x86, cpu: Convert FDIV bug detection

... to the new facility. Add a reference to the wikipedia article
explaining the FDIV test we're doing here.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1363788448-31325-4-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

5 files changed, 6 insertions, 7 deletions

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index c0ad7e75815c..25eb9488a9a5 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -223,6 +223,7 @@
 #define X86_BUG(x)              (NCAPINTS*32 + (x))
 
 #define X86_BUG_F00F            X86_BUG(0) /* Intel F00F */
+#define X86_BUG_FDIV            X86_BUG(1) /* FPU FDIV */
 
 #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
 
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 1e55e2d543b5..ea22dfaf6c5e 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -91,7 +91,6 @@ struct cpuinfo_x86 {
         /* Problems on some 486Dx4's and old 386's: */
         char                    hard_math;
         char                    rfu;
-        char                    fdiv_bug;
         char                    coma_bug;
         char                    pad0;
 #else
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index af6455e3fcc9..c59635ecbbb8 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -59,7 +59,7 @@ static void __init check_fpu(void)
          * trap_init() enabled FXSR and company _before_ testing for FP
          * problems here.
          *
-         * Test for the divl bug..
+         * Test for the divl bug: http://en.wikipedia.org/wiki/Fdiv_bug
          */
         __asm__("fninit\n\t"
                 "fldl %1\n\t"
@@ -75,9 +75,10 @@ static void __init check_fpu(void)
 
         kernel_fpu_end();
 
-        boot_cpu_data.fdiv_bug = fdiv_bug;
-        if (boot_cpu_data.fdiv_bug)
+        if (fdiv_bug) {
+                set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV);
                 pr_warn("Hmm, FPU with FDIV bug\n");
+        }
 }
 
 /*
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 2d60b2bec01c..5dfb6c65138f 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -34,7 +34,7 @@ static void show_cpuinfo_misc(struct seq_file *m, struct cpuinfo_x86 *c)
                    "fpu_exception\t: %s\n"
                    "cpuid level\t: %d\n"
                    "wp\t\t: %s\n",
-                   c->fdiv_bug ? "yes" : "no",
+                   static_cpu_has_bug(X86_BUG_FDIV) ? "yes" : "no",
                    static_cpu_has_bug(X86_BUG_F00F) ? "yes" : "no",
                    c->coma_bug ? "yes" : "no",
                    c->hard_math ? "yes" : "no",
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 90d8cc930f5e..29258c75a2f3 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -173,12 +173,10 @@ static struct resource bss_resource = {
 /* cpu data as detected by the assembly code in head.S */
 struct cpuinfo_x86 new_cpu_data __cpuinitdata = {
         .wp_works_ok = -1,
-        .fdiv_bug = -1,
 };
 /* common cpu data for all cpus */
 struct cpuinfo_x86 boot_cpu_data __read_mostly = {
         .wp_works_ok = -1,
-        .fdiv_bug = -1,
 };
 EXPORT_SYMBOL(boot_cpu_data);