usb: USBPacket: add status, rename owner -> ep

Add enum to track the status of USBPackets, use that instead of the
owner pointer to figure whenever a usb packet is currently in flight
or not.  Add some more packet status sanity checks.  Also rename the
USBEndpoint pointer from "owner" to "ep".

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

hw/usb-ehci.c

@@ -715,8 +715,8 @@ static void ehci_queues_rip_device(EHCIState *ehci, USBDevice *dev)
     EHCIQueue *q, *tmp;
 
     QTAILQ_FOREACH_SAFE(q, &ehci->queues, next, tmp) {
-        if (q->packet.owner == NULL ||
+        if (!usb_packet_is_inflight(&q->packet) ||
-            q->packet.owner->dev != dev) {
+            q->packet.ep->dev != dev) {
             continue;
         }
         ehci_free_queue(q);

hw/usb-musb.c

@@ -811,8 +811,8 @@ static void musb_async_cancel_device(MUSBState *s, USBDevice *dev)
 
     for (ep = 0; ep < 16; ep++) {
         for (dir = 0; dir < 2; dir++) {
-            if (s->ep[ep].packey[dir].p.owner == NULL ||
+            if (!usb_packet_is_inflight(&s->ep[ep].packey[dir].p) ||
-                s->ep[ep].packey[dir].p.owner->dev != dev) {
+                s->ep[ep].packey[dir].p.ep->dev != dev) {
                 continue;
             }
             usb_cancel_packet(&s->ep[ep].packey[dir].p);

hw/usb-ohci.c

@@ -1709,8 +1709,8 @@ static void ohci_mem_write(void *opaque,
 static void ohci_async_cancel_device(OHCIState *ohci, USBDevice *dev)
 {
     if (ohci->async_td &&
-        ohci->usb_packet.owner != NULL &&
+        usb_packet_is_inflight(&ohci->usb_packet) &&
-        ohci->usb_packet.owner->dev == dev) {
+        ohci->usb_packet.ep->dev == dev) {
         usb_cancel_packet(&ohci->usb_packet);
         ohci->async_td = 0;
     }

hw/usb-uhci.c

@@ -236,8 +236,8 @@ static void uhci_async_cancel_device(UHCIState *s, USBDevice *dev)
     UHCIAsync *curr, *n;
 
     QTAILQ_FOREACH_SAFE(curr, &s->async_pending, next, n) {
-        if (curr->packet.owner == NULL ||
+        if (!usb_packet_is_inflight(&curr->packet) ||
-            curr->packet.owner->dev != dev) {
+            curr->packet.ep->dev != dev) {
             continue;
         }
         uhci_async_unlink(s, curr);

hw/usb.c

@@ -291,7 +291,7 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p)
     }
     assert(dev->addr == p->devaddr);
     assert(dev->state == USB_STATE_DEFAULT);
-    assert(p->owner == NULL);
+    assert(p->state == USB_PACKET_SETUP);
 
     if (p->devep == 0) {
         /* control pipe */
@@ -315,7 +315,8 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p)
     }
 
     if (ret == USB_RET_ASYNC) {
-        p->owner = usb_ep_get(dev, p->pid, p->devep);
+        p->ep = usb_ep_get(dev, p->pid, p->devep);
+        p->state = USB_PACKET_ASYNC;
     }
     return ret;
 }
@@ -325,8 +326,8 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p)
    handle_packet. */
 void usb_packet_complete(USBDevice *dev, USBPacket *p)
 {
-    assert(p->owner != NULL);
+    assert(p->state == USB_PACKET_ASYNC);
-    p->owner = NULL;
+    p->state = USB_PACKET_COMPLETE;
     dev->port->ops->complete(dev->port, p);
 }
 
@@ -335,9 +336,9 @@ void usb_packet_complete(USBDevice *dev, USBPacket *p)
    completed.  */
 void usb_cancel_packet(USBPacket * p)
 {
-    assert(p->owner != NULL);
+    assert(p->state == USB_PACKET_ASYNC);
-    usb_device_cancel_packet(p->owner->dev, p);
+    p->state = USB_PACKET_CANCELED;
-    p->owner = NULL;
+    usb_device_cancel_packet(p->ep->dev, p);
 }
 
 
@@ -348,6 +349,8 @@ void usb_packet_init(USBPacket *p)
 
 void usb_packet_setup(USBPacket *p, int pid, uint8_t addr, uint8_t ep)
 {
+    assert(!usb_packet_is_inflight(p));
+    p->state = USB_PACKET_SETUP;
     p->pid = pid;
     p->devaddr = addr;
     p->devep = ep;
@@ -391,6 +394,7 @@ void usb_packet_skip(USBPacket *p, size_t bytes)
 
 void usb_packet_cleanup(USBPacket *p)
 {
+    assert(!usb_packet_is_inflight(p));
     qemu_iovec_destroy(&p->iov);
 }
 

hw/usb.h

@@ -289,8 +289,7 @@ typedef struct USBPortOps {
     void (*wakeup)(USBPort *port);
     /*
      * Note that port->dev will be different then the device from which
-     * the packet originated when a hub is involved, if you want the orginating
+     * the packet originated when a hub is involved.
-     * device use p->owner
      */
     void (*complete)(USBPort *port, USBPacket *p);
 } USBPortOps;
@@ -309,15 +308,24 @@ struct USBPort {
 typedef void USBCallback(USBPacket * packet, void *opaque);
 
 /* Structure used to hold information about an active USB packet.  */
+typedef enum USBPacketState {
+    USB_PACKET_UNDEFINED = 0,
+    USB_PACKET_SETUP,
+    USB_PACKET_ASYNC,
+    USB_PACKET_COMPLETE,
+    USB_PACKET_CANCELED,
+} USBPacketState;
+
 struct USBPacket {
     /* Data fields for use by the driver.  */
     int pid;
     uint8_t devaddr;
     uint8_t devep;
+    USBEndpoint *ep;
     QEMUIOVector iov;
     int result; /* transfer length or USB_RET_* status code */
     /* Internal use by the USB layer.  */
-    USBEndpoint *owner;
+    USBPacketState state;
 };
 
 void usb_packet_init(USBPacket *p);
@@ -329,6 +337,11 @@ 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);
 
+static inline bool usb_packet_is_inflight(USBPacket *p)
+{
+    return p->state == USB_PACKET_ASYNC;
+}
+
 USBDevice *usb_find_device(USBPort *port, uint8_t addr);
 
 int usb_handle_packet(USBDevice *dev, USBPacket *p);