diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 28e9aa46d1ed..94ce0f7c9d3a 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -175,6 +175,9 @@ extern void topology_register_apic(u32 apic_id, u32 acpi_id, bool present); extern void topology_register_boot_apic(u32 apic_id); extern int topology_hotplug_apic(u32 apic_id, u32 acpi_id); extern void topology_hotunplug_apic(unsigned int cpu); +extern void topology_apply_cmdline_limits_early(void); +extern void topology_init_possible_cpus(void); +extern void topology_reset_possible_cpus_up(void); #else /* !CONFIG_X86_LOCAL_APIC */ static inline void lapic_shutdown(void) { } @@ -190,6 +193,8 @@ static inline void apic_intr_mode_init(void) { } static inline void lapic_assign_system_vectors(void) { } static inline void lapic_assign_legacy_vector(unsigned int i, bool r) { } static inline bool apic_needs_pit(void) { return true; } +static inline void topology_apply_cmdline_limits_early(void) { } +static inline void topology_init_possible_cpus(void) { } #endif /* !CONFIG_X86_LOCAL_APIC */ #ifdef CONFIG_X86_X2APIC diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index f8f9a9b79395..aa30fd8cad7f 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -9,18 +9,10 @@ #include #include -#ifdef CONFIG_SMP - -extern void prefill_possible_map(void); - -#else /* CONFIG_SMP */ - -static inline void prefill_possible_map(void) {} - +#ifndef CONFIG_SMP #define cpu_physical_id(cpu) boot_cpu_physical_apicid #define cpu_acpi_id(cpu) 0 #define safe_smp_processor_id() 0 - #endif /* CONFIG_SMP */ #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index cb6bafd329f1..3e11a5a3b830 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -191,6 +191,7 @@ static inline bool topology_is_primary_thread(unsigned int cpu) { return cpumask_test_cpu(cpu, cpu_primary_thread_mask); } + #else /* CONFIG_SMP */ #define topology_max_packages() (1) static inline int diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index 80625f4194de..fc47f5216f9a 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -5,6 +5,7 @@ #include #include +#include #include #include @@ -85,73 +86,6 @@ early_initcall(smp_init_primary_thread_mask); static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { } #endif -static int __initdata setup_possible_cpus = -1; - -/* - * cpu_possible_mask should be static, it cannot change as cpu's - * are onlined, or offlined. The reason is per-cpu data-structures - * are allocated by some modules at init time, and don't expect to - * do this dynamically on cpu arrival/departure. - * cpu_present_mask on the other hand can change dynamically. - * In case when cpu_hotplug is not compiled, then we resort to current - * behaviour, which is cpu_possible == cpu_present. - * - Ashok Raj - * - * Three ways to find out the number of additional hotplug CPUs: - * - If the BIOS specified disabled CPUs in ACPI/mptables use that. - * - The user can overwrite it with possible_cpus=NUM - * - Otherwise don't reserve additional CPUs. - * We do this because additional CPUs waste a lot of memory. - * -AK - */ -__init void prefill_possible_map(void) -{ - unsigned int num_processors = topo_info.nr_assigned_cpus; - unsigned int disabled_cpus = topo_info.nr_disabled_cpus; - int i, possible; - - i = setup_max_cpus ?: 1; - if (setup_possible_cpus == -1) { - possible = topo_info.nr_assigned_cpus; -#ifdef CONFIG_HOTPLUG_CPU - if (setup_max_cpus) - possible += num_processors; -#else - if (possible > i) - possible = i; -#endif - } else - possible = setup_possible_cpus; - - total_cpus = max_t(int, possible, num_processors + disabled_cpus); - - /* nr_cpu_ids could be reduced via nr_cpus= */ - if (possible > nr_cpu_ids) { - pr_warn("%d Processors exceeds NR_CPUS limit of %u\n", - possible, nr_cpu_ids); - possible = nr_cpu_ids; - } - -#ifdef CONFIG_HOTPLUG_CPU - if (!setup_max_cpus) -#endif - if (possible > i) { - pr_warn("%d Processors exceeds max_cpus limit of %u\n", - possible, setup_max_cpus); - possible = i; - } - - set_nr_cpu_ids(possible); - - pr_info("Allowing %d CPUs, %d hotplug CPUs\n", - possible, max_t(int, possible - num_processors, 0)); - - reset_cpu_possible_mask(); - - for (i = 0; i < possible; i++) - set_cpu_possible(i, true); -} - static int topo_lookup_cpuid(u32 apic_id) { int i; @@ -293,12 +227,114 @@ void topology_hotunplug_apic(unsigned int cpu) } #endif -static int __init _setup_possible_cpus(char *str) +#ifdef CONFIG_SMP +static unsigned int max_possible_cpus __initdata = NR_CPUS; + +/** + * topology_apply_cmdline_limits_early - Apply topology command line limits early + * + * Ensure that command line limits are in effect before firmware parsing + * takes place. + */ +void __init topology_apply_cmdline_limits_early(void) { - get_option(&str, &setup_possible_cpus); + unsigned int possible = nr_cpu_ids; + + /* 'maxcpus=0' 'nosmp' 'nolapic' 'disableapic' 'noapic' */ + if (!setup_max_cpus || ioapic_is_disabled || apic_is_disabled) + possible = 1; + + /* 'possible_cpus=N' */ + possible = min_t(unsigned int, max_possible_cpus, possible); + + if (possible < nr_cpu_ids) { + pr_info("Limiting to %u possible CPUs\n", possible); + set_nr_cpu_ids(possible); + } +} + +static __init bool restrict_to_up(void) +{ + if (!smp_found_config || ioapic_is_disabled) + return true; + /* + * XEN PV is special as it does not advertise the local APIC + * properly, but provides a fake topology for it so that the + * infrastructure works. So don't apply the restrictions vs. APIC + * here. + */ + if (xen_pv_domain()) + return false; + + return apic_is_disabled; +} + +void __init topology_init_possible_cpus(void) +{ + unsigned int assigned = topo_info.nr_assigned_cpus; + unsigned int disabled = topo_info.nr_disabled_cpus; + unsigned int total = assigned + disabled; + unsigned int cpu, allowed = 1; + + if (!restrict_to_up()) { + if (WARN_ON_ONCE(assigned > nr_cpu_ids)) { + disabled += assigned - nr_cpu_ids; + assigned = nr_cpu_ids; + } + allowed = min_t(unsigned int, total, nr_cpu_ids); + } + + if (total > allowed) + pr_warn("%u possible CPUs exceed the limit of %u\n", total, allowed); + + assigned = min_t(unsigned int, allowed, assigned); + disabled = allowed - assigned; + + topo_info.nr_assigned_cpus = assigned; + topo_info.nr_disabled_cpus = disabled; + + total_cpus = allowed; + set_nr_cpu_ids(allowed); + + pr_info("Allowing %u present CPUs plus %u hotplug CPUs\n", assigned, disabled); + if (topo_info.nr_rejected_cpus) + pr_info("Rejected CPUs %u\n", topo_info.nr_rejected_cpus); + + init_cpu_present(cpumask_of(0)); + init_cpu_possible(cpumask_of(0)); + + for (cpu = 0; cpu < allowed; cpu++) { + u32 apicid = cpuid_to_apicid[cpu]; + + set_cpu_possible(cpu, true); + + if (apicid == BAD_APICID) + continue; + + set_cpu_present(cpu, test_bit(apicid, phys_cpu_present_map)); + } +} + +/* + * Late SMP disable after sizing CPU masks when APIC/IOAPIC setup failed. + */ +void __init topology_reset_possible_cpus_up(void) +{ + init_cpu_present(cpumask_of(0)); + init_cpu_possible(cpumask_of(0)); + + bitmap_zero(phys_cpu_present_map, MAX_LOCAL_APIC); + if (topo_info.boot_cpu_apic_id != BAD_APICID) + set_bit(topo_info.boot_cpu_apic_id, phys_cpu_present_map); +} + +static int __init setup_possible_cpus(char *str) +{ + get_option(&str, &max_possible_cpus); return 0; } -early_param("possible_cpus", _setup_possible_cpus); +early_param("possible_cpus", setup_possible_cpus); +#endif static int __init apic_set_disabled_cpu_apicid(char *arg) { diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index b1e52ac164b1..4e320d4d3898 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1131,6 +1131,8 @@ void __init setup_arch(char **cmdline_p) early_quirks(); + topology_apply_cmdline_limits_early(); + /* * Parse SMP configuration. Try ACPI first and then the platform * specific parser. @@ -1138,13 +1140,10 @@ void __init setup_arch(char **cmdline_p) acpi_boot_init(); x86_init.mpparse.parse_smp_cfg(); - /* - * Systems w/o ACPI and mptables might not have it mapped the local - * APIC yet, but prefill_possible_map() might need to access it. - */ + /* Last opportunity to detect and map the local APIC */ init_apic_mappings(); - prefill_possible_map(); + topology_init_possible_cpus(); init_cpu_to_node(); init_gi_nodes(); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index d850faca946d..7f85f174690f 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1147,11 +1147,7 @@ static __init void disable_smp(void) pr_info("SMP disabled\n"); disable_ioapic_support(); - - init_cpu_present(cpumask_of(0)); - init_cpu_possible(cpumask_of(0)); - - reset_phys_cpu_present_map(smp_found_config ? boot_cpu_physical_apicid : 0); + topology_reset_possible_cpus_up(); cpumask_set_cpu(0, topology_sibling_cpumask(0)); cpumask_set_cpu(0, topology_core_cpumask(0));