x86/cpu: Use common topology code for Intel

Intel CPUs use either topology leaf 0xb/0x1f evaluation or the legacy
SMP/HT evaluation based on CPUID leaf 0x1/0x4.

Move it over to the consolidated topology code and remove the random
topology hacks which are sprinkled into the Intel and the common code.

No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wang Wendy <wendy.wang@intel.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/r/20240212153624.893644349@linutronix.de

arch/x86/kernel/cpu/common.c

@@ -793,19 +793,6 @@ static void get_model_name(struct cpuinfo_x86 *c)
 	*(s + 1) = '\0';
 }
 
-void detect_num_cpu_cores(struct cpuinfo_x86 *c)
-{
-	unsigned int eax, ebx, ecx, edx;
-
-	c->x86_max_cores = 1;
-	if (!IS_ENABLED(CONFIG_SMP) || c->cpuid_level < 4)
-		return;
-
-	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
-	if (eax & 0x1f)
-		c->x86_max_cores = (eax >> 26) + 1;
-}
-
 void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
 {
 	unsigned int n, dummy, ebx, ecx, edx, l2size;
@@ -867,54 +854,6 @@ static void cpu_detect_tlb(struct cpuinfo_x86 *c)
 		tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]);
 }
 
-int detect_ht_early(struct cpuinfo_x86 *c)
-{
-#ifdef CONFIG_SMP
-	u32 eax, ebx, ecx, edx;
-
-	if (!cpu_has(c, X86_FEATURE_HT))
-		return -1;
-
-	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
-		return -1;
-
-	if (cpu_has(c, X86_FEATURE_XTOPOLOGY))
-		return -1;
-
-	cpuid(1, &eax, &ebx, &ecx, &edx);
-
-	smp_num_siblings = (ebx & 0xff0000) >> 16;
-	if (smp_num_siblings == 1)
-		pr_info_once("CPU0: Hyper-Threading is disabled\n");
-#endif
-	return 0;
-}
-
-void detect_ht(struct cpuinfo_x86 *c)
-{
-#ifdef CONFIG_SMP
-	int index_msb, core_bits;
-
-	if (topo_is_converted(c))
-		return;
-
-	if (detect_ht_early(c) < 0)
-		return;
-
-	index_msb = get_count_order(smp_num_siblings);
-	c->topo.pkg_id = apic->phys_pkg_id(c->topo.initial_apicid, index_msb);
-
-	smp_num_siblings = smp_num_siblings / c->x86_max_cores;
-
-	index_msb = get_count_order(smp_num_siblings);
-
-	core_bits = get_count_order(c->x86_max_cores);
-
-	c->topo.core_id = apic->phys_pkg_id(c->topo.initial_apicid, index_msb) &
-		((1 << core_bits) - 1);
-#endif
-}
-
 static void get_cpu_vendor(struct cpuinfo_x86 *c)
 {
 	char *v = c->x86_vendor_id;
@@ -1899,10 +1838,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 				c->x86, c->x86_model);
 	}
 
-#ifdef CONFIG_X86_64
-	detect_ht(c);
-#endif
-
 	x86_init_rdrand(c);
 	setup_pku(c);
 	setup_cet(c);

arch/x86/kernel/cpu/cpu.h

@@ -76,11 +76,7 @@ extern void init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_hygon_cacheinfo(struct cpuinfo_x86 *c);
 
-extern void detect_num_cpu_cores(struct cpuinfo_x86 *c);
-extern int detect_extended_topology_early(struct cpuinfo_x86 *c);
 extern int detect_extended_topology(struct cpuinfo_x86 *c);
-extern int detect_ht_early(struct cpuinfo_x86 *c);
-extern void detect_ht(struct cpuinfo_x86 *c);
 extern void check_null_seg_clears_base(struct cpuinfo_x86 *c);
 
 void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c);

arch/x86/kernel/cpu/intel.c

@@ -315,13 +315,6 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 	}
 
 	check_memory_type_self_snoop_errata(c);
-
-	/*
-	 * Get the number of SMT siblings early from the extended topology
-	 * leaf, if available. Otherwise try the legacy SMT detection.
-	 */
-	if (detect_extended_topology_early(c) < 0)
-		detect_ht_early(c);
 }
 
 static void bsp_init_intel(struct cpuinfo_x86 *c)
@@ -603,24 +596,6 @@ static void init_intel(struct cpuinfo_x86 *c)
 
 	intel_workarounds(c);
 
-	/*
-	 * Detect the extended topology information if available. This
-	 * will reinitialise the initial_apicid which will be used
-	 * in init_intel_cacheinfo()
-	 */
-	detect_extended_topology(c);
-
-	if (!cpu_has(c, X86_FEATURE_XTOPOLOGY)) {
-		/*
-		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
-		 * detection.
-		 */
-		detect_num_cpu_cores(c);
-#ifdef CONFIG_X86_32
-		detect_ht(c);
-#endif
-	}
-
 	init_intel_cacheinfo(c);
 
 	if (c->cpuid_level > 9) {

arch/x86/kernel/cpu/topology.c

@@ -59,28 +59,6 @@ static int detect_extended_topology_leaf(struct cpuinfo_x86 *c)
 }
 #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->topo.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

arch/x86/kernel/cpu/topology_common.c

@@ -71,7 +71,6 @@ bool topo_is_converted(struct cpuinfo_x86 *c)
 	/* Temporary until everything is converted over. */
 	switch (boot_cpu_data.x86_vendor) {
 	case X86_VENDOR_AMD:
-	case X86_VENDOR_INTEL:
 	case X86_VENDOR_HYGON:
 		return false;
 	default:
@@ -136,6 +135,10 @@ static void parse_topology(struct topo_scan *tscan, bool early)
 	case X86_VENDOR_ZHAOXIN:
 		parse_legacy(tscan);
 		break;
+	case X86_VENDOR_INTEL:
+		if (!IS_ENABLED(CONFIG_CPU_SUP_INTEL) || !cpu_parse_topology_ext(tscan))
+			parse_legacy(tscan);
+		break;
 	}
 }