mmc: core: Use CMD23 for multiblock transfers when we can.

CMD23-prefixed instead of open-ended multiblock transfers
have a performance advantage on some MMC cards.

Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index de32e6aa018a..e946bd10fe3f 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -210,6 +210,7 @@ struct mmc_host {
 #define MMC_CAP_MAX_CURRENT_400 (1 << 27)       /* Host max current limit is 400mA */
 #define MMC_CAP_MAX_CURRENT_600 (1 << 28)       /* Host max current limit is 600mA */
 #define MMC_CAP_MAX_CURRENT_800 (1 << 29)       /* Host max current limit is 800mA */
+#define MMC_CAP_CMD23           (1 << 30)       /* CMD23 supported. */
 
         mmc_pm_flag_t           pm_caps;        /* supported pm features */
 
@@ -366,5 +367,10 @@ static inline int mmc_card_wake_sdio_irq(struct mmc_host *host)
 {
         return host->pm_flags & MMC_PM_WAKE_SDIO_IRQ;
 }
+
+static inline int mmc_host_cmd23(struct mmc_host *host)
+{
+        return host->caps & MMC_CAP_CMD23;
+}
 #endif