[PATCH 04/14] ARM: v6k: introduce CPU_V6K option

Russell King - ARM Linux linux at arm.linux.org.uk
Tue Jan 18 08:35:59 EST 2011

On Tue, Jan 18, 2011 at 11:09:22AM +0000, Russell King - ARM Linux wrote:
> I'd rather not in this patch - this patch adds CPU_V6K as an alias for
> CPU_V6 - so eveywhere which referenced CPU_V6 becomes (CPU_V6 || CPU_V6K).
> We could remove it in a later patch though.

Here's a follow-up patch to do that.  There's a few other things which
could do with updating now that we have CPU_Vx* straightened out.  I've
also recently noticed that the v6 and v7 cache stuff doesn't use the
direct-call optimization (see commented out bits in cacheflush.h).

That was because my original V6 support used the block cache operations,
which had to be run-time tested for presence, and so modified the
global cpu_cache methods directly.  As the block cache stuff was dropped,
we should re-enable this optimization.

That said, I'd rather not add too much to this series as I think it needs
to go into mainline ASAP - and probably stable as well, even though it's
on the large side - once properly and fully tested.

Subject: [PATCH] ARM: v6k: DMA_CACHE_RWFO isn't appropriate for non-v6k CPUs

Limit DMA_CACHE_RWFO to only v6k SMP CPUs - V6 CPUs aren't SMP capable,
so the read/write for ownership work-around doesn't apply to them.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
 arch/arm/mm/Kconfig |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 843bc8c..808b832 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -775,7 +775,7 @@ config NEEDS_SYSCALL_FOR_CMPXCHG
 	bool "Enable read/write for ownership DMA cache maintenance"
-	depends on (CPU_V6 || CPU_V6K) && SMP
+	depends on CPU_V6K && SMP
 	default y
 	  The Snoop Control Unit on ARM11MPCore does not detect the

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