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| author | Andriy Gapon <avg@FreeBSD.org> | 2016-04-28 08:29:57 +0000 |
|---|---|---|
| committer | Andriy Gapon <avg@FreeBSD.org> | 2016-04-28 08:29:57 +0000 |
| commit | e5e4452078986a8597845e41ead6edefdb1cda21 (patch) | |
| tree | 61a66897b1d876de45e22aba2242568c9f02255f /sys/amd64/amd64/initcpu.c | |
| parent | 341134426f3e73c0cae3565a4abbac9869075ca6 (diff) | |
| download | src-e5e4452078986a8597845e41ead6edefdb1cda21.tar.gz src-e5e4452078986a8597845e41ead6edefdb1cda21.zip | |
ensure that initial local apic id is sane on AMD 10h systems
Summary:
The Initial Local APIC ID is returned by CPUID function 1 (in EBX).
On AMD Family 10h systems the way that ID is built is controlled by
an MSR bit (InitApicIdCpuIdLo). BKDG instructs BIOS to set it in a
certain way, but a BIOS can be buggy. In that case the ID can confuse
tools that use it, e.g. hwloc.
For example, on a system that I own real Local APIC IDs are configured
as 0, 1, 2, 3, but IDs reported via CPUID.1 are 0, 0x40, 0x80, 0xc0.
See: https://github.com/open-mpi/hwloc/issues/183
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D6060
Notes
Notes:
svn path=/head/; revision=298736
Diffstat (limited to 'sys/amd64/amd64/initcpu.c')
| -rw-r--r-- | sys/amd64/amd64/initcpu.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/sys/amd64/amd64/initcpu.c b/sys/amd64/amd64/initcpu.c index 15d817140437..bfc94b6a5180 100644 --- a/sys/amd64/amd64/initcpu.c +++ b/sys/amd64/amd64/initcpu.c @@ -80,6 +80,19 @@ init_amd(void) wrmsr(0xc0011029, rdmsr(0xc0011029) | 1); break; } + + /* + * BIOS may fail to set InitApicIdCpuIdLo to 1 as it should per BKDG. + * So, do it here or otherwise some tools could be confused by + * Initial Local APIC ID reported with CPUID Function 1 in EBX. + */ + if (CPUID_TO_FAMILY(cpu_id) == 0x10) { + if ((cpu_feature2 & CPUID2_HV) == 0) { + msr = rdmsr(MSR_NB_CFG1); + msr |= (uint64_t)1 << 54; + wrmsr(MSR_NB_CFG1, msr); + } + } } /* |