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>

1 files changed, 20 insertions, 0 deletions

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
  */