linux-kernel - Re: [PATCH] MIPS: c-r4k: Fix size calc when avoiding IPIs for small icache flushes

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Date:   Wed, 7 Sep 2016 16:34:59 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Paul Burton <paul.burton@...tec.com>, linux-mips@...ux-mips.org
Cc:     James Hogan <james.hogan@...tec.com>,
        Huacai Chen <chenhc@...ote.com>, linux-kernel@...r.kernel.org,
        Ralf Baechle <ralf@...ux-mips.org>
Subject: Re: [PATCH] MIPS: c-r4k: Fix size calc when avoiding IPIs for small
 icache flushes

On 09/05/2016 07:24 AM, Paul Burton wrote:
> Commit f70ddc07b637 ("MIPS: c-r4k: Avoid small flush_icache_range SMP
> calls") adds checks to force use of hit-type cache ops for small icache
> flushes where they are globalised & index-type cache ops aren't, in
> order to avoid the overhead of IPIs in those cases. However it
> calculated the size of the region being flushed incorrectly, subtracting
> the end address from the start address rather than the reverse. This
> would have led to an overflow with size wrapping round to some large
> value, and likely to the special case for avoiding IPIs not actually
> being hit.
> 
> Signed-off-by: Paul Burton <paul.burton@...tec.com>
> Cc: James Hogan <james.hogan@...tec.com>
> Fixes: f70ddc07b637 ("MIPS: c-r4k: Avoid small flush_icache_range SMP calls")

Reviewed-by: Florian Fainelli <f.fainelli@...il.com>

Yes would be good to get that in v4.8.
-- 
Florian