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Commit 7d6e7f7f authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Michael Ellerman
Browse files

powerpc/mm/thp: Return pte address if we find trans_splitting. 



For THP that is marked trans splitting, we return the pte.
This require the callers to handle the pmd_trans_splitting scenario,
if they care. All the current callers are either looking at pfn or
write_ok, hence we don't need to update them.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 691e95fd

arch/powerpc/include/asm/kvm_book3s_64.h

+2 −10
Original line number Diff line number Diff line
@@ -281,11 +281,9 @@ static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type) 


/*

 * If it's present and writable, atomically set dirty and referenced bits and

 * return the PTE, otherwise return 0. If we find a transparent hugepage

 * and if it is marked splitting we return 0;

 * return the PTE, otherwise return 0.

 */

static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing,

						 unsigned int hugepage)

static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing)

{

	pte_t old_pte, new_pte = __pte(0);
@@ -301,12 +299,6 @@ static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing, 
			cpu_relax();

			continue;

		}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

		/* If hugepage and is trans splitting return None */

		if (unlikely(hugepage &&

			     pmd_trans_splitting(pte_pmd(old_pte))))

			return __pte(0);

#endif

		/* If pte is not present return None */

		if (unlikely(!(pte_val(old_pte) & _PAGE_PRESENT)))

			return __pte(0);

arch/powerpc/kvm/book3s_64_mmu_hv.c

+3 −6
Original line number Diff line number Diff line
@@ -537,20 +537,17 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
		}

		/* if the guest wants write access, see if that is OK */

		if (!writing && hpte_is_writable(r)) {

			unsigned int hugepage_shift;

			pte_t *ptep, pte;

			unsigned long flags;



			/*

			 * We need to protect against page table destruction

			 * while looking up and updating the pte.

			 * hugepage split and collapse.

			 */

			local_irq_save(flags);

			ptep = find_linux_pte_or_hugepte(current->mm->pgd,

							 hva, &hugepage_shift);

							 hva, NULL);

			if (ptep) {

				pte = kvmppc_read_update_linux_pte(ptep, 1,

							   hugepage_shift);

				pte = kvmppc_read_update_linux_pte(ptep, 1);

				if (pte_write(pte))

					write_ok = 1;

			}

arch/powerpc/kvm/book3s_hv_rm_mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -219,7 +219,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, 
				local_irq_restore(flags);

			return H_PARAMETER;

		}

		pte = kvmppc_read_update_linux_pte(ptep, writing, hpage_shift);

		pte = kvmppc_read_update_linux_pte(ptep, writing);

		if (pte_present(pte) && !pte_protnone(pte)) {

			if (writing && !pte_write(pte))

				/* make the actual HPTE be read-only */

arch/powerpc/mm/hugetlbpage.c

+4 −5
Original line number Diff line number Diff line
@@ -1014,12 +1014,11 @@ pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, 
			 * A hugepage collapse is captured by pmd_none, because

			 * it mark the pmd none and do a hpte invalidate.

			 *

			 * A hugepage split is captured by pmd_trans_splitting

			 * because we mark the pmd trans splitting and do a

			 * hpte invalidate

			 *

			 * We don't worry about pmd_trans_splitting here, The

			 * caller if it needs to handle the splitting case

			 * should check for that.

			 */

			if (pmd_none(pmd) || pmd_trans_splitting(pmd))

			if (pmd_none(pmd))

				return NULL;



			if (pmd_huge(pmd) || pmd_large(pmd)) {