On Wed, Dec 16, 2015 at 7:53 PM, Yuanhan Liu <yuanhan.liu at linux.intel.com> wrote: > 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? :) >
Agree. >> 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". > sys/io.h in x86 case using unsigned short int types.. include/asm-generic/io.h for arm64 using it unsigned long (from linux header files) In such case keeping #define VIRTIO_PCI_REG_ADDR(hw, reg) \ (unsigned short)((hw)->io_base + (reg)) would be x86 specific and what I thought and used in this patch is #define VIRTIO_PCI_REG_ADDR(hw, reg) \ (unsigned long)((hw)->io_base + (reg)) to avoid ifdef ARM or non-x86..clutter, I know data-type is not right fit for x86 sys/io.h but considering possible address inside hw->io_base, wont effect functionality and performance my any mean. That is why at virtio_ethdev_init() i choose to keep it in hw->io_base = (uint64_t) types. Otherwise I'll have to duplicate VIRTIO_PCI_REG_XXX definition for non-x86 case, Pl. suggest better alternative. Thanks > --yliu
