Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs

From	Will Deacon <will.deacon@arm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs
Date	2017-03-22 15:20 +0100
Message-ID	<tnPhh-3Fu-59@gated-at.bofh.it> (permalink)
References	<tnOuR-32T-7@gated-at.bofh.it> <tnOEz-37h-39@gated-at.bofh.it> <tnOXU-3fe-11@gated-at.bofh.it> <tnP7z-3yz-1@gated-at.bofh.it> <tnPhh-3Fu-61@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed, Mar 22, 2017 at 10:15:04AM -0400, Sinan Kaya wrote:
> On 3/22/2017 10:04 AM, David Woodhouse wrote:
> > On Wed, 2017-03-22 at 09:54 -0400, Sinan Kaya wrote:
> >> On 3/22/2017 9:25 AM, David Woodhouse wrote:
> >>>
> >>>  
> >>> +#ifdef __aarch64__
> >>> +/* ARM64 wants to be special and not expose this through /proc
> >>> like everyone else */
> >>> +#undef HAVE_PCI_MMAP
> >>> +#endif
> >>> +
> >> Where is this ARM64 special requirement coming from?
> > 
> > The idea is that as a new platform, ARM64 shouldn't need to implement
> > legacy userspace interfaces.
> > 
> > http://lists.infradead.org/pipermail/linux-arm-kernel/2016-April/422571.html
> > 
> 
> Aren't we breaking an ABI for userspace? I know DPDK relies on this feature.

It relies on the /proc interface? That's the first I've ever heard of that
-- everybody so far has only been interested in the sysfs stuff.

Nothing's more broken than before, because we've never supported the /proc
interface, but if existing arm64 code out there is failing because of that
then I'm of course open to supporting it. I'm just surprised that nobody
else has come up with that before, since DPDK is in common use.

Can you point me at the specific code, please?

Will

Thread

[PATCH 00/17] PCI resource mmap cleanup David Woodhouse <dwmw2@infradead.org> - 2017-03-22 14:40 +0100
  [PATCH 04/17] pci: Add arch_can_pci_mmap_wc() macro David Woodhouse <dwmw2@infradead.org> - 2017-03-22 14:40 +0100
  [PATCH 15/17] sh: Use generic pci_mmap_resource_range() David Woodhouse <dwmw2@infradead.org> - 2017-03-22 14:40 +0100
  [PATCH 10/17] arm: Use generic pci_mmap_resource_range() David Woodhouse <dwmw2@infradead.org> - 2017-03-22 14:40 +0100
  [PATCH 17/17] arm64: Do not expose PCI mmap through procfs David Woodhouse <dwmw2@infradead.org> - 2017-03-22 14:40 +0100
    Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs Sinan Kaya <okaya@codeaurora.org> - 2017-03-22 15:00 +0100
      Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs David Woodhouse <dwmw2@infradead.org> - 2017-03-22 15:10 +0100
        Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs Will Deacon <will.deacon@arm.com> - 2017-03-22 15:20 +0100
          Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs Sinan Kaya <okaya@codeaurora.org> - 2017-03-22 16:50 +0100
        Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs Sinan Kaya <okaya@codeaurora.org> - 2017-03-22 15:20 +0100
    Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs Arnd Bergmann <arnd@arndb.de> - 2017-03-24 17:20 +0100
      Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs Arnd Bergmann <arnd@arndb.de> - 2017-03-24 17:20 +0100
        Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs David Woodhouse <dwmw2@infradead.org> - 2017-03-24 17:30 +0100
      Re: [PATCH 17/17] arm64: Do not expose PCI mmap through procfs David Woodhouse <dwmw2@infradead.org> - 2017-03-24 17:30 +0100
  [PATCH 18/17] x86: Use generic pci_mmap_resource_range() David Woodhouse <dwmw2@infradead.org> - 2017-03-23 15:30 +0100
  Re: [PATCH 00/17] PCI resource mmap cleanup David Woodhouse <dwmw2@infradead.org> - 2017-03-24 12:50 +0100
    Re: [PATCH 00/17] PCI resource mmap cleanup "Luck, Tony" <tony.luck@intel.com> - 2017-03-24 18:00 +0100
  Re: [PATCH 00/17] PCI resource mmap cleanup Arnd Bergmann <arnd@arndb.de> - 2017-03-24 17:30 +0100

csiph-web