[PATCH RFC 02/39] mmc: queue: Share mmc request array between partitions

Adrian Hunter
2017-02-10T13:24:16Z

eMMC can have multiple internal partitions that are represented as separate
disks / queues. However switching between partitions is only done when the
queue is empty. Consequently the array of mmc requests that are queued can
be shared between partitions saving memory.

Keep a pointer to the mmc request queue on the card, and use that instead
of allocating a new one for each partition.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/core/block.c | 11 ++-
drivers/mmc/core/queue.c | 235 ++++++++++++++++++++++++++++-------------------
drivers/mmc/core/queue.h | 2 +
include/linux/mmc/card.h | 5 +
4 files changed, 156 insertions(+), 97 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 061133f3b0b2..b6d1497c395f 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2187,6 +2187,7 @@ static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md, *part_md;
char cap_str[10];
+ int ret;

/*
* Check that the card supports the command class(es) we need.
@@ -2196,9 +2197,15 @@ static int mmc_blk_probe(struct mmc_card *card)

mmc_fixup_device(card, blk_fixups);

+ ret = mmc_queue_alloc_shared_queue(card);
+ if (ret)
+ return ret;
+
md = mmc_blk_alloc(card);
- if (IS_ERR(md))
+ if (IS_ERR(md)) {
+ mmc_queue_free_shared_queue(card);
return PTR_ERR(md);
+ }

string_get_size((u64)get_capacity(md->disk), 512, STRING_UNITS_2,
cap_str, sizeof(cap_str));
@@ -2236,6 +2243,7 @@ static int mmc_blk_probe(struct mmc_card *card)
out:
mmc_blk_remove_parts(card, md);
mmc_blk_remove_req(md);
+ mmc_queue_free_shared_queue(card);
return 0;
}

@@ -2253,6 +2261,7 @@ static void mmc_blk_remove(struct mmc_card *card)
pm_runtime_put_noidle(&card->dev);
mmc_blk_remove_req(md);
dev_set_drvdata(&card->dev, NULL);
+ mmc_queue_free_shared_queue(card);
}

static int _mmc_blk_suspend(struct mmc_card *card)
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 5cb369c2664b..031553c9be04 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -150,17 +150,13 @@ static void mmc_request_fn(struct request_queue *q)
wake_up_process(mq->thread);
}

-static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
+static struct scatterlist *mmc_alloc_sg(int sg_len)
{
struct scatterlist *sg;

sg = kmalloc_array(sg_len, sizeof(*sg), GFP_KERNEL);
- if (!sg)
- *err = -ENOMEM;
- else {
- *err = 0;
+ if (sg)
sg_init_table(sg, sg_len);
- }

return sg;
}
@@ -186,80 +182,164 @@ static void mmc_queue_setup_discard(struct request_queue *q,
queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q);
}

+static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
+{
+ kfree(mqrq->bounce_sg);
+ mqrq->bounce_sg = NULL;
+
+ kfree(mqrq->sg);
+ mqrq->sg = NULL;
+
+ kfree(mqrq->bounce_buf);
+ mqrq->bounce_buf = NULL;
+}
+
+static void mmc_queue_reqs_free_bufs(struct mmc_queue_req *mqrq, int qdepth)
+{
+ int i;
+
+ for (i = 0; i < qdepth; i++)
+ mmc_queue_req_free_bufs(&mqrq[i]);
+}
+
+static void mmc_queue_free_mqrqs(struct mmc_queue_req *mqrq, int qdepth)
+{
+ mmc_queue_reqs_free_bufs(mqrq, qdepth);
+ kfree(mqrq);
+}
+
#ifdef CONFIG_MMC_BLOCK_BOUNCE
-static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
- unsigned int bouncesz)
+static int mmc_queue_alloc_bounce_bufs(struct mmc_queue_req *mqrq, int qdepth,
+ unsigned int bouncesz)
{
int i;

- for (i = 0; i < mq->qdepth; i++) {
- mq->mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
- if (!mq->mqrq[i].bounce_buf)
- goto out_err;
- }
+ for (i = 0; i < qdepth; i++) {
+ mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+ if (!mqrq[i].bounce_buf)
+ return -ENOMEM;

- return true;
+ mqrq[i].sg = mmc_alloc_sg(1);
+ if (!mqrq[i].sg)
+ return -ENOMEM;

-out_err:
- while (--i >= 0) {
- kfree(mq->mqrq[i].bounce_buf);
- mq->mqrq[i].bounce_buf = NULL;
+ mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512);
+ if (!mqrq[i].bounce_sg)
+ return -ENOMEM;
}
- pr_warn("%s: unable to allocate bounce buffers\n",
- mmc_card_name(mq->card));
- return false;
+
+ return 0;
}

-static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
- unsigned int bouncesz)
+static bool mmc_queue_alloc_bounce(struct mmc_queue_req *mqrq, int qdepth,
+ unsigned int bouncesz)
{
- int i, ret;
+ int ret;

- for (i = 0; i < mq->qdepth; i++) {
- mq->mqrq[i].sg = mmc_alloc_sg(1, &ret);
- if (ret)
- return ret;
+ ret = mmc_queue_alloc_bounce_bufs(mqrq, qdepth, bouncesz);
+ if (ret)
+ mmc_queue_reqs_free_bufs(mqrq, qdepth);

- mq->mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
- if (ret)
- return ret;
- }
+ return !ret;
+}
+
+static unsigned int mmc_queue_calc_bouncesz(struct mmc_host *host)
+{
+ unsigned int bouncesz = MMC_QUEUE_BOUNCESZ;
+
+ if (host->max_segs != 1)
+ return 0;
+
+ if (bouncesz > host->max_req_size)
+ bouncesz = host->max_req_size;
+ if (bouncesz > host->max_seg_size)
+ bouncesz = host->max_seg_size;
+ if (bouncesz > host->max_blk_count * 512)
+ bouncesz = host->max_blk_count * 512;
+
+ if (bouncesz <= 512)
+ return 0;
+
+ return bouncesz;
+}
+#else
+static inline bool mmc_queue_alloc_bounce(struct mmc_queue_req *mqrq,
+ int qdepth, unsigned int bouncesz)
+{
+ return false;
+}

+static unsigned int mmc_queue_calc_bouncesz(struct mmc_host *host)
+{
return 0;
}
#endif

-static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
+static int mmc_queue_alloc_sgs(struct mmc_queue_req *mqrq, int qdepth,
+ int max_segs)
{
- int i, ret;
+ int i;

- for (i = 0; i < mq->qdepth; i++) {
- mq->mqrq[i].sg = mmc_alloc_sg(max_segs, &ret);
- if (ret)
- return ret;
+ for (i = 0; i < qdepth; i++) {
+ mqrq[i].sg = mmc_alloc_sg(max_segs);
+ if (!mqrq[i].sg)
+ return -ENOMEM;
}

return 0;
}

-static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
+void mmc_queue_free_shared_queue(struct mmc_card *card)
{
- kfree(mqrq->bounce_sg);
- mqrq->bounce_sg = NULL;
+ if (card->mqrq) {
+ mmc_queue_free_mqrqs(card->mqrq, card->qdepth);
+ card->mqrq = NULL;
+ }
+}

- kfree(mqrq->sg);
- mqrq->sg = NULL;
+static int __mmc_queue_alloc_shared_queue(struct mmc_card *card, int qdepth)
+{
+ struct mmc_host *host = card->host;
+ struct mmc_queue_req *mqrq;
+ unsigned int bouncesz;
+ int ret = 0;

- kfree(mqrq->bounce_buf);
- mqrq->bounce_buf = NULL;
+ if (card->mqrq)
+ return -EINVAL;
+
+ mqrq = kcalloc(qdepth, sizeof(*mqrq), GFP_KERNEL);
+ if (!mqrq)
+ return -ENOMEM;
+
+ card->mqrq = mqrq;
+ card->qdepth = qdepth;
+
+ bouncesz = mmc_queue_calc_bouncesz(host);
+
+ if (bouncesz && !mmc_queue_alloc_bounce(mqrq, qdepth, bouncesz)) {
+ bouncesz = 0;
+ pr_warn("%s: unable to allocate bounce buffers\n",
+ mmc_card_name(card));
+ }
+
+ card->bouncesz = bouncesz;
+
+ if (!bouncesz) {
+ ret = mmc_queue_alloc_sgs(mqrq, qdepth, host->max_segs);
+ if (ret)
+ goto out_err;
+ }
+
+ return ret;
+
+out_err:
+ mmc_queue_free_shared_queue(card);
+ return ret;
}

-static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq)
+int mmc_queue_alloc_shared_queue(struct mmc_card *card)
{
- int i;
-
- for (i = 0; i < mq->qdepth; i++)
- mmc_queue_req_free_bufs(&mq->mqrq[i]);
+ return __mmc_queue_alloc_shared_queue(card, 2);
}

/**
@@ -276,7 +356,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
{
struct mmc_host *host = card->host;
u64 limit = BLK_BOUNCE_HIGH;
- bool bounce = false;
int ret = -ENOMEM;

if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
@@ -287,11 +366,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
if (!mq->queue)
return -ENOMEM;

- mq->qdepth = 2;
- mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req),
- GFP_KERNEL);
- if (!mq->mqrq)
- goto blk_cleanup;
+ mq->mqrq = card->mqrq;
+ mq->qdepth = card->qdepth;
mq->mqrq_cur = &mq->mqrq[0];
mq->mqrq_prev = &mq->mqrq[1];
mq->queue->queuedata = mq;
@@ -302,44 +378,17 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
if (mmc_can_erase(card))
mmc_queue_setup_discard(mq->queue, card);

-#ifdef CONFIG_MMC_BLOCK_BOUNCE
- if (host->max_segs == 1) {
- unsigned int bouncesz;
-
- bouncesz = MMC_QUEUE_BOUNCESZ;
-
- if (bouncesz > host->max_req_size)
- bouncesz = host->max_req_size;
- if (bouncesz > host->max_seg_size)
- bouncesz = host->max_seg_size;
- if (bouncesz > (host->max_blk_count * 512))
- bouncesz = host->max_blk_count * 512;
-
- if (bouncesz > 512 &&
- mmc_queue_alloc_bounce_bufs(mq, bouncesz)) {
- blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
- blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
- blk_queue_max_segments(mq->queue, bouncesz / 512);
- blk_queue_max_segment_size(mq->queue, bouncesz);
-
- ret = mmc_queue_alloc_bounce_sgs(mq, bouncesz);
- if (ret)
- goto cleanup_queue;
- bounce = true;
- }
- }
-#endif
-
- if (!bounce) {
+ if (card->bouncesz) {
+ blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
+ blk_queue_max_hw_sectors(mq->queue, card->bouncesz / 512);
+ blk_queue_max_segments(mq->queue, card->bouncesz / 512);
+ blk_queue_max_segment_size(mq->queue, card->bouncesz);
+ } else {
blk_queue_bounce_limit(mq->queue, limit);
blk_queue_max_hw_sectors(mq->queue,
min(host->max_blk_count, host->max_req_size / 512));
blk_queue_max_segments(mq->queue, host->max_segs);
blk_queue_max_segment_size(mq->queue, host->max_seg_size);
-
- ret = mmc_queue_alloc_sgs(mq, host->max_segs);
- if (ret)
- goto cleanup_queue;
}

sema_init(&mq->thread_sem, 1);
@@ -354,11 +403,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,

return 0;

- cleanup_queue:
- mmc_queue_reqs_free_bufs(mq);
- kfree(mq->mqrq);
+cleanup_queue:
mq->mqrq = NULL;
-blk_cleanup:
blk_cleanup_queue(mq->queue);
return ret;
}
@@ -380,10 +426,7 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
blk_start_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);

- mmc_queue_reqs_free_bufs(mq);
- kfree(mq->mqrq);
mq->mqrq = NULL;
-
mq->card = NULL;
}
EXPORT_SYMBOL(mmc_cleanup_queue);
diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
index e298f100101b..298ead2b4245 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -51,6 +51,8 @@ struct mmc_queue {
int qdepth;
};

+extern int mmc_queue_alloc_shared_queue(struct mmc_card *card);
+extern void mmc_queue_free_shared_queue(struct mmc_card *card);
extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
const char *);
extern void mmc_cleanup_queue(struct mmc_queue *);
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 77e61e0a216a..119ef8f0155c 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -208,6 +208,7 @@ struct sdio_cis {
struct mmc_host;
struct sdio_func;
struct sdio_func_tuple;
+struct mmc_queue_req;

#define SDIO_MAX_FUNCS 7

@@ -300,6 +301,10 @@ struct mmc_card {
struct dentry *debugfs_root;
struct mmc_part part[MMC_NUM_PHY_PARTITION]; /* physical partitions */
unsigned int nr_parts;
+
+ struct mmc_queue_req *mqrq; /* Shared queue structure */
+ unsigned int bouncesz; /* Bounce buffer size */
+ int qdepth; /* Shared queue depth */
};

static inline bool mmc_large_sector(struct mmc_card *card)
--
1.9.1