x86: Get rid of ->hard_math and all the FPU asm fu
Reimplement FPU detection code in C and drop old, not-so-recommended
detection method in asm. Move all the relevant stuff into i387.c where
it conceptually belongs. Finally drop cpuinfo_x86.hard_math.
[ hpa: huge thanks to Borislav for taking my original concept patch
and productizing it ]
[ Boris, note to self: do not use static_cpu_has before alternatives! ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1367244262-29511-2-git-send-email-bp@alien8.de
Link: http://lkml.kernel.org/r/1365436666-9837-2-git-send-email-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 4112be9..0344534 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 @@
{
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 @@
* kernel_fpu_begin/end() in check_fpu() relies on the patched
* alternative instructions.
*/
- check_fpu();
+ if (cpu_has_fpu)
+ check_fpu();
}