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| author | jkim <jkim@FreeBSD.org> | 2009-05-04 18:05:27 +0000 |
|---|---|---|
| committer | jkim <jkim@FreeBSD.org> | 2009-05-04 18:05:27 +0000 |
| commit | 3b0819d0afb64bc978363bcb108d66e47adb5af7 (patch) | |
| tree | dfbbbc604e7bff5d5298c1ed21ea8133553ae877 /sys/amd64 | |
| parent | 5a4e3bbf097e207785aa8560452ceef9b4bea804 (diff) | |
| download | FreeBSD-src-3b0819d0afb64bc978363bcb108d66e47adb5af7.zip FreeBSD-src-3b0819d0afb64bc978363bcb108d66e47adb5af7.tar.gz | |
Unlock the largest standard CPUID on Intel CPUs for both amd64 and i386 and
fix SMP topology detection. On i386, we extend it to cover Core, Core 2,
and Core i7 processors, not just Pentium 4 family, and move it to better
place. On amd64, all supported Intel CPUs should have this MSR.
Diffstat (limited to 'sys/amd64')
| -rw-r--r-- | sys/amd64/amd64/identcpu.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/sys/amd64/amd64/identcpu.c b/sys/amd64/amd64/identcpu.c index 4ac0e5f..46b7920 100644 --- a/sys/amd64/amd64/identcpu.c +++ b/sys/amd64/amd64/identcpu.c @@ -472,6 +472,22 @@ identify_cpu(void) cpu_feature = regs[3]; cpu_feature2 = regs[2]; + /* + * Clear "Limit CPUID Maxval" bit and get the largest standard CPUID + * function number again if it is set from BIOS. It is necessary + * for probing correct CPU topology later. + * XXX This is only done on the BSP package. + */ + if (cpu_vendor_id == CPU_VENDOR_INTEL && cpu_high > 0 && cpu_high < 4) { + uint64_t msr; + msr = rdmsr(MSR_IA32_MISC_ENABLE); + if ((msr & 0x400000ULL) != 0) { + wrmsr(MSR_IA32_MISC_ENABLE, msr & ~0x400000ULL); + do_cpuid(0, regs); + cpu_high = regs[0]; + } + } + if (cpu_vendor_id == CPU_VENDOR_INTEL || cpu_vendor_id == CPU_VENDOR_AMD || cpu_vendor_id == CPU_VENDOR_CENTAUR) { |
