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>
This commit is contained in:
Seungwon Jeon
2013-02-06 17:02:46 +09:00
committed by Chris Ball
parent abd9ac1449
commit ce39f9d17c
7 changed files with 571 additions and 17 deletions

View File

@@ -18,6 +18,9 @@ struct mmc_request;
struct mmc_command {
u32 opcode;
u32 arg;
#define MMC_CMD23_ARG_REL_WR (1 << 31)
#define MMC_CMD23_ARG_PACKED ((0 << 31) | (1 << 30))
#define MMC_CMD23_ARG_TAG_REQ (1 << 29)
u32 resp[4];
unsigned int flags; /* expected response type */
#define MMC_RSP_PRESENT (1 << 0)
@@ -148,6 +151,7 @@ extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *,
extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool);
extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
extern int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd);
#define MMC_ERASE_ARG 0x00000000
#define MMC_SECURE_ERASE_ARG 0x80000000