ARM: add support for non-global kernel mappings

Add support to the kernel translation table population routines for
creating non-global mappings. This will be used by the UEFI runtime
services, which will use temporary mappings in the userland range.
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

arch/arm/mm/mmu.c

@@ -745,18 +745,20 @@ static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
 static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
 				  unsigned long end, unsigned long pfn,
 				  const struct mem_type *type,
-				  void *(*alloc)(unsigned long sz))
+				  void *(*alloc)(unsigned long sz),
+				  bool ng)
 {
 	pte_t *pte = pte_alloc(pmd, addr, type->prot_l1, alloc);
 	do {
-		set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);
+		set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)),
+			    ng ? PTE_EXT_NG : 0);
 		pfn++;
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 }
 
 static void __init __map_init_section(pmd_t *pmd, unsigned long addr,
 			unsigned long end, phys_addr_t phys,
-			const struct mem_type *type)
+			const struct mem_type *type, bool ng)
 {
 	pmd_t *p = pmd;
 
@@ -774,7 +776,7 @@ static void __init __map_init_section(pmd_t *pmd, unsigned long addr,
 		pmd++;
 #endif
 	do {
-		*pmd = __pmd(phys | type->prot_sect);
+		*pmd = __pmd(phys | type->prot_sect | (ng ? PMD_SECT_nG : 0));
 		phys += SECTION_SIZE;
 	} while (pmd++, addr += SECTION_SIZE, addr != end);
 
@@ -784,7 +786,7 @@ static void __init __map_init_section(pmd_t *pmd, unsigned long addr,
 static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 				      unsigned long end, phys_addr_t phys,
 				      const struct mem_type *type,
-				      void *(*alloc)(unsigned long sz))
+				      void *(*alloc)(unsigned long sz), bool ng)
 {
 	pmd_t *pmd = pmd_offset(pud, addr);
 	unsigned long next;
@@ -802,10 +804,10 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 		 */
 		if (type->prot_sect &&
 				((addr | next | phys) & ~SECTION_MASK) == 0) {
-			__map_init_section(pmd, addr, next, phys, type);
+			__map_init_section(pmd, addr, next, phys, type, ng);
 		} else {
 			alloc_init_pte(pmd, addr, next,
-				       __phys_to_pfn(phys), type, alloc);
+				       __phys_to_pfn(phys), type, alloc, ng);
 		}
 
 		phys += next - addr;
@@ -816,14 +818,14 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
 static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
 				  unsigned long end, phys_addr_t phys,
 				  const struct mem_type *type,
-				  void *(*alloc)(unsigned long sz))
+				  void *(*alloc)(unsigned long sz), bool ng)
 {
 	pud_t *pud = pud_offset(pgd, addr);
 	unsigned long next;
 
 	do {
 		next = pud_addr_end(addr, end);
-		alloc_init_pmd(pud, addr, next, phys, type, alloc);
+		alloc_init_pmd(pud, addr, next, phys, type, alloc, ng);
 		phys += next - addr;
 	} while (pud++, addr = next, addr != end);
 }
@@ -831,7 +833,8 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
 #ifndef CONFIG_ARM_LPAE
 static void __init create_36bit_mapping(struct mm_struct *mm,
 					struct map_desc *md,
-					const struct mem_type *type)
+					const struct mem_type *type,
+					bool ng)
 {
 	unsigned long addr, length, end;
 	phys_addr_t phys;
@@ -879,7 +882,8 @@ static void __init create_36bit_mapping(struct mm_struct *mm,
 		int i;
 
 		for (i = 0; i < 16; i++)
-			*pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER);
+			*pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER |
+				       (ng ? PMD_SECT_nG : 0));
 
 		addr += SUPERSECTION_SIZE;
 		phys += SUPERSECTION_SIZE;
@@ -889,7 +893,8 @@ static void __init create_36bit_mapping(struct mm_struct *mm,
 #endif	/* !CONFIG_ARM_LPAE */
 
 static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
-				    void *(*alloc)(unsigned long sz))
+				    void *(*alloc)(unsigned long sz),
+				    bool ng)
 {
 	unsigned long addr, length, end;
 	phys_addr_t phys;
@@ -903,7 +908,7 @@ static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
 	 * Catch 36-bit addresses
 	 */
 	if (md->pfn >= 0x100000) {
-		create_36bit_mapping(mm, md, type);
+		create_36bit_mapping(mm, md, type, ng);
 		return;
 	}
 #endif
@@ -923,7 +928,7 @@ static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
 	do {
 		unsigned long next = pgd_addr_end(addr, end);
 
-		alloc_init_pud(pgd, addr, next, phys, type, alloc);
+		alloc_init_pud(pgd, addr, next, phys, type, alloc, ng);
 
 		phys += next - addr;
 		addr = next;
@@ -952,7 +957,7 @@ static void __init create_mapping(struct map_desc *md)
 			(long long)__pfn_to_phys((u64)md->pfn), md->virtual);
 	}
 
-	__create_mapping(&init_mm, md, early_alloc);
+	__create_mapping(&init_mm, md, early_alloc, false);
 }
 
 /*