| /* |
| * linux/arch/arm/kernel/smp.c |
| * |
| * Copyright (C) 2002 ARM Limited, All Rights Reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| #include <linux/module.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/spinlock.h> |
| #include <linux/sched.h> |
| #include <linux/interrupt.h> |
| #include <linux/cache.h> |
| #include <linux/profile.h> |
| #include <linux/errno.h> |
| #include <linux/mm.h> |
| #include <linux/err.h> |
| #include <linux/cpu.h> |
| #include <linux/smp.h> |
| #include <linux/seq_file.h> |
| #include <linux/irq.h> |
| #include <linux/percpu.h> |
| #include <linux/clockchips.h> |
| |
| #include <asm/atomic.h> |
| #include <asm/cacheflush.h> |
| #include <asm/cpu.h> |
| #include <asm/cputype.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgtable.h> |
| #include <asm/pgalloc.h> |
| #include <asm/processor.h> |
| #include <asm/sections.h> |
| #include <asm/tlbflush.h> |
| #include <asm/ptrace.h> |
| #include <asm/localtimer.h> |
| #include <asm/smp_plat.h> |
| |
| /* |
| * as from 2.5, kernels no longer have an init_tasks structure |
| * so we need some other way of telling a new secondary core |
| * where to place its SVC stack |
| */ |
| struct secondary_data secondary_data; |
| |
| /* |
| * structures for inter-processor calls |
| * - A collection of single bit ipi messages. |
| */ |
| struct ipi_data { |
| spinlock_t lock; |
| unsigned long ipi_count; |
| unsigned long bits; |
| }; |
| |
| static DEFINE_PER_CPU(struct ipi_data, ipi_data) = { |
| .lock = SPIN_LOCK_UNLOCKED, |
| }; |
| |
| enum ipi_msg_type { |
| IPI_TIMER, |
| IPI_RESCHEDULE, |
| IPI_CALL_FUNC, |
| IPI_CALL_FUNC_SINGLE, |
| IPI_CPU_STOP, |
| }; |
| |
| static inline void identity_mapping_add(pgd_t *pgd, unsigned long start, |
| unsigned long end) |
| { |
| unsigned long addr, prot; |
| pmd_t *pmd; |
| |
| prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE; |
| if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) |
| prot |= PMD_BIT4; |
| |
| for (addr = start & PGDIR_MASK; addr < end;) { |
| pmd = pmd_offset(pgd + pgd_index(addr), addr); |
| pmd[0] = __pmd(addr | prot); |
| addr += SECTION_SIZE; |
| pmd[1] = __pmd(addr | prot); |
| addr += SECTION_SIZE; |
| flush_pmd_entry(pmd); |
| outer_clean_range(__pa(pmd), __pa(pmd + 1)); |
| } |
| } |
| |
| static inline void identity_mapping_del(pgd_t *pgd, unsigned long start, |
| unsigned long end) |
| { |
| unsigned long addr; |
| pmd_t *pmd; |
| |
| for (addr = start & PGDIR_MASK; addr < end; addr += PGDIR_SIZE) { |
| pmd = pmd_offset(pgd + pgd_index(addr), addr); |
| pmd[0] = __pmd(0); |
| pmd[1] = __pmd(0); |
| clean_pmd_entry(pmd); |
| outer_clean_range(__pa(pmd), __pa(pmd + 1)); |
| } |
| } |
| |
| int __cpuinit __cpu_up(unsigned int cpu) |
| { |
| struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); |
| struct task_struct *idle = ci->idle; |
| pgd_t *pgd; |
| int ret; |
| |
| /* |
| * Spawn a new process manually, if not already done. |
| * Grab a pointer to its task struct so we can mess with it |
| */ |
| if (!idle) { |
| idle = fork_idle(cpu); |
| if (IS_ERR(idle)) { |
| printk(KERN_ERR "CPU%u: fork() failed\n", cpu); |
| return PTR_ERR(idle); |
| } |
| ci->idle = idle; |
| } else { |
| /* |
| * Since this idle thread is being re-used, call |
| * init_idle() to reinitialize the thread structure. |
| */ |
| init_idle(idle, cpu); |
| } |
| |
| /* |
| * Allocate initial page tables to allow the new CPU to |
| * enable the MMU safely. This essentially means a set |
| * of our "standard" page tables, with the addition of |
| * a 1:1 mapping for the physical address of the kernel. |
| */ |
| pgd = pgd_alloc(&init_mm); |
| if (!pgd) |
| return -ENOMEM; |
| |
| if (PHYS_OFFSET != PAGE_OFFSET) { |
| #ifndef CONFIG_HOTPLUG_CPU |
| identity_mapping_add(pgd, __pa(__init_begin), __pa(__init_end)); |
| #endif |
| identity_mapping_add(pgd, __pa(_stext), __pa(_etext)); |
| identity_mapping_add(pgd, __pa(_sdata), __pa(_edata)); |
| } |
| |
| /* |
| * We need to tell the secondary core where to find |
| * its stack and the page tables. |
| */ |
| secondary_data.stack = task_stack_page(idle) + THREAD_START_SP; |
| secondary_data.pgdir = virt_to_phys(pgd); |
| __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data)); |
| outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1)); |
| |
| /* |
| * Now bring the CPU into our world. |
| */ |
| ret = boot_secondary(cpu, idle); |
| if (ret == 0) { |
| unsigned long timeout; |
| |
| /* |
| * CPU was successfully started, wait for it |
| * to come online or time out. |
| */ |
| timeout = jiffies + HZ; |
| while (time_before(jiffies, timeout)) { |
| if (cpu_online(cpu)) |
| break; |
| |
| udelay(10); |
| barrier(); |
| } |
| |
| if (!cpu_online(cpu)) |
| ret = -EIO; |
| } |
| |
| secondary_data.stack = NULL; |
| secondary_data.pgdir = 0; |
| |
| if (PHYS_OFFSET != PAGE_OFFSET) { |
| #ifndef CONFIG_HOTPLUG_CPU |
| identity_mapping_del(pgd, __pa(__init_begin), __pa(__init_end)); |
| #endif |
| identity_mapping_del(pgd, __pa(_stext), __pa(_etext)); |
| identity_mapping_del(pgd, __pa(_sdata), __pa(_edata)); |
| } |
| |
| pgd_free(&init_mm, pgd); |
| |
| if (ret) { |
| printk(KERN_CRIT "CPU%u: processor failed to boot\n", cpu); |
| |
| /* |
| * FIXME: We need to clean up the new idle thread. --rmk |
| */ |
| } |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| /* |
| * __cpu_disable runs on the processor to be shutdown. |
| */ |
| int __cpu_disable(void) |
| { |
| unsigned int cpu = smp_processor_id(); |
| struct task_struct *p; |
| int ret; |
| |
| ret = platform_cpu_disable(cpu); |
| if (ret) |
| return ret; |
| |
| /* |
| * Take this CPU offline. Once we clear this, we can't return, |
| * and we must not schedule until we're ready to give up the cpu. |
| */ |
| set_cpu_online(cpu, false); |
| |
| /* |
| * OK - migrate IRQs away from this CPU |
| */ |
| migrate_irqs(); |
| |
| /* |
| * Stop the local timer for this CPU. |
| */ |
| local_timer_stop(); |
| |
| /* |
| * Flush user cache and TLB mappings, and then remove this CPU |
| * from the vm mask set of all processes. |
| */ |
| flush_cache_all(); |
| local_flush_tlb_all(); |
| |
| read_lock(&tasklist_lock); |
| for_each_process(p) { |
| if (p->mm) |
| cpumask_clear_cpu(cpu, mm_cpumask(p->mm)); |
| } |
| read_unlock(&tasklist_lock); |
| |
| return 0; |
| } |
| |
| /* |
| * called on the thread which is asking for a CPU to be shutdown - |
| * waits until shutdown has completed, or it is timed out. |
| */ |
| void __cpu_die(unsigned int cpu) |
| { |
| if (!platform_cpu_kill(cpu)) |
| printk("CPU%u: unable to kill\n", cpu); |
| } |
| |
| /* |
| * Called from the idle thread for the CPU which has been shutdown. |
| * |
| * Note that we disable IRQs here, but do not re-enable them |
| * before returning to the caller. This is also the behaviour |
| * of the other hotplug-cpu capable cores, so presumably coming |
| * out of idle fixes this. |
| */ |
| void __ref cpu_die(void) |
| { |
| unsigned int cpu = smp_processor_id(); |
| |
| local_irq_disable(); |
| idle_task_exit(); |
| |
| /* |
| * actual CPU shutdown procedure is at least platform (if not |
| * CPU) specific |
| */ |
| platform_cpu_die(cpu); |
| |
| /* |
| * Do not return to the idle loop - jump back to the secondary |
| * cpu initialisation. There's some initialisation which needs |
| * to be repeated to undo the effects of taking the CPU offline. |
| */ |
| __asm__("mov sp, %0\n" |
| " b secondary_start_kernel" |
| : |
| : "r" (task_stack_page(current) + THREAD_SIZE - 8)); |
| } |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| /* |
| * This is the secondary CPU boot entry. We're using this CPUs |
| * idle thread stack, but a set of temporary page tables. |
| */ |
| asmlinkage void __cpuinit secondary_start_kernel(void) |
| { |
| struct mm_struct *mm = &init_mm; |
| unsigned int cpu = smp_processor_id(); |
| |
| printk("CPU%u: Booted secondary processor\n", cpu); |
| |
| /* |
| * All kernel threads share the same mm context; grab a |
| * reference and switch to it. |
| */ |
| atomic_inc(&mm->mm_count); |
| current->active_mm = mm; |
| cpumask_set_cpu(cpu, mm_cpumask(mm)); |
| cpu_switch_mm(mm->pgd, mm); |
| enter_lazy_tlb(mm, current); |
| local_flush_tlb_all(); |
| |
| cpu_init(); |
| preempt_disable(); |
| |
| /* |
| * Give the platform a chance to do its own initialisation. |
| */ |
| platform_secondary_init(cpu); |
| |
| /* |
| * Enable local interrupts. |
| */ |
| notify_cpu_starting(cpu); |
| local_irq_enable(); |
| local_fiq_enable(); |
| |
| /* |
| * Setup the percpu timer for this CPU. |
| */ |
| percpu_timer_setup(); |
| |
| calibrate_delay(); |
| |
| smp_store_cpu_info(cpu); |
| |
| /* |
| * OK, now it's safe to let the boot CPU continue |
| */ |
| set_cpu_online(cpu, true); |
| |
| /* |
| * OK, it's off to the idle thread for us |
| */ |
| cpu_idle(); |
| } |
| |
| /* |
| * Called by both boot and secondaries to move global data into |
| * per-processor storage. |
| */ |
| void __cpuinit smp_store_cpu_info(unsigned int cpuid) |
| { |
| struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid); |
| |
| cpu_info->loops_per_jiffy = loops_per_jiffy; |
| } |
| |
| void __init smp_cpus_done(unsigned int max_cpus) |
| { |
| int cpu; |
| unsigned long bogosum = 0; |
| |
| for_each_online_cpu(cpu) |
| bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; |
| |
| printk(KERN_INFO "SMP: Total of %d processors activated " |
| "(%lu.%02lu BogoMIPS).\n", |
| num_online_cpus(), |
| bogosum / (500000/HZ), |
| (bogosum / (5000/HZ)) % 100); |
| } |
| |
| void __init smp_prepare_boot_cpu(void) |
| { |
| unsigned int cpu = smp_processor_id(); |
| |
| per_cpu(cpu_data, cpu).idle = current; |
| } |
| |
| static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg) |
| { |
| unsigned long flags; |
| unsigned int cpu; |
| |
| local_irq_save(flags); |
| |
| for_each_cpu(cpu, mask) { |
| struct ipi_data *ipi = &per_cpu(ipi_data, cpu); |
| |
| spin_lock(&ipi->lock); |
| ipi->bits |= 1 << msg; |
| spin_unlock(&ipi->lock); |
| } |
| |
| /* |
| * Call the platform specific cross-CPU call function. |
| */ |
| smp_cross_call(mask); |
| |
| local_irq_restore(flags); |
| } |
| |
| void arch_send_call_function_ipi_mask(const struct cpumask *mask) |
| { |
| send_ipi_message(mask, IPI_CALL_FUNC); |
| } |
| |
| void arch_send_call_function_single_ipi(int cpu) |
| { |
| send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); |
| } |
| |
| void show_ipi_list(struct seq_file *p) |
| { |
| unsigned int cpu; |
| |
| seq_puts(p, "IPI:"); |
| |
| for_each_present_cpu(cpu) |
| seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count); |
| |
| seq_putc(p, '\n'); |
| } |
| |
| void show_local_irqs(struct seq_file *p) |
| { |
| unsigned int cpu; |
| |
| seq_printf(p, "LOC: "); |
| |
| for_each_present_cpu(cpu) |
| seq_printf(p, "%10u ", irq_stat[cpu].local_timer_irqs); |
| |
| seq_putc(p, '\n'); |
| } |
| |
| /* |
| * Timer (local or broadcast) support |
| */ |
| static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent); |
| |
| static void ipi_timer(void) |
| { |
| struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent); |
| irq_enter(); |
| evt->event_handler(evt); |
| irq_exit(); |
| } |
| |
| #ifdef CONFIG_LOCAL_TIMERS |
| asmlinkage void __exception do_local_timer(struct pt_regs *regs) |
| { |
| struct pt_regs *old_regs = set_irq_regs(regs); |
| int cpu = smp_processor_id(); |
| |
| if (local_timer_ack()) { |
| irq_stat[cpu].local_timer_irqs++; |
| ipi_timer(); |
| } |
| |
| set_irq_regs(old_regs); |
| } |
| #endif |
| |
| #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
| static void smp_timer_broadcast(const struct cpumask *mask) |
| { |
| send_ipi_message(mask, IPI_TIMER); |
| } |
| #else |
| #define smp_timer_broadcast NULL |
| #endif |
| |
| #ifndef CONFIG_LOCAL_TIMERS |
| static void broadcast_timer_set_mode(enum clock_event_mode mode, |
| struct clock_event_device *evt) |
| { |
| } |
| |
| static void local_timer_setup(struct clock_event_device *evt) |
| { |
| evt->name = "dummy_timer"; |
| evt->features = CLOCK_EVT_FEAT_ONESHOT | |
| CLOCK_EVT_FEAT_PERIODIC | |
| CLOCK_EVT_FEAT_DUMMY; |
| evt->rating = 400; |
| evt->mult = 1; |
| evt->set_mode = broadcast_timer_set_mode; |
| |
| clockevents_register_device(evt); |
| } |
| #endif |
| |
| void __cpuinit percpu_timer_setup(void) |
| { |
| unsigned int cpu = smp_processor_id(); |
| struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu); |
| |
| evt->cpumask = cpumask_of(cpu); |
| evt->broadcast = smp_timer_broadcast; |
| |
| local_timer_setup(evt); |
| } |
| |
| static DEFINE_SPINLOCK(stop_lock); |
| |
| /* |
| * ipi_cpu_stop - handle IPI from smp_send_stop() |
| */ |
| static void ipi_cpu_stop(unsigned int cpu) |
| { |
| if (system_state == SYSTEM_BOOTING || |
| system_state == SYSTEM_RUNNING) { |
| spin_lock(&stop_lock); |
| printk(KERN_CRIT "CPU%u: stopping\n", cpu); |
| dump_stack(); |
| spin_unlock(&stop_lock); |
| } |
| |
| set_cpu_online(cpu, false); |
| |
| local_fiq_disable(); |
| local_irq_disable(); |
| |
| while (1) |
| cpu_relax(); |
| } |
| |
| /* |
| * Main handler for inter-processor interrupts |
| * |
| * For ARM, the ipimask now only identifies a single |
| * category of IPI (Bit 1 IPIs have been replaced by a |
| * different mechanism): |
| * |
| * Bit 0 - Inter-processor function call |
| */ |
| asmlinkage void __exception do_IPI(struct pt_regs *regs) |
| { |
| unsigned int cpu = smp_processor_id(); |
| struct ipi_data *ipi = &per_cpu(ipi_data, cpu); |
| struct pt_regs *old_regs = set_irq_regs(regs); |
| |
| ipi->ipi_count++; |
| |
| for (;;) { |
| unsigned long msgs; |
| |
| spin_lock(&ipi->lock); |
| msgs = ipi->bits; |
| ipi->bits = 0; |
| spin_unlock(&ipi->lock); |
| |
| if (!msgs) |
| break; |
| |
| do { |
| unsigned nextmsg; |
| |
| nextmsg = msgs & -msgs; |
| msgs &= ~nextmsg; |
| nextmsg = ffz(~nextmsg); |
| |
| switch (nextmsg) { |
| case IPI_TIMER: |
| ipi_timer(); |
| break; |
| |
| case IPI_RESCHEDULE: |
| /* |
| * nothing more to do - eveything is |
| * done on the interrupt return path |
| */ |
| break; |
| |
| case IPI_CALL_FUNC: |
| generic_smp_call_function_interrupt(); |
| break; |
| |
| case IPI_CALL_FUNC_SINGLE: |
| generic_smp_call_function_single_interrupt(); |
| break; |
| |
| case IPI_CPU_STOP: |
| ipi_cpu_stop(cpu); |
| break; |
| |
| default: |
| printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n", |
| cpu, nextmsg); |
| break; |
| } |
| } while (msgs); |
| } |
| |
| set_irq_regs(old_regs); |
| } |
| |
| void smp_send_reschedule(int cpu) |
| { |
| send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE); |
| } |
| |
| void smp_send_stop(void) |
| { |
| cpumask_t mask = cpu_online_map; |
| cpu_clear(smp_processor_id(), mask); |
| if (!cpus_empty(mask)) |
| send_ipi_message(&mask, IPI_CPU_STOP); |
| } |
| |
| /* |
| * not supported here |
| */ |
| int setup_profiling_timer(unsigned int multiplier) |
| { |
| return -EINVAL; |
| } |
| |
| static void |
| on_each_cpu_mask(void (*func)(void *), void *info, int wait, |
| const struct cpumask *mask) |
| { |
| preempt_disable(); |
| |
| smp_call_function_many(mask, func, info, wait); |
| if (cpumask_test_cpu(smp_processor_id(), mask)) |
| func(info); |
| |
| preempt_enable(); |
| } |
| |
| /**********************************************************************/ |
| |
| /* |
| * TLB operations |
| */ |
| struct tlb_args { |
| struct vm_area_struct *ta_vma; |
| unsigned long ta_start; |
| unsigned long ta_end; |
| }; |
| |
| static inline void ipi_flush_tlb_all(void *ignored) |
| { |
| local_flush_tlb_all(); |
| } |
| |
| static inline void ipi_flush_tlb_mm(void *arg) |
| { |
| struct mm_struct *mm = (struct mm_struct *)arg; |
| |
| local_flush_tlb_mm(mm); |
| } |
| |
| static inline void ipi_flush_tlb_page(void *arg) |
| { |
| struct tlb_args *ta = (struct tlb_args *)arg; |
| |
| local_flush_tlb_page(ta->ta_vma, ta->ta_start); |
| } |
| |
| static inline void ipi_flush_tlb_kernel_page(void *arg) |
| { |
| struct tlb_args *ta = (struct tlb_args *)arg; |
| |
| local_flush_tlb_kernel_page(ta->ta_start); |
| } |
| |
| static inline void ipi_flush_tlb_range(void *arg) |
| { |
| struct tlb_args *ta = (struct tlb_args *)arg; |
| |
| local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end); |
| } |
| |
| static inline void ipi_flush_tlb_kernel_range(void *arg) |
| { |
| struct tlb_args *ta = (struct tlb_args *)arg; |
| |
| local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end); |
| } |
| |
| void flush_tlb_all(void) |
| { |
| if (tlb_ops_need_broadcast()) |
| on_each_cpu(ipi_flush_tlb_all, NULL, 1); |
| else |
| local_flush_tlb_all(); |
| } |
| |
| void flush_tlb_mm(struct mm_struct *mm) |
| { |
| if (tlb_ops_need_broadcast()) |
| on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mm_cpumask(mm)); |
| else |
| local_flush_tlb_mm(mm); |
| } |
| |
| void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) |
| { |
| if (tlb_ops_need_broadcast()) { |
| struct tlb_args ta; |
| ta.ta_vma = vma; |
| ta.ta_start = uaddr; |
| on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mm_cpumask(vma->vm_mm)); |
| } else |
| local_flush_tlb_page(vma, uaddr); |
| } |
| |
| void flush_tlb_kernel_page(unsigned long kaddr) |
| { |
| if (tlb_ops_need_broadcast()) { |
| struct tlb_args ta; |
| ta.ta_start = kaddr; |
| on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1); |
| } else |
| local_flush_tlb_kernel_page(kaddr); |
| } |
| |
| void flush_tlb_range(struct vm_area_struct *vma, |
| unsigned long start, unsigned long end) |
| { |
| if (tlb_ops_need_broadcast()) { |
| struct tlb_args ta; |
| ta.ta_vma = vma; |
| ta.ta_start = start; |
| ta.ta_end = end; |
| on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mm_cpumask(vma->vm_mm)); |
| } else |
| local_flush_tlb_range(vma, start, end); |
| } |
| |
| void flush_tlb_kernel_range(unsigned long start, unsigned long end) |
| { |
| if (tlb_ops_need_broadcast()) { |
| struct tlb_args ta; |
| ta.ta_start = start; |
| ta.ta_end = end; |
| on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1); |
| } else |
| local_flush_tlb_kernel_range(start, end); |
| } |