Commit 3e7cf5b0 authored by Suresh Siddha's avatar Suresh Siddha Committed by H. Peter Anvin

x86-32, fpu: Fix DNA exception during check_fpu()

Before check_fpu() is called, we have cr0.TS bit set and hence the floating
point code to check the FDIV bug was generating a DNA exception.

Use kernel_fpu_begin()/kernel_fpu_end() around the floating point
code to avoid this unnecessary device not available exception during
boot.
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1309479572.2665.1372.camel@sbsiddha-MOBL3.sc.intel.comSigned-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent b0af8dfd
...@@ -62,6 +62,8 @@ static void __init check_fpu(void) ...@@ -62,6 +62,8 @@ static void __init check_fpu(void)
return; return;
} }
kernel_fpu_begin();
/* /*
* trap_init() enabled FXSR and company _before_ testing for FP * trap_init() enabled FXSR and company _before_ testing for FP
* problems here. * problems here.
...@@ -80,6 +82,8 @@ static void __init check_fpu(void) ...@@ -80,6 +82,8 @@ static void __init check_fpu(void)
: "=m" (*&fdiv_bug) : "=m" (*&fdiv_bug)
: "m" (*&x), "m" (*&y)); : "m" (*&x), "m" (*&y));
kernel_fpu_end();
boot_cpu_data.fdiv_bug = fdiv_bug; boot_cpu_data.fdiv_bug = fdiv_bug;
if (boot_cpu_data.fdiv_bug) if (boot_cpu_data.fdiv_bug)
printk(KERN_WARNING "Hmm, FPU with FDIV bug.\n"); printk(KERN_WARNING "Hmm, FPU with FDIV bug.\n");
......
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