Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 FPU changes from Ingo Molnar:
 "There are two bigger changes in this tree:

   - Add an [early-use-]safe static_cpu_has() variant and other
     robustness improvements, including the new X86_DEBUG_STATIC_CPU_HAS
     configurable debugging facility, motivated by recent obscure FPU
     code bugs, by Borislav Petkov

   - Reimplement FPU detection code in C and drop the old asm code, by
     Peter Anvin."

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, fpu: Use static_cpu_has_safe before alternatives
  x86: Add a static_cpu_has_safe variant
  x86: Sanity-check static_cpu_has usage
  x86, cpu: Add a synthetic, always true, cpu feature
  x86: Get rid of ->hard_math and all the FPU asm fu

1 files changed, 2 insertions, 19 deletions

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 4112be9a4659..03445346ee0a 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -17,15 +17,6 @@
 #include <asm/paravirt.h>
 #include <asm/alternative.h>
 
-static int __init no_387(char *s)
-{
-	boot_cpu_data.hard_math = 0;
-	write_cr0(X86_CR0_TS | X86_CR0_EM | X86_CR0_MP | read_cr0());
-	return 1;
-}
-
-__setup("no387", no_387);
-
 static double __initdata x = 4195835.0;
 static double __initdata y = 3145727.0;
 
@@ -44,15 +35,6 @@ static void __init check_fpu(void)
 {
 	s32 fdiv_bug;
 
-	if (!boot_cpu_data.hard_math) {
-#ifndef CONFIG_MATH_EMULATION
-		pr_emerg("No coprocessor found and no math emulation present\n");
-		pr_emerg("Giving up\n");
-		for (;;) ;
-#endif
-		return;
-	}
-
 	kernel_fpu_begin();
 
 	/*
@@ -107,5 +89,6 @@ void __init check_bugs(void)
 	 * kernel_fpu_begin/end() in check_fpu() relies on the patched
 	 * alternative instructions.
 	 */
-	check_fpu();
+	if (cpu_has_fpu)
+		check_fpu();
 }