efi/x86: Move EFI runtime call setup/teardown helpers out of line

Only the arch_efi_call_virt() macro that some architectures override
needs to be a macro, given that it is variadic and encapsulates calls
via function pointers that have different prototypes.

The associated setup and teardown code are not special in this regard,
and don't need to be instantiated at each call site. So turn them into
ordinary C functions and move them out of line.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Author: ardbiesheuvel

arch/x86/include/asm/efi.h

@@ -91,19 +91,6 @@ static inline void efi_fpu_end(void)
 
 #ifdef CONFIG_X86_32
 #define EFI_X86_KERNEL_ALLOC_LIMIT		(SZ_512M - 1)
-
-#define arch_efi_call_virt_setup()					\
-({									\
-	efi_fpu_begin();						\
-	firmware_restrict_branch_speculation_start();			\
-})
-
-#define arch_efi_call_virt_teardown()					\
-({									\
-	firmware_restrict_branch_speculation_end();			\
-	efi_fpu_end();							\
-})
-
 #else /* !CONFIG_X86_32 */
 #define EFI_X86_KERNEL_ALLOC_LIMIT		EFI_ALLOC_LIMIT
 
@@ -116,14 +103,6 @@ extern bool efi_disable_ibt_for_runtime;
 	__efi_call(__VA_ARGS__);					\
 })
 
-#define arch_efi_call_virt_setup()					\
-({									\
-	efi_sync_low_kernel_mappings();					\
-	efi_fpu_begin();						\
-	firmware_restrict_branch_speculation_start();			\
-	efi_enter_mm();							\
-})
-
 #undef arch_efi_call_virt
 #define arch_efi_call_virt(p, f, args...) ({				\
 	u64 ret, ibt = ibt_save(efi_disable_ibt_for_runtime);		\
@@ -132,13 +111,6 @@ extern bool efi_disable_ibt_for_runtime;
 	ret;								\
 })
 
-#define arch_efi_call_virt_teardown()					\
-({									\
-	efi_leave_mm();							\
-	firmware_restrict_branch_speculation_end();			\
-	efi_fpu_end();							\
-})
-
 #ifdef CONFIG_KASAN
 /*
  * CONFIG_KASAN may redefine memset to __memset.  __memset function is present
@@ -168,8 +140,8 @@ extern void efi_delete_dummy_variable(void);
 extern void efi_crash_gracefully_on_page_fault(unsigned long phys_addr);
 extern void efi_free_boot_services(void);
 
-void efi_enter_mm(void);
-void efi_leave_mm(void);
+void arch_efi_call_virt_setup(void);
+void arch_efi_call_virt_teardown(void);
 
 /* kexec external ABI */
 struct efi_setup_data {

arch/x86/platform/efi/efi_32.c

@@ -140,3 +140,15 @@ void __init efi_runtime_update_mappings(void)
 		}
 	}
 }
+
+void arch_efi_call_virt_setup(void)
+{
+	efi_fpu_begin();
+	firmware_restrict_branch_speculation_start();
+}
+
+void arch_efi_call_virt_teardown(void)
+{
+	firmware_restrict_branch_speculation_end();
+	efi_fpu_end();
+}

arch/x86/platform/efi/efi_64.c

@@ -474,19 +474,34 @@ void __init efi_dump_pagetable(void)
  * can not change under us.
  * It should be ensured that there are no concurrent calls to this function.
  */
-void efi_enter_mm(void)
+static void efi_enter_mm(void)
 {
 	efi_prev_mm = current->active_mm;
 	current->active_mm = &efi_mm;
 	switch_mm(efi_prev_mm, &efi_mm, NULL);
 }
 
-void efi_leave_mm(void)
+static void efi_leave_mm(void)
 {
 	current->active_mm = efi_prev_mm;
 	switch_mm(&efi_mm, efi_prev_mm, NULL);
 }
 
+void arch_efi_call_virt_setup(void)
+{
+	efi_sync_low_kernel_mappings();
+	efi_fpu_begin();
+	firmware_restrict_branch_speculation_start();
+	efi_enter_mm();
+}
+
+void arch_efi_call_virt_teardown(void)
+{
+	efi_leave_mm();
+	firmware_restrict_branch_speculation_end();
+	efi_fpu_end();
+}
+
 static DEFINE_SPINLOCK(efi_runtime_lock);
 
 /*