usb: use iovecs in USBPacket

Zap data pointer from USBPacket, add a QEMUIOVector instead.
Add a bunch of helper functions to manage USBPacket data.
Switch over users to the new interface.

Note that USBPacket->len was used for two purposes:  First to
pass in the buffer size and second to return the number of
transfered bytes or the status code on async transfers.  There
is a new result variable for the latter.  A new status code
was added to catch uninitialized result.

Nobody creates iovecs with more than one element (yet).
Some users are (temporarely) limited to iovecs with a single
element to keep the patch size as small as possible.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/hw/usb.h b/hw/usb.h
index ded2de2..84d04df 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -285,12 +285,21 @@ struct USBPacket {
     int pid;
     uint8_t devaddr;
     uint8_t devep;
-    uint8_t *data;
-    int len;
+    QEMUIOVector iov;
+    int result; /* transfer length or USB_RET_* status code */
     /* Internal use by the USB layer.  */
     USBDevice *owner;
 };
 
+void usb_packet_init(USBPacket *p);
+void usb_packet_setup(USBPacket *p, int pid, uint8_t addr, uint8_t ep);
+void usb_packet_addbuf(USBPacket *p, void *ptr, size_t len);
+int usb_packet_map(USBPacket *p, QEMUSGList *sgl);
+void usb_packet_unmap(USBPacket *p);
+void usb_packet_copy(USBPacket *p, void *ptr, size_t bytes);
+void usb_packet_skip(USBPacket *p, size_t bytes);
+void usb_packet_cleanup(USBPacket *p);
+
 int usb_handle_packet(USBDevice *dev, USBPacket *p);
 void usb_packet_complete(USBDevice *dev, USBPacket *p);
 void usb_cancel_packet(USBPacket * p);