1 files changed, 57 insertions, 2 deletions

diff --git a/arch/arm/kernel/efi.c b/arch/arm/kernel/efi.c
index e57dbcc89123..6f9ec7d28a71 100644
--- a/arch/arm/kernel/efi.c
+++ b/arch/arm/kernel/efi.c
@@ -4,6 +4,9 @@
  */
 
 #include <linux/efi.h>
+#include <linux/memblock.h>
+#include <linux/screen_info.h>
+
 #include <asm/efi.h>
 #include <asm/mach/map.h>
 #include <asm/mmu_context.h>
@@ -22,7 +25,8 @@ static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
 }
 
 int __init efi_set_mapping_permissions(struct mm_struct *mm,
-				       efi_memory_desc_t *md)
+				       efi_memory_desc_t *md,
+				       bool ignored)
 {
 	unsigned long base, size;
 
@@ -70,6 +74,57 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
 	 * 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 efi_set_mapping_permissions(mm, md, false);
 	return 0;
 }
+
+static unsigned long __initdata cpu_state_table = EFI_INVALID_TABLE_ADDR;
+
+const efi_config_table_type_t efi_arch_tables[] __initconst = {
+	{LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
+	{}
+};
+
+static void __init load_cpu_state_table(void)
+{
+	if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {
+		struct efi_arm_entry_state *state;
+		bool dump_state = true;
+
+		state = early_memremap_ro(cpu_state_table,
+					  sizeof(struct efi_arm_entry_state));
+		if (state == NULL) {
+			pr_warn("Unable to map CPU entry state table.\n");
+			return;
+		}
+
+		if ((state->sctlr_before_ebs & 1) == 0)
+			pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n");
+		else if ((state->sctlr_after_ebs & 1) == 0)
+			pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n");
+		else
+			dump_state = false;
+
+		if (dump_state || efi_enabled(EFI_DBG)) {
+			pr_info("CPSR at EFI stub entry        : 0x%08x\n",
+				state->cpsr_before_ebs);
+			pr_info("SCTLR at EFI stub entry       : 0x%08x\n",
+				state->sctlr_before_ebs);
+			pr_info("CPSR after ExitBootServices() : 0x%08x\n",
+				state->cpsr_after_ebs);
+			pr_info("SCTLR after ExitBootServices(): 0x%08x\n",
+				state->sctlr_after_ebs);
+		}
+		early_memunmap(state, sizeof(struct efi_arm_entry_state));
+	}
+}
+
+void __init arm_efi_init(void)
+{
+	efi_init();
+
+	/* ARM does not permit early mappings to persist across paging_init() */
+	efi_memmap_unmap();
+
+	load_cpu_state_table();
+}