[PATCH v3 16/34] powerpc: mm: Add p?d_large() definitions

[Steven Price <steven.price@arm.com>]

walk_page_range() is going to be allowed to walk page tables other than
those of user space. For this it needs to know when it has reached a
'leaf' entry in the page tables. This information is provided by the
p?d_large() functions/macros.

For powerpc pmd_large() was already implemented, so hoist it out of the
CONFIG_TRANSPARENT_HUGEPAGE condition and implement the other levels.

Also since we now have a pmd_large always implemented we can drop the
pmd_is_leaf() function.

For 32 bit simply implement stubs returning 0.

CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: Michael Ellerman <mpe@ellerman.id.au>
CC: linuxppc-dev@lists.ozlabs.org
CC: kvm-ppc@vger.kernel.org
Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/powerpc/include/asm/book3s/32/pgtable.h  |  1 +
 arch/powerpc/include/asm/book3s/64/pgtable.h  | 27 ++++++++++++-------
 arch/powerpc/include/asm/nohash/32/pgtable.h  |  1 +
 .../include/asm/nohash/64/pgtable-4k.h        |  1 +
 arch/powerpc/kvm/book3s_64_mmu_radix.c        | 12 +++------
 5 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 49d76adb9bc5..036052a792c8 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -202,6 +202,7 @@ extern unsigned long ioremap_bot;
 #define pmd_none(pmd)		(!pmd_val(pmd))
 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
+#define pmd_large(pmd)		(0)
 static inline void pmd_clear(pmd_t *pmdp)
 {
 	*pmdp = __pmd(0);
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index c9bfe526ca9d..1705b1a201bd 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -907,6 +907,11 @@ static inline int pud_present(pud_t pud)
 	return (pud_raw(pud) & cpu_to_be64(_PAGE_PRESENT));
 }
 
+static inline int pud_large(pud_t pud)
+{
+	return (pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
+}
+
 extern struct page *pud_page(pud_t pud);
 extern struct page *pmd_page(pmd_t pmd);
 static inline pte_t pud_pte(pud_t pud)
@@ -954,6 +959,11 @@ static inline int pgd_present(pgd_t pgd)
 	return (pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT));
 }
 
+static inline int pgd_large(pgd_t pgd)
+{
+	return (pgd_raw(pgd) & cpu_to_be64(_PAGE_PTE));
+}
+
 static inline pte_t pgd_pte(pgd_t pgd)
 {
 	return __pte_raw(pgd_raw(pgd));
@@ -1107,6 +1117,14 @@ static inline bool pmd_access_permitted(pmd_t pmd, bool write)
 	return pte_access_permitted(pmd_pte(pmd), write);
 }
 
+/*
+ * returns true for pmd migration entries, THP, devmap, hugetlb
+ */
+static inline int pmd_large(pmd_t pmd)
+{
+	return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
+}
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 extern pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot);
 extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot);
@@ -1133,15 +1151,6 @@ pmd_hugepage_update(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp,
 	return hash__pmd_hugepage_update(mm, addr, pmdp, clr, set);
 }
 
-/*
- * returns true for pmd migration entries, THP, devmap, hugetlb
- * But compile time dependent on THP config
- */
-static inline int pmd_large(pmd_t pmd)
-{
-	return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
-}
-
 static inline pmd_t pmd_mknotpresent(pmd_t pmd)
 {
 	return __pmd(pmd_val(pmd) & ~_PAGE_PRESENT);
diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index bed433358260..ebd55449914b 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
@@ -190,6 +190,7 @@ static inline pte_t pte_mkexec(pte_t pte)
 #define pmd_none(pmd)		(!pmd_val(pmd))
 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
+#define pmd_large(pmd)		(0)
 static inline void pmd_clear(pmd_t *pmdp)
 {
 	*pmdp = __pmd(0);
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable-4k.h b/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
index c40ec32b8194..9e6fa5646c9f 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
@@ -56,6 +56,7 @@
 #define pgd_none(pgd)		(!pgd_val(pgd))
 #define pgd_bad(pgd)		(pgd_val(pgd) == 0)
 #define pgd_present(pgd)	(pgd_val(pgd) != 0)
+#define pgd_large(pgd)		(0)
 #define pgd_page_vaddr(pgd)	(pgd_val(pgd) & ~PGD_MASKED_BITS)
 
 #ifndef __ASSEMBLY__
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 1b821c6efdef..040db20ac2ab 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -363,12 +363,6 @@ static void kvmppc_pte_free(pte_t *ptep)
 	kmem_cache_free(kvm_pte_cache, ptep);
 }
 
-/* Like pmd_huge() and pmd_large(), but works regardless of config options */
-static inline int pmd_is_leaf(pmd_t pmd)
-{
-	return !!(pmd_val(pmd) & _PAGE_PTE);
-}
-
 static pmd_t *kvmppc_pmd_alloc(void)
 {
 	return kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
@@ -455,7 +449,7 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
 	for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
 		if (!pmd_present(*p))
 			continue;
-		if (pmd_is_leaf(*p)) {
+		if (pmd_large(*p)) {
 			if (full) {
 				pmd_clear(p);
 			} else {
@@ -588,7 +582,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 	else if (level <= 1)
 		new_pmd = kvmppc_pmd_alloc();
 
-	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
+	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_large(*pmd)))
 		new_ptep = kvmppc_pte_alloc();
 
 	/* Check if we might have been invalidated; let the guest retry if so */
@@ -657,7 +651,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 		new_pmd = NULL;
 	}
 	pmd = pmd_offset(pud, gpa);
-	if (pmd_is_leaf(*pmd)) {
+	if (pmd_large(*pmd)) {
 		unsigned long lgpa = gpa & PMD_MASK;
 
 		/* Check if we raced and someone else has set the same thing */
-- 
2.20.1