diff options
Diffstat (limited to 'arch/xtensa/kernel/smp.c')
| -rw-r--r-- | arch/xtensa/kernel/smp.c | 128 |
1 files changed, 127 insertions, 1 deletions
diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c index 46bdd142a07d..1c7a209795e8 100644 --- a/arch/xtensa/kernel/smp.c +++ b/arch/xtensa/kernel/smp.c @@ -40,6 +40,11 @@ # endif #endif +static void system_invalidate_dcache_range(unsigned long start, + unsigned long size); +static void system_flush_invalidate_dcache_range(unsigned long start, + unsigned long size); + /* IPI (Inter Process Interrupt) */ #define IPI_IRQ 0 @@ -106,7 +111,7 @@ void __init smp_cpus_done(unsigned int max_cpus) static int boot_secondary_processors = 1; /* Set with xt-gdb via .xt-gdb */ static DECLARE_COMPLETION(cpu_running); -void __init secondary_start_kernel(void) +void secondary_start_kernel(void) { struct mm_struct *mm = &init_mm; unsigned int cpu = smp_processor_id(); @@ -174,6 +179,9 @@ static void mx_cpu_stop(void *p) __func__, cpu, run_stall_mask, get_er(MPSCORE)); } +#ifdef CONFIG_HOTPLUG_CPU +unsigned long cpu_start_id __cacheline_aligned; +#endif unsigned long cpu_start_ccount; static int boot_secondary(unsigned int cpu, struct task_struct *ts) @@ -182,6 +190,11 @@ static int boot_secondary(unsigned int cpu, struct task_struct *ts) unsigned long ccount; int i; +#ifdef CONFIG_HOTPLUG_CPU + cpu_start_id = cpu; + system_flush_invalidate_dcache_range( + (unsigned long)&cpu_start_id, sizeof(cpu_start_id)); +#endif smp_call_function_single(0, mx_cpu_start, (void *)cpu, 1); for (i = 0; i < 2; ++i) { @@ -234,6 +247,85 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) 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(); + + /* + * 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(); + + /* + * Flush user cache and TLB mappings, and then remove this CPU + * from the vm mask set of all processes. + */ + local_flush_cache_all(); + local_flush_tlb_all(); + invalidate_page_directory(); + + clear_tasks_mm_cpumask(cpu); + + return 0; +} + +static void platform_cpu_kill(unsigned int cpu) +{ + smp_call_function_single(0, mx_cpu_stop, (void *)cpu, true); +} + +/* + * 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) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + while (time_before(jiffies, timeout)) { + system_invalidate_dcache_range((unsigned long)&cpu_start_id, + sizeof(cpu_start_id)); + if (cpu_start_id == -cpu) { + platform_cpu_kill(cpu); + return; + } + } + pr_err("CPU%u: unable to kill\n", cpu); +} + +void arch_cpu_idle_dead(void) +{ + cpu_die(); +} +/* + * 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) +{ + idle_task_exit(); + local_irq_disable(); + __asm__ __volatile__( + " movi a2, cpu_restart\n" + " jx a2\n"); +} + +#endif /* CONFIG_HOTPLUG_CPU */ + enum ipi_msg_type { IPI_RESCHEDULE = 0, IPI_CALL_FUNC, @@ -463,3 +555,37 @@ void flush_icache_range(unsigned long start, unsigned long end) }; on_each_cpu(ipi_flush_icache_range, &fd, 1); } + +/* ------------------------------------------------------------------------- */ + +static void ipi_invalidate_dcache_range(void *arg) +{ + struct flush_data *fd = arg; + __invalidate_dcache_range(fd->addr1, fd->addr2); +} + +static void system_invalidate_dcache_range(unsigned long start, + unsigned long size) +{ + struct flush_data fd = { + .addr1 = start, + .addr2 = size, + }; + on_each_cpu(ipi_invalidate_dcache_range, &fd, 1); +} + +static void ipi_flush_invalidate_dcache_range(void *arg) +{ + struct flush_data *fd = arg; + __flush_invalidate_dcache_range(fd->addr1, fd->addr2); +} + +static void system_flush_invalidate_dcache_range(unsigned long start, + unsigned long size) +{ + struct flush_data fd = { + .addr1 = start, + .addr2 = size, + }; + on_each_cpu(ipi_flush_invalidate_dcache_range, &fd, 1); +} |