Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

[firefly-linux-kernel-4.4.55.git] / include / linux / blkdev.h

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0169ba2e2e64b9c4bba07bf72b9c1194fe2db08a..a9562bb029d00ad3dddd551ec35ef9f361c44872 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -197,6 +197,9 @@ struct request {
 
        /* for bidi */
        struct request *next_rq;
+
+       ktime_t                 lat_hist_io_start;
+       int                     lat_hist_enabled;
 };
 
 static inline unsigned short req_get_ioprio(struct request *req)
@@ -797,6 +800,7 @@ extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 extern int blk_queue_enter(struct request_queue *q, gfp_t gfp);
 extern void blk_queue_exit(struct request_queue *q);
 extern void blk_start_queue(struct request_queue *q);
+extern void blk_start_queue_async(struct request_queue *q);
 extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);
 extern void __blk_stop_queue(struct request_queue *q);
@@ -889,7 +893,7 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
 {
        struct request_queue *q = rq->q;
 
-       if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
+       if (unlikely(rq->cmd_type != REQ_TYPE_FS))
                return q->limits.max_hw_sectors;
 
        if (!q->limits.chunk_sectors || (rq->cmd_flags & REQ_DISCARD))
@@ -1366,6 +1370,13 @@ static inline void put_dev_sector(Sector p)
        page_cache_release(p.v);
 }
 
+static inline bool __bvec_gap_to_prev(struct request_queue *q,
+                               struct bio_vec *bprv, unsigned int offset)
+{
+       return offset ||
+               ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
+}
+
 /*
  * Check if adding a bio_vec after bprv with offset would create a gap in
  * the SG list. Most drivers don't care about this, but some do.
@@ -1375,18 +1386,22 @@ static inline bool bvec_gap_to_prev(struct request_queue *q,
 {
        if (!queue_virt_boundary(q))
                return false;
-       return offset ||
-               ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
+       return __bvec_gap_to_prev(q, bprv, offset);
 }
 
 static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
                         struct bio *next)
 {
-       if (!bio_has_data(prev))
-               return false;
+       if (bio_has_data(prev) && queue_virt_boundary(q)) {
+               struct bio_vec pb, nb;
+
+               bio_get_last_bvec(prev, &pb);
+               bio_get_first_bvec(next, &nb);
 
-       return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1],
-                               next->bi_io_vec[0].bv_offset);
+               return __bvec_gap_to_prev(q, &pb, nb.bv_offset);
+       }
+
+       return false;
 }
 
 static inline bool req_gap_back_merge(struct request *req, struct bio *bio)
@@ -1644,6 +1659,79 @@ extern int bdev_write_page(struct block_device *, sector_t, struct page *,
                                                struct writeback_control *);
 extern long bdev_direct_access(struct block_device *, sector_t,
                void __pmem **addr, unsigned long *pfn, long size);
+
+/*
+ * X-axis for IO latency histogram support.
+ */
+static const u_int64_t latency_x_axis_us[] = {
+       100,
+       200,
+       300,
+       400,
+       500,
+       600,
+       700,
+       800,
+       900,
+       1000,
+       1200,
+       1400,
+       1600,
+       1800,
+       2000,
+       2500,
+       3000,
+       4000,
+       5000,
+       6000,
+       7000,
+       9000,
+       10000
+};
+
+#define BLK_IO_LAT_HIST_DISABLE         0
+#define BLK_IO_LAT_HIST_ENABLE          1
+#define BLK_IO_LAT_HIST_ZERO            2
+
+struct io_latency_state {
+       u_int64_t       latency_y_axis_read[ARRAY_SIZE(latency_x_axis_us) + 1];
+       u_int64_t       latency_reads_elems;
+       u_int64_t       latency_y_axis_write[ARRAY_SIZE(latency_x_axis_us) + 1];
+       u_int64_t       latency_writes_elems;
+};
+
+static inline void
+blk_update_latency_hist(struct io_latency_state *s,
+                       int read,
+                       u_int64_t delta_us)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(latency_x_axis_us); i++) {
+               if (delta_us < (u_int64_t)latency_x_axis_us[i]) {
+                       if (read)
+                               s->latency_y_axis_read[i]++;
+                       else
+                               s->latency_y_axis_write[i]++;
+                       break;
+               }
+       }
+       if (i == ARRAY_SIZE(latency_x_axis_us)) {
+               /* Overflowed the histogram */
+               if (read)
+                       s->latency_y_axis_read[i]++;
+               else
+                       s->latency_y_axis_write[i]++;
+       }
+       if (read)
+               s->latency_reads_elems++;
+       else
+               s->latency_writes_elems++;
+}
+
+void blk_zero_latency_hist(struct io_latency_state *s);
+ssize_t blk_latency_hist_show(struct io_latency_state *s, char *buf);
+
 #else /* CONFIG_BLOCK */
 
 struct block_device;