With the IOMMU infrastructure introduced before 1.2, we need to use
dma_memory_map() to obtain a qemu pointer to memory from an IO bus address.
However, dma_memory_map() alters the given length to reflect the length
over which the used DMA translation is valid - which could be either more
or less than the requested length.
usb_packet_map() does not correctly handle these cases, simply failing if
dma_memory_map() alters the requested length. If dma_memory_map()
increased the length, we just need to use the requested length for the
qemu_iovec_add(). However, if it decreased the length, it means that a
single DMA translation is not valid for the whole sglist element, and so
we need to loop, splitting it up into multiple iovec entries for each
piece with a DMA translation (in practice >2 pieces is unlikely).
This patch implements the correct behaviour
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
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>
Reorganize usb source files. Create a new hw/usb/ directory and move
all usb source code to that place. Also make filenames a bit more
descriptive. Host adapters are prefixed with "hch-" now, usb device
emulations are prefixed with "dev-". Fixup paths Makefile and include
paths to make it compile. No code changes.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
