Re: [RFC v6 06/62] powerpc: use helper functions in __hash_page_64K() for 64K PTE

From: Aneesh Kumar K.V
Date: Thu Jul 20 2017 - 01:58:35 EST


Ram Pai <linuxram@xxxxxxxxxx> writes:

> replace redundant code in __hash_page_64K() with helper
> functions pte_get_hash_gslot() and pte_set_hash_slot()
>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>


> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
> ---
> arch/powerpc/mm/hash64_64k.c | 24 ++++--------------------
> 1 files changed, 4 insertions(+), 20 deletions(-)
>
> diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
> index 0012618..645f621 100644
> --- a/arch/powerpc/mm/hash64_64k.c
> +++ b/arch/powerpc/mm/hash64_64k.c
> @@ -244,7 +244,6 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
> unsigned long flags, int ssize)
> {
> real_pte_t rpte;
> - unsigned long *hidxp;
> unsigned long hpte_group;
> unsigned long rflags, pa;
> unsigned long old_pte, new_pte;
> @@ -289,18 +288,12 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
>
> vpn = hpt_vpn(ea, vsid, ssize);
> if (unlikely(old_pte & H_PAGE_HASHPTE)) {
> - unsigned long hash, slot, hidx;
> -
> - hash = hpt_hash(vpn, shift, ssize);
> - hidx = __rpte_to_hidx(rpte, 0);
> - if (hidx & _PTEIDX_SECONDARY)
> - hash = ~hash;
> - slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
> - slot += hidx & _PTEIDX_GROUP_IX;
> + unsigned long gslot;
> /*
> * There MIGHT be an HPTE for this pte
> */
> - if (mmu_hash_ops.hpte_updatepp(slot, rflags, vpn, MMU_PAGE_64K,
> + gslot = pte_get_hash_gslot(vpn, shift, ssize, rpte, 0);
> + if (mmu_hash_ops.hpte_updatepp(gslot, rflags, vpn, MMU_PAGE_64K,
> MMU_PAGE_64K, ssize,
> flags) == -1)
> old_pte &= ~_PAGE_HPTEFLAGS;
> @@ -350,17 +343,8 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
> return -1;
> }
>
> - /*
> - * Insert slot number & secondary bit in PTE second half.
> - */
> - hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
> - rpte.hidx &= ~(0xfUL);
> - *hidxp = rpte.hidx | (slot & 0xfUL);
> - /*
> - * check __real_pte for details on matching smp_rmb()
> - */
> - smp_wmb();
> new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | H_PAGE_HASHPTE;
> + new_pte |= pte_set_hash_slot(ptep, rpte, 0, slot);
> }
> *ptep = __pte(new_pte & ~H_PAGE_BUSY);
> return 0;
> --
> 1.7.1