[PATCH V15 05/22] mmc: core: Add parameter use_blk_mq

[Adrian Hunter]

Until mmc has blk-mq support fully implemented and tested, add a parameter
use_blk_mq, set to true if config option MMC_MQ_DEFAULT is selected, which
it is by default.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 drivers/mmc/Kconfig      | 10 ++++++++++
 drivers/mmc/core/core.c  |  7 +++++++
 drivers/mmc/core/core.h  |  2 ++
 drivers/mmc/core/host.c  |  2 ++
 drivers/mmc/core/host.h  |  4 ++++
 include/linux/mmc/host.h |  1 +
 6 files changed, 26 insertions(+)

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index ec21388311db..42565562577c 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -12,6 +12,16 @@ menuconfig MMC
 	  If you want MMC/SD/SDIO support, you should say Y here and
 	  also to your specific host controller driver.
 
+config MMC_MQ_DEFAULT
+	bool "MMC: use blk-mq I/O path by default"
+	depends on MMC && BLOCK
+	default y
+	---help---
+	  This option enables the new blk-mq based I/O path for MMC block
+	  devices by default.  With the option the mmc_core.use_blk_mq
+	  module/boot option defaults to Y, without it to N, but it can
+	  still be overridden either way.
+
 if MMC
 
 source "drivers/mmc/core/Kconfig"
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7ca6e4866a8b..617802f45386 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -66,6 +66,13 @@
 bool use_spi_crc = 1;
 module_param(use_spi_crc, bool, 0);
 
+#ifdef CONFIG_MMC_MQ_DEFAULT
+bool mmc_use_blk_mq = true;
+#else
+bool mmc_use_blk_mq = false;
+#endif
+module_param_named(use_blk_mq, mmc_use_blk_mq, bool, S_IWUSR | S_IRUGO);
+
 static int mmc_schedule_delayed_work(struct delayed_work *work,
 				     unsigned long delay)
 {
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 3e3d21304e5f..136617d2f971 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -35,6 +35,8 @@ struct mmc_bus_ops {
 	int (*reset)(struct mmc_host *);
 };
 
+extern bool mmc_use_blk_mq;
+
 void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
 void mmc_detach_bus(struct mmc_host *host);
 
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 64b03d6eaf18..409a68a96a0a 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -404,6 +404,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 
 	host->fixed_drv_type = -EINVAL;
 
+	host->use_blk_mq = mmc_use_blk_mq;
+
 	return host;
 }
 
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index fb689a1065ed..6eaf558e62d6 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -74,6 +74,10 @@ static inline bool mmc_card_hs400es(struct mmc_card *card)
 	return card->host->ios.enhanced_strobe;
 }
 
+static inline bool mmc_host_use_blk_mq(struct mmc_host *host)
+{
+	return host->use_blk_mq;
+}
 
 #endif
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index e7743eca1021..ce2075d6f429 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -380,6 +380,7 @@ struct mmc_host {
 	unsigned int		doing_retune:1;	/* re-tuning in progress */
 	unsigned int		retune_now:1;	/* do re-tuning at next req */
 	unsigned int		retune_paused:1; /* re-tuning is temporarily disabled */
+	unsigned int		use_blk_mq:1;	/* use blk-mq */
 
 	int			rescan_disable;	/* disable card detection */
 	int			rescan_entered;	/* used with nonremovable devices */
-- 
1.9.1