The following commit has been merged into the x86/boot branch of tip:

Commit-ID:     ce2c403c26c1ed0e28fc541ab30fe13ff50236be
Gitweb:        https://git.kernel.org/tip/ce2c403c26c1ed0e28fc541ab30fe13ff50236be
Author:        Alexander Shishkin <alexander.shishkin@linux.intel.com>
AuthorDate:    Fri, 20 Jun 2025 16:53:12 +03:00
Committer:     Dave Hansen <dave.hansen@linux.intel.com>
CommitterDate: Fri, 20 Jun 2025 10:48:50 -07:00

x86/efi: Move runtime service initialization to arch/x86

The EFI call in start_kernel() is guarded by #ifdef CONFIG_X86. Move
the thing to the arch_cpu_finalize_init() path on x86 and get rid of
the #ifdef in start_kernel().

No functional change intended.

Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/all/20250620135325.3300848-5-kirill.shutemov%40linux.intel.com
---
 arch/x86/kernel/cpu/common.c | 7 +++++++
 init/main.c                  | 5 -----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8feb8fd..4f430be 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -26,6 +26,7 @@
 #include <linux/pgtable.h>
 #include <linux/stackprotector.h>
 #include <linux/utsname.h>
+#include <linux/efi.h>
 
 #include <asm/alternative.h>
 #include <asm/cmdline.h>
@@ -2530,6 +2531,12 @@ void __init arch_cpu_finalize_init(void)
 	fpu__init_cpu();
 
 	/*
+	 * This needs to follow the FPU initializtion, since EFI depends on it.
+	 */
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		efi_enter_virtual_mode();
+
+	/*
 	 * Ensure that access to the per CPU representation has the initial
 	 * boot CPU configuration.
 	 */
diff --git a/init/main.c b/init/main.c
index 225a582..f9f401b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -53,7 +53,6 @@
 #include <linux/cpuset.h>
 #include <linux/memcontrol.h>
 #include <linux/cgroup.h>
-#include <linux/efi.h>
 #include <linux/tick.h>
 #include <linux/sched/isolation.h>
 #include <linux/interrupt.h>
@@ -1068,10 +1067,6 @@ void start_kernel(void)
 
 	pid_idr_init();
 	anon_vma_init();
-#ifdef CONFIG_X86
-	if (efi_enabled(EFI_RUNTIME_SERVICES))
-		efi_enter_virtual_mode();
-#endif
 	thread_stack_cache_init();
 	cred_init();
 	fork_init();