/*
* Block error status values. See block/blk-core:blk_errors for the details.
+ * Alpha cannot write a byte atomically, so we need to use 32-bit value.
*/
+#if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
+typedef u32 __bitwise blk_status_t;
+#else
typedef u8 __bitwise blk_status_t;
+#endif
#define BLK_STS_OK 0
#define BLK_STS_NOTSUPP ((__force blk_status_t)1)
#define BLK_STS_TIMEOUT ((__force blk_status_t)2)
#define BLK_STS_AGAIN ((__force blk_status_t)12)
+/*
+ * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
+ * device related resources are unavailable, but the driver can guarantee
+ * that the queue will be rerun in the future once resources become
+ * available again. This is typically the case for device specific
+ * resources that are consumed for IO. If the driver fails allocating these
+ * resources, we know that inflight (or pending) IO will free these
+ * resource upon completion.
+ *
+ * This is different from BLK_STS_RESOURCE in that it explicitly references
+ * a device specific resource. For resources of wider scope, allocation
+ * failure can happen without having pending IO. This means that we can't
+ * rely on request completions freeing these resources, as IO may not be in
+ * flight. Examples of that are kernel memory allocations, DMA mappings, or
+ * any other system wide resources.
+ */
+#define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
+
struct blk_issue_stat {
u64 stat;
};