1 files changed, 34 insertions, 4 deletions

diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index a34fd3b12e2b..7baf2cc04e1e 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -6,29 +6,35 @@
 
 #ifdef CONFIG_EFI
 extern void efi_init(void);
-extern void efi_idmap_init(void);
+extern void efi_virtmap_init(void);
 #else
 #define efi_init()
-#define efi_idmap_init()
+#define efi_virtmap_init()
 #endif
 
 #define efi_call_virt(f, ...)                                           \
 ({                                                                      \
-        efi_##f##_t *__f = efi.systab->runtime->f;                      \
+        efi_##f##_t *__f;                                               \
         efi_status_t __s;                                               \
                                                                         \
         kernel_neon_begin();                                            \
+        efi_virtmap_load();                                             \
+        __f = efi.systab->runtime->f;                                   \
         __s = __f(__VA_ARGS__);                                         \
+        efi_virtmap_unload();                                           \
         kernel_neon_end();                                              \
         __s;                                                            \
 })
 
 #define __efi_call_virt(f, ...)                                         \
 ({                                                                      \
-        efi_##f##_t *__f = efi.systab->runtime->f;                      \
+        efi_##f##_t *__f;                                               \
                                                                         \
         kernel_neon_begin();                                            \
+        efi_virtmap_load();                                             \
+        __f = efi.systab->runtime->f;                                   \
         __f(__VA_ARGS__);                                               \
+        efi_virtmap_unload();                                           \
         kernel_neon_end();                                              \
 })
 
@@ -44,4 +50,28 @@ extern void efi_idmap_init(void);
 
 #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__)
 
+#define EFI_ALLOC_ALIGN         SZ_64K
+
+/*
+ * On ARM systems, virtually remapped UEFI runtime services are set up in three
+ * distinct stages:
+ * - The stub retrieves the final version of the memory map from UEFI, populates
+ *   the virt_addr fields and calls the SetVirtualAddressMap() [SVAM] runtime
+ *   service to communicate the new mapping to the firmware (Note that the new
+ *   mapping is not live at this time)
+ * - During early boot, the page tables are allocated and populated based on the
+ *   virt_addr fields in the memory map, but only if all descriptors with the
+ *   EFI_MEMORY_RUNTIME attribute have a non-zero value for virt_addr. If this
+ *   succeeds, the EFI_VIRTMAP flag is set to indicate that the virtual mappings
+ *   have been installed successfully.
+ * - During an early initcall(), the UEFI Runtime Services are enabled and the
+ *   EFI_RUNTIME_SERVICES bit set if some conditions are met, i.e., we need a
+ *   non-early mapping of the UEFI system table, and we need to have the virtmap
+ *   installed.
+ */
+#define EFI_VIRTMAP             EFI_ARCH_1
+
+void efi_virtmap_load(void);
+void efi_virtmap_unload(void);
+
 #endif /* _ASM_EFI_H */