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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 <adrian.hunter@intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Adrian Hunter 2017-11-29 15:41:04 +02:00 committed by Ulf Hansson
parent 81196976ed
commit 1e8e55b670
4 changed files with 326 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

150
drivers/mmc/core/block.c
View File

@ -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);

2
drivers/mmc/core/block.h
View File

@ -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);

162
drivers/mmc/core/queue.c
View File

@ -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);

18
drivers/mmc/core/queue.h
View File

@ -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];
}