diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/smp.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/smp.c | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c new file mode 100644 index 000000000000..ae1bd270f308 --- /dev/null +++ b/arch/powerpc/platforms/pseries/smp.c @@ -0,0 +1,471 @@ +/* + * 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 <linux/config.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/cache.h> +#include <linux/err.h> +#include <linux/sysdev.h> +#include <linux/cpu.h> + +#include <asm/ptrace.h> +#include <asm/atomic.h> +#include <asm/irq.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/io.h> +#include <asm/prom.h> +#include <asm/smp.h> +#include <asm/paca.h> +#include <asm/time.h> +#include <asm/machdep.h> +#include <asm/xics.h> +#include <asm/cputable.h> +#include <asm/firmware.h> +#include <asm/system.h> +#include <asm/rtas.h> +#include <asm/plpar_wrappers.h> +#include <asm/pSeries_reconfig.h> +#include <asm/mpic.h> + +#ifdef DEBUG +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + +/* + * The primary thread of each non-boot processor is recorded here before + * smp init. + */ +static cpumask_t of_spin_map; + +extern void pSeries_secondary_smp_init(unsigned long); + +#ifdef CONFIG_HOTPLUG_CPU + +/* 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; +} + +int pSeries_cpu_disable(void) +{ + int cpu = smp_processor_id(); + + cpu_clear(cpu, cpu_online_map); + systemcfg->processorCount--; + + /*fix boot_cpuid here*/ + if (cpu == 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; +} + +/* + * Update cpu_present_map and paca(s) for a new cpu node. The wrinkle + * here is that a cpu device node may represent up to two logical cpus + * in the SMT case. We must honor the assumption in other code that + * the logical ids for sibling SMT threads x and y are adjacent, such + * that x^1 == y and y^1 == x. + */ +static int pSeries_add_processor(struct device_node *np) +{ + unsigned int cpu; + cpumask_t candidate_map, tmp = CPU_MASK_NONE; + int err = -ENOSPC, len, nthreads, i; + u32 *intserv; + + intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len); + if (!intserv) + return 0; + + nthreads = len / sizeof(u32); + for (i = 0; i < nthreads; i++) + cpu_set(i, tmp); + + lock_cpu_hotplug(); + + BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map)); + + /* Get a bitmap of unoccupied slots. */ + cpus_xor(candidate_map, cpu_possible_map, cpu_present_map); + if (cpus_empty(candidate_map)) { + /* If we get here, it most likely means that NR_CPUS is + * less than the partition's max processors setting. + */ + printk(KERN_ERR "Cannot add cpu %s; this system configuration" + " supports %d logical cpus.\n", np->full_name, + cpus_weight(cpu_possible_map)); + goto out_unlock; + } + + while (!cpus_empty(tmp)) + if (cpus_subset(tmp, candidate_map)) + /* Found a range where we can insert the new cpu(s) */ + break; + else + cpus_shift_left(tmp, tmp, nthreads); + + if (cpus_empty(tmp)) { + printk(KERN_ERR "Unable to find space in cpu_present_map for" + " processor %s with %d thread(s)\n", np->name, + nthreads); + goto out_unlock; + } + + for_each_cpu_mask(cpu, tmp) { + BUG_ON(cpu_isset(cpu, cpu_present_map)); + cpu_set(cpu, cpu_present_map); + set_hard_smp_processor_id(cpu, *intserv++); + } + err = 0; +out_unlock: + unlock_cpu_hotplug(); + return err; +} + +/* + * Update the present map for a cpu node which is going away, and set + * the hard id in the paca(s) to -1 to be consistent with boot time + * convention for non-present cpus. + */ +static void pSeries_remove_processor(struct device_node *np) +{ + unsigned int cpu; + int len, nthreads, i; + u32 *intserv; + + intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len); + if (!intserv) + return; + + nthreads = len / sizeof(u32); + + lock_cpu_hotplug(); + for (i = 0; i < nthreads; i++) { + for_each_present_cpu(cpu) { + if (get_hard_smp_processor_id(cpu) != intserv[i]) + continue; + BUG_ON(cpu_online(cpu)); + cpu_clear(cpu, cpu_present_map); + set_hard_smp_processor_id(cpu, -1); + break; + } + if (cpu == NR_CPUS) + printk(KERN_WARNING "Could not find cpu to remove " + "with physical id 0x%x\n", intserv[i]); + } + unlock_cpu_hotplug(); +} + +static int pSeries_smp_notifier(struct notifier_block *nb, unsigned long action, void *node) +{ + int err = NOTIFY_OK; + + switch (action) { + case PSERIES_RECONFIG_ADD: + if (pSeries_add_processor(node)) + err = NOTIFY_BAD; + break; + case PSERIES_RECONFIG_REMOVE: + pSeries_remove_processor(node); + break; + default: + err = NOTIFY_DONE; + break; + } + return err; +} + +static struct notifier_block pSeries_smp_nb = { + .notifier_call = pSeries_smp_notifier, +}; + +#endif /* CONFIG_HOTPLUG_CPU */ + +/** + * smp_startup_cpu() - start the given cpu + * + * At boot time, there is nothing to do for primary threads which were + * started from Open Firmware. For anything else, call RTAS with the + * appropriate start location. + * + * 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; + int start_cpu; + + if (cpu_isset(lcpu, of_spin_map)) + /* Already started by OF and sitting in spin loop */ + return 1; + + pcpu = get_hard_smp_processor_id(lcpu); + + /* Fixup atomic count: it exited inside IRQ handler. */ + paca[lcpu].__current->thread_info->preempt_count = 0; + + /* + * If the RTAS start-cpu token does not exist then presume the + * cpu is already spinning. + */ + start_cpu = rtas_token("start-cpu"); + if (start_cpu == RTAS_UNKNOWN_SERVICE) + return 1; + + status = rtas_call(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; +} + +#ifdef CONFIG_XICS +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 (firmware_has_feature(FW_FEATURE_SPLPAR)) + vpa_init(cpu); + + cpu_clear(cpu, of_spin_map); + +} +#endif /* CONFIG_XICS */ + +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 int smp_pSeries_cpu_bootable(unsigned int nr) +{ + /* Special case - we inhibit secondary thread startup + * during boot if the user requests it. Odd-numbered + * cpus are assumed to be secondary threads. + */ + if (system_state < SYSTEM_RUNNING && + cpu_has_feature(CPU_FTR_SMT) && + !smt_enabled_at_boot && nr % 2 != 0) + return 0; + + return 1; +} +#ifdef CONFIG_MPIC +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, +}; +#endif +#ifdef CONFIG_XICS +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, + .cpu_bootable = smp_pSeries_cpu_bootable, +}; +#endif + +/* This is called very early */ +void __init smp_init_pSeries(void) +{ + int i; + + DBG(" -> smp_init_pSeries()\n"); + + switch (ppc64_interrupt_controller) { +#ifdef CONFIG_MPIC + case IC_OPEN_PIC: + smp_ops = &pSeries_mpic_smp_ops; + break; +#endif +#ifdef CONFIG_XICS + case IC_PPC_XIC: + smp_ops = &pSeries_xics_smp_ops; + break; +#endif + default: + panic("Invalid interrupt controller"); + } + +#ifdef CONFIG_HOTPLUG_CPU + smp_ops->cpu_disable = pSeries_cpu_disable; + smp_ops->cpu_die = pSeries_cpu_die; + + /* Processors can be added/removed only on LPAR */ + if (systemcfg->platform == PLATFORM_PSERIES_LPAR) + pSeries_reconfig_notifier_register(&pSeries_smp_nb); +#endif + + /* Mark threads which are still spinning in hold loops. */ + if (cpu_has_feature(CPU_FTR_SMT)) { + for_each_present_cpu(i) { + if (i % 2 == 0) + /* + * Even-numbered logical cpus correspond to + * primary threads. + */ + cpu_set(i, of_spin_map); + } + } else { + of_spin_map = cpu_present_map; + } + + cpu_clear(boot_cpuid, of_spin_map); + + /* 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"); +} + |