x86/fpu: Propagate once per boot quirk into fpu__init_system_xstate()

Linearize the call sequence in xsave_init():

	fpu__init_system_xstate();
	fpu__init_cpu_xstate();

We do this by propagating the boot-once quirk into
fpu__init_system_xstate(). fpu__init_cpu_xstate() is
safe to be called multiple time.

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/fpu/xsave.c b/arch/x86/kernel/fpu/xsave.c
index fd656cbdd31585f62d8a1a78ed7c13fad436af76..9d5ff90916b177a5a8de33e94de7fdbd4d9e6f0c 100644 (file)
--- a/arch/x86/kernel/fpu/xsave.c
+++ b/arch/x86/kernel/fpu/xsave.c
@@ -652,6 +652,11 @@ static void __init init_xstate_size(void)
 void fpu__init_system_xstate(void)
 {
        unsigned int eax, ebx, ecx, edx;
+       static bool on_boot_cpu = 1;
+
+       if (!on_boot_cpu)
+               return;
+       on_boot_cpu = 0;
 
        if (!cpu_has_xsave) {
                pr_info("x86/fpu: Legacy x87 FPU detected.\n");
@@ -714,14 +719,8 @@ void fpu__init_system_xstate(void)
  */
 void xsave_init(void)
 {
-       static char on_boot_cpu = 1;
-
-       if (on_boot_cpu) {
-               on_boot_cpu = 0;
-               fpu__init_system_xstate();
-       } else {
-               fpu__init_cpu_xstate();
-       }
+       fpu__init_system_xstate();
+       fpu__init_cpu_xstate();
 }
 
 /*