Messages in this thread | | | Subject | Re: [GIT PULL 1/2] asm-generic: rework PCI I/O space access | From | John Garry <> | Date | Fri, 17 Dec 2021 15:27:09 +0000 |
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On 17/12/2021 14:32, Arnd Bergmann wrote: >> I was interesting in the IOPORT_NATIVE flag (or whatever we call it) as >> it solves the problem of drivers which "unconditionally do inb()/outb() >> without checking the validity of the address using firmware or other >> methods first" being built for (and loaded on and crashing) unsuitable >> systems. Such a problem is in [0] >> >> So if we want to support that later, then it seems that someone would >> need to go back and re-edit many same driver Kconfigs – like hwmon, for >> example. I think it's better to avoid that and do it now. >> >> Arnd, any opinion on that? >> >> I'm happy to help with that effort. > I looked at the options the other day and couldn't really find any that > fell into this category, so I suggested that Niklas would skip that for the > moment.
From looking at the patch Niklas directed us at, as I understand, HAS_IOPORT is to decide whether the arch/platform may support PIO accessors - inb et al. And on that basis I am confused why it is not selected for arm64. And further compounded by:
config INDIRECT_PIO bool "Access I/O in non-MMIO mode" depends on ARM64 + depends on HAS_IOPORT
If arm64 does not select, then why depend on it?
> If you have a better way of finding the affected drivers, > that would be great.
Assuming arm64 should select HAS_IOPORT, I am talking about f71805f as an example. According to that patch, this driver additionally depends on HAS_IOPORT; however I would rather arm64, like powerpc, should not allow that driver to be built at all.
Thanks, John
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