ARM: dts: add support for TX6S with LVDS output

[karo-tx-linux.git] / block / blk-mq-tag.c

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 1aab39f71d9544c89e82c9540050bc40a83d3eed..c1b92426c95e28139134e51a68de2f724f8979f5 100644 (file)
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -43,9 +43,16 @@ bool blk_mq_has_free_tags(struct blk_mq_tags *tags)
        return bt_has_free_tags(&tags->bitmap_tags);
 }
 
-static inline void bt_index_inc(unsigned int *index)
+static inline int bt_index_inc(int index)
 {
-       *index = (*index + 1) & (BT_WAIT_QUEUES - 1);
+       return (index + 1) & (BT_WAIT_QUEUES - 1);
+}
+
+static inline void bt_index_atomic_inc(atomic_t *index)
+{
+       int old = atomic_read(index);
+       int new = bt_index_inc(old);
+       atomic_cmpxchg(index, old, new);
 }
 
 /*
@@ -69,14 +76,14 @@ static void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags)
        int i, wake_index;
 
        bt = &tags->bitmap_tags;
-       wake_index = bt->wake_index;
+       wake_index = atomic_read(&bt->wake_index);
        for (i = 0; i < BT_WAIT_QUEUES; i++) {
                struct bt_wait_state *bs = &bt->bs[wake_index];
 
                if (waitqueue_active(&bs->wait))
                        wake_up(&bs->wait);
 
-               bt_index_inc(&wake_index);
+               wake_index = bt_index_inc(wake_index);
        }
 }
 
@@ -212,12 +219,14 @@ static struct bt_wait_state *bt_wait_ptr(struct blk_mq_bitmap_tags *bt,
                                         struct blk_mq_hw_ctx *hctx)
 {
        struct bt_wait_state *bs;
+       int wait_index;
 
        if (!hctx)
                return &bt->bs[0];
 
-       bs = &bt->bs[hctx->wait_index];
-       bt_index_inc(&hctx->wait_index);
+       wait_index = atomic_read(&hctx->wait_index);
+       bs = &bt->bs[wait_index];
+       bt_index_atomic_inc(&hctx->wait_index);
        return bs;
 }
 
@@ -239,18 +248,12 @@ static int bt_get(struct blk_mq_alloc_data *data,
 
        bs = bt_wait_ptr(bt, hctx);
        do {
-               bool was_empty;
-
-               was_empty = list_empty(&wait.task_list);
                prepare_to_wait(&bs->wait, &wait, TASK_UNINTERRUPTIBLE);
 
                tag = __bt_get(hctx, bt, last_tag);
                if (tag != -1)
                        break;
 
-               if (was_empty)
-                       atomic_set(&bs->wait_cnt, bt->wake_cnt);
-
                blk_mq_put_ctx(data->ctx);
 
                io_schedule();
@@ -313,18 +316,19 @@ static struct bt_wait_state *bt_wake_ptr(struct blk_mq_bitmap_tags *bt)
 {
        int i, wake_index;
 
-       wake_index = bt->wake_index;
+       wake_index = atomic_read(&bt->wake_index);
        for (i = 0; i < BT_WAIT_QUEUES; i++) {
                struct bt_wait_state *bs = &bt->bs[wake_index];
 
                if (waitqueue_active(&bs->wait)) {
-                       if (wake_index != bt->wake_index)
-                               bt->wake_index = wake_index;
+                       int o = atomic_read(&bt->wake_index);
+                       if (wake_index != o)
+                               atomic_cmpxchg(&bt->wake_index, o, wake_index);
 
                        return bs;
                }
 
-               bt_index_inc(&wake_index);
+               wake_index = bt_index_inc(wake_index);
        }
 
        return NULL;
@@ -334,6 +338,7 @@ static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag)
 {
        const int index = TAG_TO_INDEX(bt, tag);
        struct bt_wait_state *bs;
+       int wait_cnt;
 
        /*
         * The unlock memory barrier need to order access to req in free
@@ -342,10 +347,19 @@ static void bt_clear_tag(struct blk_mq_bitmap_tags *bt, unsigned int tag)
        clear_bit_unlock(TAG_TO_BIT(bt, tag), &bt->map[index].word);
 
        bs = bt_wake_ptr(bt);
-       if (bs && atomic_dec_and_test(&bs->wait_cnt)) {
-               atomic_set(&bs->wait_cnt, bt->wake_cnt);
-               bt_index_inc(&bt->wake_index);
+       if (!bs)
+               return;
+
+       wait_cnt = atomic_dec_return(&bs->wait_cnt);
+       if (wait_cnt == 0) {
+wake:
+               atomic_add(bt->wake_cnt, &bs->wait_cnt);
+               bt_index_atomic_inc(&bt->wake_index);
                wake_up(&bs->wait);
+       } else if (wait_cnt < 0) {
+               wait_cnt = atomic_inc_return(&bs->wait_cnt);
+               if (!wait_cnt)
+                       goto wake;
        }
 }
 
@@ -499,10 +513,13 @@ static int bt_alloc(struct blk_mq_bitmap_tags *bt, unsigned int depth,
                return -ENOMEM;
        }
 
-       for (i = 0; i < BT_WAIT_QUEUES; i++)
+       bt_update_count(bt, depth);
+
+       for (i = 0; i < BT_WAIT_QUEUES; i++) {
                init_waitqueue_head(&bt->bs[i].wait);
+               atomic_set(&bt->bs[i].wait_cnt, bt->wake_cnt);
+       }
 
-       bt_update_count(bt, depth);
        return 0;
 }