[PATCH v2 0/3] fix memremap on ARM

[Dan Williams]

On Thu, Mar 3, 2016 at 9:16 AM, Ard Biesheuvel
<ard.biesheuvel at linaro.org> wrote:
> On 3 March 2016 at 18:13, Russell King - ARM Linux
> <linux at arm.linux.org.uk> wrote:
>> On Thu, Mar 03, 2016 at 05:24:41PM +0100, Ard Biesheuvel wrote:
>>> If there are no remaining objections, may I suggest that Dan takes
>>> patch #1 and #2, and that I put the third patch into Russell's patch
>>> system? The only strict ordering requirement is that #1 is merged
>>> before #2 and #3 both hit mainline, and that is solved by taking #1
>>> and #2 in order.
>>
>> How does the dependency between 1 and 3 get satisfied?  Your comment
>> makes no sense to me.
>>
>
> Patch #3 introduces a function arch_memremap_wb() on the ARM side
> which will never get called unless patch #2 is also merged. Once both
> #2 and #3 are in, the memremap() call that #1 reverts will use
> MT_MEMORY_RW attributes rather than MT_DEVICE_CACHED, so #1 needs to
> go first, but #2 and #3 can go in in either order.
>
> In other words, there are no build dependencies between the patches,
> but to prevent pxa2xx-flash from using MT_MEMORY_RW attributes, it
> needs to go in before #2

Can we add a new MEMREMAP_ type for this case so that we don't need to
keep carrying the confusing ioremap_cache() which means different
things to different archs and silently falls back to uncached on some
archs.