|
@@ -311,3 +311,115 @@ EXPORT_SYMBOL(blk_queue_max_write_same_sectors);
|
|
|
void blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
|
|
|
{
|
|
|
if (!max_segments) {
|
|
|
+ max_segments = 1;
|
|
|
+ printk(KERN_INFO "%s: set to minimum %d\n",
|
|
|
+ __func__, max_segments);
|
|
|
+ }
|
|
|
+
|
|
|
+ q->limits.max_segments = max_segments;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(blk_queue_max_segments);
|
|
|
+
|
|
|
+/**
|
|
|
+ * blk_queue_max_segment_size - set max segment size for blk_rq_map_sg
|
|
|
+ * @q: the request queue for the device
|
|
|
+ * @max_size: max size of segment in bytes
|
|
|
+ *
|
|
|
+ * Description:
|
|
|
+ * Enables a low level driver to set an upper limit on the size of a
|
|
|
+ * coalesced segment
|
|
|
+ **/
|
|
|
+void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size)
|
|
|
+{
|
|
|
+ if (max_size < PAGE_CACHE_SIZE) {
|
|
|
+ max_size = PAGE_CACHE_SIZE;
|
|
|
+ printk(KERN_INFO "%s: set to minimum %d\n",
|
|
|
+ __func__, max_size);
|
|
|
+ }
|
|
|
+
|
|
|
+ q->limits.max_segment_size = max_size;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(blk_queue_max_segment_size);
|
|
|
+
|
|
|
+/**
|
|
|
+ * blk_queue_logical_block_size - set logical block size for the queue
|
|
|
+ * @q: the request queue for the device
|
|
|
+ * @size: the logical block size, in bytes
|
|
|
+ *
|
|
|
+ * Description:
|
|
|
+ * This should be set to the lowest possible block size that the
|
|
|
+ * storage device can address. The default of 512 covers most
|
|
|
+ * hardware.
|
|
|
+ **/
|
|
|
+void blk_queue_logical_block_size(struct request_queue *q, unsigned short size)
|
|
|
+{
|
|
|
+ q->limits.logical_block_size = size;
|
|
|
+
|
|
|
+ if (q->limits.physical_block_size < size)
|
|
|
+ q->limits.physical_block_size = size;
|
|
|
+
|
|
|
+ if (q->limits.io_min < q->limits.physical_block_size)
|
|
|
+ q->limits.io_min = q->limits.physical_block_size;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(blk_queue_logical_block_size);
|
|
|
+
|
|
|
+/**
|
|
|
+ * blk_queue_physical_block_size - set physical block size for the queue
|
|
|
+ * @q: the request queue for the device
|
|
|
+ * @size: the physical block size, in bytes
|
|
|
+ *
|
|
|
+ * Description:
|
|
|
+ * This should be set to the lowest possible sector size that the
|
|
|
+ * hardware can operate on without reverting to read-modify-write
|
|
|
+ * operations.
|
|
|
+ */
|
|
|
+void blk_queue_physical_block_size(struct request_queue *q, unsigned int size)
|
|
|
+{
|
|
|
+ q->limits.physical_block_size = size;
|
|
|
+
|
|
|
+ if (q->limits.physical_block_size < q->limits.logical_block_size)
|
|
|
+ q->limits.physical_block_size = q->limits.logical_block_size;
|
|
|
+
|
|
|
+ if (q->limits.io_min < q->limits.physical_block_size)
|
|
|
+ q->limits.io_min = q->limits.physical_block_size;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(blk_queue_physical_block_size);
|
|
|
+
|
|
|
+/**
|
|
|
+ * blk_queue_alignment_offset - set physical block alignment offset
|
|
|
+ * @q: the request queue for the device
|
|
|
+ * @offset: alignment offset in bytes
|
|
|
+ *
|
|
|
+ * Description:
|
|
|
+ * Some devices are naturally misaligned to compensate for things like
|
|
|
+ * the legacy DOS partition table 63-sector offset. Low-level drivers
|
|
|
+ * should call this function for devices whose first sector is not
|
|
|
+ * naturally aligned.
|
|
|
+ */
|
|
|
+void blk_queue_alignment_offset(struct request_queue *q, unsigned int offset)
|
|
|
+{
|
|
|
+ q->limits.alignment_offset =
|
|
|
+ offset & (q->limits.physical_block_size - 1);
|
|
|
+ q->limits.misaligned = 0;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(blk_queue_alignment_offset);
|
|
|
+
|
|
|
+/**
|
|
|
+ * blk_limits_io_min - set minimum request size for a device
|
|
|
+ * @limits: the queue limits
|
|
|
+ * @min: smallest I/O size in bytes
|
|
|
+ *
|
|
|
+ * Description:
|
|
|
+ * Some devices have an internal block size bigger than the reported
|
|
|
+ * hardware sector size. This function can be used to signal the
|
|
|
+ * smallest I/O the device can perform without incurring a performance
|
|
|
+ * penalty.
|
|
|
+ */
|
|
|
+void blk_limits_io_min(struct queue_limits *limits, unsigned int min)
|
|
|
+{
|
|
|
+ limits->io_min = min;
|
|
|
+
|
|
|
+ if (limits->io_min < limits->logical_block_size)
|
|
|
+ limits->io_min = limits->logical_block_size;
|
|
|
+
|
|
|
+ if (limits->io_min < limits->physical_block_size)
|