/* * SMP boot-related support * * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co * David Mosberger-Tang * Copyright (C) 2001, 2004-2005 Intel Corp * Rohit Seth * Suresh Siddha * Gordon Jin * Ashok Raj * * 01/05/16 Rohit Seth Moved SMP booting functions from smp.c to here. * 01/04/27 David Mosberger Added ITC synching code. * 02/07/31 David Mosberger Switch over to hotplug-CPU boot-sequence. * smp_boot_cpus()/smp_commence() is replaced by * smp_prepare_cpus()/__cpu_up()/smp_cpus_done(). * 04/06/21 Ashok Raj Added CPU Hotplug Support * 04/12/26 Jin Gordon * 04/12/26 Rohit Seth * Add multi-threading and multi-core detection * 05/01/30 Suresh Siddha * Setup cpu_sibling_map and cpu_core_map */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SMP_DEBUG 0 #if SMP_DEBUG #define Dprintk(x...) printk(x) #else #define Dprintk(x...) #endif #ifdef CONFIG_HOTPLUG_CPU #ifdef CONFIG_PERMIT_BSP_REMOVE #define bsp_remove_ok 1 #else #define bsp_remove_ok 0 #endif /* * Store all idle threads, this can be reused instead of creating * a new thread. Also avoids complicated thread destroy functionality * for idle threads. */ struct task_struct *idle_thread_array[NR_CPUS]; /* * Global array allocated for NR_CPUS at boot time */ struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS]; /* * start_ap in head.S uses this to store current booting cpu * info. */ struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0]; #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]); #define get_idle_for_cpu(x) (idle_thread_array[(x)]) #define set_idle_for_cpu(x,p) (idle_thread_array[(x)] = (p)) #else #define get_idle_for_cpu(x) (NULL) #define set_idle_for_cpu(x,p) #define set_brendez_area(x) #endif /* * ITC synchronization related stuff: */ #define MASTER (0) #define SLAVE (SMP_CACHE_BYTES/8) #define NUM_ROUNDS 64 /* magic value */ #define NUM_ITERS 5 /* likewise */ static DEFINE_SPINLOCK(itc_sync_lock); static volatile unsigned long go[SLAVE + 1]; #define DEBUG_ITC_SYNC 0 extern void start_ap (void); extern unsigned long ia64_iobase; struct task_struct *task_for_booting_cpu; /* * State for each CPU */ DEFINE_PER_CPU(int, cpu_state); /* Bitmasks of currently online, and possible CPUs */ cpumask_t cpu_online_map; EXPORT_SYMBOL(cpu_online_map); cpumask_t cpu_possible_map = CPU_MASK_NONE; EXPORT_SYMBOL(cpu_possible_map); cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned; DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map); EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); int smp_num_siblings = 1; /* which logical CPU number maps to which CPU (physical APIC ID) */ volatile int ia64_cpu_to_sapicid[NR_CPUS]; EXPORT_SYMBOL(ia64_cpu_to_sapicid); static volatile cpumask_t cpu_callin_map; struct smp_boot_data smp_boot_data __initdata; unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */ char __initdata no_int_routing; unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */ #ifdef CONFIG_FORCE_CPEI_RETARGET #define CPEI_OVERRIDE_DEFAULT (1) #else #define CPEI_OVERRIDE_DEFAULT (0) #endif unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT; static int __init cmdl_force_cpei(char *str) { int value=0; get_option (&str, &value); force_cpei_retarget = value; return 1; } __setup("force_cpei=", cmdl_force_cpei); static int __init nointroute (char *str) { no_int_routing = 1; printk ("no_int_routing on\n"); return 1; } __setup("nointroute", nointroute); static void fix_b0_for_bsp(void) { #ifdef CONFIG_HOTPLUG_CPU int cpuid; static int fix_bsp_b0 = 1; cpuid = smp_processor_id(); /* * Cache the b0 value on the first AP that comes up */ if (!(fix_bsp_b0 && cpuid)) return; sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0]; printk ("Fixed BSP b0 value from CPU %d\n", cpuid); fix_bsp_b0 = 0; #endif } void sync_master (void *arg) { unsigned long flags, i; go[MASTER] = 0; local_irq_save(flags); { for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) { while (!go[MASTER]) cpu_relax(); go[MASTER] = 0; go[SLAVE] = ia64_get_itc(); } } local_irq_restore(flags); } /* * Return the number of cycles by which our itc differs from the itc on the master * (time-keeper) CPU. A positive number indicates our itc is ahead of the master, * negative that it is behind. */ static inline long get_delta (long *rt, long *master) { unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0; unsigned long tcenter, t0, t1, tm; long i; for (i = 0; i < NUM_ITERS; ++i) { t0 = ia64_get_itc(); go[MASTER] = 1; while (!(tm = go[SLAVE])) cpu_relax(); go[SLAVE] = 0; t1 = ia64_get_itc(); if (t1 - t0 < best_t1 - best_t0) best_t0 = t0, best_t1 = t1, best_tm = tm; } *rt = best_t1 - best_t0; *master = best_tm - best_t0; /* average best_t0 and best_t1 without overflow: */ tcenter = (best_t0/2 + best_t1/2); if (best_t0 % 2 + best_t1 % 2 == 2) ++tcenter; return tcenter - best_tm; } /* * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU * (normally the time-keeper CPU). We use a closed loop to eliminate the possibility of * unaccounted-for errors (such as getting a machine check in the middle of a calibration * step). The basic idea is for the slave to ask the master what itc value it has and to * read its own itc before and after the master responds. Each iteration gives us three * timestamps: * * slave master * * t0 ---\ * ---\ * ---> * tm * /--- * /--- * t1 <--- * * * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0 * and t1. If we achieve this, the clocks are synchronized provided the interconnect * between the slave and the master is symmetric. Even if the interconnect were * asymmetric, we would still know that the synchronization error is smaller than the * roundtrip latency (t0 - t1). * * When the interconnect is quiet and symmetric, this lets us synchronize the itc to * within one or two cycles. However, we can only *guarantee* that the synchronization is * accurate to within a round-trip time, which is typically in the range of several * hundred cycles (e.g., ~500 cycles). In practice, this means that the itc's are usually * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better * than half a micro second or so. */ void ia64_sync_itc (unsigned int master) { long i, delta, adj, adjust_latency = 0, done = 0; unsigned long flags, rt, master_time_stamp, bound; #if DEBUG_ITC_SYNC struct { long rt; /* roundtrip time */ long master; /* master's timestamp */ long diff; /* difference between midpoint and master's timestamp */ long lat; /* estimate of itc adjustment latency */ } t[NUM_ROUNDS]; #endif /* * Make sure local timer ticks are disabled while we sync. If * they were enabled, we'd have to worry about nasty issues * like setting the ITC ahead of (or a long time before) the * next scheduled tick. */ BUG_ON((ia64_get_itv() & (1 << 16)) == 0); go[MASTER] = 1; if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) { printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master); return; } while (go[MASTER]) cpu_relax(); /* wait for master to be ready */ spin_lock_irqsave(&itc_sync_lock, flags); { for (i = 0; i < NUM_ROUNDS; ++i) { delta = get_delta(&rt, &master_time_stamp); if (delta == 0) { done = 1; /* let's lock on to this... */ bound = rt; } if (!done) { if (i > 0) { adjust_latency += -delta; adj = -delta + adjust_latency/4; } else adj = -delta; ia64_set_itc(ia64_get_itc() + adj); } #if DEBUG_ITC_SYNC t[i].rt = rt; t[i].master = master_time_stamp; t[i].diff = delta; t[i].lat = adjust_latency/4; #endif } } spin_unlock_irqrestore(&itc_sync_lock, flags); #if DEBUG_ITC_SYNC for (i = 0; i < NUM_ROUNDS; ++i) printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n", t[i].rt, t[i].master, t[i].diff, t[i].lat); #endif printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, " "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt); } /* * Ideally sets up per-cpu profiling hooks. Doesn't do much now... */ static inline void __devinit smp_setup_percpu_timer (void) { } static void __cpuinit smp_callin (void) { int cpuid, phys_id, itc_master; struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo; extern void ia64_init_itm(void); extern volatile int time_keeper_id; #ifdef CONFIG_PERFMON extern void pfm_init_percpu(void); #endif cpuid = smp_processor_id(); phys_id = hard_smp_processor_id(); itc_master = time_keeper_id; if (cpu_online(cpuid)) { printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n", phys_id, cpuid); BUG(); } fix_b0_for_bsp(); lock_ipi_calllock(); spin_lock(&vector_lock); /* Setup the per cpu irq handling data structures */ __setup_vector_irq(cpuid); cpu_set(cpuid, cpu_online_map); per_cpu(cpu_state, cpuid) = CPU_ONLINE; spin_unlock(&vector_lock); unlock_ipi_calllock(); smp_setup_percpu_timer(); ia64_mca_cmc_vector_setup(); /* Setup vector on AP */ #ifdef CONFIG_PERFMON pfm_init_percpu(); #endif local_irq_enable(); if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) { /* * Synchronize the ITC with the BP. Need to do this after irqs are * enabled because ia64_sync_itc() calls smp_call_function_single(), which * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls * local_bh_enable(), which bugs out if irqs are not enabled... */ Dprintk("Going to syncup ITC with ITC Master.\n"); ia64_sync_itc(itc_master); } /* * Get our bogomips. */ ia64_init_itm(); /* * Delay calibration can be skipped if new processor is identical to the * previous processor. */ last_cpuinfo = cpu_data(cpuid - 1); this_cpuinfo = local_cpu_data; if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq || last_cpuinfo->proc_freq != this_cpuinfo->proc_freq || last_cpuinfo->features != this_cpuinfo->features || last_cpuinfo->revision != this_cpuinfo->revision || last_cpuinfo->family != this_cpuinfo->family || last_cpuinfo->archrev != this_cpuinfo->archrev || last_cpuinfo->model != this_cpuinfo->model) calibrate_delay(); local_cpu_data->loops_per_jiffy = loops_per_jiffy; #ifdef CONFIG_IA32_SUPPORT ia32_gdt_init(); #endif /* * Allow the master to continue. */ cpu_set(cpuid, cpu_callin_map); Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid); } /* * Activate a secondary processor. head.S calls this. */ int __cpuinit start_secondary (void *unused) { /* Early console may use I/O ports */ ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase)); Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id()); efi_map_pal_code(); cpu_init(); preempt_disable(); smp_callin(); cpu_idle(); return 0; } struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs) { return NULL; } struct create_idle { struct work_struct work; struct task_struct *idle; struct completion done; int cpu; }; void __cpuinit do_fork_idle(struct work_struct *work) { struct create_idle *c_idle = container_of(work, struct create_idle, work); c_idle->idle = fork_idle(c_idle->cpu); complete(&c_idle->done); } static int __cpuinit do_boot_cpu (int sapicid, int cpu) { int timeout; struct create_idle c_idle = { .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle), .cpu = cpu, .done = COMPLETION_INITIALIZER(c_idle.done), }; c_idle.idle = get_idle_for_cpu(cpu); if (c_idle.idle) { init_idle(c_idle.idle, cpu); goto do_rest; } /* * We can't use kernel_thread since we must avoid to reschedule the child. */ if (!keventd_up() || current_is_keventd()) c_idle.work.func(&c_idle.work); else { schedule_work(&c_idle.work); wait_for_completion(&c_idle.done); } if (IS_ERR(c_idle.idle)) panic("failed fork for CPU %d", cpu); set_idle_for_cpu(cpu, c_idle.idle); do_rest: task_for_booting_cpu = c_idle.idle; Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid); set_brendez_area(cpu); platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0); /* * Wait 10s total for the AP to start */ Dprintk("Waiting on callin_map ..."); for (timeout = 0; timeout < 100000; timeout++) { if (cpu_isset(cpu, cpu_callin_map)) break; /* It has booted */ udelay(100); } Dprintk("\n"); if (!cpu_isset(cpu, cpu_callin_map)) { printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid); ia64_cpu_to_sapicid[cpu] = -1; cpu_clear(cpu, cpu_online_map); /* was set in smp_callin() */ return -EINVAL; } return 0; } static int __init decay (char *str) { int ticks; get_option (&str, &ticks); return 1; } __setup("decay=", decay); /* * Initialize the logical CPU number to SAPICID mapping */ void __init smp_build_cpu_map (void) { int sapicid, cpu, i; int boot_cpu_id = hard_smp_processor_id(); for (cpu = 0; cpu < NR_CPUS; cpu++) { ia64_cpu_to_sapicid[cpu] = -1; } ia64_cpu_to_sapicid[0] = boot_cpu_id; cpus_clear(cpu_present_map); cpu_set(0, cpu_present_map); cpu_set(0, cpu_possible_map); for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) { sapicid = smp_boot_data.cpu_phys_id[i]; if (sapicid == boot_cpu_id) continue; cpu_set(cpu, cpu_present_map); cpu_set(cpu, cpu_possible_map); ia64_cpu_to_sapicid[cpu] = sapicid; cpu++; } } /* * Cycle through the APs sending Wakeup IPIs to boot each. */ void __init smp_prepare_cpus (unsigned int max_cpus) { int boot_cpu_id = hard_smp_processor_id(); /* * Initialize the per-CPU profiling counter/multiplier */ smp_setup_percpu_timer(); /* * We have the boot CPU online for sure. */ cpu_set(0, cpu_online_map); cpu_set(0, cpu_callin_map); local_cpu_data->loops_per_jiffy = loops_per_jiffy; ia64_cpu_to_sapicid[0] = boot_cpu_id; printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id); current_thread_info()->cpu = 0; /* * If SMP should be disabled, then really disable it! */ if (!max_cpus) { printk(KERN_INFO "SMP mode deactivated.\n"); cpus_clear(cpu_online_map); cpus_clear(cpu_present_map); cpus_clear(cpu_possible_map); cpu_set(0, cpu_online_map); cpu_set(0, cpu_present_map); cpu_set(0, cpu_possible_map); return; } } void __devinit smp_prepare_boot_cpu(void) { cpu_set(smp_processor_id(), cpu_online_map); cpu_set(smp_processor_id(), cpu_callin_map); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; paravirt_post_smp_prepare_boot_cpu(); } #ifdef CONFIG_HOTPLUG_CPU static inline void clear_cpu_sibling_map(int cpu) { int i; for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu)) cpu_clear(cpu, per_cpu(cpu_sibling_map, i)); for_each_cpu_mask(i, cpu_core_map[cpu]) cpu_clear(cpu, cpu_core_map[i]); per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE; } static void remove_siblinginfo(int cpu) { int last = 0; if (cpu_data(cpu)->threads_per_core == 1 && cpu_data(cpu)->cores_per_socket == 1) { cpu_clear(cpu, cpu_core_map[cpu]); cpu_clear(cpu, per_cpu(cpu_sibling_map, cpu)); return; } last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0); /* remove it from all sibling map's */ clear_cpu_sibling_map(cpu); } extern void fixup_irqs(void); int migrate_platform_irqs(unsigned int cpu) { int new_cpei_cpu; irq_desc_t *desc = NULL; cpumask_t mask; int retval = 0; /* * dont permit CPEI target to removed. */ if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) { printk ("CPU (%d) is CPEI Target\n", cpu); if (can_cpei_retarget()) { /* * Now re-target the CPEI to a different processor */ new_cpei_cpu = any_online_cpu(cpu_online_map); mask = cpumask_of_cpu(new_cpei_cpu); set_cpei_target_cpu(new_cpei_cpu); desc = irq_desc + ia64_cpe_irq; /* * Switch for now, immediately, we need to do fake intr * as other interrupts, but need to study CPEI behaviour with * polling before making changes. */ if (desc) { desc->chip->disable(ia64_cpe_irq); desc->chip->set_affinity(ia64_cpe_irq, mask); desc->chip->enable(ia64_cpe_irq); printk ("Re-targetting CPEI to cpu %d\n", new_cpei_cpu); } } if (!desc) { printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu); retval = -EBUSY; } } return retval; } /* must be called with cpucontrol mutex held */ int __cpu_disable(void) { int cpu = smp_processor_id(); /* * dont permit boot processor for now */ if (cpu == 0 && !bsp_remove_ok) { printk ("Your platform does not support removal of BSP\n"); return (-EBUSY); } if (ia64_platform_is("sn2")) { if (!sn_cpu_disable_allowed(cpu)) return -EBUSY; } cpu_clear(cpu, cpu_online_map); if (migrate_platform_irqs(cpu)) { cpu_set(cpu, cpu_online_map); return (-EBUSY); } remove_siblinginfo(cpu); cpu_clear(cpu, cpu_online_map); fixup_irqs(); local_flush_tlb_all(); cpu_clear(cpu, cpu_callin_map); return 0; } void __cpu_die(unsigned int cpu) { unsigned int i; for (i = 0; i < 100; i++) { /* They ack this in play_dead by setting CPU_DEAD */ if (per_cpu(cpu_state, cpu) == CPU_DEAD) { printk ("CPU %d is now offline\n", cpu); return; } msleep(100); } printk(KERN_ERR "CPU %u didn't die...\n", cpu); } #endif /* CONFIG_HOTPLUG_CPU */ void smp_cpus_done (unsigned int dummy) { int cpu; unsigned long bogosum = 0; /* * Allow the user to impress friends. */ for_each_online_cpu(cpu) { bogosum += cpu_data(cpu)->loops_per_jiffy; } printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n", (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100); } static inline void __devinit set_cpu_sibling_map(int cpu) { int i; for_each_online_cpu(i) { if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) { cpu_set(i, cpu_core_map[cpu]); cpu_set(cpu, cpu_core_map[i]); if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) { cpu_set(i, per_cpu(cpu_sibling_map, cpu)); cpu_set(cpu, per_cpu(cpu_sibling_map, i)); } } } } int __cpuinit __cpu_up (unsigned int cpu) { int ret; int sapicid; sapicid = ia64_cpu_to_sapicid[cpu]; if (sapicid == -1) return -EINVAL; /* * Already booted cpu? not valid anymore since we dont * do idle loop tightspin anymore. */ if (cpu_isset(cpu, cpu_callin_map)) return -EINVAL; per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; /* Processor goes to start_secondary(), sets online flag */ ret = do_boot_cpu(sapicid, cpu); if (ret < 0) return ret; if (cpu_data(cpu)->threads_per_core == 1 && cpu_data(cpu)->cores_per_socket == 1) { cpu_set(cpu, per_cpu(cpu_sibling_map, cpu)); cpu_set(cpu, cpu_core_map[cpu]); return 0; } set_cpu_sibling_map(cpu); return 0; } /* * Assume that CPUs have been discovered by some platform-dependent interface. For * SoftSDV/Lion, that would be ACPI. * * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP(). */ void __init init_smp_config(void) { struct fptr { unsigned long fp; unsigned long gp; } *ap_startup; long sal_ret; /* Tell SAL where to drop the APs. */ ap_startup = (struct fptr *) start_ap; sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ, ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0); if (sal_ret < 0) printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n", ia64_sal_strerror(sal_ret)); } /* * identify_siblings(cpu) gets called from identify_cpu. This populates the * information related to logical execution units in per_cpu_data structure. */ void __devinit identify_siblings(struct cpuinfo_ia64 *c) { s64 status; u16 pltid; pal_logical_to_physical_t info; status = ia64_pal_logical_to_phys(-1, &info); if (status != PAL_STATUS_SUCCESS) { if (status != PAL_STATUS_UNIMPLEMENTED) { printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n", status); return; } info.overview_ppid = 0; info.overview_cpp = 1; info.overview_tpc = 1; } status = ia64_sal_physical_id_info(&pltid); if (status != PAL_STATUS_SUCCESS) { if (status != PAL_STATUS_UNIMPLEMENTED) printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status); return; } c->socket_id = (pltid << 8) | info.overview_ppid; if (info.overview_cpp == 1 && info.overview_tpc == 1) return; c->cores_per_socket = info.overview_cpp; c->threads_per_core = info.overview_tpc; c->num_log = info.overview_num_log; c->core_id = info.log1_cid; c->thread_id = info.log1_tid; } /* * returns non zero, if multi-threading is enabled * on at least one physical package. Due to hotplug cpu * and (maxcpus=), all threads may not necessarily be enabled * even though the processor supports multi-threading. */ int is_multithreading_enabled(void) { int i, j; for_each_present_cpu(i) { for_each_present_cpu(j) { if (j == i) continue; if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) { if (cpu_data(j)->core_id == cpu_data(i)->core_id) return 1; } } } return 0; } EXPORT_SYMBOL_GPL(is_multithreading_enabled);