git: 7fd7b6b4a5dd - stable/13 - Prefer CPUID leaf 1Fh for Intel CPU topology detection.
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Date: Sat, 20 Nov 2021 00:26:50 UTC
The branch stable/13 has been updated by mav: URL: https://cgit.FreeBSD.org/src/commit/?id=7fd7b6b4a5dd6e32a50966e7c7d0ae6e6e34beba commit 7fd7b6b4a5dd6e32a50966e7c7d0ae6e6e34beba Author: Alexander Motin <mav@FreeBSD.org> AuthorDate: 2021-11-06 04:48:37 +0000 Commit: Alexander Motin <mav@FreeBSD.org> CommitDate: 2021-11-20 00:26:29 +0000 Prefer CPUID leaf 1Fh for Intel CPU topology detection. Leaf 1Fh is a prefered extended version of 0Bh. It is supported by new Lader Lake CPUs, though does not report anything new so far. MFC after: 2 weeks (cherry picked from commit 6badb512a94df667f0df1484fb288ece186305bd) --- sys/x86/x86/mp_x86.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/sys/x86/x86/mp_x86.c b/sys/x86/x86/mp_x86.c index ca1125886619..7724370c2c93 100644 --- a/sys/x86/x86/mp_x86.c +++ b/sys/x86/x86/mp_x86.c @@ -380,7 +380,7 @@ topo_probe_intel_0x4(void) /* * Determine topology of processing units for Intel CPUs - * using CPUID Leaf 11, if supported. + * using CPUID Leaf 1Fh or 0Bh, if supported. * See: * - Intel 64 Architecture Processor Topology Enumeration * - Intel 64 and IA-32 ArchitecturesSoftware Developer’s Manual, @@ -390,13 +390,23 @@ topo_probe_intel_0x4(void) static void topo_probe_intel_0xb(void) { - u_int p[4]; + u_int leaf; + u_int p[4] = { 0 }; int bits; int type; int i; - /* Fall back if CPU leaf 11 doesn't really exist. */ - cpuid_count(0x0b, 0, p); + /* Prefer leaf 1Fh (V2 Extended Topology Enumeration). */ + if (cpu_high >= 0x1f) { + leaf = 0x1f; + cpuid_count(leaf, 0, p); + } + /* Fall back to leaf 0Bh (Extended Topology Enumeration). */ + if (p[1] == 0) { + leaf = 0x0b; + cpuid_count(leaf, 0, p); + } + /* Fall back to leaf 04h (Deterministic Cache Parameters). */ if (p[1] == 0) { topo_probe_intel_0x4(); return; @@ -404,7 +414,7 @@ topo_probe_intel_0xb(void) /* We only support three levels for now. */ for (i = 0; ; i++) { - cpuid_count(0x0b, i, p); + cpuid_count(leaf, i, p); bits = p[0] & 0x1f; type = (p[2] >> 8) & 0xff; @@ -412,13 +422,12 @@ topo_probe_intel_0xb(void) if (type == 0) break; - /* TODO: check for duplicate (re-)assignment */ if (type == CPUID_TYPE_SMT) core_id_shift = bits; else if (type == CPUID_TYPE_CORE) pkg_id_shift = bits; - else - printf("unknown CPU level type %d\n", type); + else if (bootverbose) + printf("Topology level type %d shift: %d\n", type, bits); } if (pkg_id_shift < core_id_shift) {