[dpdk-dev,v2,6/7] virtio: fix pci accesses for ppc64 in legacy mode
Commit Message
From: David Marchand <david.marchand@6wind.com>
Although ppc supports both endianesses, qemu supposes that the cpu is
big endian and enforces this for the virtio-net stuff.
Fix PCI accesses in legacy mode. Only ppc64le is supported at the moment.
Signed-off-by: David Marchand <david.marchand@6wind.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
drivers/net/virtio/virtio_pci.c | 68 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
@@ -55,20 +55,88 @@
*/
#define VIRTIO_PCI_CONFIG(hw) (((hw)->use_msix) ? 24 : 20)
+/*
+ * Since we are in legacy mode:
+ * http://ozlabs.org/~rusty/virtio-spec/virtio-0.9.5.pdf
+ *
+ * "Note that this is possible because while the virtio header is PCI (i.e.
+ * little) endian, the device-specific region is encoded in the native endian of
+ * the guest (where such distinction is applicable)."
+ *
+ * For powerpc which supports both, qemu supposes that cpu is big endian and
+ * enforces this for the virtio-net stuff.
+ */
+
static void
legacy_read_dev_config(struct virtio_hw *hw, size_t offset,
void *dst, int length)
{
+#ifdef RTE_ARCH_PPC_64
+ int size;
+
+ while (length > 0) {
+ if (length >= 4) {
+ size = 4;
+ rte_eal_pci_ioport_read(&hw->io, dst, size,
+ VIRTIO_PCI_CONFIG(hw) + offset);
+ *(uint32_t *)dst = rte_be_to_cpu_32(*(uint32_t *)dst);
+ } else if (length >= 2) {
+ size = 2;
+ rte_eal_pci_ioport_read(&hw->io, dst, size,
+ VIRTIO_PCI_CONFIG(hw) + offset);
+ *(uint16_t *)dst = rte_be_to_cpu_16(*(uint16_t *)dst);
+ } else {
+ size = 1;
+ rte_eal_pci_ioport_read(&hw->io, dst, size,
+ VIRTIO_PCI_CONFIG(hw) + offset);
+ }
+
+ dst = (char *)dst + size;
+ offset += size;
+ length -= size;
+ }
+#else
rte_eal_pci_ioport_read(&hw->io, dst, length,
VIRTIO_PCI_CONFIG(hw) + offset);
+#endif
}
static void
legacy_write_dev_config(struct virtio_hw *hw, size_t offset,
const void *src, int length)
{
+#ifdef RTE_ARCH_PPC_64
+ union {
+ uint32_t u32;
+ uint16_t u16;
+ } tmp;
+ int size;
+
+ while (length > 0) {
+ if (length >= 4) {
+ size = 4;
+ tmp.u32 = rte_cpu_to_be_32(*(const uint32_t *)src);
+ rte_eal_pci_ioport_write(&hw->io, &tmp.u32, size,
+ VIRTIO_PCI_CONFIG(hw) + offset);
+ } else if (length >= 2) {
+ size = 2;
+ tmp.u16 = rte_cpu_to_be_16(*(const uint16_t *)src);
+ rte_eal_pci_ioport_write(&hw->io, &tmp.u16, size,
+ VIRTIO_PCI_CONFIG(hw) + offset);
+ } else {
+ size = 1;
+ rte_eal_pci_ioport_write(&hw->io, src, size,
+ VIRTIO_PCI_CONFIG(hw) + offset);
+ }
+
+ src = (const char *)src + size;
+ offset += size;
+ length -= size;
+ }
+#else
rte_eal_pci_ioport_write(&hw->io, src, length,
VIRTIO_PCI_CONFIG(hw) + offset);
+#endif
}
static uint64_t