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>

3 files changed, 14 insertions, 0 deletions

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 237f253f2fe0..61b2c30c903b 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -310,6 +310,11 @@ static inline void mmc_part_add(struct mmc_card *card, unsigned int size,
         card->nr_parts++;
 }
 
+static inline bool mmc_large_sector(struct mmc_card *card)
+{
+        return card->ext_csd.data_sector_size == 4096;
+}
+
 /*
  *  The world is not perfect and supplies us with broken mmc/sdio devices.
  *  For at least some of these bugs we need a work-around.
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 495d1336149c..39613b9a6fc5 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -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
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index a0466c03f5e1..fd5fd5a6026f 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -465,6 +465,11 @@ static inline int mmc_host_uhs(struct mmc_host *host)
                  MMC_CAP_UHS_DDR50);
 }
 
+static inline int mmc_host_packed_wr(struct mmc_host *host)
+{
+        return host->caps2 & MMC_CAP2_PACKED_WR;
+}
+
 #ifdef CONFIG_MMC_CLKGATE
 void mmc_host_clk_hold(struct mmc_host *host);
 void mmc_host_clk_release(struct mmc_host *host);