GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

mmc: block: Add CQE support

Browse source 
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
Download patch file Download diff file Expand all files Collapse all files

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);