Re: [dpdk-dev] [ [PATCH v2] 07/13] linuxapp: eal: arm: Always return 0 for rte_eal_iopl_init()

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

On Mon, Dec 14, 2015 at 08:54:08PM +0530, Santosh Shukla wrote:
> On Mon, Dec 14, 2015 at 8:07 PM, Jerin Jacob
> <jerin.jacob@caviumnetworks.com> wrote:
> > On Mon, Dec 14, 2015 at 06:30:26PM +0530, Santosh Shukla wrote:
> >> iopl() syscall not supported in linux-arm/arm64 so always return 0 value.
> >>
> >> Signed-off-by: Santosh Shukla <sshukla@mvista.com>
> >> ---
> >>  lib/librte_eal/linuxapp/eal/eal.c |    3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
> >> index 635ec36..2617037 100644
> >> --- a/lib/librte_eal/linuxapp/eal/eal.c
> >> +++ b/lib/librte_eal/linuxapp/eal/eal.c
> >> @@ -716,6 +716,9 @@ rte_eal_iopl_init(void)
> >>               return -1;
> >>       return 0;
> >>  #else
> >> +#if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64)
> >> +     return 0; /* iopl syscall not supported for ARM/ARM64 */
> >
> > I guess for other architectures also iopl not supported.I think better
> > to move this function to eal. Else this function will return 'true' for
> > ppc64
> >
> 
> didn't understood. This func is in eal right? and for ppc64, function

meant to abstract through lib/librte_eal/common/include/arch/
to avoid #ifdef clutter

> will return -1 (false). Although i could include ppc64 / tile or
> invert the logic such a way that non-x86 arch to return default true
> value.
> 
> However iopl() used for virtio and only two arch using x86/ now arm. I
> am not sure ppc64/tile or other arch has any plan to use virtio pmd
> thus care for iopl().

Why not? With your patch, dpdk-virtio has very minimal dependency on
architecture (implementing raw_*) or even we can have generic routine for that

> 
> > or have at least postive logic,
> > #if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) ||
> > defined(RTE_ARCH_X86_X32)
> >
> >
> >> +#endif
> >>       return -1;
> >>  #endif
> >>  }
> >> --
> >> 1.7.9.5
> >>