#include #include #include #include #include #include #include #include #include #include #include /* Number of siblings per CPU package */ int smp_num_siblings = 1; EXPORT_SYMBOL(smp_num_siblings); /* Last level cache ID of each logical CPU */ DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID; /* bitmap of online cpus */ cpumask_t cpu_online_map __read_mostly; EXPORT_SYMBOL(cpu_online_map); cpumask_t cpu_callin_map; cpumask_t cpu_callout_map; cpumask_t cpu_possible_map; EXPORT_SYMBOL(cpu_possible_map); /* representing HT siblings of each logical CPU */ DEFINE_PER_CPU(cpumask_t, cpu_sibling_map); EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); /* representing HT and core siblings of each logical CPU */ DEFINE_PER_CPU(cpumask_t, cpu_core_map); EXPORT_PER_CPU_SYMBOL(cpu_core_map); /* Per CPU bogomips and other parameters */ DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); /* ready for x86_64, no harm for x86, since it will overwrite after alloc */ unsigned char *trampoline_base = __va(SMP_TRAMPOLINE_BASE); /* representing cpus for which sibling maps can be computed */ static cpumask_t cpu_sibling_setup_map; /* Set if we find a B stepping CPU */ int __cpuinitdata smp_b_stepping; static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c) { #ifdef CONFIG_X86_32 /* * Mask B, Pentium, but not Pentium MMX */ if (c->x86_vendor == X86_VENDOR_INTEL && c->x86 == 5 && c->x86_mask >= 1 && c->x86_mask <= 4 && c->x86_model <= 3) /* * Remember we have B step Pentia with bugs */ smp_b_stepping = 1; /* * Certain Athlons might work (for various values of 'work') in SMP * but they are not certified as MP capable. */ if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) { if (num_possible_cpus() == 1) goto valid_k7; /* Athlon 660/661 is valid. */ if ((c->x86_model == 6) && ((c->x86_mask == 0) || (c->x86_mask == 1))) goto valid_k7; /* Duron 670 is valid */ if ((c->x86_model == 7) && (c->x86_mask == 0)) goto valid_k7; /* * Athlon 662, Duron 671, and Athlon >model 7 have capability * bit. It's worth noting that the A5 stepping (662) of some * Athlon XP's have the MP bit set. * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for * more. */ if (((c->x86_model == 6) && (c->x86_mask >= 2)) || ((c->x86_model == 7) && (c->x86_mask >= 1)) || (c->x86_model > 7)) if (cpu_has_mp) goto valid_k7; /* If we get here, not a certified SMP capable AMD system. */ add_taint(TAINT_UNSAFE_SMP); } valid_k7: ; #endif } void smp_checks(void) { if (smp_b_stepping) printk(KERN_WARNING "WARNING: SMP operation may be unreliable" "with B stepping processors.\n"); /* * Don't taint if we are running SMP kernel on a single non-MP * approved Athlon */ if (tainted & TAINT_UNSAFE_SMP) { if (num_online_cpus()) printk(KERN_INFO "WARNING: This combination of AMD" "processors is not suitable for SMP.\n"); else tainted &= ~TAINT_UNSAFE_SMP; } } /* * The bootstrap kernel entry code has set these up. Save them for * a given CPU */ void __cpuinit smp_store_cpu_info(int id) { struct cpuinfo_x86 *c = &cpu_data(id); *c = boot_cpu_data; c->cpu_index = id; if (id != 0) identify_secondary_cpu(c); smp_apply_quirks(c); } void __cpuinit set_cpu_sibling_map(int cpu) { int i; struct cpuinfo_x86 *c = &cpu_data(cpu); cpu_set(cpu, cpu_sibling_setup_map); if (smp_num_siblings > 1) { for_each_cpu_mask(i, cpu_sibling_setup_map) { if (c->phys_proc_id == cpu_data(i).phys_proc_id && c->cpu_core_id == cpu_data(i).cpu_core_id) { cpu_set(i, per_cpu(cpu_sibling_map, cpu)); cpu_set(cpu, per_cpu(cpu_sibling_map, i)); cpu_set(i, per_cpu(cpu_core_map, cpu)); cpu_set(cpu, per_cpu(cpu_core_map, i)); cpu_set(i, c->llc_shared_map); cpu_set(cpu, cpu_data(i).llc_shared_map); } } } else { cpu_set(cpu, per_cpu(cpu_sibling_map, cpu)); } cpu_set(cpu, c->llc_shared_map); if (current_cpu_data.x86_max_cores == 1) { per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu); c->booted_cores = 1; return; } for_each_cpu_mask(i, cpu_sibling_setup_map) { if (per_cpu(cpu_llc_id, cpu) != BAD_APICID && per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) { cpu_set(i, c->llc_shared_map); cpu_set(cpu, cpu_data(i).llc_shared_map); } if (c->phys_proc_id == cpu_data(i).phys_proc_id) { cpu_set(i, per_cpu(cpu_core_map, cpu)); cpu_set(cpu, per_cpu(cpu_core_map, i)); /* * Does this new cpu bringup a new core? */ if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) { /* * for each core in package, increment * the booted_cores for this new cpu */ if (first_cpu(per_cpu(cpu_sibling_map, i)) == i) c->booted_cores++; /* * increment the core count for all * the other cpus in this package */ if (i != cpu) cpu_data(i).booted_cores++; } else if (i != cpu && !c->booted_cores) c->booted_cores = cpu_data(i).booted_cores; } } } /* maps the cpu to the sched domain representing multi-core */ cpumask_t cpu_coregroup_map(int cpu) { struct cpuinfo_x86 *c = &cpu_data(cpu); /* * For perf, we return last level cache shared map. * And for power savings, we return cpu_core_map */ if (sched_mc_power_savings || sched_smt_power_savings) return per_cpu(cpu_core_map, cpu); else return c->llc_shared_map; } /* * Currently trivial. Write the real->protected mode * bootstrap into the page concerned. The caller * has made sure it's suitably aligned. */ unsigned long __cpuinit setup_trampoline(void) { memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data); return virt_to_phys(trampoline_base); } #ifdef CONFIG_X86_32 /* * We are called very early to get the low memory for the * SMP bootup trampoline page. */ void __init smp_alloc_memory(void) { trampoline_base = alloc_bootmem_low_pages(PAGE_SIZE); /* * Has to be in very low memory so we can execute * real-mode AP code. */ if (__pa(trampoline_base) >= 0x9F000) BUG(); } #endif void impress_friends(void) { int cpu; unsigned long bogosum = 0; /* * Allow the user to impress friends. */ Dprintk("Before bogomips.\n"); for_each_possible_cpu(cpu) if (cpu_isset(cpu, cpu_callout_map)) bogosum += cpu_data(cpu).loops_per_jiffy; printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n", num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100); Dprintk("Before bogocount - setting activated=1.\n"); } #ifdef CONFIG_HOTPLUG_CPU void remove_siblinginfo(int cpu) { int sibling; struct cpuinfo_x86 *c = &cpu_data(cpu); for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) { cpu_clear(cpu, per_cpu(cpu_core_map, sibling)); /*/ * last thread sibling in this cpu core going down */ if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) cpu_data(sibling).booted_cores--; } for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu)) cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling)); cpus_clear(per_cpu(cpu_sibling_map, cpu)); cpus_clear(per_cpu(cpu_core_map, cpu)); c->phys_proc_id = 0; c->cpu_core_id = 0; cpu_clear(cpu, cpu_sibling_setup_map); } int additional_cpus __initdata = -1; static __init int setup_additional_cpus(char *s) { return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL; } early_param("additional_cpus", setup_additional_cpus); /* * cpu_possible_map 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 dont expect to * do this dynamically on cpu arrival/departure. * cpu_present_map 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 additional_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) { int i; int possible; if (additional_cpus == -1) { if (disabled_cpus > 0) additional_cpus = disabled_cpus; else additional_cpus = 0; } possible = num_processors + additional_cpus; if (possible > NR_CPUS) possible = NR_CPUS; printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n", possible, max_t(int, possible - num_processors, 0)); for (i = 0; i < possible; i++) cpu_set(i, cpu_possible_map); } static void __ref remove_cpu_from_maps(int cpu) { cpu_clear(cpu, cpu_online_map); #ifdef CONFIG_X86_64 cpu_clear(cpu, cpu_callout_map); cpu_clear(cpu, cpu_callin_map); /* was set by cpu_init() */ clear_bit(cpu, (unsigned long *)&cpu_initialized); clear_node_cpumask(cpu); #endif } int __cpu_disable(void) { int cpu = smp_processor_id(); /* * Perhaps use cpufreq to drop frequency, but that could go * into generic code. * * We won't take down the boot processor on i386 due to some * interrupts only being able to be serviced by the BSP. * Especially so if we're not using an IOAPIC -zwane */ if (cpu == 0) return -EBUSY; if (nmi_watchdog == NMI_LOCAL_APIC) stop_apic_nmi_watchdog(NULL); clear_local_APIC(); /* * HACK: * Allow any queued timer interrupts to get serviced * This is only a temporary solution until we cleanup * fixup_irqs as we do for IA64. */ local_irq_enable(); mdelay(1); local_irq_disable(); remove_siblinginfo(cpu); /* It's now safe to remove this processor from the online map */ remove_cpu_from_maps(cpu); fixup_irqs(cpu_online_map); return 0; } void __cpu_die(unsigned int cpu) { /* We don't do anything here: idle task is faking death itself. */ unsigned int i; for (i = 0; i < 10; i++) { /* They ack this in play_dead by setting CPU_DEAD */ if (per_cpu(cpu_state, cpu) == CPU_DEAD) { printk(KERN_INFO "CPU %d is now offline\n", cpu); if (1 == num_online_cpus()) alternatives_smp_switch(0); return; } msleep(100); } printk(KERN_ERR "CPU %u didn't die...\n", cpu); } #else /* ... !CONFIG_HOTPLUG_CPU */ int __cpu_disable(void) { return -ENOSYS; } void __cpu_die(unsigned int cpu) { /* We said "no" in __cpu_disable */ BUG(); } #endif /* * If the BIOS enumerates physical processors before logical, * maxcpus=N at enumeration-time can be used to disable HT. */ static int __init parse_maxcpus(char *arg) { extern unsigned int maxcpus; maxcpus = simple_strtoul(arg, NULL, 0); return 0; } early_param("maxcpus", parse_maxcpus);