Anton Blanchard <an...@ozlabs.org> writes:
> From: Anton Blanchard <an...@samba.org>
>
> In many cases we disable interrupts right before calling
> find_linux_pte_or_hugepte().
>
> find_linux_pte_or_hugepte() first checks interrupts are disabled
> before calling __find_linux_pte_or_hugepte():
>
> if (!arch_irqs_disabled()) {
> pr_info("%s called with irq enabled\n", __func__);
> dump_stack();
> }
> return __find_linux_pte_or_hugepte(pgdir, ea, is_thp, shift);
>
> We know interrupts are disabled, but since the arch_irqs_*() macros
> are hidden from the compiler with inline assembly, gcc does not. We
> end up with a pretty awful load hit store:
>
> li r9,0
> lbz r24,570(r13)
> stb r9,570(r13) <----
> lbz r9,570(r13) <---- ouch
> cmpdi cr7,r9,0
> bne cr7,c000000000049d30
>
> Find these cases, and call __find_linux_pte_or_hugepte() directly.
>
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
> Signed-off-by: Anton Blanchard <an...@samba.org>
> ---
> arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
> arch/powerpc/kvm/book3s_hv_rm_mmu.c | 2 +-
> arch/powerpc/kvm/e500_mmu_host.c | 2 +-
> arch/powerpc/mm/hash_utils_64.c | 2 +-
> arch/powerpc/mm/hugetlbpage.c | 2 +-
> arch/powerpc/mm/tlb_hash64.c | 5 +++--
> arch/powerpc/perf/callchain.c | 2 +-
> 7 files changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> index 05f09ae..ff53db5 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> @@ -543,7 +543,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run,
> struct kvm_vcpu *vcpu,
> * hugepage split and collapse.
> */
> local_irq_save(flags);
> - ptep = find_linux_pte_or_hugepte(current->mm->pgd,
> + ptep = __find_linux_pte_or_hugepte(current->mm->pgd,
> hva, NULL, NULL);
> if (ptep) {
> pte = kvmppc_read_update_linux_pte(ptep, 1);
> diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> index 99b4e9d..8ee1f49 100644
> --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
> @@ -225,7 +225,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long
> flags,
> &hpage_shift);
> else {
> local_irq_save(irq_flags);
> - ptep = find_linux_pte_or_hugepte(pgdir, hva, NULL,
> + ptep = __find_linux_pte_or_hugepte(pgdir, hva, NULL,
> &hpage_shift);
> }
> if (ptep) {
> diff --git a/arch/powerpc/kvm/e500_mmu_host.c
> b/arch/powerpc/kvm/e500_mmu_host.c
> index b0333cc..b6487f5 100644
> --- a/arch/powerpc/kvm/e500_mmu_host.c
> +++ b/arch/powerpc/kvm/e500_mmu_host.c
> @@ -476,7 +476,7 @@ static inline int kvmppc_e500_shadow_map(struct
> kvmppc_vcpu_e500 *vcpu_e500,
> * can't run hence pfn won't change.
> */
> local_irq_save(flags);
> - ptep = find_linux_pte_or_hugepte(pgdir, hva, NULL, NULL);
> + ptep = __find_linux_pte_or_hugepte(pgdir, hva, NULL, NULL);
> if (ptep) {
> pte_t pte = READ_ONCE(*ptep);
>
> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
> index 5926896..5e47caa 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -1384,7 +1384,7 @@ void hash_preload(struct mm_struct *mm, unsigned long
> ea,
> * THP pages use update_mmu_cache_pmd. We don't do
> * hash preload there. Hence can ignore THP here
> */
> - ptep = find_linux_pte_or_hugepte(pgdir, ea, NULL, &hugepage_shift);
> + ptep = __find_linux_pte_or_hugepte(pgdir, ea, NULL, &hugepage_shift);
> if (!ptep)
> goto out_exit;
>
> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
> index 5aac1a3..ee8bc5b 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -637,7 +637,7 @@ follow_huge_addr(struct mm_struct *mm, unsigned long
> address, int write)
> struct page *page = ERR_PTR(-EINVAL);
>
> local_irq_save(flags);
> - ptep = find_linux_pte_or_hugepte(mm->pgd, address, &is_thp, &shift);
> + ptep = __find_linux_pte_or_hugepte(mm->pgd, address, &is_thp, &shift);
> if (!ptep)
> goto no_page;
> pte = READ_ONCE(*ptep);
> diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c
> index 4517aa4..f41bf3d 100644
> --- a/arch/powerpc/mm/tlb_hash64.c
> +++ b/arch/powerpc/mm/tlb_hash64.c
> @@ -209,8 +209,9 @@ void __flush_hash_table_range(struct mm_struct *mm,
> unsigned long start,
> local_irq_save(flags);
> arch_enter_lazy_mmu_mode();
> for (; start < end; start += PAGE_SIZE) {
> - pte_t *ptep = find_linux_pte_or_hugepte(mm->pgd, start, &is_thp,
> - &hugepage_shift);
> + pte_t *ptep = __find_linux_pte_or_hugepte(mm->pgd, start,
> + &is_thp,
> + &hugepage_shift);
> unsigned long pte;
>
> if (ptep == NULL)
> diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
> index 0fc2671..f4d1d88 100644
> --- a/arch/powerpc/perf/callchain.c
> +++ b/arch/powerpc/perf/callchain.c
> @@ -127,7 +127,7 @@ static int read_user_stack_slow(void __user *ptr, void
> *buf, int nb)
> return -EFAULT;
>
> local_irq_save(flags);
> - ptep = find_linux_pte_or_hugepte(pgdir, addr, NULL, &shift);
> + ptep = __find_linux_pte_or_hugepte(pgdir, addr, NULL, &shift);
> if (!ptep)
> goto err_out;
> if (!shift)
> --
> 2.7.4
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