Fix issues with ARMv6+v6k+v7 kernels

Quoted 29 lines · Russell King - ARM Linux

Quoted 8 lines · Tony Lindgren

Quoted 7 lines · Santosh Shilimkar

Quoted 7 lines

From: Dave Martin [mailto:dave.martin at linaro.org]

You could also have a "v7+" unified kernel -- i.e., supporting OMAP3+4+SMP.
This is what we currently do in Linaro, since we're focusing on v7 and above.

Quoted 8 lines

Quoted 4 lines

This sounds good way forward considering future OMAP architectures as well.

But I let Tony comment on this idea.

AFAIK these issues will be hopefully sorted out by the time the next merge window opens. For the -rc cycle, disabling SMP in config if ARMv6 is selected should do the trick.

That's not soo easy - as we don't know in the Kconfig whether we include ARMv6 rather than ARMv6K. It's exactly the same problem I ran into which inflated the v6v7 patchset.

Maybe the best thing to do is:

config CPU_32v6K

        bool "Support ARM V6K processor extensions" if !SMP
        depends on CPU_V6 || CPU_V7
        default y if SMP && !(ARCH_MX3 || ARCH_OMAP2)

Quoted 4 lines

drop the ' && !(ARCH_MX3 || ARCH_OMAP2)' and just let people run into the resulting undefined instruction traps if they try to run the kernel on V6 non-K hardware. Not ideal, but I don't see any other 'simple' solution to this.

This should be good enough. We're looking for a temporary stopgate solution to prevent people from corrupting their data, and the real fix will be available in the next kernel.