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Date: Wed, 18 May 2016 21:57:59 +0100
From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Gerlach <d-gerlach@ti.com>, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
        Russ Dill <russ.dill@ti.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
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        Alexandre Belloni <alexandre.belloni@free-electrons.com>,
        Nishanth Menon <nm@ti.com>
Subject: Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap
Message-ID: <20160518205758.GY5783@n2100.arm.linux.org.uk>
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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.

-- 
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