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usb: Convert usb_packet_{map, unmap} to universal DMA helpers

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The USB UHCI and EHCI drivers were converted some time ago to use the
pci_dma_*() helper functions.  However, this conversion was not complete
because in some places both these drivers do DMA via the usb_packet_map()
function in usb-libhw.c.  That function directly used
cpu_physical_memory_map().

Now that the sglist code uses DMA wrappers properly, we can convert the
functions in usb-libhw.c, thus conpleting the conversion of UHCI and EHCI
to use the DMA wrappers.

Note that usb_packet_map() invokes dma_memory_map() with a NULL invalidate
callback function.  When IOMMU support is added, this will mean that
usb_packet_map() and the corresponding usb_packet_unmap() must be called in
close proximity without dropping the qemu device lock - otherwise the guest
might invalidate IOMMU mappings while they are still in use by the device
code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
David Gibson 2012-06-27 14:50:42 +10:00 • committed by Anthony Liguori
parent 10ca2943aa
commit e2f89926f1
4 changed files with 15 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

21
hw/usb/libhw.c
View file

@ -26,15 +26,15 @@
int usb_packet_map(USBPacket *p, QEMUSGList *sgl)
{
int is_write = (p->pid == USB_TOKEN_IN);
target_phys_addr_t len;
DMADirection dir = (p->pid == USB_TOKEN_IN) ?
DMA_DIRECTION_FROM_DEVICE : DMA_DIRECTION_TO_DEVICE;
dma_addr_t len;
void *mem;
int i;
for (i = 0; i < sgl->nsg; i++) {
len = sgl->sg[i].len;
mem = cpu_physical_memory_map(sgl->sg[i].base, &len,
is_write);
mem = dma_memory_map(sgl->dma, sgl->sg[i].base, &len, dir);
if (!mem) {
goto err;
}
@ -46,18 +46,19 @@ int usb_packet_map(USBPacket *p, QEMUSGList *sgl)
return 0;
err:
usb_packet_unmap(p);
usb_packet_unmap(p, sgl);
return -1;
}
void usb_packet_unmap(USBPacket *p)
void usb_packet_unmap(USBPacket *p, QEMUSGList *sgl)
{
int is_write = (p->pid == USB_TOKEN_IN);
DMADirection dir = (p->pid == USB_TOKEN_IN) ?
DMA_DIRECTION_FROM_DEVICE : DMA_DIRECTION_TO_DEVICE;
int i;
for (i = 0; i < p->iov.niov; i++) {
cpu_physical_memory_unmap(p->iov.iov[i].iov_base,
p->iov.iov[i].iov_len, is_write,
p->iov.iov[i].iov_len);
dma_memory_unmap(sgl->dma, p->iov.iov[i].iov_base,
p->iov.iov[i].iov_len, dir,
p->iov.iov[i].iov_len);
}
}