x86/fpu: Remove fpstate_xstate_init_size() boot quirk
fpstate_xstate_init_size() is called in fpu__cpu_init(), which is
run on every CPU, every time they are brought online.
But we want to call fpstate_xstate_init_size() only once. Move it to
fpu__detect(), which only runs once, on the boot CPU.
Also clean up the flow of fpstate_xstate_init_size() a bit, by
removing a 'return' from the middle of the function.
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/init.c b/arch/x86/kernel/fpu/init.c
index 0b16f61..3e0fee5 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -109,13 +109,12 @@
setup_clear_cpu_cap(X86_FEATURE_XSAVE);
setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
xstate_size = sizeof(struct i387_soft_struct);
- return;
+ } else {
+ if (cpu_has_fxsr)
+ xstate_size = sizeof(struct i387_fxsave_struct);
+ else
+ xstate_size = sizeof(struct i387_fsave_struct);
}
-
- if (cpu_has_fxsr)
- xstate_size = sizeof(struct i387_fxsave_struct);
- else
- xstate_size = sizeof(struct i387_fsave_struct);
}
/*
@@ -151,12 +150,6 @@
cr0 |= X86_CR0_EM;
write_cr0(cr0);
- /*
- * fpstate_xstate_init_size() is only called once, to avoid overriding
- * 'xstate_size' during (secondary CPU) bootup or during CPU hotplug.
- */
- if (xstate_size == 0)
- fpstate_xstate_init_size();
mxcsr_feature_mask_init();
xsave_init();
@@ -194,5 +187,7 @@
else
clear_cpu_cap(c, X86_FEATURE_FPU);
- /* The final cr0 value is set in fpu_init() */
+ /* The final cr0 value is set later, in fpu_init() */
+
+ fpstate_xstate_init_size();
}