; - struct mmc_queue_req *mqrq_cur = mq->mqrq_cur; + struct mmc_queue_req *mqrq_cur = NULL; struct mmc_queue_req *mq_rq; struct request *old_req; struct mmc_async_req *new_areq; struct mmc_async_req *old_areq; bool req_pending = true; - if (!new_req && !mq->mqrq_prev->req) + if (new_req) { + mqrq_cur = mmc_queue_req_find(mq, new_req); + if (!mqrq_cur) { + WARN_ON(1); + mmc_blk_requeue(mq->queue, new_req); + new_req = NULL; + } + } + + if (!mq->qcnt) return; do { @@ -1643,7 +1663,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) !IS_ALIGNED(blk_rq_sectors(new_req), 8)) { pr_err("%s: Transfer size is not 4KB sector size aligned\n", new_req->rq_disk->disk_name); - mmc_blk_rw_cmd_abort(card, new_req); + mmc_blk_rw_cmd_abort(mq, card, new_req, mqrq_cur); return; } @@ -1659,8 +1679,6 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) * and there is nothing more to do until it is * complete. */ - if (status == MMC_BLK_NEW_REQUEST) - mq->new_request = true; return; } @@ -1693,7 +1711,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) pr_err("%s BUG rq_tot %d d_xfer %d\n", __func__, blk_rq_bytes(old_req), brq->data.bytes_xfered); - mmc_blk_rw_cmd_abort(card, old_req); + mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq); return; } break; @@ -1701,11 +1719,14 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) req_pending = mmc_blk_rw_cmd_err(md, card, brq, old_req, req_pending); if (mmc_blk_reset(md, card->host, type)) { if (req_pending) - mmc_blk_rw_cmd_abort(card, old_req); + mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq); + else + mmc_queue_req_free(mq, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; } if (!req_pending) { + mmc_queue_req_free(mq, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; } @@ -1718,7 +1739,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) case MMC_BLK_ABORT: if (!mmc_blk_reset(md, card->host, type)) break; - mmc_blk_rw_cmd_abort(card, old_req); + mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; case MMC_BLK_DATA_ERR: { @@ -1728,7 +1749,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) if (!err) break; if (err == -ENODEV) { - mmc_blk_rw_cmd_abort(card, old_req); + mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; } @@ -1750,18 +1771,19 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) req_pending = blk_end_request(old_req, -EIO, brq->data.blksz); if (!req_pending) { + mmc_queue_req_free(mq, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; } break; case MMC_BLK_NOMEDIUM: - mmc_blk_rw_cmd_abort(card, old_req); + mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; default: pr_err("%s: Unhandled return value (%d)", old_req->rq_disk->disk_name, status); - mmc_blk_rw_cmd_abort(card, old_req); + mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq); mmc_blk_rw_try_restart(mq, new_req, mqrq_cur); return; } @@ -1778,6 +1800,8 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req) mq_rq->brq.retune_retry_done = retune_retry_done; } } while (req_pending); + + mmc_queue_req_free(mq, mq_rq); } void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) @@ -1785,9 +1809,8 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) int ret; struct mmc_blk_data *md = mq->blkdata; struct mmc_card *card = md->queue.card; - bool req_is_special = mmc_req_is_special(req); - if (req && !mq->mqrq_prev->req) + if (req && !mq->qcnt) /* claim host only for the first request */ mmc_get_card(card); @@ -1799,20 +1822,19 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) goto out; } - mq->new_request = false; if (req && req_op(req) == REQ_OP_DISCARD) { /* complete ongoing async transfer before issuing discard */ - if (card->host->areq) + if (mq->qcnt) mmc_blk_issue_rw_rq(mq, NULL); mmc_blk_issue_discard_rq(mq, req); } else if (req && req_op(req) == REQ_OP_SECURE_ERASE) { /* complete ongoing async transfer before issuing secure erase*/ - if (card->host->areq) + if (mq->qcnt) mmc_blk_issue_rw_rq(mq, NULL); mmc_blk_issue_secdiscard_rq(mq, req); } else if (req && req_op(req) == REQ_OP_FLUSH) { /* complete ongoing async transfer before issuing flush */ - if (card->host->areq) + if (mq->qcnt) mmc_blk_issue_rw_rq(mq, NULL); mmc_blk_issue_flush(mq, req); } else { @@ -1821,13 +1843,7 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) } out: - if ((!req && !mq->new_request) || req_is_special) - /* - * Release host when there are no more requests - * and after special request(discard, flush) is done. - * In case sepecial request, there is no reentry to - * the 'mmc_blk_issue_rq' with 'mqrq_prev->req'. - */ + if (!mq->qcnt) mmc_put_card(card); } diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 493eb10ce580..4a2045527b62 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -40,6 +40,35 @@ static int mmc_prep_request(struct request_queue *q, struct request *req) return BLKPREP_OK; } +struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *mq, + struct request *req) +{ + struct mmc_queue_req *mqrq; + int i = ffz(mq->qslots); + + if (i >= mq->qdepth) + return NULL; + + mqrq = &mq->mqrq[i]; + WARN_ON(mqrq->req || mq->qcnt >= mq->qdepth || + test_bit(mqrq->task_id, &mq->qslots)); + mqrq->req = req; + mq->qcnt += 1; + __set_bit(mqrq->task_id, &mq->qslots); + + return mqrq; +} + +void mmc_queue_req_free(struct mmc_queue *mq, + struct mmc_queue_req *mqrq) +{ + WARN_ON(!mqrq->req || mq->qcnt < 1 || + !test_bit(mqrq->task_id, &mq->qslots)); + mqrq->req = NULL; + mq->qcnt -= 1; + __clear_bit(mqrq->task_id, &mq->qslots); +} + static int mmc_queue_thread(void *d) { struct mmc_queue *mq = d; @@ -50,7 +79,7 @@ static int mmc_queue_thread(void *d) down(&mq->thread_sem); do { - struct request *req = NULL; + struct request *req; spin_lock_irq(q->queue_lock); set_current_state(TASK_INTERRUPTIBLE); @@ -63,38 +92,17 @@ static int mmc_queue_thread(void *d) * Dispatch queue is empty so set flags for * mmc_request_fn() to wake us up. */ - if (mq->mqrq_prev->req) + if (mq->qcnt) cntx->is_waiting_last_req = true; else mq->asleep = true; } - mq->mqrq_cur->req = req; spin_unlock_irq(q->queue_lock); - if (req || mq->mqrq_prev->req) { - bool req_is_special = mmc_req_is_special(req); - + if (req || mq->qcnt) { set_current_state(TASK_RUNNING); mmc_blk_issue_rq(mq, req); cond_resched(); - if (mq->new_request) { - mq->new_request = false; - continue; /* fetch again */ - } - - /* - * Current request becomes previous request - * and vice versa. - * In case of special requests, current request - * has been finished. Do not assign it to previous - * request. - */ - if (req_is_special) - mq->mqrq_cur->req = NULL; - - mq->mqrq_prev->brq.mrq.data = NULL; - mq->mqrq_prev->req = NULL; - swap(mq->mqrq_prev, mq->mqrq_cur); } else { if (kthread_should_stop()) { set_current_state(TASK_RUNNING); @@ -177,6 +185,20 @@ static void mmc_queue_setup_discard(struct request_queue *q, queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q); } +static struct mmc_queue_req *mmc_queue_alloc_mqrqs(int qdepth) +{ + struct mmc_queue_req *mqrq; + int i; + + mqrq = kcalloc(qdepth, sizeof(*mqrq), GFP_KERNEL); + if (mqrq) { + for (i = 0; i < qdepth; i++) + mqrq[i].task_id = i; + } + + return mqrq; +} + #ifdef CONFIG_MMC_BLOCK_BOUNCE static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq, unsigned int bouncesz) @@ -279,12 +301,9 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, return -ENOMEM; mq->qdepth = 2; - mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req), - GFP_KERNEL); + mq->mqrq = mmc_queue_alloc_mqrqs(mq->qdepth); if (!mq->mqrq) goto blk_cleanup; - mq->mqrq_cur = &mq->mqrq[0]; - mq->mqrq_prev = &mq->mqrq[1]; mq->queue->queuedata = mq; blk_queue_prep_rq(mq->queue, mmc_prep_request); diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h index e298f100101b..967808df45b8 100644 --- a/drivers/mmc/core/queue.h +++ b/drivers/mmc/core/queue.h @@ -34,21 +34,21 @@ struct mmc_queue_req { struct scatterlist *bounce_sg; unsigned int bounce_sg_len; struct mmc_async_req areq; + int task_id; }; struct mmc_queue { struct mmc_card *card; struct task_struct *thread; struct semaphore thread_sem; - bool new_request; bool suspended; bool asleep; struct mmc_blk_data *blkdata; struct request_queue *queue; struct mmc_queue_req *mqrq; - struct mmc_queue_req *mqrq_cur; - struct mmc_queue_req *mqrq_prev; int qdepth; + int qcnt; + unsigned long qslots; }; extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *, @@ -64,4 +64,8 @@ extern void mmc_queue_bounce_post(struct mmc_queue_req *); extern int mmc_access_rpmb(struct mmc_queue *); +extern struct mmc_queue_req *mmc_queue_req_find(struct mmc_queue *, + struct request *); +extern void mmc_queue_req_free(struct mmc_queue *, struct mmc_queue_req *); + #endif -- 2.20.1