Merge remote-tracking branch 'common/android-4.4' into android-4.4.y

3 files changed, 74 insertions, 3 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 4df0c68e87e8..1689075e2229 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -183,6 +183,17 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 			pr_debug("%s:     %d bytes transferred: %d\n",
 				mmc_hostname(host),
 				mrq->data->bytes_xfered, mrq->data->error);
+			if (mrq->lat_hist_enabled) {
+				ktime_t completion;
+				u_int64_t delta_us;
+
+				completion = ktime_get();
+				delta_us = ktime_us_delta(completion,
+							  mrq->io_start);
+				blk_update_latency_hist(&host->io_lat_s,
+					(mrq->data->flags & MMC_DATA_READ),
+					delta_us);
+			}
 			trace_mmc_blk_rw_end(cmd->opcode, cmd->arg, mrq->data);
 		}
 
@@ -627,6 +638,11 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
 	}
 
 	if (!err && areq) {
+		if (host->latency_hist_enabled) {
+			areq->mrq->io_start = ktime_get();
+			areq->mrq->lat_hist_enabled = 1;
+		} else
+			areq->mrq->lat_hist_enabled = 0;
 		trace_mmc_blk_rw_start(areq->mrq->cmd->opcode,
 				       areq->mrq->cmd->arg,
 				       areq->mrq->data);
@@ -1964,7 +1980,7 @@ void mmc_init_erase(struct mmc_card *card)
 }
 
 static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
-				          unsigned int arg, unsigned int qty)
+					  unsigned int arg, unsigned int qty)
 {
 	unsigned int erase_timeout;
 
@@ -2907,6 +2923,54 @@ static void __exit mmc_exit(void)
 	destroy_workqueue(workqueue);
 }
 
+static ssize_t
+latency_hist_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct mmc_host *host = cls_dev_to_mmc_host(dev);
+
+	return blk_latency_hist_show(&host->io_lat_s, buf);
+}
+
+/*
+ * Values permitted 0, 1, 2.
+ * 0 -> Disable IO latency histograms (default)
+ * 1 -> Enable IO latency histograms
+ * 2 -> Zero out IO latency histograms
+ */
+static ssize_t
+latency_hist_store(struct device *dev, struct device_attribute *attr,
+		   const char *buf, size_t count)
+{
+	struct mmc_host *host = cls_dev_to_mmc_host(dev);
+	long value;
+
+	if (kstrtol(buf, 0, &value))
+		return -EINVAL;
+	if (value == BLK_IO_LAT_HIST_ZERO)
+		blk_zero_latency_hist(&host->io_lat_s);
+	else if (value == BLK_IO_LAT_HIST_ENABLE ||
+		 value == BLK_IO_LAT_HIST_DISABLE)
+		host->latency_hist_enabled = value;
+	return count;
+}
+
+static DEVICE_ATTR(latency_hist, S_IRUGO | S_IWUSR,
+		   latency_hist_show, latency_hist_store);
+
+void
+mmc_latency_hist_sysfs_init(struct mmc_host *host)
+{
+	if (device_create_file(&host->class_dev, &dev_attr_latency_hist))
+		dev_err(&host->class_dev,
+			"Failed to create latency_hist sysfs entry\n");
+}
+
+void
+mmc_latency_hist_sysfs_exit(struct mmc_host *host)
+{
+	device_remove_file(&host->class_dev, &dev_attr_latency_hist);
+}
+
 subsys_initcall(mmc_init);
 module_exit(mmc_exit);
 
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index fcf7829c759e..17068839c74b 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -32,8 +32,6 @@
 #include "slot-gpio.h"
 #include "pwrseq.h"
 
-#define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
-
 static DEFINE_IDR(mmc_host_idr);
 static DEFINE_SPINLOCK(mmc_host_lock);
 
@@ -394,6 +392,8 @@ int mmc_add_host(struct mmc_host *host)
 	mmc_add_host_debugfs(host);
 #endif
 
+	mmc_latency_hist_sysfs_init(host);
+
 	mmc_start_host(host);
 	if (!(host->pm_flags & MMC_PM_IGNORE_PM_NOTIFY))
 		register_pm_notifier(&host->pm_notify);
@@ -422,6 +422,8 @@ void mmc_remove_host(struct mmc_host *host)
 	mmc_remove_host_debugfs(host);
 #endif
 
+	mmc_latency_hist_sysfs_exit(host);
+
 	device_del(&host->class_dev);
 
 	led_trigger_unregister_simple(host->led);
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index 992bf5397633..bf38533406fd 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -12,6 +12,8 @@
 #define _MMC_CORE_HOST_H
 #include <linux/mmc/host.h>
 
+#define cls_dev_to_mmc_host(d)	container_of(d, struct mmc_host, class_dev)
+
 int mmc_register_host_class(void);
 void mmc_unregister_host_class(void);
 
@@ -21,5 +23,8 @@ void mmc_retune_hold(struct mmc_host *host);
 void mmc_retune_release(struct mmc_host *host);
 int mmc_retune(struct mmc_host *host);
 
+void mmc_latency_hist_sysfs_init(struct mmc_host *host);
+void mmc_latency_hist_sysfs_exit(struct mmc_host *host);
+
 #endif