Merge tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

Pull powerpc fixes from Michael Ellerman:

 - fix for mm_dec_nr_pmds() from Scott.

 - fixes for oopses seen with KVM + THP from Aneesh.

 - build fixes from Aneesh & Shreyas.

* tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc/mm: Fix build error with CONFIG_PPC_TRANSACTIONAL_MEM disabled
  powerpc/kvm: Fix ppc64_defconfig + PPC_POWERNV=n build error
  powerpc/mm/thp: Return pte address if we find trans_splitting.
  powerpc/mm/thp: Make page table walk safe against thp split/collapse
  KVM: PPC: Remove page table walk helpers
  KVM: PPC: Use READ_ONCE when dereferencing pte_t pointer
  powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()

1 files changed, 23 insertions, 9 deletions

diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index cc536d4a75ef..4d33e199edcc 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -338,6 +338,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	pte_t *ptep;
 	unsigned int wimg = 0;
 	pgd_t *pgdir;
+	unsigned long flags;
 
 	/* used to check for invalidations in progress */
 	mmu_seq = kvm->mmu_notifier_seq;
@@ -468,15 +469,28 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 
 
 	pgdir = vcpu_e500->vcpu.arch.pgdir;
-	ptep = lookup_linux_ptep(pgdir, hva, &tsize_pages);
-	if (pte_present(*ptep))
-		wimg = (*ptep >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
-	else {
-		if (printk_ratelimit())
-			pr_err("%s: pte not present: gfn %lx, pfn %lx\n",
-				__func__, (long)gfn, pfn);
-		ret = -EINVAL;
-		goto out;
+	/*
+	 * We are just looking at the wimg bits, so we don't
+	 * care much about the trans splitting bit.
+	 * We are holding kvm->mmu_lock so a notifier invalidate
+	 * can't run hence pfn won't change.
+	 */
+	local_irq_save(flags);
+	ptep = find_linux_pte_or_hugepte(pgdir, hva, NULL);
+	if (ptep) {
+		pte_t pte = READ_ONCE(*ptep);
+
+		if (pte_present(pte)) {
+			wimg = (pte_val(pte) >> PTE_WIMGE_SHIFT) &
+				MAS2_WIMGE_MASK;
+			local_irq_restore(flags);
+		} else {
+			local_irq_restore(flags);
+			pr_err_ratelimited("%s: pte not present: gfn %lx,pfn %lx\n",
+					   __func__, (long)gfn, pfn);
+			ret = -EINVAL;
+			goto out;
+		}
 	}
 	kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);