diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2020-05-05 12:47:12 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-05 21:20:14 +1000 |
| commit | 2f92447f9f96583112420aa3cfb400ded55f667e (patch) | |
| tree | ddf1f301ca478c1aa3a82cf1c64c639e2921be86 /arch/powerpc/mm | |
| parent | 7900757ce1b4affda1591aa3fd073e27d202f406 (diff) | |
powerpc/book3s64/hash: Use the pte_t address from the caller
Don't fetch the pte value using lockless page table walk. Instead use the value from the
caller. hash_preload is called with ptl lock held. So it is safe to use the
pte_t address directly.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200505071729.54912-6-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/book3s64/hash_utils.c | 27 |
1 files changed, 5 insertions, 22 deletions
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 525eac4ee2c2..3d727f73a8db 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -1546,14 +1546,11 @@ static bool should_hash_preload(struct mm_struct *mm, unsigned long ea) } #endif -static void hash_preload(struct mm_struct *mm, unsigned long ea, +static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea, bool is_exec, unsigned long trap) { - int hugepage_shift; unsigned long vsid; pgd_t *pgdir; - pte_t *ptep; - unsigned long flags; int rc, ssize, update_flags = 0; unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0); @@ -1575,30 +1572,18 @@ static void hash_preload(struct mm_struct *mm, unsigned long ea, vsid = get_user_vsid(&mm->context, ea, ssize); if (!vsid) return; - /* - * Hash doesn't like irqs. Walking linux page table with irq disabled - * saves us from holding multiple locks. - */ - local_irq_save(flags); - /* - * THP pages use update_mmu_cache_pmd. We don't do - * hash preload there. Hence can ignore THP here - */ - ptep = find_current_mm_pte(pgdir, ea, NULL, &hugepage_shift); - if (!ptep) - goto out_exit; - - WARN_ON(hugepage_shift); #ifdef CONFIG_PPC_64K_PAGES /* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on * a 64K kernel), then we don't preload, hash_page() will take * care of it once we actually try to access the page. * That way we don't have to duplicate all of the logic for segment * page size demotion here + * Called with PTL held, hence can be sure the value won't change in + * between. */ if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep)) - goto out_exit; + return; #endif /* CONFIG_PPC_64K_PAGES */ /* Is that local to this CPU ? */ @@ -1623,8 +1608,6 @@ static void hash_preload(struct mm_struct *mm, unsigned long ea, mm_ctx_user_psize(&mm->context), mm_ctx_user_psize(&mm->context), pte_val(*ptep)); -out_exit: - local_irq_restore(flags); } /* @@ -1675,7 +1658,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, return; } - hash_preload(vma->vm_mm, address, is_exec, trap); + hash_preload(vma->vm_mm, ptep, address, is_exec, trap); } #ifdef CONFIG_PPC_TRANSACTIONAL_MEM |