Messages in this thread | | | Subject | Re: [PATCH v2 2/3] ARM: Use include/asm-generic/io.h | From | Catalin Marinas <> | Date | Sat, 12 Jul 2014 15:18:11 +0100 |
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On 12 Jul 2014, at 13:27, Arnd Bergmann <arnd@arndb.de> wrote:
> On Friday 11 July 2014, Catalin Marinas wrote: >> >> On Fri, Jul 11, 2014 at 04:31:11PM +0100, Thierry Reding wrote: >>> diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h >>> index a78562f21aab..ef54f5c8a7ae 100644 >>> --- a/arch/arm/include/asm/io.h >>> +++ b/arch/arm/include/asm/io.h >> [...] >>> -#define iowrite16be(v,p) ({ __iowmb(); __raw_writew((__force __u16)cpu_to_be16(v), p); }) >>> -#define iowrite32be(v,p) ({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); }) >> >> Aren't you losing the barrier semantics here? The generic iowrite*be() >> functions call __raw_write*() directly which don't have a barrier >> (write* accessors do). > > Indeed, sorry for missing this. The generic implementation still makes sense for > include/asm-generic, but arm32 and arm64 must provide their own versions here.
I think this would be the easiest. But the asm-generic/io.h needs some #ifndef iowrite16be checks.
(in arm64 we missed the iowrite*be barriers completely, so not broken by this patch; Thierry could update arm64 as well with patch 3/3)
Catalin
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