Merge branch 'for-jens' of http://evilpiepirate.org/git/linux-bcache into for-3.10/core
This contains Kents prep work for the immutable bio_vecs.
diff --git a/block/blk-core.c b/block/blk-core.c
index 7236b82..f224d17 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -30,6 +30,7 @@
#include <linux/list_sort.h>
#include <linux/delay.h>
#include <linux/ratelimit.h>
+#include <linux/pm_runtime.h>
#define CREATE_TRACE_POINTS
#include <trace/events/block.h>
@@ -1253,6 +1254,16 @@
}
EXPORT_SYMBOL_GPL(part_round_stats);
+#ifdef CONFIG_PM_RUNTIME
+static void blk_pm_put_request(struct request *rq)
+{
+ if (rq->q->dev && !(rq->cmd_flags & REQ_PM) && !--rq->q->nr_pending)
+ pm_runtime_mark_last_busy(rq->q->dev);
+}
+#else
+static inline void blk_pm_put_request(struct request *rq) {}
+#endif
+
/*
* queue lock must be held
*/
@@ -1263,6 +1274,8 @@
if (unlikely(--req->ref_count))
return;
+ blk_pm_put_request(req);
+
elv_completed_request(q, req);
/* this is a bio leak */
@@ -2042,6 +2055,28 @@
}
}
+#ifdef CONFIG_PM_RUNTIME
+/*
+ * Don't process normal requests when queue is suspended
+ * or in the process of suspending/resuming
+ */
+static struct request *blk_pm_peek_request(struct request_queue *q,
+ struct request *rq)
+{
+ if (q->dev && (q->rpm_status == RPM_SUSPENDED ||
+ (q->rpm_status != RPM_ACTIVE && !(rq->cmd_flags & REQ_PM))))
+ return NULL;
+ else
+ return rq;
+}
+#else
+static inline struct request *blk_pm_peek_request(struct request_queue *q,
+ struct request *rq)
+{
+ return rq;
+}
+#endif
+
/**
* blk_peek_request - peek at the top of a request queue
* @q: request queue to peek at
@@ -2064,6 +2099,11 @@
int ret;
while ((rq = __elv_next_request(q)) != NULL) {
+
+ rq = blk_pm_peek_request(q, rq);
+ if (!rq)
+ break;
+
if (!(rq->cmd_flags & REQ_STARTED)) {
/*
* This is the first time the device driver
@@ -2989,6 +3029,149 @@
}
EXPORT_SYMBOL(blk_finish_plug);
+#ifdef CONFIG_PM_RUNTIME
+/**
+ * blk_pm_runtime_init - Block layer runtime PM initialization routine
+ * @q: the queue of the device
+ * @dev: the device the queue belongs to
+ *
+ * Description:
+ * Initialize runtime-PM-related fields for @q and start auto suspend for
+ * @dev. Drivers that want to take advantage of request-based runtime PM
+ * should call this function after @dev has been initialized, and its
+ * request queue @q has been allocated, and runtime PM for it can not happen
+ * yet(either due to disabled/forbidden or its usage_count > 0). In most
+ * cases, driver should call this function before any I/O has taken place.
+ *
+ * This function takes care of setting up using auto suspend for the device,
+ * the autosuspend delay is set to -1 to make runtime suspend impossible
+ * until an updated value is either set by user or by driver. Drivers do
+ * not need to touch other autosuspend settings.
+ *
+ * The block layer runtime PM is request based, so only works for drivers
+ * that use request as their IO unit instead of those directly use bio's.
+ */
+void blk_pm_runtime_init(struct request_queue *q, struct device *dev)
+{
+ q->dev = dev;
+ q->rpm_status = RPM_ACTIVE;
+ pm_runtime_set_autosuspend_delay(q->dev, -1);
+ pm_runtime_use_autosuspend(q->dev);
+}
+EXPORT_SYMBOL(blk_pm_runtime_init);
+
+/**
+ * blk_pre_runtime_suspend - Pre runtime suspend check
+ * @q: the queue of the device
+ *
+ * Description:
+ * This function will check if runtime suspend is allowed for the device
+ * by examining if there are any requests pending in the queue. If there
+ * are requests pending, the device can not be runtime suspended; otherwise,
+ * the queue's status will be updated to SUSPENDING and the driver can
+ * proceed to suspend the device.
+ *
+ * For the not allowed case, we mark last busy for the device so that
+ * runtime PM core will try to autosuspend it some time later.
+ *
+ * This function should be called near the start of the device's
+ * runtime_suspend callback.
+ *
+ * Return:
+ * 0 - OK to runtime suspend the device
+ * -EBUSY - Device should not be runtime suspended
+ */
+int blk_pre_runtime_suspend(struct request_queue *q)
+{
+ int ret = 0;
+
+ spin_lock_irq(q->queue_lock);
+ if (q->nr_pending) {
+ ret = -EBUSY;
+ pm_runtime_mark_last_busy(q->dev);
+ } else {
+ q->rpm_status = RPM_SUSPENDING;
+ }
+ spin_unlock_irq(q->queue_lock);
+ return ret;
+}
+EXPORT_SYMBOL(blk_pre_runtime_suspend);
+
+/**
+ * blk_post_runtime_suspend - Post runtime suspend processing
+ * @q: the queue of the device
+ * @err: return value of the device's runtime_suspend function
+ *
+ * Description:
+ * Update the queue's runtime status according to the return value of the
+ * device's runtime suspend function and mark last busy for the device so
+ * that PM core will try to auto suspend the device at a later time.
+ *
+ * This function should be called near the end of the device's
+ * runtime_suspend callback.
+ */
+void blk_post_runtime_suspend(struct request_queue *q, int err)
+{
+ spin_lock_irq(q->queue_lock);
+ if (!err) {
+ q->rpm_status = RPM_SUSPENDED;
+ } else {
+ q->rpm_status = RPM_ACTIVE;
+ pm_runtime_mark_last_busy(q->dev);
+ }
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_post_runtime_suspend);
+
+/**
+ * blk_pre_runtime_resume - Pre runtime resume processing
+ * @q: the queue of the device
+ *
+ * Description:
+ * Update the queue's runtime status to RESUMING in preparation for the
+ * runtime resume of the device.
+ *
+ * This function should be called near the start of the device's
+ * runtime_resume callback.
+ */
+void blk_pre_runtime_resume(struct request_queue *q)
+{
+ spin_lock_irq(q->queue_lock);
+ q->rpm_status = RPM_RESUMING;
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_pre_runtime_resume);
+
+/**
+ * blk_post_runtime_resume - Post runtime resume processing
+ * @q: the queue of the device
+ * @err: return value of the device's runtime_resume function
+ *
+ * Description:
+ * Update the queue's runtime status according to the return value of the
+ * device's runtime_resume function. If it is successfully resumed, process
+ * the requests that are queued into the device's queue when it is resuming
+ * and then mark last busy and initiate autosuspend for it.
+ *
+ * This function should be called near the end of the device's
+ * runtime_resume callback.
+ */
+void blk_post_runtime_resume(struct request_queue *q, int err)
+{
+ spin_lock_irq(q->queue_lock);
+ if (!err) {
+ q->rpm_status = RPM_ACTIVE;
+ __blk_run_queue(q);
+ pm_runtime_mark_last_busy(q->dev);
+ pm_runtime_autosuspend(q->dev);
+ } else {
+ q->rpm_status = RPM_SUSPENDED;
+ }
+ spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL(blk_post_runtime_resume);
+#endif
+
int __init blk_dev_init(void)
{
BUILD_BUG_ON(__REQ_NR_BITS > 8 *
diff --git a/block/elevator.c b/block/elevator.c
index a0ffdd9..eba5b04 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -34,6 +34,7 @@
#include <linux/blktrace_api.h>
#include <linux/hash.h>
#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
#include <trace/events/block.h>
@@ -536,6 +537,27 @@
e->type->ops.elevator_bio_merged_fn(q, rq, bio);
}
+#ifdef CONFIG_PM_RUNTIME
+static void blk_pm_requeue_request(struct request *rq)
+{
+ if (rq->q->dev && !(rq->cmd_flags & REQ_PM))
+ rq->q->nr_pending--;
+}
+
+static void blk_pm_add_request(struct request_queue *q, struct request *rq)
+{
+ if (q->dev && !(rq->cmd_flags & REQ_PM) && q->nr_pending++ == 0 &&
+ (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING))
+ pm_request_resume(q->dev);
+}
+#else
+static inline void blk_pm_requeue_request(struct request *rq) {}
+static inline void blk_pm_add_request(struct request_queue *q,
+ struct request *rq)
+{
+}
+#endif
+
void elv_requeue_request(struct request_queue *q, struct request *rq)
{
/*
@@ -550,6 +572,8 @@
rq->cmd_flags &= ~REQ_STARTED;
+ blk_pm_requeue_request(rq);
+
__elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE);
}
@@ -572,6 +596,8 @@
{
trace_block_rq_insert(q, rq);
+ blk_pm_add_request(q, rq);
+
rq->q = q;
if (rq->cmd_flags & REQ_SOFTBARRIER) {
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 538289f..e8de670 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -176,6 +176,7 @@
__REQ_IO_STAT, /* account I/O stat */
__REQ_MIXED_MERGE, /* merge of different types, fail separately */
__REQ_KERNEL, /* direct IO to kernel pages */
+ __REQ_PM, /* runtime pm request */
__REQ_NR_BITS, /* stops here */
};
@@ -226,5 +227,6 @@
#define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE)
#define REQ_SECURE (1 << __REQ_SECURE)
#define REQ_KERNEL (1 << __REQ_KERNEL)
+#define REQ_PM (1 << __REQ_PM)
#endif /* __LINUX_BLK_TYPES_H */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 78feda9..89d89c7 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -361,6 +361,12 @@
*/
struct kobject kobj;
+#ifdef CONFIG_PM_RUNTIME
+ struct device *dev;
+ int rpm_status;
+ unsigned int nr_pending;
+#endif
+
/*
* queue settings
*/
@@ -961,6 +967,27 @@
extern void blk_put_queue(struct request_queue *);
/*
+ * block layer runtime pm functions
+ */
+#ifdef CONFIG_PM_RUNTIME
+extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
+extern int blk_pre_runtime_suspend(struct request_queue *q);
+extern void blk_post_runtime_suspend(struct request_queue *q, int err);
+extern void blk_pre_runtime_resume(struct request_queue *q);
+extern void blk_post_runtime_resume(struct request_queue *q, int err);
+#else
+static inline void blk_pm_runtime_init(struct request_queue *q,
+ struct device *dev) {}
+static inline int blk_pre_runtime_suspend(struct request_queue *q)
+{
+ return -ENOSYS;
+}
+static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
+static inline void blk_pre_runtime_resume(struct request_queue *q) {}
+static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
+#endif
+
+/*
* blk_plug permits building a queue of related requests by holding the I/O
* fragments for a short period. This allows merging of sequential requests
* into single larger request. As the requests are moved from a per-task list to
