Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030788AbbEERxX (ORCPT ); Tue, 5 May 2015 13:53:23 -0400 Received: from mail-wg0-f41.google.com ([74.125.82.41]:33904 "EHLO mail-wg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932966AbbEERxS (ORCPT ); Tue, 5 May 2015 13:53:18 -0400 From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Andy Lutomirski , Borislav Petkov , Dave Hansen , Fenghua Yu , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Thomas Gleixner Subject: [PATCH 121/208] x86/fpu: Factor out FPU bug checks into fpu/bugs.c Date: Tue, 5 May 2015 19:50:13 +0200 Message-Id: <1430848300-27877-43-git-send-email-mingo@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1430848300-27877-1-git-send-email-mingo@kernel.org> References: <1430848300-27877-1-git-send-email-mingo@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4491 Lines: 177 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: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/Makefile | 2 +- arch/x86/kernel/fpu/bugs.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/fpu/init.c | 60 ------------------------------------------------------------ 3 files changed, 65 insertions(+), 61 deletions(-) diff --git a/arch/x86/kernel/fpu/Makefile b/arch/x86/kernel/fpu/Makefile index 50464a716b87..2020a2b7a597 100644 --- a/arch/x86/kernel/fpu/Makefile +++ b/arch/x86/kernel/fpu/Makefile @@ -2,4 +2,4 @@ # Build rules for the FPU support code: # -obj-y += init.o core.o xsave.o +obj-y += init.o bugs.o core.o xsave.o diff --git a/arch/x86/kernel/fpu/bugs.c b/arch/x86/kernel/fpu/bugs.c new file mode 100644 index 000000000000..400a3d713fb2 --- /dev/null +++ b/arch/x86/kernel/fpu/bugs.c @@ -0,0 +1,64 @@ +/* + * x86 FPU bug checks: + */ +#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(); +} 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 @@ -5,66 +5,6 @@ #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: */ static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/