[patch 23/53] x86/cpu/topology: Move registration out of APIC code

Thomas Gleixner
2023-08-07T13:54:18Z

The APIC/CPU registration sits in the middle of the APIC code. In fact this
is a topology evaluation function and has nothing to do with the inner
workings of the local APIC.

Move it out into a file which reflects what this is about.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/apic.h | 2
arch/x86/kernel/apic/apic.c | 185 -----------------------------------------
arch/x86/kernel/cpu/Makefile | 12 +-
arch/x86/kernel/cpu/topology.c | 184 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 195 insertions(+), 188 deletions(-)

--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -171,6 +171,8 @@ extern bool apic_needs_pit(void);

extern void apic_send_IPI_allbutself(unsigned int vector);

+extern void topology_register_boot_apic(u32 apic_id);
+
#else /* !CONFIG_X86_LOCAL_APIC */
static inline void lapic_shutdown(void) { }
#define local_apic_timer_c2_ok 1
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -68,26 +68,12 @@

#include "local.h"

-unsigned int num_processors;
-
-unsigned disabled_cpus;
-
/* Processor that is doing the boot up */
u32 boot_cpu_physical_apicid __ro_after_init = BAD_APICID;
EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);

u8 boot_cpu_apic_version __ro_after_init;

-/* Bitmap of physically present CPUs. */
-DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC);
-
-/*
- * Processor to be disabled specified by kernel parameter
- * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
- * avoid undefined behaviour caused by sending INIT from AP to BSP.
- */
-static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
-
/*
* This variable controls which CPUs receive external NMIs. By default,
* external NMIs are delivered only to the BSP.
@@ -107,14 +93,6 @@ static inline bool apic_accessible(void)
return x2apic_mode || apic_mmio_base;
}

-/*
- * Map cpu index to physical APIC ID
- */
-DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_apicid, BAD_APICID);
-DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, CPU_ACPIID_INVALID);
-EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
-EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
-
#ifdef CONFIG_X86_32
/* Local APIC was disabled by the BIOS and enabled by the kernel */
static int enabled_via_apicbase __ro_after_init;
@@ -1676,8 +1654,6 @@ void apic_ap_setup(void)
end_local_APIC_setup();
}

-static __init void cpu_set_boot_apic(void);
-
static __init void apic_read_boot_cpu_id(bool x2apic)
{
/*
@@ -1692,7 +1668,8 @@ static __init void apic_read_boot_cpu_id
boot_cpu_physical_apicid = read_apic_id();
boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
}
- cpu_set_boot_apic();
+ topology_register_boot_apic(boot_cpu_physical_apicid);
+ x86_32_probe_bigsmp_early();
}

#ifdef CONFIG_X86_X2APIC
@@ -2291,155 +2268,6 @@ void disconnect_bsp_APIC(int virt_wire_s
apic_write(APIC_LVT1, value);
}

-/*
- * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
- * contiguously, it equals to current allocated max logical CPU ID plus 1.
- * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
- * so the maximum of nr_logical_cpuids is nr_cpu_ids.
- *
- * NOTE: Reserve 0 for BSP.
- */
-static int nr_logical_cpuids = 1;
-
-/*
- * Used to store mapping between logical CPU IDs and APIC IDs.
- */
-u32 cpuid_to_apicid[] = { [0 ... NR_CPUS - 1] = BAD_APICID, };
-
-bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
-{
- return phys_id == (u64)cpuid_to_apicid[cpu];
-}
-
-#ifdef CONFIG_SMP
-static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
-{
- /* Isolate the SMT bit(s) in the APICID and check for 0 */
- u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
-
- if (smp_num_siblings == 1 || !(apicid & mask))
- cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
-}
-
-/*
- * Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
- * during early boot. Initialize the primary thread mask before SMP
- * bringup.
- */
-static int __init smp_init_primary_thread_mask(void)
-{
- unsigned int cpu;
-
- /*
- * XEN/PV provides either none or useless topology information.
- * Pretend that all vCPUs are primary threads.
- */
- if (xen_pv_domain()) {
- cpumask_copy(&__cpu_primary_thread_mask, cpu_possible_mask);
- return 0;
- }
-
- for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
- cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
- return 0;
-}
-early_initcall(smp_init_primary_thread_mask);
-#else
-static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
-#endif
-
-/*
- * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
- * and cpuid_to_apicid[] synchronized.
- */
-static int allocate_logical_cpuid(int apicid)
-{
- int i;
-
- /*
- * cpuid <-> apicid mapping is persistent, so when a cpu is up,
- * check if the kernel has allocated a cpuid for it.
- */
- for (i = 0; i < nr_logical_cpuids; i++) {
- if (cpuid_to_apicid[i] == apicid)
- return i;
- }
-
- /* Allocate a new cpuid. */
- if (nr_logical_cpuids >= nr_cpu_ids) {
- WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
- "Processor %d/0x%x and the rest are ignored.\n",
- nr_cpu_ids, nr_logical_cpuids, apicid);
- return -EINVAL;
- }
-
- cpuid_to_apicid[nr_logical_cpuids] = apicid;
- return nr_logical_cpuids++;
-}
-
-static void cpu_update_apic(int cpu, u32 apicid)
-{
-#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
- early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
-#endif
- set_cpu_possible(cpu, true);
- set_bit(apicid, phys_cpu_present_map);
- set_cpu_present(cpu, true);
- num_processors++;
-
- if (system_state != SYSTEM_BOOTING)
- cpu_mark_primary_thread(cpu, apicid);
-}
-
-static __init void cpu_set_boot_apic(void)
-{
- cpuid_to_apicid[0] = boot_cpu_physical_apicid;
- cpu_update_apic(0, boot_cpu_physical_apicid);
- x86_32_probe_bigsmp_early();
-}
-
-int generic_processor_info(int apicid)
-{
- int cpu, max = nr_cpu_ids;
-
- /* The boot CPU must be set before MADT/MPTABLE parsing happens */
- if (cpuid_to_apicid[0] == BAD_APICID)
- panic("Boot CPU APIC not registered yet\n");
-
- if (apicid == boot_cpu_physical_apicid)
- return 0;
-
- if (disabled_cpu_apicid == apicid) {
- int thiscpu = num_processors + disabled_cpus;
-
- pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n",
- thiscpu, apicid);
-
- disabled_cpus++;
- return -ENODEV;
- }
-
- if (num_processors >= nr_cpu_ids) {
- int thiscpu = max + disabled_cpus;
-
- pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
- "Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
-
- disabled_cpus++;
- return -EINVAL;
- }
-
- cpu = allocate_logical_cpuid(apicid);
- if (cpu < 0) {
- disabled_cpus++;
- return -EINVAL;
- }
-
- cpu_update_apic(cpu, apicid);
- return cpu;
-}
-
-
void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
bool dmar)
{
@@ -2828,15 +2656,6 @@ static int __init lapic_insert_resource(
*/
late_initcall(lapic_insert_resource);

-static int __init apic_set_disabled_cpu_apicid(char *arg)
-{
- if (!arg || !get_option(&arg, &disabled_cpu_apicid))
- return -EINVAL;
-
- return 0;
-}
-early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
-
static int __init apic_set_extnmi(char *arg)
{
if (!arg)
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -26,14 +26,16 @@ obj-y += bugs.o
obj-y += aperfmperf.o
obj-y += cpuid-deps.o
obj-y += umwait.o
+obj-y += capflags.o powerflags.o

-obj-$(CONFIG_PROC_FS) += proc.o
-obj-y += capflags.o powerflags.o
+obj-$(CONFIG_X86_LOCAL_APIC) += topology.o

-obj-$(CONFIG_IA32_FEAT_CTL) += feat_ctl.o
+obj-$(CONFIG_PROC_FS) += proc.o
+
+obj-$(CONFIG_IA32_FEAT_CTL) += feat_ctl.o
ifdef CONFIG_CPU_SUP_INTEL
-obj-y += intel.o intel_pconfig.o tsx.o
-obj-$(CONFIG_PM) += intel_epb.o
+obj-y += intel.o intel_pconfig.o tsx.o
+obj-$(CONFIG_PM) += intel_epb.o
endif
obj-$(CONFIG_CPU_SUP_AMD) += amd.o
obj-$(CONFIG_CPU_SUP_HYGON) += hygon.o
--- /dev/null
+++ b/arch/x86/kernel/cpu/topology.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/cpu.h>
+
+#include <xen/xen.h>
+
+#include <asm/apic.h>
+#include <asm/mpspec.h>
+#include <asm/smp.h>
+
+/*
+ * Map cpu index to physical APIC ID
+ */
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_apicid, BAD_APICID);
+DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, CPU_ACPIID_INVALID);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
+EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
+
+/* Bitmap of physically present CPUs. */
+DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC) __read_mostly;
+
+/* Used for CPU number allocation and parallel CPU bringup */
+u32 cpuid_to_apicid[] __read_mostly = { [0 ... NR_CPUS - 1] = BAD_APICID, };
+
+/*
+ * Processor to be disabled specified by kernel parameter
+ * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
+ * avoid undefined behaviour caused by sending INIT from AP to BSP.
+ */
+static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
+
+unsigned int num_processors;
+unsigned disabled_cpus;
+
+/*
+ * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
+ * contiguously, it equals to current allocated max logical CPU ID plus 1.
+ * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
+ * so the maximum of nr_logical_cpuids is nr_cpu_ids.
+ *
+ * NOTE: Reserve 0 for BSP.
+ */
+static int nr_logical_cpuids = 1;
+
+bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+ return phys_id == (u64)cpuid_to_apicid[cpu];
+}
+
+#ifdef CONFIG_SMP
+static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
+{
+ /* Isolate the SMT bit(s) in the APICID and check for 0 */
+ u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
+
+ if (smp_num_siblings == 1 || !(apicid & mask))
+ cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
+}
+
+/*
+ * Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
+ * during early boot. Initialize the primary thread mask before SMP
+ * bringup.
+ */
+static int __init smp_init_primary_thread_mask(void)
+{
+ unsigned int cpu;
+
+ /*
+ * XEN/PV provides either none or useless topology information.
+ * Pretend that all vCPUs are primary threads.
+ */
+ if (xen_pv_domain()) {
+ cpumask_copy(&__cpu_primary_thread_mask, cpu_possible_mask);
+ return 0;
+ }
+
+ for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
+ cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
+ return 0;
+}
+early_initcall(smp_init_primary_thread_mask);
+#else
+static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
+#endif
+
+/*
+ * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
+ * and cpuid_to_apicid[] synchronized.
+ */
+static int allocate_logical_cpuid(int apicid)
+{
+ int i;
+
+ /*
+ * cpuid <-> apicid mapping is persistent, so when a cpu is up,
+ * check if the kernel has allocated a cpuid for it.
+ */
+ for (i = 0; i < nr_logical_cpuids; i++) {
+ if (cpuid_to_apicid[i] == apicid)
+ return i;
+ }
+
+ /* Allocate a new cpuid. */
+ if (nr_logical_cpuids >= nr_cpu_ids) {
+ WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
+ "Processor %d/0x%x and the rest are ignored.\n",
+ nr_cpu_ids, nr_logical_cpuids, apicid);
+ return -EINVAL;
+ }
+
+ cpuid_to_apicid[nr_logical_cpuids] = apicid;
+ return nr_logical_cpuids++;
+}
+
+static void cpu_update_apic(int cpu, u32 apicid)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
+ early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
+#endif
+ set_cpu_possible(cpu, true);
+ set_bit(apicid, phys_cpu_present_map);
+ set_cpu_present(cpu, true);
+ num_processors++;
+
+ if (system_state != SYSTEM_BOOTING)
+ cpu_mark_primary_thread(cpu, apicid);
+}
+
+void __init topology_register_boot_apic(u32 apic_id)
+{
+ cpuid_to_apicid[0] = apic_id;
+ cpu_update_apic(0, apic_id);
+}
+
+int generic_processor_info(int apicid)
+{
+ int cpu, max = nr_cpu_ids;
+
+ /* The boot CPU must be set before MADT/MPTABLE parsing happens */
+ if (cpuid_to_apicid[0] == BAD_APICID)
+ panic("Boot CPU APIC not registered yet\n");
+
+ if (apicid == boot_cpu_physical_apicid)
+ return 0;
+
+ if (disabled_cpu_apicid == apicid) {
+ int thiscpu = num_processors + disabled_cpus;
+
+ pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n",
+ thiscpu, apicid);
+
+ disabled_cpus++;
+ return -ENODEV;
+ }
+
+ if (num_processors >= nr_cpu_ids) {
+ int thiscpu = max + disabled_cpus;
+
+ pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
+ "Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
+
+ disabled_cpus++;
+ return -EINVAL;
+ }
+
+ cpu = allocate_logical_cpuid(apicid);
+ if (cpu < 0) {
+ disabled_cpus++;
+ return -EINVAL;
+ }
+
+ cpu_update_apic(cpu, apicid);
+ return cpu;
+}
+
+static int __init apic_set_disabled_cpu_apicid(char *arg)
+{
+ if (!arg || !get_option(&arg, &disabled_cpu_apicid))
+ return -EINVAL;
+
+ return 0;
+}
+early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);