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| author | Grant Likely <grant.likely@secretlab.ca> | 2012-12-07 17:02:47 +0000 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2012-12-07 17:02:47 +0000 |
| commit | 7730cba2a50332c194f50a58b86359ea39a82bd1 (patch) | |
| tree | 64c8d7228da1454c02288068e57a9c61f8b0acd0 /arch/x86/kernel/head_32.S | |
| parent | c20151dff8a6d503c0d0cc4387c33a618cdabcb7 (diff) | |
| parent | b69f0859dc8e633c5d8c06845811588fe17e68b3 (diff) | |
| download | blackbird-op-linux-7730cba2a50332c194f50a58b86359ea39a82bd1.tar.gz blackbird-op-linux-7730cba2a50332c194f50a58b86359ea39a82bd1.zip | |
Merge tag 'v3.7-rc8' into spi/next
Linux 3.7-rc8
Diffstat (limited to 'arch/x86/kernel/head_32.S')
| -rw-r--r-- | arch/x86/kernel/head_32.S | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 957a47aec64e..4dac2f68ed4a 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -292,8 +292,8 @@ default_entry: * be using the global pages. * * NOTE! If we are on a 486 we may have no cr4 at all! - * Specifically, cr4 exists if and only if CPUID exists, - * which in turn exists if and only if EFLAGS.ID exists. + * Specifically, cr4 exists if and only if CPUID exists + * and has flags other than the FPU flag set. */ movl $X86_EFLAGS_ID,%ecx pushl %ecx @@ -308,6 +308,11 @@ default_entry: testl %ecx,%eax jz 6f # No ID flag = no CPUID = no CR4 + movl $1,%eax + cpuid + andl $~1,%edx # Ignore CPUID.FPU + jz 6f # No flags or only CPUID.FPU = no CR4 + movl pa(mmu_cr4_features),%eax movl %eax,%cr4 |
