[usb] Include setup packet within I/O buffer for message transfers

The USB API currently assumes that host controllers will have
immediate data buffer space available in which to store the setup
packet.  This is true for xHCI, partially true for EHCI (which happens
to have 12 bytes of padding in each transfer descriptor due to
alignment requirements), and not true at all for UHCI.

Include the setup packet within the I/O buffer passed to the host
controller's message() method, thereby eliminating the requirement for
host controllers to provide immediate data buffers.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/src/drivers/usb/xhci.c b/src/drivers/usb/xhci.c
index 523a1c0b..831e8e6e 100644
--- a/src/drivers/usb/xhci.c
+++ b/src/drivers/usb/xhci.c
@@ -2472,16 +2472,15 @@ static int xhci_endpoint_mtu ( struct usb_endpoint *ep ) {
  * Enqueue message transfer
  *
  * @v ep		USB endpoint
- * @v packet		Setup packet
  * @v iobuf		I/O buffer
  * @ret rc		Return status code
  */
 static int xhci_endpoint_message ( struct usb_endpoint *ep,
-				   struct usb_setup_packet *packet,
 				   struct io_buffer *iobuf ) {
 	struct xhci_endpoint *endpoint = usb_endpoint_get_hostdata ( ep );
-	unsigned int input = ( le16_to_cpu ( packet->request ) & USB_DIR_IN );
-	size_t len = iob_len ( iobuf );
+	struct usb_setup_packet *packet;
+	unsigned int input;
+	size_t len;
 	union xhci_trb trbs[ 1 /* setup */ + 1 /* possible data */ +
 			     1 /* status */ ];
 	union xhci_trb *trb = trbs;
@@ -2495,11 +2494,16 @@ static int xhci_endpoint_message ( struct usb_endpoint *ep,
 
 	/* Construct setup stage TRB */
 	memset ( trbs, 0, sizeof ( trbs ) );
+	assert ( iob_len ( iobuf ) >= sizeof ( *packet ) );
+	packet = iobuf->data;
+	iob_pull ( iobuf, sizeof ( *packet ) );
 	setup = &(trb++)->setup;
 	memcpy ( &setup->packet, packet, sizeof ( setup->packet ) );
 	setup->len = cpu_to_le32 ( sizeof ( *packet ) );
 	setup->flags = XHCI_TRB_IDT;
 	setup->type = XHCI_TRB_SETUP;
+	len = iob_len ( iobuf );
+	input = ( packet->request & cpu_to_le16 ( USB_DIR_IN ) );
 	if ( len )
 		setup->direction = ( input ? XHCI_SETUP_IN : XHCI_SETUP_OUT );