[RFC PATCH] x86: Kill CONFIG_X86_HT

[Borislav Petkov <bp@alien8.de>]

From: Borislav Petkov <bp@suse.de>

In talking to Aravind recently about making certain AMD topology
attributes available to the MCE injection module, it seemed like that
CONFIG_X86_HT thing is more or less superfluous. It is def_bool y,
depends on SMP and gets enabled in the majority of .configs - distro and
otherwise - out there.

So let's kill it and make code behind it depend directly on SMP.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Walter <dwalter@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jacob Shin <jacob.w.shin@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
---
 arch/x86/Kconfig                      | 8 ++------
 arch/x86/include/asm/topology.h       | 2 +-
 arch/x86/kernel/cpu/amd.c             | 6 +++---
 arch/x86/kernel/cpu/common.c          | 4 ++--
 arch/x86/kernel/cpu/intel_cacheinfo.c | 8 ++++----
 5 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 9a8a72b8ce73..f90843416574 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -263,10 +263,6 @@ config X86_64_SMP
 	def_bool y
 	depends on X86_64 && SMP
 
-config X86_HT
-	def_bool y
-	depends on SMP
-
 config X86_32_LAZY_GS
 	def_bool y
 	depends on X86_32 && !CC_STACKPROTECTOR
@@ -900,7 +896,7 @@ config NR_CPUS
 
 config SCHED_SMT
 	bool "SMT (Hyperthreading) scheduler support"
-	depends on X86_HT
+	depends on SMP
 	---help---
 	  SMT scheduler support improves the CPU scheduler's decision making
 	  when dealing with Intel Pentium 4 chips with HyperThreading at a
@@ -910,7 +906,7 @@ config SCHED_SMT
 config SCHED_MC
 	def_bool y
 	prompt "Multi-core scheduler support"
-	depends on X86_HT
+	depends on SMP
 	---help---
 	  Multi-core scheduler support improves the CPU scheduler's decision
 	  making when dealing with multi-core CPU chips at a cost of slightly
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 5a77593fdace..0fb46482dfde 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -26,7 +26,7 @@
 #define _ASM_X86_TOPOLOGY_H
 
 #ifdef CONFIG_X86_32
-# ifdef CONFIG_X86_HT
+# ifdef CONFIG_SMP
 #  define ENABLE_TOPO_DEFINES
 # endif
 #else
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 94e7051fba1a..5bd3a99dc20b 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -288,7 +288,7 @@ static int nearby_node(int apicid)
  *     Assumption: Number of cores in each internal node is the same.
  * (2) AMD processors supporting compute units
  */
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 static void amd_get_topology(struct cpuinfo_x86 *c)
 {
 	u32 nodes, cores_per_cu = 1;
@@ -341,7 +341,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
  */
 static void amd_detect_cmp(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 	unsigned bits;
 	int cpu = smp_processor_id();
 
@@ -420,7 +420,7 @@ static void srat_detect_node(struct cpuinfo_x86 *c)
 
 static void early_init_amd_mc(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 	unsigned bits, ecx;
 
 	/* Multi core CPU? */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1b4ce4c7d2a8..0fc2c7ab1d61 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -475,7 +475,7 @@ static void cpu_detect_tlb(struct cpuinfo_x86 *c)
 
 void detect_ht(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 	u32 eax, ebx, ecx, edx;
 	int index_msb, core_bits;
 	static bool printed;
@@ -811,7 +811,7 @@ static void generic_identify(struct cpuinfo_x86 *c)
 	if (c->cpuid_level >= 0x00000001) {
 		c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xFF;
 #ifdef CONFIG_X86_32
-# ifdef CONFIG_X86_HT
+# ifdef CONFIG_SMP
 		c->apicid = apic->phys_pkg_id(c->initial_apicid, 0);
 # else
 		c->apicid = c->initial_apicid;
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index edcb0e28c336..be4febc58b94 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -654,7 +654,7 @@ unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c)
 	unsigned int new_l1d = 0, new_l1i = 0; /* Cache sizes from cpuid(4) */
 	unsigned int new_l2 = 0, new_l3 = 0, i; /* Cache sizes from cpuid(4) */
 	unsigned int l2_id = 0, l3_id = 0, num_threads_sharing, index_msb;
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 	unsigned int cpu = c->cpu_index;
 #endif
 
@@ -773,19 +773,19 @@ unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c)
 
 	if (new_l2) {
 		l2 = new_l2;
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 		per_cpu(cpu_llc_id, cpu) = l2_id;
 #endif
 	}
 
 	if (new_l3) {
 		l3 = new_l3;
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 		per_cpu(cpu_llc_id, cpu) = l3_id;
 #endif
 	}
 
-#ifdef CONFIG_X86_HT
+#ifdef CONFIG_SMP
 	/*
 	 * If cpu_llc_id is not yet set, this means cpuid_level < 4 which in
 	 * turns means that the only possibility is SMT (as indicated in
-- 
2.3.5