Hello Michael,
On Tue, 2020-02-18 at 15:36 +1100, Michael Ellerman wrote:
> In kvmppc_unmap_free_pte() in book3s_64_mmu_radix.c, we use the
> non-constant value PTE_INDEX_SIZE to clear a PTE page.
>
> We can instead use the constant RADIX_PTE_INDEX_SIZE, because we know
> this code will only be running when the Radix MMU is active.
>
> Note that we already use RADIX_PTE_INDEX_SIZE for the allocation of
> kvm_pte_cache.
>
> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> ---
> arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> index 803940d79b73..134fbc1f029f 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> @@ -425,7 +425,7 @@ static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
> unsigned int lpid)
> {
> if (full) {
> - memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
> + memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
> } else {
> pte_t *p = pte;
> unsigned long it;
Looks fine to mee.
For book3s_64, pgtable.h says:
extern unsigned long __pte_index_size;
#define PTE_INDEX_SIZE __pte_index_size
powerpc/mm/pgtable_64.c defines/export the variable:
unsigned long __pte_index_size;
EXPORT_SYMBOL(__pte_index_size);
And book3s64/radix_pgtable.c set the value in radix__early_init_mmu().
__pte_index_size = RADIX_PTE_INDEX_SIZE;
So I think it's ok to use the value directly in book3s_64_mmu_radix.c.
The include dependency looks fine for that to work.
FWIW:
Reviewed-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx>
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