3 files changed, 23 insertions, 8 deletions

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index c9dcc181d4d1..029189db84de 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -98,6 +98,7 @@ extern void efi_set_executable(efi_memory_desc_t *md, bool executable);
 extern int efi_memblock_x86_reserve_range(void);
 extern void efi_call_phys_prelog(void);
 extern void efi_call_phys_epilog(void);
+extern void efi_unmap_memmap(void);
 
 #ifndef CONFIG_EFI
 /*
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index a2bb18e02839..6fd7752cee96 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1035,6 +1035,18 @@ void __init setup_arch(char **cmdline_p)
         arch_init_ideal_nops();
 
         register_refined_jiffies(CLOCK_TICK_RATE);
+
+#ifdef CONFIG_EFI
+        /* Once setup is done above, disable efi_enabled on mismatched
+         * firmware/kernel archtectures since there is no support for
+         * runtime services.
+         */
+        if (efi_enabled && IS_ENABLED(CONFIG_X86_64) != efi_64bit) {
+                pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
+                efi_unmap_memmap();
+                efi_enabled = 0;
+        }
+#endif
 }
 
 #ifdef CONFIG_X86_32
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index aded2a91162a..9bae3b73fccc 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -70,11 +70,15 @@ EXPORT_SYMBOL(efi);
 struct efi_memory_map memmap;
 
 bool efi_64bit;
-static bool efi_native;
 
 static struct efi efi_phys __initdata;
 static efi_system_table_t efi_systab __initdata;
 
+static inline bool efi_is_native(void)
+{
+        return IS_ENABLED(CONFIG_X86_64) == efi_64bit;
+}
+
 static int __init setup_noefi(char *arg)
 {
         efi_enabled = 0;
@@ -420,7 +424,7 @@ void __init efi_reserve_boot_services(void)
         }
 }
 
-static void __init efi_unmap_memmap(void)
+void __init efi_unmap_memmap(void)
 {
         if (memmap.map) {
                 early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
@@ -432,7 +436,7 @@ void __init efi_free_boot_services(void)
 {
         void *p;
 
-        if (!efi_native)
+        if (!efi_is_native())
                 return;
 
         for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
@@ -684,12 +688,10 @@ void __init efi_init(void)
                 return;
         }
         efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
-        efi_native = !efi_64bit;
 #else
         efi_phys.systab = (efi_system_table_t *)
                           (boot_params.efi_info.efi_systab |
                           ((__u64)boot_params.efi_info.efi_systab_hi<<32));
-        efi_native = efi_64bit;
 #endif
 
         if (efi_systab_init(efi_phys.systab)) {
@@ -723,7 +725,7 @@ void __init efi_init(void)
          * that doesn't match the kernel 32/64-bit mode.
          */
 
-        if (!efi_native)
+        if (!efi_is_native())
                 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
         else if (efi_runtime_init()) {
                 efi_enabled = 0;
@@ -735,7 +737,7 @@ void __init efi_init(void)
                 return;
         }
 #ifdef CONFIG_X86_32
-        if (efi_native) {
+        if (efi_is_native()) {
                 x86_platform.get_wallclock = efi_get_time;
                 x86_platform.set_wallclock = efi_set_rtc_mmss;
         }
@@ -834,7 +836,7 @@ void __init efi_enter_virtual_mode(void)
          * non-native EFI
          */
 
-        if (!efi_native) {
+        if (!efi_is_native()) {
                 efi_unmap_memmap();
                 return;
         }