x86/efi: Add mixed runtime services support

Setup the runtime services based on whether we're booting in EFI native
mode or not. For non-native mode we need to thunk from 64-bit into
32-bit mode before invoking the EFI runtime services.

Using the runtime services after SetVirtualAddressMap() is slightly more
complicated because we need to ensure that all the addresses we pass to
the firmware are below the 4GB boundary so that they can be addressed
with 32-bit pointers, see efi_setup_page_tables().

Signed-off-by: Matt Fleming <matt.fleming@intel.com>

arch/x86/include/asm/efi.h

@@ -154,6 +154,27 @@ static inline bool efi_is_native(void)
 
 extern struct console early_efi_console;
 extern void parse_efi_setup(u64 phys_addr, u32 data_len);
+
+#ifdef CONFIG_EFI_MIXED
+extern void efi_thunk_runtime_setup(void);
+extern efi_status_t efi_thunk_set_virtual_address_map(
+	void *phys_set_virtual_address_map,
+	unsigned long memory_map_size,
+	unsigned long descriptor_size,
+	u32 descriptor_version,
+	efi_memory_desc_t *virtual_map);
+#else
+static inline void efi_thunk_runtime_setup(void) {}
+static inline efi_status_t efi_thunk_set_virtual_address_map(
+	void *phys_set_virtual_address_map,
+	unsigned long memory_map_size,
+	unsigned long descriptor_size,
+	u32 descriptor_version,
+	efi_memory_desc_t *virtual_map)
+{
+	return EFI_SUCCESS;
+}
+#endif /* CONFIG_EFI_MIXED */
 #else
 /*
  * IF EFI is not configured, have the EFI calls return -ENOSYS.

arch/x86/platform/efi/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_EFI) 		+= efi.o efi_$(BITS).o efi_stub_$(BITS).o
 obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o
 obj-$(CONFIG_EARLY_PRINTK_EFI)	+= early_printk.o
+obj-$(CONFIG_EFI_MIXED)		+= efi_thunk_$(BITS).o

arch/x86/platform/efi/efi.c

@@ -588,37 +588,85 @@ static int __init efi_systab_init(void *phys)
 	return 0;
 }
 
-static int __init efi_runtime_init(void)
+static int __init efi_runtime_init32(void)
 {
-	efi_runtime_services_t *runtime;
+	efi_runtime_services_32_t *runtime;
+
+	runtime = early_ioremap((unsigned long)efi.systab->runtime,
+			sizeof(efi_runtime_services_32_t));
+	if (!runtime) {
+		pr_err("Could not map the runtime service table!\n");
+		return -ENOMEM;
+	}
 
 	/*
-	 * Check out the runtime services table. We need to map
-	 * the runtime services table so that we can grab the physical
-	 * address of several of the EFI runtime functions, needed to
-	 * set the firmware into virtual mode.
+	 * We will only need *early* access to the following two
+	 * EFI runtime services before set_virtual_address_map
+	 * is invoked.
 	 */
+	efi_phys.get_time = (efi_get_time_t *)
+			(unsigned long)runtime->get_time;
+	efi_phys.set_virtual_address_map =
+			(efi_set_virtual_address_map_t *)
+			(unsigned long)runtime->set_virtual_address_map;
+	/*
+	 * Make efi_get_time can be called before entering
+	 * virtual mode.
+	 */
+	efi.get_time = phys_efi_get_time;
+	early_iounmap(runtime, sizeof(efi_runtime_services_32_t));
+
+	return 0;
+}
+
+static int __init efi_runtime_init64(void)
+{
+	efi_runtime_services_64_t *runtime;
+
 	runtime = early_ioremap((unsigned long)efi.systab->runtime,
-				sizeof(efi_runtime_services_t));
+			sizeof(efi_runtime_services_64_t));
 	if (!runtime) {
 		pr_err("Could not map the runtime service table!\n");
 		return -ENOMEM;
 	}
+
 	/*
-	 * We will only need *early* access to the following
-	 * two EFI runtime services before set_virtual_address_map
+	 * We will only need *early* access to the following two
+	 * EFI runtime services before set_virtual_address_map
 	 * is invoked.
 	 */
-	efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
+	efi_phys.get_time = (efi_get_time_t *)
+			(unsigned long)runtime->get_time;
 	efi_phys.set_virtual_address_map =
-		(efi_set_virtual_address_map_t *)
-		runtime->set_virtual_address_map;
+			(efi_set_virtual_address_map_t *)
+			(unsigned long)runtime->set_virtual_address_map;
 	/*
 	 * Make efi_get_time can be called before entering
 	 * virtual mode.
 	 */
 	efi.get_time = phys_efi_get_time;
-	early_iounmap(runtime, sizeof(efi_runtime_services_t));
+	early_iounmap(runtime, sizeof(efi_runtime_services_64_t));
+
+	return 0;
+}
+
+static int __init efi_runtime_init(void)
+{
+	int rv;
+
+	/*
+	 * Check out the runtime services table. We need to map
+	 * the runtime services table so that we can grab the physical
+	 * address of several of the EFI runtime functions, needed to
+	 * set the firmware into virtual mode.
+	 */
+	if (efi_enabled(EFI_64BIT))
+		rv = efi_runtime_init64();
+	else
+		rv = efi_runtime_init32();
+
+	if (rv)
+		return rv;
 
 	return 0;
 }
@@ -841,6 +889,22 @@ void __init old_map_region(efi_memory_desc_t *md)
 		       (unsigned long long)md->phys_addr);
 }
 
+static void native_runtime_setup(void)
+{
+	efi.get_time = virt_efi_get_time;
+	efi.set_time = virt_efi_set_time;
+	efi.get_wakeup_time = virt_efi_get_wakeup_time;
+	efi.set_wakeup_time = virt_efi_set_wakeup_time;
+	efi.get_variable = virt_efi_get_variable;
+	efi.get_next_variable = virt_efi_get_next_variable;
+	efi.set_variable = virt_efi_set_variable;
+	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
+	efi.reset_system = virt_efi_reset_system;
+	efi.query_variable_info = virt_efi_query_variable_info;
+	efi.update_capsule = virt_efi_update_capsule;
+	efi.query_capsule_caps = virt_efi_query_capsule_caps;
+}
+
 /* Merge contiguous regions of the same type and attribute */
 static void __init efi_merge_regions(void)
 {
@@ -1023,11 +1087,20 @@ void __init efi_enter_virtual_mode(void)
 	efi_sync_low_kernel_mappings();
 
 	if (!efi_setup) {
-		status = phys_efi_set_virtual_address_map(
-			memmap.desc_size * count,
-			memmap.desc_size,
-			memmap.desc_version,
-			(efi_memory_desc_t *)__pa(new_memmap));
+		if (efi_is_native()) {
+			status = phys_efi_set_virtual_address_map(
+					memmap.desc_size * count,
+					memmap.desc_size,
+					memmap.desc_version,
+					(efi_memory_desc_t *)__pa(new_memmap));
+		} else {
+			status = efi_thunk_set_virtual_address_map(
+					efi_phys.set_virtual_address_map,
+					memmap.desc_size * count,
+					memmap.desc_size,
+					memmap.desc_version,
+					(efi_memory_desc_t *)__pa(new_memmap));
+		}
 
 		if (status != EFI_SUCCESS) {
 			pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
@@ -1043,19 +1116,13 @@ void __init efi_enter_virtual_mode(void)
 	 * Call EFI services through wrapper functions.
 	 */
 	efi.runtime_version = efi_systab.hdr.revision;
-	efi.get_time = virt_efi_get_time;
-	efi.set_time = virt_efi_set_time;
-	efi.get_wakeup_time = virt_efi_get_wakeup_time;
-	efi.set_wakeup_time = virt_efi_set_wakeup_time;
-	efi.get_variable = virt_efi_get_variable;
-	efi.get_next_variable = virt_efi_get_next_variable;
-	efi.set_variable = virt_efi_set_variable;
-	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
-	efi.reset_system = virt_efi_reset_system;
+
+	if (efi_is_native())
+		native_runtime_setup();
+	else
+		efi_thunk_runtime_setup();
+
 	efi.set_virtual_address_map = NULL;
-	efi.query_variable_info = virt_efi_query_variable_info;
-	efi.update_capsule = virt_efi_update_capsule;
-	efi.query_capsule_caps = virt_efi_query_capsule_caps;
 
 	efi_runtime_mkexec();