x86: use the hybrid leaf to build a cpukinds based on the core type

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

NEWS

@@ -21,6 +21,7 @@ Version 2.4.0
 -------------
 * API
   + Add hwloc/cpukinds.h for reporting information about hybrid CPUs.
+    - Use x86 CPUID hybrid leaf to identify Intel Atom and Core cores.
 * Backends
   + Properly handle Linux kernel 5.10+ exposing ACPI HMAT information
     with knowledge of Generic Initiators.

hwloc/topology-x86.c

@@ -181,6 +181,7 @@ enum hwloc_x86_disc_flags {
 
 #define has_topoext(features) ((features)[6] & (1 << 22))
 #define has_x2apic(features) ((features)[4] & (1 << 21))
+#define has_hybrid(features) ((features)[18] & (1 << 15))
 
 struct cacheinfo {
   hwloc_obj_cache_type_t type;
@@ -217,6 +218,9 @@ struct procinfo {
   unsigned cpustepping;
   unsigned cpumodelnumber;
   unsigned cpufamilynumber;
+
+  unsigned hybridcoretype;
+  unsigned hybridnativemodel;
 };
 
 enum cpuid_type {
@@ -681,6 +685,15 @@ static void look_proc(struct hwloc_backend *backend, struct procinfo *infos, uns
     }
   }
 
+  if (highest_cpuid >= 0x1a && has_hybrid(features)) {
+    /* Get hybrid cpu information from cpuid 0x1a */
+    eax = 0x1a;
+    ecx = 0;
+    cpuid_or_from_dump(&eax, &ebx, &ecx, &edx, src_cpuiddump);
+    infos->hybridcoretype = eax >> 24;
+    infos->hybridnativemodel = eax & 0xffffff;
+  }
+
   /*********************************************************************************
    * Get the hierarchy of thread, core, die, package, etc. from CPU-specific leaves
    */
@@ -1280,8 +1293,41 @@ look_procs(struct hwloc_backend *backend, struct procinfo *infos, unsigned long
     hwloc_bitmap_free(orig_cpuset);
   }
 
-  if (data->apicid_unique)
+  if (data->apicid_unique) {
     summarize(backend, infos, flags);
+
+    if (has_hybrid(features)) {
+      /* use hybrid info for cpukinds */
+      hwloc_bitmap_t atomset = hwloc_bitmap_alloc();
+      hwloc_bitmap_t coreset = hwloc_bitmap_alloc();
+      for(i=0; i<nbprocs; i++) {
+        if (infos[i].hybridcoretype == 0x20)
+          hwloc_bitmap_set(atomset, i);
+        else if (infos[i].hybridcoretype == 0x40)
+          hwloc_bitmap_set(coreset, i);
+      }
+      /* register IntelAtom set if any */
+      if (!hwloc_bitmap_iszero(atomset)) {
+        struct hwloc_info_s infoattr;
+        infoattr.name = (char *) "CoreType";
+        infoattr.value = (char *) "IntelAtom";
+        hwloc_internal_cpukinds_register(topology, atomset, HWLOC_CPUKIND_EFFICIENCY_UNKNOWN, &infoattr, 1, 0);
+        /* the cpuset is given to the callee */
+      } else {
+        hwloc_bitmap_free(atomset);
+      }
+      /* register IntelCore set if any */
+      if (!hwloc_bitmap_iszero(coreset)) {
+        struct hwloc_info_s infoattr;
+        infoattr.name = (char *) "CoreType";
+        infoattr.value = (char *) "IntelCore";
+        hwloc_internal_cpukinds_register(topology, coreset, HWLOC_CPUKIND_EFFICIENCY_UNKNOWN, &infoattr, 1, 0);
+        /* the cpuset is given to the callee */
+      } else {
+        hwloc_bitmap_free(coreset);
+      }
+    }
+  }
   /* if !data->apicid_unique, do nothing and return success, so that the caller does nothing either */
 
   return 0;
@@ -1360,7 +1406,7 @@ int hwloc_look_x86(struct hwloc_backend *backend, unsigned long flags)
   unsigned highest_cpuid;
   unsigned highest_ext_cpuid;
   /* This stores cpuid features with the same indexing as Linux */
-  unsigned features[10] = { 0 };
+  unsigned features[19] = { 0 };
   struct procinfo *infos = NULL;
   enum cpuid_type cpuid_type = unknown;
   hwloc_x86_os_state_t os_state;
@@ -1460,6 +1506,7 @@ int hwloc_look_x86(struct hwloc_backend *backend, unsigned long flags)
     ecx = 0;
     cpuid_or_from_dump(&eax, &ebx, &ecx, &edx, src_cpuiddump);
     features[9] = ebx;
+    features[18] = edx;
   }
 
   if (cpuid_type != intel && highest_ext_cpuid >= 0x80000001) {

include/hwloc/cpukinds.h

@@ -36,7 +36,7 @@ extern "C" {
  * may be obtained with hwloc_cpukinds_get_by_cpuset().
  *
  * Each set is described by an abstracted efficiency value and
- * an array of info attributes.
+ * an array of info attributes (for instance the "CoreType").
  *
  * A higher efficiency value means intrinsic greater performance
  * (and possibly less performance/power efficiency).
@@ -99,7 +99,7 @@ hwloc_cpukinds_get_by_cpuset(hwloc_topology_t topology,
  * the efficiency of all kinds is set to \c -1,
  * and kinds are reported in no specific order.
  *
- * The array of info attributes
+ * The array of info attributes (for instance the "CoreType")
  * and its length are returned in \p infos or \p nr_infos.
  * The array belongs to the topology, it should not be freed or modified.
  *