efi/arm*: Take the Memory Attributes table into account

Call into the generic memory attributes table support code at the
appropriate times during the init sequence so that the UEFI Runtime
Services region are mapped according to the strict permissions it
specifies.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-15-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/arm64/include/asm/efi.h

@@ -14,6 +14,8 @@ extern void efi_init(void);
 
 int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
 
+#define efi_set_mapping_permissions	efi_create_mapping
+
 #define efi_call_virt(f, ...)						\
 ({									\
 	efi_##f##_t *__f;						\

drivers/firmware/efi/arm-init.c

@@ -206,6 +206,7 @@ void __init efi_init(void)
 		return;
 
 	reserve_regions();
+	efi_memattr_init();
 	early_memunmap(efi.memmap.map, params.mmap_size);
 
 	if (IS_ENABLED(CONFIG_ARM)) {

drivers/firmware/efi/arm-runtime.c

@@ -77,9 +77,15 @@ static bool __init efi_virtmap_init(void)
 			systab_found = true;
 		}
 	}
-	if (!systab_found)
+	if (!systab_found) {
 		pr_err("No virtual mapping found for the UEFI System Table\n");
-	return systab_found;
+		return false;
+	}
+
+	if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
+		return false;
+
+	return true;
 }
 
 /*