Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap

From	Russell King - ARM Linux <linux@armlinux.org.uk>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap
Date	2016-05-18 23:00 +0200
Message-ID	<rAgJs-6ZU-21@gated-at.bofh.it> (permalink)
References	<rx1dT-5zE-1@gated-at.bofh.it> <rAaun-3d5-41@gated-at.bofh.it> <rAdVf-5eB-11@gated-at.bofh.it> <rAggp-6OT-3@gated-at.bofh.it>
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On Wed, May 18, 2016 at 10:25:03PM +0200, Arnd Bergmann wrote:
> The ARM version of ioremap_exec() that gets added in this patch is cached
> (like memremap()), but then the asm-generic version is not? This is
> even more confusing, it should at least do roughly the same thing across
> architectures.
> 
> There should also be some documentation about what the expected behavior is, e.g.:
> 
> - is memremap_exec() by default cached or not? (I assume it would
>   be like memremap())
> - If we have an interface that does explicit uncached executable mapping,
>   what about architectures on which this is not possible? Should they
>   fall back to cached or non-executable, or cause a link error?  

Another important point is whether atomic instructions / kernel locks
can be located within the mapped memory.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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Thread

Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap Russell King - ARM Linux <linux@armlinux.org.uk> - 2016-05-12 18:40 +0200
  Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap Dave Gerlach <d-gerlach@ti.com> - 2016-05-18 16:20 +0200
    Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap Russell King - ARM Linux <linux@armlinux.org.uk> - 2016-05-18 20:00 +0200
      Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap Arnd Bergmann <arnd@arndb.de> - 2016-05-18 22:30 +0200
        Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap Russell King - ARM Linux <linux@armlinux.org.uk> - 2016-05-18 23:00 +0200
          Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap Dave Gerlach <d-gerlach@ti.com> - 2016-05-25 17:50 +0200

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