/* * arch/s390/kernel/smp.c * * Copyright (C) IBM Corp. 1999,2006 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), * Martin Schwidefsky (schwidefsky@de.ibm.com) * Heiko Carstens (heiko.carstens@de.ibm.com) * * based on other smp stuff by * (c) 1995 Alan Cox, CymruNET Ltd * (c) 1998 Ingo Molnar * * We work with logical cpu numbering everywhere we can. The only * functions using the real cpu address (got from STAP) are the sigp * functions. For all other functions we use the identity mapping. * That means that cpu_number_map[i] == i for every cpu. cpu_number_map is * used e.g. to find the idle task belonging to a logical cpu. Every array * in the kernel is sorted by the logical cpu number and not by the physical * one which is causing all the confusion with __cpu_logical_map and * cpu_number_map in other architectures. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern volatile int __cpu_logical_map[]; /* * An array with a pointer the lowcore of every CPU. */ struct _lowcore *lowcore_ptr[NR_CPUS]; cpumask_t cpu_online_map = CPU_MASK_NONE; cpumask_t cpu_possible_map = CPU_MASK_NONE; static struct task_struct *current_set[NR_CPUS]; static void smp_ext_bitcall(int, ec_bit_sig); /* * Structure and data for __smp_call_function_map(). This is designed to * minimise static memory requirements. It also looks cleaner. */ static DEFINE_SPINLOCK(call_lock); struct call_data_struct { void (*func) (void *info); void *info; cpumask_t started; cpumask_t finished; int wait; }; static struct call_data_struct * call_data; /* * 'Call function' interrupt callback */ static void do_call_function(void) { void (*func) (void *info) = call_data->func; void *info = call_data->info; int wait = call_data->wait; cpu_set(smp_processor_id(), call_data->started); (*func)(info); if (wait) cpu_set(smp_processor_id(), call_data->finished);; } static void __smp_call_function_map(void (*func) (void *info), void *info, int nonatomic, int wait, cpumask_t map) { struct call_data_struct data; int cpu, local = 0; /* * Can deadlock when interrupts are disabled or if in wrong context, * caller must disable preemption */ WARN_ON(irqs_disabled() || in_irq() || preemptible()); /* * Check for local function call. We have to have the same call order * as in on_each_cpu() because of machine_restart_smp(). */ if (cpu_isset(smp_processor_id(), map)) { local = 1; cpu_clear(smp_processor_id(), map); } cpus_and(map, map, cpu_online_map); if (cpus_empty(map)) goto out; data.func = func; data.info = info; data.started = CPU_MASK_NONE; data.wait = wait; if (wait) data.finished = CPU_MASK_NONE; spin_lock_bh(&call_lock); call_data = &data; for_each_cpu_mask(cpu, map) smp_ext_bitcall(cpu, ec_call_function); /* Wait for response */ while (!cpus_equal(map, data.started)) cpu_relax(); if (wait) while (!cpus_equal(map, data.finished)) cpu_relax(); spin_unlock_bh(&call_lock); out: local_irq_disable(); if (local) func(info); local_irq_enable(); } /* * smp_call_function: * @func: the function to run; this must be fast and non-blocking * @info: an arbitrary pointer to pass to the function * @nonatomic: unused * @wait: if true, wait (atomically) until function has completed on other CPUs * * Run a function on all other CPUs. * * You must not call this function with disabled interrupts or from a * hardware interrupt handler. Must be called with preemption disabled. * You may call it from a bottom half. */ int smp_call_function(void (*func) (void *info), void *info, int nonatomic, int wait) { cpumask_t map; map = cpu_online_map; cpu_clear(smp_processor_id(), map); __smp_call_function_map(func, info, nonatomic, wait, map); return 0; } EXPORT_SYMBOL(smp_call_function); /* * smp_call_function_on: * @func: the function to run; this must be fast and non-blocking * @info: an arbitrary pointer to pass to the function * @nonatomic: unused * @wait: if true, wait (atomically) until function has completed on other CPUs * @cpu: the CPU where func should run * * Run a function on one processor. * * You must not call this function with disabled interrupts or from a * hardware interrupt handler. Must be called with preemption disabled. * You may call it from a bottom half. */ int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic, int wait, int cpu) { cpumask_t map = CPU_MASK_NONE; cpu_set(cpu, map); __smp_call_function_map(func, info, nonatomic, wait, map); return 0; } EXPORT_SYMBOL(smp_call_function_on); static void do_send_stop(void) { int cpu, rc; /* stop all processors */ for_each_online_cpu(cpu) { if (cpu == smp_processor_id()) continue; do { rc = signal_processor(cpu, sigp_stop); } while (rc == sigp_busy); } } static void do_store_status(void) { int cpu, rc; /* store status of all processors in their lowcores (real 0) */ for_each_online_cpu(cpu) { if (cpu == smp_processor_id()) continue; do { rc = signal_processor_p( (__u32)(unsigned long) lowcore_ptr[cpu], cpu, sigp_store_status_at_address); } while(rc == sigp_busy); } } static void do_wait_for_stop(void) { int cpu; /* Wait for all other cpus to enter stopped state */ for_each_online_cpu(cpu) { if (cpu == smp_processor_id()) continue; while(!smp_cpu_not_running(cpu)) cpu_relax(); } } /* * this function sends a 'stop' sigp to all other CPUs in the system. * it goes straight through. */ void smp_send_stop(void) { /* Disable all interrupts/machine checks */ __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK); /* write magic number to zero page (absolute 0) */ lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC; /* stop other processors. */ do_send_stop(); /* wait until other processors are stopped */ do_wait_for_stop(); /* store status of other processors. */ do_store_status(); } /* * Reboot, halt and power_off routines for SMP. */ void machine_restart_smp(char * __unused) { smp_send_stop(); do_reipl(); } void machine_halt_smp(void) { smp_send_stop(); if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0) __cpcmd(vmhalt_cmd, NULL, 0, NULL); signal_processor(smp_processor_id(), sigp_stop_and_store_status); for (;;); } void machine_power_off_smp(void) { smp_send_stop(); if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0) __cpcmd(vmpoff_cmd, NULL, 0, NULL); signal_processor(smp_processor_id(), sigp_stop_and_store_status); for (;;); } /* * This is the main routine where commands issued by other * cpus are handled. */ static void do_ext_call_interrupt(__u16 code) { unsigned long bits; /* * handle bit signal external calls * * For the ec_schedule signal we have to do nothing. All the work * is done automatically when we return from the interrupt. */ bits = xchg(&S390_lowcore.ext_call_fast, 0); if (test_bit(ec_call_function, &bits)) do_call_function(); } /* * Send an external call sigp to another cpu and return without waiting * for its completion. */ static void smp_ext_bitcall(int cpu, ec_bit_sig sig) { /* * Set signaling bit in lowcore of target cpu and kick it */ set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast); while(signal_processor(cpu, sigp_emergency_signal) == sigp_busy) udelay(10); } #ifndef CONFIG_64BIT /* * this function sends a 'purge tlb' signal to another CPU. */ void smp_ptlb_callback(void *info) { local_flush_tlb(); } void smp_ptlb_all(void) { on_each_cpu(smp_ptlb_callback, NULL, 0, 1); } EXPORT_SYMBOL(smp_ptlb_all); #endif /* ! CONFIG_64BIT */ /* * this function sends a 'reschedule' IPI to another CPU. * it goes straight through and wastes no time serializing * anything. Worst case is that we lose a reschedule ... */ void smp_send_reschedule(int cpu) { smp_ext_bitcall(cpu, ec_schedule); } /* * parameter area for the set/clear control bit callbacks */ struct ec_creg_mask_parms { unsigned long orvals[16]; unsigned long andvals[16]; }; /* * callback for setting/clearing control bits */ static void smp_ctl_bit_callback(void *info) { struct ec_creg_mask_parms *pp = info; unsigned long cregs[16]; int i; __ctl_store(cregs, 0, 15); for (i = 0; i <= 15; i++) cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i]; __ctl_load(cregs, 0, 15); } /* * Set a bit in a control register of all cpus */ void smp_ctl_set_bit(int cr, int bit) { struct ec_creg_mask_parms parms; memset(&parms.orvals, 0, sizeof(parms.orvals)); memset(&parms.andvals, 0xff, sizeof(parms.andvals)); parms.orvals[cr] = 1 << bit; on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1); } /* * Clear a bit in a control register of all cpus */ void smp_ctl_clear_bit(int cr, int bit) { struct ec_creg_mask_parms parms; memset(&parms.orvals, 0, sizeof(parms.orvals)); memset(&parms.andvals, 0xff, sizeof(parms.andvals)); parms.andvals[cr] = ~(1L << bit); on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1); } /* * Lets check how many CPUs we have. */ static unsigned int __init smp_count_cpus(void) { unsigned int cpu, num_cpus; __u16 boot_cpu_addr; /* * cpu 0 is the boot cpu. See smp_prepare_boot_cpu. */ boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr; current_thread_info()->cpu = 0; num_cpus = 1; for (cpu = 0; cpu <= 65535; cpu++) { if ((__u16) cpu == boot_cpu_addr) continue; __cpu_logical_map[1] = (__u16) cpu; if (signal_processor(1, sigp_sense) == sigp_not_operational) continue; num_cpus++; } printk("Detected %d CPU's\n",(int) num_cpus); printk("Boot cpu address %2X\n", boot_cpu_addr); return num_cpus; } /* * Activate a secondary processor. */ int __devinit start_secondary(void *cpuvoid) { /* Setup the cpu */ cpu_init(); preempt_disable(); /* Enable TOD clock interrupts on the secondary cpu. */ init_cpu_timer(); #ifdef CONFIG_VIRT_TIMER /* Enable cpu timer interrupts on the secondary cpu. */ init_cpu_vtimer(); #endif /* Enable pfault pseudo page faults on this cpu. */ pfault_init(); /* Mark this cpu as online */ cpu_set(smp_processor_id(), cpu_online_map); /* Switch on interrupts */ local_irq_enable(); /* Print info about this processor */ print_cpu_info(&S390_lowcore.cpu_data); /* cpu_idle will call schedule for us */ cpu_idle(); return 0; } static void __init smp_create_idle(unsigned int cpu) { struct task_struct *p; /* * don't care about the psw and regs settings since we'll never * reschedule the forked task. */ p = fork_idle(cpu); if (IS_ERR(p)) panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p)); current_set[cpu] = p; } /* Reserving and releasing of CPUs */ static DEFINE_SPINLOCK(smp_reserve_lock); static int smp_cpu_reserved[NR_CPUS]; int smp_get_cpu(cpumask_t cpu_mask) { unsigned long flags; int cpu; spin_lock_irqsave(&smp_reserve_lock, flags); /* Try to find an already reserved cpu. */ for_each_cpu_mask(cpu, cpu_mask) { if (smp_cpu_reserved[cpu] != 0) { smp_cpu_reserved[cpu]++; /* Found one. */ goto out; } } /* Reserve a new cpu from cpu_mask. */ for_each_cpu_mask(cpu, cpu_mask) { if (cpu_online(cpu)) { smp_cpu_reserved[cpu]++; goto out; } } cpu = -ENODEV; out: spin_unlock_irqrestore(&smp_reserve_lock, flags); return cpu; } void smp_put_cpu(int cpu) { unsigned long flags; spin_lock_irqsave(&smp_reserve_lock, flags); smp_cpu_reserved[cpu]--; spin_unlock_irqrestore(&smp_reserve_lock, flags); } static int cpu_stopped(int cpu) { __u32 status; /* Check for stopped state */ if (signal_processor_ps(&status, 0, cpu, sigp_sense) == sigp_status_stored) { if (status & 0x40) return 1; } return 0; } /* Upping and downing of CPUs */ int __cpu_up(unsigned int cpu) { struct task_struct *idle; struct _lowcore *cpu_lowcore; struct stack_frame *sf; sigp_ccode ccode; int curr_cpu; for (curr_cpu = 0; curr_cpu <= 65535; curr_cpu++) { __cpu_logical_map[cpu] = (__u16) curr_cpu; if (cpu_stopped(cpu)) break; } if (!cpu_stopped(cpu)) return -ENODEV; ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]), cpu, sigp_set_prefix); if (ccode){ printk("sigp_set_prefix failed for cpu %d " "with condition code %d\n", (int) cpu, (int) ccode); return -EIO; } idle = current_set[cpu]; cpu_lowcore = lowcore_ptr[cpu]; cpu_lowcore->kernel_stack = (unsigned long) task_stack_page(idle) + (THREAD_SIZE); sf = (struct stack_frame *) (cpu_lowcore->kernel_stack - sizeof(struct pt_regs) - sizeof(struct stack_frame)); memset(sf, 0, sizeof(struct stack_frame)); sf->gprs[9] = (unsigned long) sf; cpu_lowcore->save_area[15] = (unsigned long) sf; __ctl_store(cpu_lowcore->cregs_save_area[0], 0, 15); asm volatile( " stam 0,15,0(%0)" : : "a" (&cpu_lowcore->access_regs_save_area) : "memory"); cpu_lowcore->percpu_offset = __per_cpu_offset[cpu]; cpu_lowcore->current_task = (unsigned long) idle; cpu_lowcore->cpu_data.cpu_nr = cpu; eieio(); while (signal_processor(cpu,sigp_restart) == sigp_busy) udelay(10); while (!cpu_online(cpu)) cpu_relax(); return 0; } static unsigned int __initdata additional_cpus; static unsigned int __initdata possible_cpus; void __init smp_setup_cpu_possible_map(void) { unsigned int phy_cpus, pos_cpus, cpu; phy_cpus = smp_count_cpus(); pos_cpus = min(phy_cpus + additional_cpus, (unsigned int) NR_CPUS); if (possible_cpus) pos_cpus = min(possible_cpus, (unsigned int) NR_CPUS); for (cpu = 0; cpu < pos_cpus; cpu++) cpu_set(cpu, cpu_possible_map); phy_cpus = min(phy_cpus, pos_cpus); for (cpu = 0; cpu < phy_cpus; cpu++) cpu_set(cpu, cpu_present_map); } #ifdef CONFIG_HOTPLUG_CPU static int __init setup_additional_cpus(char *s) { additional_cpus = simple_strtoul(s, NULL, 0); return 0; } early_param("additional_cpus", setup_additional_cpus); static int __init setup_possible_cpus(char *s) { possible_cpus = simple_strtoul(s, NULL, 0); return 0; } early_param("possible_cpus", setup_possible_cpus); int __cpu_disable(void) { unsigned long flags; struct ec_creg_mask_parms cr_parms; int cpu = smp_processor_id(); spin_lock_irqsave(&smp_reserve_lock, flags); if (smp_cpu_reserved[cpu] != 0) { spin_unlock_irqrestore(&smp_reserve_lock, flags); return -EBUSY; } cpu_clear(cpu, cpu_online_map); /* Disable pfault pseudo page faults on this cpu. */ pfault_fini(); memset(&cr_parms.orvals, 0, sizeof(cr_parms.orvals)); memset(&cr_parms.andvals, 0xff, sizeof(cr_parms.andvals)); /* disable all external interrupts */ cr_parms.orvals[0] = 0; cr_parms.andvals[0] = ~(1<<15 | 1<<14 | 1<<13 | 1<<12 | 1<<11 | 1<<10 | 1<< 6 | 1<< 4); /* disable all I/O interrupts */ cr_parms.orvals[6] = 0; cr_parms.andvals[6] = ~(1<<31 | 1<<30 | 1<<29 | 1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24); /* disable most machine checks */ cr_parms.orvals[14] = 0; cr_parms.andvals[14] = ~(1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24); smp_ctl_bit_callback(&cr_parms); spin_unlock_irqrestore(&smp_reserve_lock, flags); return 0; } void __cpu_die(unsigned int cpu) { /* Wait until target cpu is down */ while (!smp_cpu_not_running(cpu)) cpu_relax(); printk("Processor %d spun down\n", cpu); } void cpu_die(void) { idle_task_exit(); signal_processor(smp_processor_id(), sigp_stop); BUG(); for(;;); } #endif /* CONFIG_HOTPLUG_CPU */ /* * Cycle through the processors and setup structures. */ void __init smp_prepare_cpus(unsigned int max_cpus) { unsigned long stack; unsigned int cpu; int i; /* request the 0x1201 emergency signal external interrupt */ if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0) panic("Couldn't request external interrupt 0x1201"); memset(lowcore_ptr,0,sizeof(lowcore_ptr)); /* * Initialize prefix pages and stacks for all possible cpus */ print_cpu_info(&S390_lowcore.cpu_data); for_each_possible_cpu(i) { lowcore_ptr[i] = (struct _lowcore *) __get_free_pages(GFP_KERNEL|GFP_DMA, sizeof(void*) == 8 ? 1 : 0); stack = __get_free_pages(GFP_KERNEL,ASYNC_ORDER); if (lowcore_ptr[i] == NULL || stack == 0ULL) panic("smp_boot_cpus failed to allocate memory\n"); *(lowcore_ptr[i]) = S390_lowcore; lowcore_ptr[i]->async_stack = stack + (ASYNC_SIZE); stack = __get_free_pages(GFP_KERNEL,0); if (stack == 0ULL) panic("smp_boot_cpus failed to allocate memory\n"); lowcore_ptr[i]->panic_stack = stack + (PAGE_SIZE); #ifndef CONFIG_64BIT if (MACHINE_HAS_IEEE) { lowcore_ptr[i]->extended_save_area_addr = (__u32) __get_free_pages(GFP_KERNEL,0); if (lowcore_ptr[i]->extended_save_area_addr == 0) panic("smp_boot_cpus failed to " "allocate memory\n"); } #endif } #ifndef CONFIG_64BIT if (MACHINE_HAS_IEEE) ctl_set_bit(14, 29); /* enable extended save area */ #endif set_prefix((u32)(unsigned long) lowcore_ptr[smp_processor_id()]); for_each_possible_cpu(cpu) if (cpu != smp_processor_id()) smp_create_idle(cpu); } void __devinit smp_prepare_boot_cpu(void) { BUG_ON(smp_processor_id() != 0); cpu_set(0, cpu_online_map); S390_lowcore.percpu_offset = __per_cpu_offset[0]; current_set[0] = current; } void smp_cpus_done(unsigned int max_cpus) { cpu_present_map = cpu_possible_map; } /* * the frequency of the profiling timer can be changed * by writing a multiplier value into /proc/profile. * * usually you want to run this on all CPUs ;) */ int setup_profiling_timer(unsigned int multiplier) { return 0; } static DEFINE_PER_CPU(struct cpu, cpu_devices); static int __init topology_init(void) { int cpu; int ret; for_each_possible_cpu(cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); c->hotpluggable = 1; ret = register_cpu(c, cpu); if (ret) printk(KERN_WARNING "topology_init: register_cpu %d " "failed (%d)\n", cpu, ret); } return 0; } subsys_initcall(topology_init); EXPORT_SYMBOL(cpu_online_map); EXPORT_SYMBOL(cpu_possible_map); EXPORT_SYMBOL(lowcore_ptr); EXPORT_SYMBOL(smp_ctl_set_bit); EXPORT_SYMBOL(smp_ctl_clear_bit); EXPORT_SYMBOL(smp_get_cpu); EXPORT_SYMBOL(smp_put_cpu);