Date: Fri, 14 Apr 2017 14:48:56 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r316844 - stable/11/sys/x86/x86 Message-ID: <201704141448.v3EEmuhk075059@repo.freebsd.org>
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Author: avg Date: Fri Apr 14 14:48:55 2017 New Revision: 316844 URL: https://svnweb.freebsd.org/changeset/base/316844 Log: MFC r316017,r316020: add SMT detection for newer AMD processors Modified: stable/11/sys/x86/x86/mp_x86.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/x86/x86/mp_x86.c ============================================================================== --- stable/11/sys/x86/x86/mp_x86.c Fri Apr 14 14:45:44 2017 (r316843) +++ stable/11/sys/x86/x86/mp_x86.c Fri Apr 14 14:48:55 2017 (r316844) @@ -226,11 +226,10 @@ add_deterministic_cache(int type, int le * Determine topology of processing units and caches for AMD CPUs. * See: * - AMD CPUID Specification (Publication # 25481) - * - BKDG For AMD Family 10h Processors (Publication # 31116), section 2.15 * - BKDG for AMD NPT Family 0Fh Processors (Publication # 32559) - * XXX At the moment the code does not recognize grouping of AMD CMT threads, - * if supported, into cores, so each thread is treated as being in its own - * core. In other words, each logical CPU is considered to be a core. + * - BKDG For AMD Family 10h Processors (Publication # 31116) + * - BKDG For AMD Family 15h Models 00h-0Fh Processors (Publication # 42301) + * - BKDG For AMD Family 16h Models 00h-0Fh Processors (Publication # 48751) */ static void topo_probe_amd(void) @@ -254,6 +253,22 @@ topo_probe_amd(void) pkg_id_shift = mask_width((cpu_procinfo2 & AMDID_CMP_CORES) + 1); + /* + * Families prior to 16h define the following value as + * cores per compute unit and we don't really care about the AMD + * compute units at the moment. Perhaps we should treat them as + * cores and cores within the compute units as hardware threads, + * but that's up for debate. + * Later families define the value as threads per compute unit, + * so we are following AMD's nomenclature here. + */ + if ((amd_feature2 & AMDID2_TOPOLOGY) != 0 && + CPUID_TO_FAMILY(cpu_id) >= 0x16) { + cpuid_count(0x8000001e, 0, p); + share_count = ((p[1] >> 8) & 0xff) + 1; + core_id_shift = mask_width(share_count); + } + if ((amd_feature2 & AMDID2_TOPOLOGY) != 0) { for (i = 0; ; i++) { cpuid_count(0x8000001d, i, p);
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