mips: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate, replace 5leve-fixup.h with pgtable-nop4d.h and
drop usage of __ARCH_USE_5LEVEL_HACK.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Mike Rapoport <rppt@kernel.org>

8 files changed, 38 insertions, 12 deletions

diff --git a/arch/mips/mm/c-r3k.c b/arch/mips/mm/c-r3k.c
index 0ca401ddf3b7..15bb8cf59828 100644
--- a/arch/mips/mm/c-r3k.c
+++ b/arch/mips/mm/c-r3k.c
@@ -241,6 +241,7 @@ static void r3k_flush_cache_page(struct vm_area_struct *vma,
 	int exec = vma->vm_flags & VM_EXEC;
 	struct mm_struct *mm = vma->vm_mm;
 	pgd_t *pgdp;
+	p4d_t *p4dp;
 	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
@@ -253,7 +254,8 @@ static void r3k_flush_cache_page(struct vm_area_struct *vma,
 		return;
 
 	pgdp = pgd_offset(mm, addr);
-	pudp = pud_offset(pgdp, addr);
+	p4dp = p4d_offset(pgdp, addr);
+	pudp = pud_offset(p4dp, addr);
 	pmdp = pmd_offset(pudp, addr);
 	ptep = pte_offset(pmdp, addr);
 
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 9d82cb9ced55..5f3d0103b95d 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -654,6 +654,7 @@ static inline void local_r4k_flush_cache_page(void *args)
 	struct mm_struct *mm = vma->vm_mm;
 	int map_coherent = 0;
 	pgd_t *pgdp;
+	p4d_t *p4dp;
 	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
@@ -668,7 +669,8 @@ static inline void local_r4k_flush_cache_page(void *args)
 
 	addr &= PAGE_MASK;
 	pgdp = pgd_offset(mm, addr);
-	pudp = pud_offset(pgdp, addr);
+	p4dp = p4d_offset(pgdp, addr);
+	pudp = pud_offset(p4dp, addr);
 	pmdp = pmd_offset(pudp, addr);
 	ptep = pte_offset(pmdp, addr);
 
diff --git a/arch/mips/mm/c-tx39.c b/arch/mips/mm/c-tx39.c
index b7c8a9d79c35..686867270627 100644
--- a/arch/mips/mm/c-tx39.c
+++ b/arch/mips/mm/c-tx39.c
@@ -170,6 +170,7 @@ static void tx39_flush_cache_page(struct vm_area_struct *vma, unsigned long page
 	int exec = vma->vm_flags & VM_EXEC;
 	struct mm_struct *mm = vma->vm_mm;
 	pgd_t *pgdp;
+	p4d_t *p4dp;
 	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
@@ -183,7 +184,8 @@ static void tx39_flush_cache_page(struct vm_area_struct *vma, unsigned long page
 
 	page &= PAGE_MASK;
 	pgdp = pgd_offset(mm, page);
-	pudp = pud_offset(pgdp, page);
+	p4dp = p4d_offset(pgdp, page);
+	pudp = pud_offset(p4dp, page);
 	pmdp = pmd_offset(pudp, page);
 	ptep = pte_offset(pmdp, page);
 
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 524af96c8131..1e8d00793784 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -294,6 +294,7 @@ vmalloc_fault:
 		 */
 		int offset = pgd_index(address);
 		pgd_t *pgd, *pgd_k;
+		p4d_t *p4d, *p4d_k;
 		pud_t *pud, *pud_k;
 		pmd_t *pmd, *pmd_k;
 		pte_t *pte_k;
@@ -305,8 +306,13 @@ vmalloc_fault:
 			goto no_context;
 		set_pgd(pgd, *pgd_k);
 
-		pud = pud_offset(pgd, address);
-		pud_k = pud_offset(pgd_k, address);
+		p4d = p4d_offset(pgd, address);
+		p4d_k = p4d_offset(pgd_k, address);
+		if (!p4d_present(*p4d_k))
+			goto no_context;
+
+		pud = pud_offset(p4d, address);
+		pud_k = pud_offset(p4d_k, address);
 		if (!pud_present(*pud_k))
 			goto no_context;
 
diff --git a/arch/mips/mm/hugetlbpage.c b/arch/mips/mm/hugetlbpage.c
index cef152234312..77ffece9c270 100644
--- a/arch/mips/mm/hugetlbpage.c
+++ b/arch/mips/mm/hugetlbpage.c
@@ -25,11 +25,13 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
 		      unsigned long sz)
 {
 	pgd_t *pgd;
+	p4d_t *p4d;
 	pud_t *pud;
 	pte_t *pte = NULL;
 
 	pgd = pgd_offset(mm, addr);
-	pud = pud_alloc(mm, pgd, addr);
+	p4d = p4d_alloc(mm, pgd, addr);
+	pud = pud_alloc(mm, p4d, addr);
 	if (pud)
 		pte = (pte_t *)pmd_alloc(mm, pud, addr);
 
@@ -40,14 +42,18 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
 		       unsigned long sz)
 {
 	pgd_t *pgd;
+	p4d_t *p4d;
 	pud_t *pud;
 	pmd_t *pmd = NULL;
 
 	pgd = pgd_offset(mm, addr);
 	if (pgd_present(*pgd)) {
-		pud = pud_offset(pgd, addr);
-		if (pud_present(*pud))
-			pmd = pmd_offset(pud, addr);
+		p4d = p4d_offset(pgd, addr);
+		if (p4d_present(*p4d)) {
+			pud = pud_offset(p4d, addr);
+			if (pud_present(*pud))
+				pmd = pmd_offset(pud, addr);
+		}
 	}
 	return (pte_t *) pmd;
 }
diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c
index 1601d90b087b..8317f337a86e 100644
--- a/arch/mips/mm/ioremap.c
+++ b/arch/mips/mm/ioremap.c
@@ -78,11 +78,15 @@ static int remap_area_pages(unsigned long address, phys_addr_t phys_addr,
 	flush_cache_all();
 	BUG_ON(address >= end);
 	do {
+		p4d_t *p4d;
 		pud_t *pud;
 		pmd_t *pmd;
 
 		error = -ENOMEM;
-		pud = pud_alloc(&init_mm, dir, address);
+		p4d = p4d_alloc(&init_mm, dir, address);
+		if (!p4d)
+			break;
+		pud = pud_alloc(&init_mm, p4d, address);
 		if (!pud)
 			break;
 		pmd = pmd_alloc(&init_mm, pud, address);
diff --git a/arch/mips/mm/pgtable-32.c b/arch/mips/mm/pgtable-32.c
index 621a01fbef64..37c7a01427d2 100644
--- a/arch/mips/mm/pgtable-32.c
+++ b/arch/mips/mm/pgtable-32.c
@@ -56,6 +56,7 @@ void __init pagetable_init(void)
 	pgd_t *pgd_base;
 #ifdef CONFIG_HIGHMEM
 	pgd_t *pgd;
+	p4d_t *p4d;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
@@ -82,7 +83,8 @@ void __init pagetable_init(void)
 	fixrange_init(vaddr & PMD_MASK, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
 
 	pgd = swapper_pg_dir + pgd_index(vaddr);
-	pud = pud_offset(pgd, vaddr);
+	p4d = p4d_offset(pgd, vaddr);
+	pud = pud_offset(p4d, vaddr);
 	pmd = pmd_offset(pud, vaddr);
 	pte = pte_offset_kernel(pmd, vaddr);
 	pkmap_page_table = pte;
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 83b450ddbbc2..d7a9d5f211f0 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -295,6 +295,7 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 {
 	unsigned long flags;
 	pgd_t *pgdp;
+	p4d_t *p4dp;
 	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
@@ -320,7 +321,8 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 	mtc0_tlbw_hazard();
 	tlb_probe();
 	tlb_probe_hazard();
-	pudp = pud_offset(pgdp, address);
+	p4dp = p4d_offset(pgdp, address);
+	pudp = pud_offset(p4dp, address);
 	pmdp = pmd_offset(pudp, address);
 	idx = read_c0_index();
 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT