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author | Paul Mundt <lethal@linux-sh.org> | 2010-04-26 12:08:55 +0200 |
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committer | Paul Mundt <lethal@linux-sh.org> | 2010-04-26 12:08:55 +0200 |
commit | 763142d1efb56effe614d71185781796c4b83c78 (patch) | |
tree | f886c239786fd4be028e3a45006c5cc5c1b3a3f2 /arch/sh/kernel/smp.c | |
parent | sh: cache secondary CPUs idle loop. (diff) | |
download | linux-763142d1efb56effe614d71185781796c4b83c78.tar.xz linux-763142d1efb56effe614d71185781796c4b83c78.zip |
sh: CPU hotplug support.
This adds preliminary support for CPU hotplug for SH SMP systems.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/smp.c')
-rw-r--r-- | arch/sh/kernel/smp.c | 103 |
1 files changed, 101 insertions, 2 deletions
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 21e7f8a9f3e4..86cd6f94b53b 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -79,6 +79,105 @@ void __init smp_prepare_boot_cpu(void) per_cpu(cpu_state, cpu) = CPU_ONLINE; } +#ifdef CONFIG_HOTPLUG_CPU +void native_cpu_die(unsigned int cpu) +{ + unsigned int i; + + for (i = 0; i < 10; i++) { + smp_rmb(); + if (per_cpu(cpu_state, cpu) == CPU_DEAD) { + if (system_state == SYSTEM_RUNNING) + pr_info("CPU %u is now offline\n", cpu); + + return; + } + + msleep(100); + } + + pr_err("CPU %u didn't die...\n", cpu); +} + +int native_cpu_disable(unsigned int cpu) +{ + return cpu == 0 ? -EPERM : 0; +} + +void play_dead_common(void) +{ + idle_task_exit(); + irq_ctx_exit(raw_smp_processor_id()); + mb(); + + __get_cpu_var(cpu_state) = CPU_DEAD; + local_irq_disable(); +} + +void native_play_dead(void) +{ + play_dead_common(); +} + +int __cpu_disable(void) +{ + unsigned int cpu = smp_processor_id(); + struct task_struct *p; + int ret; + + ret = mp_ops->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(cpu); + + /* + * 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; +} +#else /* ... !CONFIG_HOTPLUG_CPU */ +int native_cpu_disable(void) +{ + return -ENOSYS; +} + +void native_cpu_die(unsigned int cpu) +{ + /* We said "no" in __cpu_disable */ + BUG(); +} + +void native_play_dead(void) +{ + BUG(); +} +#endif + asmlinkage void __cpuinit start_secondary(void) { unsigned int cpu = smp_processor_id(); @@ -88,8 +187,8 @@ asmlinkage void __cpuinit start_secondary(void) atomic_inc(&mm->mm_count); atomic_inc(&mm->mm_users); current->active_mm = mm; - BUG_ON(current->mm); enter_lazy_tlb(mm, current); + local_flush_tlb_all(); per_cpu_trap_init(); @@ -156,6 +255,7 @@ int __cpuinit __cpu_up(unsigned int cpu) break; udelay(10); + barrier(); } if (cpu_online(cpu)) @@ -270,7 +370,6 @@ static void flush_tlb_mm_ipi(void *mm) * behalf of debugees, kswapd stealing pages from another process etc). * Kanoj 07/00. */ - void flush_tlb_mm(struct mm_struct *mm) { preempt_disable(); |