init: Invoke arch_cpu_finalize_init() earlier

commit 9df9d2f0471b4c4702670380b8d8a45b40b23a7d upstream

X86 is reworking the boot process so that initializations which are not
required during early boot can be moved into the late boot process and out
of the fragile and restricted initial boot phase.

arch_cpu_finalize_init() is the obvious place to do such initializations,
but arch_cpu_finalize_init() is invoked too late in start_kernel() e.g. for
initializing the FPU completely. fork_init() requires that the FPU is
initialized as the size of task_struct on X86 depends on the size of the
required FPU register buffer.

Fortunately none of the init calls between calibrate_delay() and
arch_cpu_finalize_init() is relevant for the functionality of
arch_cpu_finalize_init().

Invoke it right after calibrate_delay() where everything which is relevant
for arch_cpu_finalize_init() has been set up already.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/r/20230613224545.612182854@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/init/main.c b/init/main.c
index fa3b4c99616e..3ad2400e7aa4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1107,6 +1107,9 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
 		late_time_init();
 	sched_clock_init();
 	calibrate_delay();
+
+	arch_cpu_finalize_init();
+
 	pid_idr_init();
 	anon_vma_init();
 #ifdef CONFIG_X86
@@ -1135,8 +1138,6 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
 
 	poking_init();
 
-	arch_cpu_finalize_init();
-
 	acpi_subsystem_init();
 	arch_post_acpi_subsys_init();
 	kcsan_init();