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-rw-r--r--arch/x86/kernel/cpu/topology.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c
new file mode 100644
index 0000000000..0270925fe0
--- /dev/null
+++ b/arch/x86/kernel/cpu/topology.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check for extended topology enumeration cpuid leaf 0xb and if it
+ * exists, use it for populating initial_apicid and cpu topology
+ * detection.
+ */
+
+#include <linux/cpu.h>
+#include <asm/apic.h>
+#include <asm/memtype.h>
+#include <asm/processor.h>
+
+#include "cpu.h"
+
+/* leaf 0xb SMT level */
+#define SMT_LEVEL 0
+
+/* extended topology sub-leaf types */
+#define INVALID_TYPE 0
+#define SMT_TYPE 1
+#define CORE_TYPE 2
+#define DIE_TYPE 5
+
+#define LEAFB_SUBTYPE(ecx) (((ecx) >> 8) & 0xff)
+#define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f)
+#define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff)
+
+unsigned int __max_die_per_package __read_mostly = 1;
+EXPORT_SYMBOL(__max_die_per_package);
+
+#ifdef CONFIG_SMP
+/*
+ * Check if given CPUID extended topology "leaf" is implemented
+ */
+static int check_extended_topology_leaf(int leaf)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
+
+ if (ebx == 0 || (LEAFB_SUBTYPE(ecx) != SMT_TYPE))
+ return -1;
+
+ return 0;
+}
+/*
+ * Return best CPUID Extended Topology Leaf supported
+ */
+static int detect_extended_topology_leaf(struct cpuinfo_x86 *c)
+{
+ if (c->cpuid_level >= 0x1f) {
+ if (check_extended_topology_leaf(0x1f) == 0)
+ return 0x1f;
+ }
+
+ if (c->cpuid_level >= 0xb) {
+ if (check_extended_topology_leaf(0xb) == 0)
+ return 0xb;
+ }
+
+ return -1;
+}
+#endif
+
+int detect_extended_topology_early(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ unsigned int eax, ebx, ecx, edx;
+ int leaf;
+
+ leaf = detect_extended_topology_leaf(c);
+ if (leaf < 0)
+ return -1;
+
+ set_cpu_cap(c, X86_FEATURE_XTOPOLOGY);
+
+ cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
+ /*
+ * initial apic id, which also represents 32-bit extended x2apic id.
+ */
+ c->initial_apicid = edx;
+ smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
+#endif
+ return 0;
+}
+
+/*
+ * Check for extended topology enumeration cpuid leaf, and if it
+ * exists, use it for populating initial_apicid and cpu topology
+ * detection.
+ */
+int detect_extended_topology(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ unsigned int eax, ebx, ecx, edx, sub_index;
+ unsigned int ht_mask_width, core_plus_mask_width, die_plus_mask_width;
+ unsigned int core_select_mask, core_level_siblings;
+ unsigned int die_select_mask, die_level_siblings;
+ unsigned int pkg_mask_width;
+ bool die_level_present = false;
+ int leaf;
+
+ leaf = detect_extended_topology_leaf(c);
+ if (leaf < 0)
+ return -1;
+
+ /*
+ * Populate HT related information from sub-leaf level 0.
+ */
+ cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
+ c->initial_apicid = edx;
+ core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
+ smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
+ core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+ die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
+ pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+
+ sub_index = 1;
+ while (true) {
+ cpuid_count(leaf, sub_index, &eax, &ebx, &ecx, &edx);
+
+ /*
+ * Check for the Core type in the implemented sub leaves.
+ */
+ if (LEAFB_SUBTYPE(ecx) == CORE_TYPE) {
+ core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
+ core_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+ die_level_siblings = core_level_siblings;
+ die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+ }
+ if (LEAFB_SUBTYPE(ecx) == DIE_TYPE) {
+ die_level_present = true;
+ die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
+ die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+ }
+
+ if (LEAFB_SUBTYPE(ecx) != INVALID_TYPE)
+ pkg_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
+ else
+ break;
+
+ sub_index++;
+ }
+
+ core_select_mask = (~(-1 << pkg_mask_width)) >> ht_mask_width;
+ die_select_mask = (~(-1 << die_plus_mask_width)) >>
+ core_plus_mask_width;
+
+ c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid,
+ ht_mask_width) & core_select_mask;
+
+ if (die_level_present) {
+ c->cpu_die_id = apic->phys_pkg_id(c->initial_apicid,
+ core_plus_mask_width) & die_select_mask;
+ }
+
+ c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid,
+ pkg_mask_width);
+ /*
+ * Reinit the apicid, now that we have extended initial_apicid.
+ */
+ c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
+
+ c->x86_max_cores = (core_level_siblings / smp_num_siblings);
+ __max_die_per_package = (die_level_siblings / core_level_siblings);
+#endif
+ return 0;
+}