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>

2 files changed, 29 insertions, 2 deletions

diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index e06a199423c0..b2cc7b4552a1 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/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();
+}
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 77f7ac3668cb..91d31ac422d6 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/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);
 
 /*