[PATCH v2] ARM: Define wfi() macro for v6 processors

-----Original Message-----
From: Dave Martin [mailto:dave.martin at linaro.org]
Sent: Tuesday, February 08, 2011 5:52 PM
To: Arnd Bergmann
Cc: linux-arm-kernel at lists.infradead.org; Russell King - ARM Linux;
Nicolas Pitre; Tony Lindgren; Santosh Shilimkar; linux-
omap at vger.kernel.org; Jean Pihet
Subject: Re: [PATCH v2] ARM: Define wfi() macro for v6 processors

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On Tue, Feb 08, 2011 at 11:01:25AM +0000, Dave Martin wrote:

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For v6, wfi is architected as a defined MCR instruction, so
use that definition.

[...]

On Tue, Feb 08, 2011 at 01:11:51PM +0100, Arnd Bergmann wrote:

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I don't see any users of the sev/wfe/wfi macros in the current

kernel,

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so removing them seems like a good strategy to avoid people from
using them incorrectly.

If the definitions differ between v5/v6/v7 CPUs, any common code
using them would need to do either binary patching of some sort
or abstract the difference between the CPU in some other way.

Dave, what code do you have in mind as a possible user?

The OMAP BSP has its own version of this, which I'm suggesting
to port to the more generic macros in system.h, now that they
exist.

Omap 'sev' version is removed some time back. We were keeping
WFI opcode version because of V6 and V7 compatibility issue. With
resent CPU_32v6K from Russell, that should also get addressed.

I shall remove the omap wfi version as soon as RMK's series is
merged.

Regards,
Santosh