/* * SMP support for pSeries machines. * * Dave Engebretsen, Peter Bergner, and * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com * * Plus various changes from other IBM teams... * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #undef DEBUG #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 "mpic.h" #ifdef DEBUG #define DBG(fmt...) udbg_printf(fmt) #else #define DBG(fmt...) #endif extern void pSeries_secondary_smp_init(unsigned long); /* Get state of physical CPU. * Return codes: * 0 - The processor is in the RTAS stopped state * 1 - stop-self is in progress * 2 - The processor is not in the RTAS stopped state * -1 - Hardware Error * -2 - Hardware Busy, Try again later. */ static int query_cpu_stopped(unsigned int pcpu) { int cpu_status; int status, qcss_tok; qcss_tok = rtas_token("query-cpu-stopped-state"); if (qcss_tok == RTAS_UNKNOWN_SERVICE) return -1; status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); if (status != 0) { printk(KERN_ERR "RTAS query-cpu-stopped-state failed: %i\n", status); return status; } return cpu_status; } #ifdef CONFIG_HOTPLUG_CPU int pSeries_cpu_disable(void) { systemcfg->processorCount--; /*fix boot_cpuid here*/ if (smp_processor_id() == boot_cpuid) boot_cpuid = any_online_cpu(cpu_online_map); /* FIXME: abstract this to not be platform specific later on */ xics_migrate_irqs_away(); return 0; } void pSeries_cpu_die(unsigned int cpu) { int tries; int cpu_status; unsigned int pcpu = get_hard_smp_processor_id(cpu); for (tries = 0; tries < 25; tries++) { cpu_status = query_cpu_stopped(pcpu); if (cpu_status == 0 || cpu_status == -1) break; msleep(200); } if (cpu_status != 0) { printk("Querying DEAD? cpu %i (%i) shows %i\n", cpu, pcpu, cpu_status); } /* Isolation and deallocation are definatly done by * drslot_chrp_cpu. If they were not they would be * done here. Change isolate state to Isolate and * change allocation-state to Unusable. */ paca[cpu].cpu_start = 0; } /* Search all cpu device nodes for an offline logical cpu. If a * device node has a "ibm,my-drc-index" property (meaning this is an * LPAR), paranoid-check whether we own the cpu. For each "thread" * of a cpu, if it is offline and has the same hw index as before, * grab that in preference. */ static unsigned int find_physical_cpu_to_start(unsigned int old_hwindex) { struct device_node *np = NULL; unsigned int best = -1U; while ((np = of_find_node_by_type(np, "cpu"))) { int nr_threads, len; u32 *index = (u32 *)get_property(np, "ibm,my-drc-index", NULL); u32 *tid = (u32 *) get_property(np, "ibm,ppc-interrupt-server#s", &len); if (!tid) tid = (u32 *)get_property(np, "reg", &len); if (!tid) continue; /* If there is a drc-index, make sure that we own * the cpu. */ if (index) { int state; int rc = rtas_get_sensor(9003, *index, &state); if (rc != 0 || state != 1) continue; } nr_threads = len / sizeof(u32); while (nr_threads--) { if (0 == query_cpu_stopped(tid[nr_threads])) { best = tid[nr_threads]; if (best == old_hwindex) goto out; } } } out: of_node_put(np); return best; } /** * smp_startup_cpu() - start the given cpu * * At boot time, there is nothing to do. At run-time, call RTAS with * the appropriate start location, if the cpu is in the RTAS stopped * state. * * Returns: * 0 - failure * 1 - success */ static inline int __devinit smp_startup_cpu(unsigned int lcpu) { int status; unsigned long start_here = __pa((u32)*((unsigned long *) pSeries_secondary_smp_init)); unsigned int pcpu; /* At boot time the cpus are already spinning in hold * loops, so nothing to do. */ if (system_state < SYSTEM_RUNNING) return 1; pcpu = find_physical_cpu_to_start(get_hard_smp_processor_id(lcpu)); if (pcpu == -1U) { printk(KERN_INFO "No more cpus available, failing\n"); return 0; } /* Fixup atomic count: it exited inside IRQ handler. */ paca[lcpu].__current->thread_info->preempt_count = 0; /* At boot this is done in prom.c. */ paca[lcpu].hw_cpu_id = pcpu; status = rtas_call(rtas_token("start-cpu"), 3, 1, NULL, pcpu, start_here, lcpu); if (status != 0) { printk(KERN_ERR "start-cpu failed: %i\n", status); return 0; } return 1; } #else /* ... CONFIG_HOTPLUG_CPU */ static inline int __devinit smp_startup_cpu(unsigned int lcpu) { return 1; } #endif /* CONFIG_HOTPLUG_CPU */ static inline void smp_xics_do_message(int cpu, int msg) { set_bit(msg, &xics_ipi_message[cpu].value); mb(); xics_cause_IPI(cpu); } static void smp_xics_message_pass(int target, int msg) { unsigned int i; if (target < NR_CPUS) { smp_xics_do_message(target, msg); } else { for_each_online_cpu(i) { if (target == MSG_ALL_BUT_SELF && i == smp_processor_id()) continue; smp_xics_do_message(i, msg); } } } static int __init smp_xics_probe(void) { xics_request_IPIs(); return cpus_weight(cpu_possible_map); } static void __devinit smp_xics_setup_cpu(int cpu) { if (cpu != boot_cpuid) xics_setup_cpu(); if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) vpa_init(cpu); /* * Put the calling processor into the GIQ. This is really only * necessary from a secondary thread as the OF start-cpu interface * performs this function for us on primary threads. */ rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE, (1UL << interrupt_server_size) - 1 - default_distrib_server, 1); } static DEFINE_SPINLOCK(timebase_lock); static unsigned long timebase = 0; static void __devinit pSeries_give_timebase(void) { spin_lock(&timebase_lock); rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); timebase = get_tb(); spin_unlock(&timebase_lock); while (timebase) barrier(); rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); } static void __devinit pSeries_take_timebase(void) { while (!timebase) barrier(); spin_lock(&timebase_lock); set_tb(timebase >> 32, timebase & 0xffffffff); timebase = 0; spin_unlock(&timebase_lock); } static void __devinit smp_pSeries_kick_cpu(int nr) { BUG_ON(nr < 0 || nr >= NR_CPUS); if (!smp_startup_cpu(nr)) return; /* * The processor is currently spinning, waiting for the * cpu_start field to become non-zero After we set cpu_start, * the processor will continue on to secondary_start */ paca[nr].cpu_start = 1; } static struct smp_ops_t pSeries_mpic_smp_ops = { .message_pass = smp_mpic_message_pass, .probe = smp_mpic_probe, .kick_cpu = smp_pSeries_kick_cpu, .setup_cpu = smp_mpic_setup_cpu, }; static struct smp_ops_t pSeries_xics_smp_ops = { .message_pass = smp_xics_message_pass, .probe = smp_xics_probe, .kick_cpu = smp_pSeries_kick_cpu, .setup_cpu = smp_xics_setup_cpu, }; /* This is called very early */ void __init smp_init_pSeries(void) { int ret, i; DBG(" -> smp_init_pSeries()\n"); if (ppc64_interrupt_controller == IC_OPEN_PIC) smp_ops = &pSeries_mpic_smp_ops; else smp_ops = &pSeries_xics_smp_ops; #ifdef CONFIG_HOTPLUG_CPU smp_ops->cpu_disable = pSeries_cpu_disable; smp_ops->cpu_die = pSeries_cpu_die; #endif /* Start secondary threads on SMT systems; primary threads * are already in the running state. */ for_each_present_cpu(i) { if (query_cpu_stopped(get_hard_smp_processor_id(i)) == 0) { printk("%16.16x : starting thread\n", i); DBG("%16.16x : starting thread\n", i); rtas_call(rtas_token("start-cpu"), 3, 1, &ret, get_hard_smp_processor_id(i), __pa((u32)*((unsigned long *) pSeries_secondary_smp_init)), i); } } /* Non-lpar has additional take/give timebase */ if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { smp_ops->give_timebase = pSeries_give_timebase; smp_ops->take_timebase = pSeries_take_timebase; } DBG(" <- smp_init_pSeries()\n"); }