Date: Sat, 8 Apr 2017 14:16:42 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r316643 - head/sys/x86/x86 Message-ID: <201704081416.v38EGglS088251@repo.freebsd.org>
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Author: avg Date: Sat Apr 8 14:16:42 2017 New Revision: 316643 URL: https://svnweb.freebsd.org/changeset/base/316643 Log: use msr 0xc001100c to discover multi-node AMD processors This is applicable only to the older processors that do not have the AMD Topology extension. Opteron 6100-series "Magny-Cours" processors had multiple nodes within a package and didn't have the Topology extension. Without this change FreeBSD would assume that those processors have a single L3 cache shared by all cores while, in fact, each node has its own L3 cache. Many thanks to Freddie Cash <fjwcash@gmail.com> for providing valuable hardware information. MFC after: 2 weeks Modified: head/sys/x86/x86/mp_x86.c Modified: head/sys/x86/x86/mp_x86.c ============================================================================== --- head/sys/x86/x86/mp_x86.c Sat Apr 8 10:00:39 2017 (r316642) +++ head/sys/x86/x86/mp_x86.c Sat Apr 8 14:16:42 2017 (r316643) @@ -236,7 +236,9 @@ static void topo_probe_amd(void) { u_int p[4]; + uint64_t v; int level; + int nodes_per_socket; int share_count; int type; int i; @@ -295,13 +297,18 @@ topo_probe_amd(void) caches[1].present = 1; } if (((p[3] >> 18) & 0x3fff) != 0) { - - /* - * TODO: Account for dual-node processors - * where each node within a package has its own - * L3 cache. - */ - caches[2].id_shift = pkg_id_shift; + nodes_per_socket = 1; + if ((amd_feature2 & AMDID2_NODE_ID) != 0) { + /* + * Handle multi-node processors that + * have multiple chips, each with its + * own L3 cache, on the same die. + */ + v = rdmsr(0xc001100c); + nodes_per_socket = 1 + ((v >> 3) & 0x7); + } + caches[2].id_shift = + pkg_id_shift - mask_width(nodes_per_socket); caches[2].present = 1; } }
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