NVMe: Abort timed out commands

Send nvme abort command to io requests that have timed out on an
initialized device. If the command is not returned after another timeout,
schedule the controller for reset.

Signed-off-by: Keith Busch <keith.busch@intel.com>
[fix endianness issues]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 117d877..69ae03f 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -95,6 +95,7 @@
 	u32 max_hw_sectors;
 	u32 stripe_size;
 	u16 oncs;
+	u16 abort_limit;
 	u8 initialized;
 };
 
diff --git a/include/uapi/linux/nvme.h b/include/uapi/linux/nvme.h
index 989c04e..e5ab622 100644
--- a/include/uapi/linux/nvme.h
+++ b/include/uapi/linux/nvme.h
@@ -350,6 +350,16 @@
 	__u32			rsvd11[5];
 };
 
+struct nvme_abort_cmd {
+	__u8			opcode;
+	__u8			flags;
+	__u16			command_id;
+	__u32			rsvd1[9];
+	__le16			sqid;
+	__u16			cid;
+	__u32			rsvd11[5];
+};
+
 struct nvme_download_firmware {
 	__u8			opcode;
 	__u8			flags;
@@ -384,6 +394,7 @@
 		struct nvme_download_firmware dlfw;
 		struct nvme_format_cmd format;
 		struct nvme_dsm_cmd dsm;
+		struct nvme_abort_cmd abort;
 	};
 };