mmc: support packed write command for eMMC4.5 devices
This patch supports packed write command of eMMC4.5 devices. Several
writes can be grouped in packed command and all data of the individual
commands can be sent in a single transfer on the bus. Large amounts of
data in one transfer rather than several data of small size are
effective for eMMC write internally. As a result, packed command help
write throughput be improved. The following tables show the results
of packed write.
Type A:
test none | packed
iozone 25.8 | 31
tiotest 27.6 | 31.2
lmdd 31.2 | 35.4
Type B:
test none | packed
iozone 44.1 | 51.1
tiotest 47.9 | 52.5
lmdd 51.6 | 59.2
Type C:
test none | packed
iozone 19.5 | 32
tiotest 19.9 | 34.5
lmdd 22.8 | 40.7
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 5e09710..fa4e44e 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -362,6 +362,49 @@
}
EXPORT_SYMBOL(mmc_cleanup_queue);
+int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
+{
+ struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
+ struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
+ int ret = 0;
+
+
+ mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
+ if (!mqrq_cur->packed) {
+ pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
+ mmc_card_name(card));
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
+ if (!mqrq_prev->packed) {
+ pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
+ mmc_card_name(card));
+ kfree(mqrq_cur->packed);
+ mqrq_cur->packed = NULL;
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ INIT_LIST_HEAD(&mqrq_cur->packed->list);
+ INIT_LIST_HEAD(&mqrq_prev->packed->list);
+
+out:
+ return ret;
+}
+
+void mmc_packed_clean(struct mmc_queue *mq)
+{
+ struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
+ struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
+
+ kfree(mqrq_cur->packed);
+ mqrq_cur->packed = NULL;
+ kfree(mqrq_prev->packed);
+ mqrq_prev->packed = NULL;
+}
+
/**
* mmc_queue_suspend - suspend a MMC request queue
* @mq: MMC queue to suspend
@@ -406,6 +449,41 @@
}
}
+static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
+ struct mmc_packed *packed,
+ struct scatterlist *sg,
+ enum mmc_packed_type cmd_type)
+{
+ struct scatterlist *__sg = sg;
+ unsigned int sg_len = 0;
+ struct request *req;
+
+ if (mmc_packed_wr(cmd_type)) {
+ unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
+ unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
+ unsigned int len, remain, offset = 0;
+ u8 *buf = (u8 *)packed->cmd_hdr;
+
+ remain = hdr_sz;
+ do {
+ len = min(remain, max_seg_sz);
+ sg_set_buf(__sg, buf + offset, len);
+ offset += len;
+ remain -= len;
+ (__sg++)->page_link &= ~0x02;
+ sg_len++;
+ } while (remain);
+ }
+
+ list_for_each_entry(req, &packed->list, queuelist) {
+ sg_len += blk_rq_map_sg(mq->queue, req, __sg);
+ __sg = sg + (sg_len - 1);
+ (__sg++)->page_link &= ~0x02;
+ }
+ sg_mark_end(sg + (sg_len - 1));
+ return sg_len;
+}
+
/*
* Prepare the sg list(s) to be handed of to the host driver
*/
@@ -414,14 +492,26 @@
unsigned int sg_len;
size_t buflen;
struct scatterlist *sg;
+ enum mmc_packed_type cmd_type;
int i;
- if (!mqrq->bounce_buf)
- return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
+ cmd_type = mqrq->cmd_type;
+
+ if (!mqrq->bounce_buf) {
+ if (mmc_packed_cmd(cmd_type))
+ return mmc_queue_packed_map_sg(mq, mqrq->packed,
+ mqrq->sg, cmd_type);
+ else
+ return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
+ }
BUG_ON(!mqrq->bounce_sg);
- sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
+ if (mmc_packed_cmd(cmd_type))
+ sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
+ mqrq->bounce_sg, cmd_type);
+ else
+ sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
mqrq->bounce_sg_len = sg_len;