From 0bf23f3d6cadb2f0961d0ea370371cf35480bcb5 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 26 Apr 2015 14:48:08 +0200 Subject: x86/fpu: Factor out FPU bug checks into fpu/bugs.c Create separate fpu/bugs.c code so that if we read generic FPU code we don't have to wade through all the bugcheck related code first. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/init.c | 60 ---------------------------------------------- 1 file changed, 60 deletions(-) (limited to 'arch/x86/kernel/fpu/init.c') diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 69cdadd49ddf..63cd1703d25c 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -4,66 +4,6 @@ #include #include -/* - * Boot time CPU/FPU FDIV bug detection code: - */ - -static double __initdata x = 4195835.0; -static double __initdata y = 3145727.0; - -/* - * This used to check for exceptions.. - * However, it turns out that to support that, - * the XMM trap handlers basically had to - * be buggy. So let's have a correct XMM trap - * handler, and forget about printing out - * some status at boot. - * - * We should really only care about bugs here - * anyway. Not features. - */ -static void __init check_fpu(void) -{ - s32 fdiv_bug; - - kernel_fpu_begin(); - - /* - * trap_init() enabled FXSR and company _before_ testing for FP - * problems here. - * - * Test for the divl bug: http://en.wikipedia.org/wiki/Fdiv_bug - */ - __asm__("fninit\n\t" - "fldl %1\n\t" - "fdivl %2\n\t" - "fmull %2\n\t" - "fldl %1\n\t" - "fsubp %%st,%%st(1)\n\t" - "fistpl %0\n\t" - "fwait\n\t" - "fninit" - : "=m" (*&fdiv_bug) - : "m" (*&x), "m" (*&y)); - - kernel_fpu_end(); - - if (fdiv_bug) { - set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV); - pr_warn("Hmm, FPU with FDIV bug\n"); - } -} - -void fpu__init_check_bugs(void) -{ - /* - * kernel_fpu_begin/end() in check_fpu() relies on the patched - * alternative instructions. - */ - if (cpu_has_fpu) - check_fpu(); -} - /* * The earliest FPU detection code: */ -- cgit