diff options
| -rw-r--r-- | arch/mips/Kconfig | 11 | ||||
| -rw-r--r-- | arch/mips/include/asm/smp-ops.h | 4 | ||||
| -rw-r--r-- | arch/mips/include/asm/smp.h | 19 | ||||
| -rw-r--r-- | arch/mips/kernel/process.c | 13 | ||||
| -rw-r--r-- | arch/mips/kernel/smp-up.c | 16 | ||||
| -rw-r--r-- | arch/mips/kernel/smp.c | 17 | ||||
| -rw-r--r-- | arch/mips/kernel/topology.c | 5 |
7 files changed, 78 insertions, 7 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index b29f028..eb7e8d7 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -784,8 +784,17 @@ config SYS_HAS_EARLY_PRINTK bool config HOTPLUG_CPU + bool "Support for hot-pluggable CPUs" + depends on SMP && HOTPLUG && SYS_SUPPORTS_HOTPLUG_CPU + help + Say Y here to allow turning CPUs off and on. CPUs can be + controlled through /sys/devices/system/cpu. + (Note: power management support will enable this option + automatically on SMP systems. ) + Say N if you want to disable CPU hotplug. + +config SYS_SUPPORTS_HOTPLUG_CPU bool - default n config I8259 bool diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h index 64ffc02..fd54554 100644 --- a/arch/mips/include/asm/smp-ops.h +++ b/arch/mips/include/asm/smp-ops.h @@ -26,6 +26,10 @@ struct plat_smp_ops { void (*boot_secondary)(int cpu, struct task_struct *idle); void (*smp_setup)(void); void (*prepare_cpus)(unsigned int max_cpus); +#ifdef CONFIG_HOTPLUG_CPU + int (*cpu_disable)(void); + void (*cpu_die)(unsigned int cpu); +#endif }; extern void register_smp_ops(struct plat_smp_ops *ops); diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h index 2f83fa8..01f813d 100644 --- a/arch/mips/include/asm/smp.h +++ b/arch/mips/include/asm/smp.h @@ -41,6 +41,7 @@ extern int __cpu_logical_map[NR_CPUS]; /* Octeon - Tell another core to flush its icache */ #define SMP_ICACHE_FLUSH 0x4 +extern cpumask_t cpu_callin_map; extern void asmlinkage smp_bootstrap(void); @@ -56,6 +57,24 @@ static inline void smp_send_reschedule(int cpu) mp_ops->send_ipi_single(cpu, SMP_RESCHEDULE_YOURSELF); } +#ifdef CONFIG_HOTPLUG_CPU +static inline int __cpu_disable(void) +{ + extern struct plat_smp_ops *mp_ops; /* private */ + + return mp_ops->cpu_disable(); +} + +static inline void __cpu_die(unsigned int cpu) +{ + extern struct plat_smp_ops *mp_ops; /* private */ + + mp_ops->cpu_die(cpu); +} + +extern void play_dead(void); +#endif + extern asmlinkage void smp_call_function_interrupt(void); extern void arch_send_call_function_single_ipi(int cpu); diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 1eaaa45..c09d681 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -50,10 +50,15 @@ */ void __noreturn cpu_idle(void) { + int cpu; + + /* CPU is going idle. */ + cpu = smp_processor_id(); + /* endless idle loop with no priority at all */ while (1) { tick_nohz_stop_sched_tick(1); - while (!need_resched()) { + while (!need_resched() && cpu_online(cpu)) { #ifdef CONFIG_MIPS_MT_SMTC extern void smtc_idle_loop_hook(void); @@ -62,6 +67,12 @@ void __noreturn cpu_idle(void) if (cpu_wait) (*cpu_wait)(); } +#ifdef CONFIG_HOTPLUG_CPU + if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) && + (system_state == SYSTEM_RUNNING || + system_state == SYSTEM_BOOTING)) + play_dead(); +#endif tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); schedule(); diff --git a/arch/mips/kernel/smp-up.c b/arch/mips/kernel/smp-up.c index 878e373..2508d55 100644 --- a/arch/mips/kernel/smp-up.c +++ b/arch/mips/kernel/smp-up.c @@ -55,6 +55,18 @@ static void __init up_prepare_cpus(unsigned int max_cpus) { } +#ifdef CONFIG_HOTPLUG_CPU +static int up_cpu_disable(void) +{ + return -ENOSYS; +} + +static void up_cpu_die(unsigned int cpu) +{ + BUG(); +} +#endif + struct plat_smp_ops up_smp_ops = { .send_ipi_single = up_send_ipi_single, .send_ipi_mask = up_send_ipi_mask, @@ -64,4 +76,8 @@ struct plat_smp_ops up_smp_ops = { .boot_secondary = up_boot_secondary, .smp_setup = up_smp_setup, .prepare_cpus = up_prepare_cpus, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_disable = up_cpu_disable, + .cpu_die = up_cpu_die, +#endif }; diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 58f4679..bc7d9b0 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -45,7 +45,7 @@ #include <asm/mipsmtregs.h> #endif /* CONFIG_MIPS_MT_SMTC */ -static volatile cpumask_t cpu_callin_map; /* Bitmask of started secondaries */ +volatile cpumask_t cpu_callin_map; /* Bitmask of started secondaries */ int __cpu_number_map[NR_CPUS]; /* Map physical to logical */ int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */ @@ -201,6 +201,8 @@ void __devinit smp_prepare_boot_cpu(void) * and keep control until "cpu_online(cpu)" is set. Note: cpu is * physical, not logical. */ +static struct task_struct *cpu_idle_thread[NR_CPUS]; + int __cpuinit __cpu_up(unsigned int cpu) { struct task_struct *idle; @@ -210,9 +212,16 @@ int __cpuinit __cpu_up(unsigned int cpu) * The following code is purely to make sure * Linux can schedule processes on this slave. */ - idle = fork_idle(cpu); - if (IS_ERR(idle)) - panic(KERN_ERR "Fork failed for CPU %d", cpu); + if (!cpu_idle_thread[cpu]) { + idle = fork_idle(cpu); + cpu_idle_thread[cpu] = idle; + + if (IS_ERR(idle)) + panic(KERN_ERR "Fork failed for CPU %d", cpu); + } else { + idle = cpu_idle_thread[cpu]; + init_idle(idle, cpu); + } mp_ops->boot_secondary(cpu, idle); diff --git a/arch/mips/kernel/topology.c b/arch/mips/kernel/topology.c index 660e44e..cf3eb61 100644 --- a/arch/mips/kernel/topology.c +++ b/arch/mips/kernel/topology.c @@ -17,7 +17,10 @@ static int __init topology_init(void) #endif /* CONFIG_NUMA */ for_each_present_cpu(i) { - ret = register_cpu(&per_cpu(cpu_devices, i), i); + struct cpu *c = &per_cpu(cpu_devices, i); + + c->hotpluggable = 1; + ret = register_cpu(c, i); if (ret) printk(KERN_WARNING "topology_init: register_cpu %d " "failed (%d)\n", i, ret); |