block: add support for IO CPU affinity

[linux-2.6-omap-h63xx.git] / block / blk-settings.c

diff --git a/block/blk-settings.c b/block/blk-settings.c
index bb93d4c32775abdc2fdba16c3bc208fb20045f47..a60e959a12c481d78dd965857552d5f31b2fc1f1 100644 (file)
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -32,6 +32,23 @@ void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
 }
 EXPORT_SYMBOL(blk_queue_prep_rq);
 
+/**
+ * blk_queue_set_discard - set a discard_sectors function for queue
+ * @q:         queue
+ * @dfn:       prepare_discard function
+ *
+ * It's possible for a queue to register a discard callback which is used
+ * to transform a discard request into the appropriate type for the
+ * hardware. If none is registered, then discard requests are failed
+ * with %EOPNOTSUPP.
+ *
+ */
+void blk_queue_set_discard(struct request_queue *q, prepare_discard_fn *dfn)
+{
+       q->prepare_discard_fn = dfn;
+}
+EXPORT_SYMBOL(blk_queue_set_discard);
+
 /**
  * blk_queue_merge_bvec - set a merge_bvec function for queue
  * @q:         queue
@@ -127,7 +144,7 @@ EXPORT_SYMBOL(blk_queue_make_request);
  *    Different hardware can have different requirements as to what pages
  *    it can do I/O directly to. A low level driver can call
  *    blk_queue_bounce_limit to have lower memory pages allocated as bounce
- *    buffers for doing I/O to pages residing above @page.
+ *    buffers for doing I/O to pages residing above @dma_addr.
  **/
 void blk_queue_bounce_limit(struct request_queue *q, u64 dma_addr)
 {
@@ -212,7 +229,7 @@ EXPORT_SYMBOL(blk_queue_max_phys_segments);
  * Description:
  *    Enables a low level driver to set an upper limit on the number of
  *    hw data segments in a request.  This would be the largest number of
- *    address/length pairs the host adapter can actually give as once
+ *    address/length pairs the host adapter can actually give at once
  *    to the device.
  **/
 void blk_queue_max_hw_segments(struct request_queue *q,
@@ -286,8 +303,14 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
        t->max_hw_segments = min(t->max_hw_segments, b->max_hw_segments);
        t->max_segment_size = min(t->max_segment_size, b->max_segment_size);
        t->hardsect_size = max(t->hardsect_size, b->hardsect_size);
-       if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))
+       if (!t->queue_lock)
+               WARN_ON_ONCE(1);
+       else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
+               unsigned long flags;
+               spin_lock_irqsave(t->queue_lock, flags);
                queue_flag_clear(QUEUE_FLAG_CLUSTER, t);
+               spin_unlock_irqrestore(t->queue_lock, flags);
+       }
 }
 EXPORT_SYMBOL(blk_queue_stack_limits);
 
@@ -296,11 +319,10 @@ EXPORT_SYMBOL(blk_queue_stack_limits);
  * @q:     the request queue for the device
  * @mask:  pad mask
  *
- * Set pad mask.  Direct IO requests are padded to the mask specified.
+ * Set dma pad mask.
  *
- * Appending pad buffer to a request modifies ->data_len such that it
- * includes the pad buffer.  The original requested data length can be
- * obtained using blk_rq_raw_data_len().
+ * Appending pad buffer to a request modifies the last entry of a
+ * scatter list such that it includes the pad buffer.
  **/
 void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
 {
@@ -308,6 +330,23 @@ void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
 }
 EXPORT_SYMBOL(blk_queue_dma_pad);
 
+/**
+ * blk_queue_update_dma_pad - update pad mask
+ * @q:     the request queue for the device
+ * @mask:  pad mask
+ *
+ * Update dma pad mask.
+ *
+ * Appending pad buffer to a request modifies the last entry of a
+ * scatter list such that it includes the pad buffer.
+ **/
+void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
+{
+       if (mask > q->dma_pad_mask)
+               q->dma_pad_mask = mask;
+}
+EXPORT_SYMBOL(blk_queue_update_dma_pad);
+
 /**
  * blk_queue_dma_drain - Set up a drain buffer for excess dma.
  * @q:  the request queue for the device
@@ -371,7 +410,7 @@ EXPORT_SYMBOL(blk_queue_segment_boundary);
  * @mask:  alignment mask
  *
  * description:
- *    set required memory and length aligment for direct dma transactions.
+ *    set required memory and length alignment for direct dma transactions.
  *    this is used when buiding direct io requests for the queue.
  *
  **/
@@ -387,7 +426,7 @@ EXPORT_SYMBOL(blk_queue_dma_alignment);
  * @mask:  alignment mask
  *
  * description:
- *    update required memory and length aligment for direct dma transactions.
+ *    update required memory and length alignment for direct dma transactions.
  *    If the requested alignment is larger than the current alignment, then
  *    the current queue alignment is updated to the new value, otherwise it
  *    is left alone.  The design of this is to allow multiple objects
@@ -404,7 +443,7 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
 }
 EXPORT_SYMBOL(blk_queue_update_dma_alignment);
 
-static int __init blk_settings_init(void)
+int __init blk_settings_init(void)
 {
        blk_max_low_pfn = max_low_pfn - 1;
        blk_max_pfn = max_pfn - 1;