From 1e8e55b67030c6a2fef893d428bdcd611f73705c Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 29 Nov 2017 15:41:04 +0200 Subject: [PATCH] mmc: block: Add CQE support Add CQE support to the block driver, including: - optionally using DCMD for flush requests - "manually" issuing discard requests - issuing read / write requests to the CQE - supporting block-layer timeouts - handling recovery - supporting re-tuning CQE offers 25% - 50% better random multi-threaded I/O. There is a slight (e.g. 2%) drop in sequential read speed but no observable change to sequential write. CQE automatically sends the commands to complete requests. However it only supports reads / writes and so-called "direct commands" (DCMD). Furthermore DCMD is limited to one command at a time, but discards require 3 commands. That makes issuing discards through CQE very awkward, but some CQE's don't support DCMD anyway. So for discards, the existing non-CQE approach is taken, where the mmc core code issues the 3 commands one at a time i.e. mmc_erase(). Where DCMD is used, is for issuing flushes. Signed-off-by: Adrian Hunter Acked-by: Linus Walleij Signed-off-by: Ulf Hansson Tested-by: Linus Walleij --- drivers/mmc/core/block.c | 150 ++++++++++++++++++++++++++++++++++++++++++- drivers/mmc/core/block.h | 2 + drivers/mmc/core/queue.c | 162 +++++++++++++++++++++++++++++++++++++++++++++-- drivers/mmc/core/queue.h | 18 ++++++ 4 files changed, 326 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c index 7874c3b..7275ac5 100644 --- a/drivers/mmc/core/block.c +++ b/drivers/mmc/core/block.c @@ -112,6 +112,7 @@ struct mmc_blk_data { #define MMC_BLK_WRITE BIT(1) #define MMC_BLK_DISCARD BIT(2) #define MMC_BLK_SECDISCARD BIT(3) +#define MMC_BLK_CQE_RECOVERY BIT(4) /* * Only set in main mmc_blk_data associated @@ -1730,6 +1731,138 @@ static void mmc_blk_data_prep(struct mmc_queue *mq, struct mmc_queue_req *mqrq, *do_data_tag_p = do_data_tag; } +#define MMC_CQE_RETRIES 2 + +static void mmc_blk_cqe_complete_rq(struct mmc_queue *mq, struct request *req) +{ + struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req); + struct mmc_request *mrq = &mqrq->brq.mrq; + struct request_queue *q = req->q; + struct mmc_host *host = mq->card->host; + unsigned long flags; + bool put_card; + int err; + + mmc_cqe_post_req(host, mrq); + + if (mrq->cmd && mrq->cmd->error) + err = mrq->cmd->error; + else if (mrq->data && mrq->data->error) + err = mrq->data->error; + else + err = 0; + + if (err) { + if (mqrq->retries++ < MMC_CQE_RETRIES) + blk_mq_requeue_request(req, true); + else + blk_mq_end_request(req, BLK_STS_IOERR); + } else if (mrq->data) { + if (blk_update_request(req, BLK_STS_OK, mrq->data->bytes_xfered)) + blk_mq_requeue_request(req, true); + else + __blk_mq_end_request(req, BLK_STS_OK); + } else { + blk_mq_end_request(req, BLK_STS_OK); + } + + spin_lock_irqsave(q->queue_lock, flags); + + mq->in_flight[mmc_issue_type(mq, req)] -= 1; + + put_card = (mmc_tot_in_flight(mq) == 0); + + mmc_cqe_check_busy(mq); + + spin_unlock_irqrestore(q->queue_lock, flags); + + if (!mq->cqe_busy) + blk_mq_run_hw_queues(q, true); + + if (put_card) + mmc_put_card(mq->card, &mq->ctx); +} + +void mmc_blk_cqe_recovery(struct mmc_queue *mq) +{ + struct mmc_card *card = mq->card; + struct mmc_host *host = card->host; + int err; + + pr_debug("%s: CQE recovery start\n", mmc_hostname(host)); + + err = mmc_cqe_recovery(host); + if (err) + mmc_blk_reset(mq->blkdata, host, MMC_BLK_CQE_RECOVERY); + else + mmc_blk_reset_success(mq->blkdata, MMC_BLK_CQE_RECOVERY); + + pr_debug("%s: CQE recovery done\n", mmc_hostname(host)); +} + +static void mmc_blk_cqe_req_done(struct mmc_request *mrq) +{ + struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req, + brq.mrq); + struct request *req = mmc_queue_req_to_req(mqrq); + struct request_queue *q = req->q; + struct mmc_queue *mq = q->queuedata; + + /* + * Block layer timeouts race with completions which means the normal + * completion path cannot be used during recovery. + */ + if (mq->in_recovery) + mmc_blk_cqe_complete_rq(mq, req); + else + blk_mq_complete_request(req); +} + +static int mmc_blk_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq) +{ + mrq->done = mmc_blk_cqe_req_done; + mrq->recovery_notifier = mmc_cqe_recovery_notifier; + + return mmc_cqe_start_req(host, mrq); +} + +static struct mmc_request *mmc_blk_cqe_prep_dcmd(struct mmc_queue_req *mqrq, + struct request *req) +{ + struct mmc_blk_request *brq = &mqrq->brq; + + memset(brq, 0, sizeof(*brq)); + + brq->mrq.cmd = &brq->cmd; + brq->mrq.tag = req->tag; + + return &brq->mrq; +} + +static int mmc_blk_cqe_issue_flush(struct mmc_queue *mq, struct request *req) +{ + struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req); + struct mmc_request *mrq = mmc_blk_cqe_prep_dcmd(mqrq, req); + + mrq->cmd->opcode = MMC_SWITCH; + mrq->cmd->arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) | + (EXT_CSD_FLUSH_CACHE << 16) | + (1 << 8) | + EXT_CSD_CMD_SET_NORMAL; + mrq->cmd->flags = MMC_CMD_AC | MMC_RSP_R1B; + + return mmc_blk_cqe_start_req(mq->card->host, mrq); +} + +static int mmc_blk_cqe_issue_rw_rq(struct mmc_queue *mq, struct request *req) +{ + struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req); + + mmc_blk_data_prep(mq, mqrq, 0, NULL, NULL); + + return mmc_blk_cqe_start_req(mq->card->host, &mqrq->brq.mrq); +} + static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq, struct mmc_card *card, int disable_multi, @@ -2038,7 +2171,10 @@ void mmc_blk_mq_complete(struct request *req) { struct mmc_queue *mq = req->q->queuedata; - mmc_blk_mq_complete_rq(mq, req); + if (mq->use_cqe) + mmc_blk_cqe_complete_rq(mq, req); + else + mmc_blk_mq_complete_rq(mq, req); } static void mmc_blk_mq_poll_completion(struct mmc_queue *mq, @@ -2212,6 +2348,9 @@ out_post_req: static int mmc_blk_wait_for_idle(struct mmc_queue *mq, struct mmc_host *host) { + if (mq->use_cqe) + return host->cqe_ops->cqe_wait_for_idle(host); + return mmc_blk_rw_wait(mq, NULL); } @@ -2250,11 +2389,18 @@ enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req) return MMC_REQ_FAILED_TO_START; } return MMC_REQ_FINISHED; + case MMC_ISSUE_DCMD: case MMC_ISSUE_ASYNC: switch (req_op(req)) { + case REQ_OP_FLUSH: + ret = mmc_blk_cqe_issue_flush(mq, req); + break; case REQ_OP_READ: case REQ_OP_WRITE: - ret = mmc_blk_mq_issue_rw_rq(mq, req); + if (mq->use_cqe) + ret = mmc_blk_cqe_issue_rw_rq(mq, req); + else + ret = mmc_blk_mq_issue_rw_rq(mq, req); break; default: WARN_ON_ONCE(1); diff --git a/drivers/mmc/core/block.h b/drivers/mmc/core/block.h index 6d34e87..f472ce5 100644 --- a/drivers/mmc/core/block.h +++ b/drivers/mmc/core/block.h @@ -7,6 +7,8 @@ struct request; void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req); +void mmc_blk_cqe_recovery(struct mmc_queue *mq); + enum mmc_issued; enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req); diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 54bec4c..8d632d2 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -40,18 +40,142 @@ static int mmc_prep_request(struct request_queue *q, struct request *req) return BLKPREP_OK; } +static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq) +{ + /* Allow only 1 DCMD at a time */ + return mq->in_flight[MMC_ISSUE_DCMD]; +} + +void mmc_cqe_check_busy(struct mmc_queue *mq) +{ + if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq)) + mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY; + + mq->cqe_busy &= ~MMC_CQE_QUEUE_FULL; +} + +static inline bool mmc_cqe_can_dcmd(struct mmc_host *host) +{ + return host->caps2 & MMC_CAP2_CQE_DCMD; +} + +enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host, + struct request *req) +{ + switch (req_op(req)) { + case REQ_OP_DRV_IN: + case REQ_OP_DRV_OUT: + case REQ_OP_DISCARD: + case REQ_OP_SECURE_ERASE: + return MMC_ISSUE_SYNC; + case REQ_OP_FLUSH: + return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC; + default: + return MMC_ISSUE_ASYNC; + } +} + enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req) { + struct mmc_host *host = mq->card->host; + + if (mq->use_cqe) + return mmc_cqe_issue_type(host, req); + if (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE) return MMC_ISSUE_ASYNC; return MMC_ISSUE_SYNC; } +static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq) +{ + if (!mq->recovery_needed) { + mq->recovery_needed = true; + schedule_work(&mq->recovery_work); + } +} + +void mmc_cqe_recovery_notifier(struct mmc_request *mrq) +{ + struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req, + brq.mrq); + struct request *req = mmc_queue_req_to_req(mqrq); + struct request_queue *q = req->q; + struct mmc_queue *mq = q->queuedata; + unsigned long flags; + + spin_lock_irqsave(q->queue_lock, flags); + __mmc_cqe_recovery_notifier(mq); + spin_unlock_irqrestore(q->queue_lock, flags); +} + +static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req) +{ + struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req); + struct mmc_request *mrq = &mqrq->brq.mrq; + struct mmc_queue *mq = req->q->queuedata; + struct mmc_host *host = mq->card->host; + enum mmc_issue_type issue_type = mmc_issue_type(mq, req); + bool recovery_needed = false; + + switch (issue_type) { + case MMC_ISSUE_ASYNC: + case MMC_ISSUE_DCMD: + if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) { + if (recovery_needed) + __mmc_cqe_recovery_notifier(mq); + return BLK_EH_RESET_TIMER; + } + /* No timeout */ + return BLK_EH_HANDLED; + default: + /* Timeout is handled by mmc core */ + return BLK_EH_RESET_TIMER; + } +} + static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req, bool reserved) { - return BLK_EH_RESET_TIMER; + struct request_queue *q = req->q; + struct mmc_queue *mq = q->queuedata; + unsigned long flags; + int ret; + + spin_lock_irqsave(q->queue_lock, flags); + + if (mq->recovery_needed || !mq->use_cqe) + ret = BLK_EH_RESET_TIMER; + else + ret = mmc_cqe_timed_out(req); + + spin_unlock_irqrestore(q->queue_lock, flags); + + return ret; +} + +static void mmc_mq_recovery_handler(struct work_struct *work) +{ + struct mmc_queue *mq = container_of(work, struct mmc_queue, + recovery_work); + struct request_queue *q = mq->queue; + + mmc_get_card(mq->card, &mq->ctx); + + mq->in_recovery = true; + + mmc_blk_cqe_recovery(mq); + + mq->in_recovery = false; + + spin_lock_irq(q->queue_lock); + mq->recovery_needed = false; + spin_unlock_irq(q->queue_lock); + + mmc_put_card(mq->card, &mq->ctx); + + blk_mq_run_hw_queues(q, true); } static int mmc_queue_thread(void *d) @@ -223,9 +347,10 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, struct request_queue *q = req->q; struct mmc_queue *mq = q->queuedata; struct mmc_card *card = mq->card; + struct mmc_host *host = card->host; enum mmc_issue_type issue_type; enum mmc_issued issued; - bool get_card; + bool get_card, cqe_retune_ok; int ret; if (mmc_card_removed(mq->card)) { @@ -237,7 +362,19 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, spin_lock_irq(q->queue_lock); + if (mq->recovery_needed) { + spin_unlock_irq(q->queue_lock); + return BLK_STS_RESOURCE; + } + switch (issue_type) { + case MMC_ISSUE_DCMD: + if (mmc_cqe_dcmd_busy(mq)) { + mq->cqe_busy |= MMC_CQE_DCMD_BUSY; + spin_unlock_irq(q->queue_lock); + return BLK_STS_RESOURCE; + } + break; case MMC_ISSUE_ASYNC: break; default: @@ -254,6 +391,7 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, mq->in_flight[issue_type] += 1; get_card = (mmc_tot_in_flight(mq) == 1); + cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1); spin_unlock_irq(q->queue_lock); @@ -265,6 +403,11 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, if (get_card) mmc_get_card(card, &mq->ctx); + if (mq->use_cqe) { + host->retune_now = host->need_retune && cqe_retune_ok && + !host->hold_retune; + } + blk_mq_start_request(req); issued = mmc_blk_mq_issue_rq(mq, req); @@ -326,6 +469,7 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) /* Initialize thread_sem even if it is not used */ sema_init(&mq->thread_sem, 1); + INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler); INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work); mutex_init(&mq->complete_lock); @@ -375,10 +519,18 @@ free_tag_set: static int mmc_mq_init(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock) { + struct mmc_host *host = card->host; int q_depth; int ret; - q_depth = MMC_QUEUE_DEPTH; + /* + * The queue depth for CQE must match the hardware because the request + * tag is used to index the hardware queue. + */ + if (mq->use_cqe) + q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth); + else + q_depth = MMC_QUEUE_DEPTH; ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_ops, lock); if (ret) @@ -408,7 +560,9 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, mq->card = card; - if (mmc_host_use_blk_mq(host)) + mq->use_cqe = host->cqe_enabled; + + if (mq->use_cqe || mmc_host_use_blk_mq(host)) return mmc_mq_init(mq, card, lock); mq->queue = blk_alloc_queue(GFP_KERNEL); diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h index ce92498..1d7d3b0 100644 --- a/drivers/mmc/core/queue.h +++ b/drivers/mmc/core/queue.h @@ -17,6 +17,7 @@ enum mmc_issued { enum mmc_issue_type { MMC_ISSUE_SYNC, + MMC_ISSUE_DCMD, MMC_ISSUE_ASYNC, MMC_ISSUE_MAX, }; @@ -92,8 +93,15 @@ struct mmc_queue { int qcnt; int in_flight[MMC_ISSUE_MAX]; + unsigned int cqe_busy; +#define MMC_CQE_DCMD_BUSY BIT(0) +#define MMC_CQE_QUEUE_FULL BIT(1) + bool use_cqe; + bool recovery_needed; + bool in_recovery; bool rw_wait; bool waiting; + struct work_struct recovery_work; wait_queue_head_t wait; struct request *complete_req; struct mutex complete_lock; @@ -108,11 +116,21 @@ extern void mmc_queue_resume(struct mmc_queue *); extern unsigned int mmc_queue_map_sg(struct mmc_queue *, struct mmc_queue_req *); +void mmc_cqe_check_busy(struct mmc_queue *mq); +void mmc_cqe_recovery_notifier(struct mmc_request *mrq); + enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req); static inline int mmc_tot_in_flight(struct mmc_queue *mq) { return mq->in_flight[MMC_ISSUE_SYNC] + + mq->in_flight[MMC_ISSUE_DCMD] + + mq->in_flight[MMC_ISSUE_ASYNC]; +} + +static inline int mmc_cqe_qcnt(struct mmc_queue *mq) +{ + return mq->in_flight[MMC_ISSUE_DCMD] + mq->in_flight[MMC_ISSUE_ASYNC]; } -- 2.7.4