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.h b/drivers/mmc/card/queue.h
index e20c27b..031bf63 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -12,6 +12,23 @@
struct mmc_data data;
};
+enum mmc_packed_type {
+ MMC_PACKED_NONE = 0,
+ MMC_PACKED_WRITE,
+};
+
+#define mmc_packed_cmd(type) ((type) != MMC_PACKED_NONE)
+#define mmc_packed_wr(type) ((type) == MMC_PACKED_WRITE)
+
+struct mmc_packed {
+ struct list_head list;
+ u32 cmd_hdr[1024];
+ unsigned int blocks;
+ u8 nr_entries;
+ u8 retries;
+ s16 idx_failure;
+};
+
struct mmc_queue_req {
struct request *req;
struct mmc_blk_request brq;
@@ -20,6 +37,8 @@
struct scatterlist *bounce_sg;
unsigned int bounce_sg_len;
struct mmc_async_req mmc_active;
+ enum mmc_packed_type cmd_type;
+ struct mmc_packed *packed;
};
struct mmc_queue {
@@ -49,4 +68,7 @@
extern void mmc_queue_bounce_pre(struct mmc_queue_req *);
extern void mmc_queue_bounce_post(struct mmc_queue_req *);
+extern int mmc_packed_init(struct mmc_queue *, struct mmc_card *);
+extern void mmc_packed_clean(struct mmc_queue *);
+
#endif