[tip:x86/asm] x86/fpu: Remove check_fpu() indirection

From: tip-bot for Borislav Petkov
Date: Wed Apr 13 2016 - 07:43:42 EST


Commit-ID: de82fbc3823b7b15ee03466ebfb1c5ec7cc1a941
Gitweb: http://git.kernel.org/tip/de82fbc3823b7b15ee03466ebfb1c5ec7cc1a941
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Tue, 5 Apr 2016 08:29:54 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 13 Apr 2016 11:37:43 +0200

x86/fpu: Remove check_fpu() indirection

Rename it to fpu__init_check_bugs() and do the CPU feature check at
entry, thus getting rid of the old fpu__init_check_bugs() wrapper.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1459837795-2588-6-git-send-email-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/fpu/bugs.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/fpu/bugs.c b/arch/x86/kernel/fpu/bugs.c
index 224b5ec..aad34aa 100644
--- a/arch/x86/kernel/fpu/bugs.c
+++ b/arch/x86/kernel/fpu/bugs.c
@@ -21,11 +21,15 @@ static double __initdata y = 3145727.0;
* We should really only care about bugs here
* anyway. Not features.
*/
-static void __init check_fpu(void)
+void __init fpu__init_check_bugs(void)
{
u32 cr0_saved;
s32 fdiv_bug;

+ /* kernel_fpu_begin/end() relies on patched alternative instructions. */
+ if (!boot_cpu_has(X86_FEATURE_FPU))
+ return;
+
/* We might have CR0::TS set already, clear it: */
cr0_saved = read_cr0();
write_cr0(cr0_saved & ~X86_CR0_TS);
@@ -59,13 +63,3 @@ static void __init check_fpu(void)
pr_warn("Hmm, FPU with FDIV bug\n");
}
}
-
-void __init fpu__init_check_bugs(void)
-{
- /*
- * kernel_fpu_begin/end() in check_fpu() relies on the patched
- * alternative instructions.
- */
- if (boot_cpu_has(X86_FEATURE_FPU))
- check_fpu();
-}