r174051 | cognet | 2007-11-28 14:21:17 -0800 (Wed, 28 Nov 2007) | 6 lines

Correct the logic : we can just invalidate the cache lines, and not
write-back them, only if PREWRITE is not set, and if the buffer is
cache-line aligned.

MFC After:	1 week

Index: sys/arm/arm/busdma_machdep.c
===================================================================
--- sys/arm/arm/busdma_machdep.c	(revision 174050)
+++ sys/arm/arm/busdma_machdep.c	(revision 174051)
@@ -1090,7 +1090,7 @@
 		cpu_l2cache_wb_range((vm_offset_t)buf, len);
 	}
 	if (op & BUS_DMASYNC_PREREAD) {
-		if ((op & BUS_DMASYNC_PREWRITE) ||
+		if (!(op & BUS_DMASYNC_PREWRITE) &&
 		    ((((vm_offset_t)(buf) | len) & arm_dcache_align_mask) == 0)) {
 			cpu_dcache_inv_range((vm_offset_t)buf, len);
 			cpu_l2cache_inv_range((vm_offset_t)buf, len);



r177457 | sam | 2008-03-20 09:04:13 -0700 (Thu, 20 Mar 2008) | 8 lines

Correct cache handling for xfer requests marked URQ_REQUEST: many (if not
all uses) involve a read but usbd_start_transfer only does a PREWRITE; change
this to BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE as I'm not sure if any
users do write+read.

Reviewed by:	cognet, imp
MFC after:	1 month

Index: sys/dev/usb/usbdi.c
===================================================================
--- sys/dev/usb/usbdi.c	(revision 177456)
+++ sys/dev/usb/usbdi.c	(revision 177457)
@@ -384,7 +384,8 @@
 			 * sync the dmamap for the request data in the SETUP
 			 * packet.
 			 */
-			bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE);
+			bus_dmamap_sync(tag, dmap->map,
+			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 		} else
 			bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREREAD);
 	}



r177459 | sam | 2008-03-20 09:19:25 -0700 (Thu, 20 Mar 2008) | 12 lines

Workaround design botch in usb: blindly mixing bus_dma with PIO does not
work on architectures with a write-back cache as the PIO writes end up
in the cache which the sync(BUS_DMASYNC_POSTREAD) in usb_transfer_complete
then discards; compensate in the xfer methods that do PIO by pushing the
writes out of the cache before usb_transfer_complete is called.

This fixes USB on xscale and likely other places.

Sponsored by:	hobnob
Reviewed by:	cognet, imp
MFC after:	1 month

Index: sys/dev/usb/ohci.c
===================================================================
--- sys/dev/usb/ohci.c	(revision 177458)
+++ sys/dev/usb/ohci.c	(revision 177459)
@@ -1560,6 +1560,20 @@
 	xfer->hcpriv = NULL;
 }
 
+/*
+ * XXX write back xfer data for architectures with a write-back
+ *     data cache; this is a hack because usb is mis-architected
+ *     in blindly mixing bus_dma w/ PIO.
+ */
+static __inline void
+hacksync(usbd_xfer_handle xfer)
+{
+	usbd_pipe_handle pipe = xfer->pipe;
+	bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag;
+	struct usb_dma_mapping *dmap = &xfer->dmamap;
+	bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE);
+}
+
 void
 ohci_rhsc(ohci_softc_t *sc, usbd_xfer_handle xfer)
 {
@@ -1591,6 +1605,7 @@
 	xfer->actlen = xfer->length;
 	xfer->status = USBD_NORMAL_COMPLETION;
 
+	hacksync(xfer);	/* XXX to compensate for usb_transfer_complete */
 	usb_transfer_complete(xfer);
 }
 
@@ -2722,6 +2737,7 @@
  ret:
 	xfer->status = err;
 	s = splusb();
+	hacksync(xfer);	/* XXX to compensate for usb_transfer_complete */
 	usb_transfer_complete(xfer);
 	splx(s);
 	return (USBD_IN_PROGRESS);
Index: sys/dev/usb/ehci.c
===================================================================
--- sys/dev/usb/ehci.c	(revision 177458)
+++ sys/dev/usb/ehci.c	(revision 177459)
@@ -653,6 +653,20 @@
 	ehci_pcd_able(sc, 1);
 }
 
+/*
+ * XXX write back xfer data for architectures with a write-back
+ *     data cache; this is a hack because usb is mis-architected
+ *     in blindly mixing bus_dma w/ PIO.
+ */
+static __inline void
+hacksync(usbd_xfer_handle xfer)
+{
+	usbd_pipe_handle pipe = xfer->pipe;
+	bus_dma_tag_t tag = pipe->device->bus->buffer_dmatag;
+	struct usb_dma_mapping *dmap = &xfer->dmamap;
+	bus_dmamap_sync(tag, dmap->map, BUS_DMASYNC_PREWRITE);
+}
+
 void
 ehci_pcd(ehci_softc_t *sc, usbd_xfer_handle xfer)
 {
@@ -679,6 +693,7 @@
 	xfer->actlen = xfer->length;
 	xfer->status = USBD_NORMAL_COMPLETION;
 
+	hacksync(xfer);	/* XXX to compensate for usb_transfer_complete */
 	usb_transfer_complete(xfer);
 }
 
@@ -2072,6 +2087,7 @@
  ret:
 	xfer->status = err;
 	s = splusb();
+	hacksync(xfer);	/* XXX to compensate for usb_transfer_complete */
 	usb_transfer_complete(xfer);
 	splx(s);
 	return (USBD_IN_PROGRESS);