From f7d924894265794f447ea799dd853400749b5a22 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Mon, 30 Nov 2015 13:28:19 +0100
Subject: arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARM

This refactors the EFI init and runtime code that will be shared
between arm64 and ARM so that it can be built for both archs.

Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/efi.h |  9 +++++++++
 arch/arm64/kernel/efi.c      | 23 +++++++++++++++++++++++
 2 files changed, 32 insertions(+)

(limited to 'arch')

diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index ef572206f1c3..8e88a696c9cb 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -2,7 +2,9 @@
 #define _ASM_EFI_H
 
 #include <asm/io.h>
+#include <asm/mmu_context.h>
 #include <asm/neon.h>
+#include <asm/tlbflush.h>
 
 #ifdef CONFIG_EFI
 extern void efi_init(void);
@@ -10,6 +12,8 @@ extern void efi_init(void);
 #define efi_init()
 #endif
 
+int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
+
 #define efi_call_virt(f, ...)						\
 ({									\
 	efi_##f##_t *__f;						\
@@ -63,6 +67,11 @@ extern void efi_init(void);
  *   Services are enabled and the EFI_RUNTIME_SERVICES bit set.
  */
 
+static inline void efi_set_pgd(struct mm_struct *mm)
+{
+	switch_mm(NULL, mm, NULL);
+}
+
 void efi_virtmap_load(void);
 void efi_virtmap_unload(void);
 
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index bd3b2f5adf0c..b6abc852f2a1 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -17,6 +17,29 @@
 
 #include <asm/efi.h>
 
+int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
+{
+	pteval_t prot_val;
+
+	/*
+	 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
+	 * executable, everything else can be mapped with the XN bits
+	 * set.
+	 */
+	if ((md->attribute & EFI_MEMORY_WB) == 0)
+		prot_val = PROT_DEVICE_nGnRE;
+	else if (md->type == EFI_RUNTIME_SERVICES_CODE ||
+		 !PAGE_ALIGNED(md->phys_addr))
+		prot_val = pgprot_val(PAGE_KERNEL_EXEC);
+	else
+		prot_val = pgprot_val(PAGE_KERNEL);
+
+	create_pgd_mapping(mm, md->phys_addr, md->virt_addr,
+			   md->num_pages << EFI_PAGE_SHIFT,
+			   __pgprot(prot_val | PTE_NG));
+	return 0;
+}
+
 static int __init arm64_dmi_init(void)
 {
 	/*
-- 
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