On Wed, Dec 16, 2015 at 07:31:57PM +0530, Santosh Shukla wrote:
> On Wed, Dec 16, 2015 at 7:18 PM, Yuanhan Liu
> <yuanhan.liu at linux.intel.com> wrote:
> > On Mon, Dec 14, 2015 at 06:30:24PM +0530, Santosh Shukla wrote:
> >> In x86 case io_base to store ioport address not more than 65535 ioports.
> >> i.e..0
> >> to ffff but in non-x86 case in particular arm64 it need to store more than
> >> 32
> >> bit address so changing io_base datatype from 32 to 64.
> >>
> >> Signed-off-by: Santosh Shukla <sshukla at mvista.com>
> >> ---
> >> drivers/net/virtio/virtio_ethdev.c | 2 +-
> >> drivers/net/virtio/virtio_pci.h | 4 ++--
> >> 2 files changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/net/virtio/virtio_ethdev.c
> >> b/drivers/net/virtio/virtio_ethdev.c
> >> index d928339..620e0d4 100644
> >> --- a/drivers/net/virtio/virtio_ethdev.c
> >> +++ b/drivers/net/virtio/virtio_ethdev.c
> >> @@ -1291,7 +1291,7 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
> >> return -1;
> >>
> >> hw->use_msix = virtio_has_msix(&pci_dev->addr);
> >> - hw->io_base = (uint32_t)(uintptr_t)pci_dev->mem_resource[0].addr;
> >> + hw->io_base = (uint64_t)(uintptr_t)pci_dev->mem_resource[0].addr;
> >
> > I'd suggest to move the io_base assignment (and cast) into
> > virtio_ioport_init()
> > so that we could do the correct cast there, say cast it to uint32_t for
> > X86, and uint64_t for others.
> >
>
> Ok.
>
> This was deliberately done considering your 1.0 virtio spec patch do
> care for uint64_t types and in arm64 case, If I plan to use those
> future patches, IMO it make more sense to me keep it in uint64_t way;
I did different cast, 32 bit for legacy virtio pci device, and 64 bit
for modern virtio pci device.
> Also in x86 case max address could of type 0x1000-101f and so forth;
> changing data-type to uint64_t default wont effect such address,
> right?
Right, but what's the harm of doing the right cast? :)
> And hw->io_base by looking at virtio_pci.h function like
> inb/outb etc.. takes io_base address as unsigned long types which is
> arch dependent; i.e.. 4 byte for 32 bit and 8 for 64 bit so the lower
> level rd/wr apis are taking care of data-types accordingly.
Didn't get it. inb/outb takes "unsigned short" arguments, but not
"unsigned long".
--yliu
