arch/x86/kernel/cpu/topology_amd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/cpu.h>
   3
   4 #include <asm/apic.h>
   5 #include <asm/memtype.h>
   6 #include <asm/processor.h>
   7
   8 #include "cpu.h"
   9
  10 static bool parse_8000_0008(struct topo_scan *tscan)
  11 {
  12         struct {
  13                 // ecx
  14                 u32     cpu_nthreads            :  8, // Number of physical threads - 1
  15                                                 :  4, // Reserved
  16                         apicid_coreid_len       :  4, // Number of thread core ID bits (shift) in APIC ID
  17                         perf_tsc_len            :  2, // Performance time-stamp counter size
  18                                                 : 14; // Reserved
  19         } ecx;
  20         unsigned int sft;
  21
  22         if (tscan->c->extended_cpuid_level < 0x80000008)
  23                 return false;
  24
  25         cpuid_leaf_reg(0x80000008, CPUID_ECX, &ecx);
  26
  27         /* If the thread bits are 0, then get the shift value from ecx.cpu_nthreads */
  28         sft = ecx.apicid_coreid_len;
  29         if (!sft)
  30                 sft = get_count_order(ecx.cpu_nthreads + 1);
  31
  32         /*
  33          * cpu_nthreads describes the number of threads in the package
  34          * sft is the number of APIC ID bits per package
  35          *
  36          * As the number of actual threads per core is not described in
  37          * this leaf, just set the CORE domain shift and let the later
  38          * parsers set SMT shift. Assume one thread per core by default
  39          * which is correct if there are no other CPUID leafs to parse.
  40          */
  41         topology_update_dom(tscan, TOPO_SMT_DOMAIN, 0, 1);
  42         topology_set_dom(tscan, TOPO_CORE_DOMAIN, sft, ecx.cpu_nthreads + 1);
  43         return true;
  44 }
  45
  46 static void store_node(struct topo_scan *tscan, u16 nr_nodes, u16 node_id)
  47 {
  48         /*
  49          * Starting with Fam 17h the DIE domain could probably be used to
  50          * retrieve the node info on AMD/HYGON. Analysis of CPUID dumps
  51          * suggests it's the topmost bit(s) of the CPU cores area, but
  52          * that's guess work and neither enumerated nor documented.
  53          *
  54          * Up to Fam 16h this does not work at all and the legacy node ID
  55          * has to be used.
  56          */
  57         tscan->amd_nodes_per_pkg = nr_nodes;
  58         tscan->amd_node_id = node_id;
  59 }
  60
  61 static bool parse_8000_001e(struct topo_scan *tscan, bool has_topoext)
  62 {
  63         struct {
  64                 // eax
  65                 u32     ext_apic_id             : 32; // Extended APIC ID
  66                 // ebx
  67                 u32     core_id                 :  8, // Unique per-socket logical core unit ID
  68                         core_nthreads           :  8, // #Threads per core (zero-based)
  69                                                 : 16; // Reserved
  70                 // ecx
  71                 u32     node_id                 :  8, // Node (die) ID of invoking logical CPU
  72                         nnodes_per_socket       :  3, // #nodes in invoking logical CPU's package/socket
  73                                                 : 21; // Reserved
  74                 // edx
  75                 u32                             : 32; // Reserved
  76         } leaf;
  77
  78         if (!boot_cpu_has(X86_FEATURE_TOPOEXT))
  79                 return false;
  80
  81         cpuid_leaf(0x8000001e, &leaf);
  82
  83         tscan->c->topo.initial_apicid = leaf.ext_apic_id;
  84
  85         /*
  86          * If leaf 0xb is available, then the domain shifts are set
  87          * already and nothing to do here. Only valid for family >= 0x17.
  88          */
  89         if (!has_topoext && tscan->c->x86 >= 0x17) {
  90                 /*
  91                  * Leaf 0x80000008 set the CORE domain shift already.
  92                  * Update the SMT domain, but do not propagate it.
  93                  */
  94                 unsigned int nthreads = leaf.core_nthreads + 1;
  95
  96                 topology_update_dom(tscan, TOPO_SMT_DOMAIN, get_count_order(nthreads), nthreads);
  97         }
  98
  99         store_node(tscan, leaf.nnodes_per_socket + 1, leaf.node_id);
 100
 101         if (tscan->c->x86_vendor == X86_VENDOR_AMD) {
 102                 if (tscan->c->x86 == 0x15)
 103                         tscan->c->topo.cu_id = leaf.core_id;
 104
 105                 cacheinfo_amd_init_llc_id(tscan->c, leaf.node_id);
 106         } else {
 107                 /*
 108                  * Package ID is ApicId[6..] on certain Hygon CPUs. See
 109                  * commit e0ceeae708ce for explanation. The topology info
 110                  * is screwed up: The package shift is always 6 and the
 111                  * node ID is bit [4:5].
 112                  */
 113                 if (!boot_cpu_has(X86_FEATURE_HYPERVISOR) && tscan->c->x86_model <= 0x3) {
 114                         topology_set_dom(tscan, TOPO_CORE_DOMAIN, 6,
 115                                          tscan->dom_ncpus[TOPO_CORE_DOMAIN]);
 116                 }
 117                 cacheinfo_hygon_init_llc_id(tscan->c);
 118         }
 119         return true;
 120 }
 121
 122 static void parse_fam10h_node_id(struct topo_scan *tscan)
 123 {
 124         union {
 125                 struct {
 126                         u64     node_id         :  3,
 127                                 nodes_per_pkg   :  3,
 128                                 unused          : 58;
 129                 };
 130                 u64             msr;
 131         } nid;
 132
 133         if (!boot_cpu_has(X86_FEATURE_NODEID_MSR))
 134                 return;
 135
 136         rdmsrl(MSR_FAM10H_NODE_ID, nid.msr);
 137         store_node(tscan, nid.nodes_per_pkg + 1, nid.node_id);
 138         tscan->c->topo.llc_id = nid.node_id;
 139 }
 140
 141 static void legacy_set_llc(struct topo_scan *tscan)
 142 {
 143         unsigned int apicid = tscan->c->topo.initial_apicid;
 144
 145         /* If none of the parsers set LLC ID then use the die ID for it. */
 146         if (tscan->c->topo.llc_id == BAD_APICID)
 147                 tscan->c->topo.llc_id = apicid >> tscan->dom_shifts[TOPO_CORE_DOMAIN];
 148 }
 149
 150 static void topoext_fixup(struct topo_scan *tscan)
 151 {
 152         struct cpuinfo_x86 *c = tscan->c;
 153         u64 msrval;
 154
 155         /* Try to re-enable TopologyExtensions if switched off by BIOS */
 156         if (cpu_has(c, X86_FEATURE_TOPOEXT) || c->x86_vendor != X86_VENDOR_AMD ||
 157             c->x86 != 0x15 || c->x86_model < 0x10 || c->x86_model > 0x6f)
 158                 return;
 159
 160         if (msr_set_bit(0xc0011005, 54) <= 0)
 161                 return;
 162
 163         rdmsrl(0xc0011005, msrval);
 164         if (msrval & BIT_64(54)) {
 165                 set_cpu_cap(c, X86_FEATURE_TOPOEXT);
 166                 pr_info_once(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
 167         }
 168 }
 169
 170 static void parse_topology_amd(struct topo_scan *tscan)
 171 {
 172         bool has_topoext = false;
 173
 174         /*
 175          * If the extended topology leaf 0x8000_001e is available
 176          * try to get SMT, CORE, TILE, and DIE shifts from extended
 177          * CPUID leaf 0x8000_0026 on supported processors first. If
 178          * extended CPUID leaf 0x8000_0026 is not supported, try to
 179          * get SMT and CORE shift from leaf 0xb first, then try to
 180          * get the CORE shift from leaf 0x8000_0008.
 181          */
 182         if (cpu_feature_enabled(X86_FEATURE_TOPOEXT))
 183                 has_topoext = cpu_parse_topology_ext(tscan);
 184
 185         if (cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES))
 186                 tscan->c->topo.cpu_type = cpuid_ebx(0x80000026);
 187
 188         if (!has_topoext && !parse_8000_0008(tscan))
 189                 return;
 190
 191         /* Prefer leaf 0x8000001e if available */
 192         if (parse_8000_001e(tscan, has_topoext))
 193                 return;
 194
 195         /* Try the NODEID MSR */
 196         parse_fam10h_node_id(tscan);
 197 }
 198
 199 void cpu_parse_topology_amd(struct topo_scan *tscan)
 200 {
 201         tscan->amd_nodes_per_pkg = 1;
 202         topoext_fixup(tscan);
 203         parse_topology_amd(tscan);
 204         legacy_set_llc(tscan);
 205
 206         if (tscan->amd_nodes_per_pkg > 1)
 207                 set_cpu_cap(tscan->c, X86_FEATURE_AMD_DCM);
 208 }
 209
 210 void cpu_topology_fixup_amd(struct topo_scan *tscan)
 211 {
 212         struct cpuinfo_x86 *c = tscan->c;
 213
 214         /*
 215          * Adjust the core_id relative to the node when there is more than
 216          * one node.
 217          */
 218         if (tscan->c->x86 < 0x17 && tscan->amd_nodes_per_pkg > 1)
 219                 c->topo.core_id %= tscan->dom_ncpus[TOPO_CORE_DOMAIN] / tscan->amd_nodes_per_pkg;
 220 }