ARM: implement create_mapping_late() for EFI use

This implements create_mapping_late(), which we will use to populate
the UEFI Runtime Services page tables.

Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

2 files changed, 22 insertions, 0 deletions

diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index f98c7f32c9c8..9b7c328fb207 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -42,6 +42,8 @@ enum {
 extern void iotable_init(struct map_desc *, int);
 extern void vm_reserve_area_early(unsigned long addr, unsigned long size,
                                   void *caller);
+extern void create_mapping_late(struct mm_struct *mm, struct map_desc *md,
+                                bool ng);
 
 #ifdef CONFIG_DEBUG_LL
 extern void debug_ll_addr(unsigned long *paddr, unsigned long *vaddr);
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 2d9f628a7fe8..8c69830e791a 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -724,6 +724,14 @@ static void __init *early_alloc(unsigned long sz)
         return early_alloc_aligned(sz, sz);
 }
 
+static void *__init late_alloc(unsigned long sz)
+{
+        void *ptr = (void *)__get_free_pages(PGALLOC_GFP, get_order(sz));
+
+        BUG_ON(!ptr);
+        return ptr;
+}
+
 static pte_t * __init pte_alloc(pmd_t *pmd, unsigned long addr,
                                 unsigned long prot,
                                 void *(*alloc)(unsigned long sz))
@@ -960,6 +968,18 @@ static void __init create_mapping(struct map_desc *md)
         __create_mapping(&init_mm, md, early_alloc, false);
 }
 
+void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md,
+                                bool ng)
+{
+#ifdef CONFIG_ARM_LPAE
+        pud_t *pud = pud_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
+        if (WARN_ON(!pud))
+                return;
+        pmd_alloc(mm, pud, 0);
+#endif
+        __create_mapping(mm, md, late_alloc, ng);
+}
+
 /*
  * Create the architecture specific mappings
  */