v4.19.13 snapshot.
diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
new file mode 100644
index 0000000..9f43ba0
--- /dev/null
+++ b/arch/arm/kernel/efi.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <asm/mach/map.h>
+#include <asm/mmu_context.h>
+
+static int __init set_permissions(pte_t *ptep, pgtable_t token,
+ unsigned long addr, void *data)
+{
+ efi_memory_desc_t *md = data;
+ pte_t pte = *ptep;
+
+ if (md->attribute & EFI_MEMORY_RO)
+ pte = set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
+ if (md->attribute & EFI_MEMORY_XP)
+ pte = set_pte_bit(pte, __pgprot(L_PTE_XN));
+ set_pte_ext(ptep, pte, PTE_EXT_NG);
+ return 0;
+}
+
+int __init efi_set_mapping_permissions(struct mm_struct *mm,
+ efi_memory_desc_t *md)
+{
+ unsigned long base, size;
+
+ base = md->virt_addr;
+ size = md->num_pages << EFI_PAGE_SHIFT;
+
+ /*
+ * We can only use apply_to_page_range() if we can guarantee that the
+ * entire region was mapped using pages. This should be the case if the
+ * region does not cover any naturally aligned SECTION_SIZE sized
+ * blocks.
+ */
+ if (round_down(base + size, SECTION_SIZE) <
+ round_up(base, SECTION_SIZE) + SECTION_SIZE)
+ return apply_to_page_range(mm, base, size, set_permissions, md);
+
+ return 0;
+}
+
+int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
+{
+ struct map_desc desc = {
+ .virtual = md->virt_addr,
+ .pfn = __phys_to_pfn(md->phys_addr),
+ .length = md->num_pages * EFI_PAGE_SIZE,
+ };
+
+ /*
+ * Order is important here: memory regions may have all of the
+ * bits below set (and usually do), so we check them in order of
+ * preference.
+ */
+ if (md->attribute & EFI_MEMORY_WB)
+ desc.type = MT_MEMORY_RWX;
+ else if (md->attribute & EFI_MEMORY_WT)
+ desc.type = MT_MEMORY_RWX_NONCACHED;
+ else if (md->attribute & EFI_MEMORY_WC)
+ desc.type = MT_DEVICE_WC;
+ else
+ desc.type = MT_DEVICE;
+
+ create_mapping_late(mm, &desc, true);
+
+ /*
+ * If stricter permissions were specified, apply them now.
+ */
+ if (md->attribute & (EFI_MEMORY_RO | EFI_MEMORY_XP))
+ return efi_set_mapping_permissions(mm, md);
+ return 0;
+}