xhci: Remove more doorbell-related reads
The unused space in the doorbell is now marked as RsvdZ, not RsvdP, so
we can avoid reading the doorbell before writing it.
Update the doorbell-related defines to produce the entire doorbell value
from a single macro. Document the doorbell format in a comment.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 170c367..7f236fd 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -436,22 +436,18 @@
/**
* struct doorbell_array
*
+ * Bits 0 - 7: Endpoint target
+ * Bits 8 - 15: RsvdZ
+ * Bits 16 - 31: Stream ID
+ *
* Section 5.6
*/
struct xhci_doorbell_array {
u32 doorbell[256];
};
-#define DB_TARGET_MASK 0xFFFFFF00
-#define DB_STREAM_ID_MASK 0x0000FFFF
-#define DB_TARGET_HOST 0x0
-#define DB_STREAM_ID_HOST 0x0
-#define DB_MASK (0xff << 8)
-
-/* Endpoint Target - bits 0:7 */
-#define EPI_TO_DB(p) (((p) + 1) & 0xff)
-#define STREAM_ID_TO_DB(p) (((p) & 0xffff) << 16)
-
+#define DB_VALUE(ep, stream) ((((ep) + 1) & 0xff) | ((stream) << 16))
+#define DB_VALUE_HOST 0x00000000
/**
* struct xhci_protocol_caps