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Date: Tue, 5 May 2015 19:50:13 +0200
From: Ingo Molnar <mingo@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Andy Lutomirski <luto@...capital.net>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Fenghua Yu <fenghua.yu@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Oleg Nesterov <oleg@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 121/208] 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 <bp@...en8.de>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
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 <asm/fpu/internal.h>
+
+/*
+ * 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 <asm/tlbflush.h>
/*
- * 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
--
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