diff options
Diffstat (limited to 'arch/arm/kernel/smp.c')
| -rw-r--r-- | arch/arm/kernel/smp.c | 109 |
1 files changed, 100 insertions, 9 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 82616494574..edb5a406922 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -80,19 +80,23 @@ static DEFINE_SPINLOCK(smp_call_function_lock); int __cpuinit __cpu_up(unsigned int cpu) { - struct task_struct *idle; + struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); + struct task_struct *idle = ci->idle; pgd_t *pgd; pmd_t *pmd; int ret; /* - * Spawn a new process manually. Grab a pointer to - * its task struct so we can mess with it + * Spawn a new process manually, if not already done. + * Grab a pointer to its task struct so we can mess with it */ - idle = fork_idle(cpu); - if (IS_ERR(idle)) { - printk(KERN_ERR "CPU%u: fork() failed\n", cpu); - return PTR_ERR(idle); + 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; } /* @@ -155,6 +159,91 @@ int __cpuinit __cpu_up(unsigned int cpu) return ret; } +#ifdef CONFIG_HOTPLUG_CPU +/* + * __cpu_disable runs on the processor to be shutdown. + */ +int __cpuexit __cpu_disable(void) +{ + unsigned int cpu = smp_processor_id(); + struct task_struct *p; + int ret; + + ret = mach_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. + */ + cpu_clear(cpu, cpu_online_map); + + /* + * OK - migrate IRQs away from this CPU + */ + migrate_irqs(); + + /* + * 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) + cpu_clear(cpu, p->mm->cpu_vm_mask); + } + 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 __cpuexit __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 __cpuexit 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" ((void *)current->thread_info + 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. @@ -236,6 +325,8 @@ void __init smp_prepare_boot_cpu(void) { unsigned int cpu = smp_processor_id(); + per_cpu(cpu_data, cpu).idle = current; + cpu_set(cpu, cpu_possible_map); cpu_set(cpu, cpu_present_map); cpu_set(cpu, cpu_online_map); @@ -309,8 +400,8 @@ int smp_call_function_on_cpu(void (*func)(void *info), void *info, int retry, printk(KERN_CRIT "CPU%u: smp_call_function timeout for %p(%p)\n" " callmap %lx pending %lx, %swait\n", - smp_processor_id(), func, info, callmap, data.pending, - wait ? "" : "no "); + smp_processor_id(), func, info, *cpus_addr(callmap), + *cpus_addr(data.pending), wait ? "" : "no "); /* * TRACE |