[PATCH -V5 13/25] powerpc: Update tlbie/tlbiel as per ISA doc

[David Gibson]

On Thu, Apr 04, 2013 at 11:27:51AM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
> 
> This make sure we handle multiple page size segment correctly.

This needs a much more detailed message.  In what way was the existing
code not matching the ISA documentation?  What consequences did that
have?

> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> ---
>  arch/powerpc/mm/hash_native_64.c |   30 ++++++++++++++++++++++++++++--
>  1 file changed, 28 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
> index b461b2d..ac84fa6 100644
> --- a/arch/powerpc/mm/hash_native_64.c
> +++ b/arch/powerpc/mm/hash_native_64.c
> @@ -61,7 +61,10 @@ static inline void __tlbie(unsigned long vpn, int psize, int apsize, int ssize)
>  
>  	switch (psize) {
>  	case MMU_PAGE_4K:
> +		/* clear out bits after (52) [0....52.....63] */
> +		va &= ~((1ul << (64 - 52)) - 1);
>  		va |= ssize << 8;
> +		va |= mmu_psize_defs[apsize].sllp << 6;

sllp is the per-segment encoding, so it sure must be looked up via
psize, not apsize.

>  		asm volatile(ASM_FTR_IFCLR("tlbie %0,0", PPC_TLBIE(%1,%0), %2)
>  			     : : "r" (va), "r"(0), "i" (CPU_FTR_ARCH_206)
>  			     : "memory");
> @@ -69,9 +72,19 @@ static inline void __tlbie(unsigned long vpn, int psize, int apsize, int ssize)
>  	default:
>  		/* We need 14 to 14 + i bits of va */
>  		penc = mmu_psize_defs[psize].penc[apsize];
> -		va &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
> +		va &= ~((1ul << mmu_psize_defs[apsize].shift) - 1);
>  		va |= penc << 12;
>  		va |= ssize << 8;
> +		/* Add AVAL part */
> +		if (psize != apsize) {
> +			/*
> +			 * MPSS, 64K base page size and 16MB parge page size
> +			 * We don't need all the bits, but this seems to work.
> +			 * vpn cover upto 65 bits of va. (0...65) and we need
> +			 * 58..64 bits of va.

"seems to work" is not a comment I like to see in core MMU code...

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
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