diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 4259072f5bd0..2aef96f20b30 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -128,10 +128,54 @@ print_cpus_func(online); print_cpus_func(possible); print_cpus_func(present); +/* + * Print values for NR_CPUS and offlined cpus + */ +static ssize_t print_cpus_kernel_max(struct sysdev_class *class, char *buf) +{ + int n = snprintf(buf, PAGE_SIZE-2, "%d\n", CONFIG_NR_CPUS - 1); + return n; +} +static SYSDEV_CLASS_ATTR(kernel_max, 0444, print_cpus_kernel_max, NULL); + +/* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */ +unsigned int total_cpus; + +static ssize_t print_cpus_offline(struct sysdev_class *class, char *buf) +{ + int n = 0, len = PAGE_SIZE-2; + cpumask_var_t offline; + + /* display offline cpus < nr_cpu_ids */ + if (!alloc_cpumask_var(&offline, GFP_KERNEL)) + return -ENOMEM; + cpumask_complement(offline, cpu_online_mask); + n = cpulist_scnprintf(buf, len, offline); + free_cpumask_var(offline); + + /* display offline cpus >= nr_cpu_ids */ + if (total_cpus && nr_cpu_ids < total_cpus) { + if (n && n < len) + buf[n++] = ','; + + if (nr_cpu_ids == total_cpus-1) + n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids); + else + n += snprintf(&buf[n], len - n, "%d-%d", + nr_cpu_ids, total_cpus-1); + } + + n += snprintf(&buf[n], len - n, "\n"); + return n; +} +static SYSDEV_CLASS_ATTR(offline, 0444, print_cpus_offline, NULL); + static struct sysdev_class_attribute *cpu_state_attr[] = { &attr_online_map, &attr_possible_map, &attr_present_map, + &attr_kernel_max, + &attr_offline, }; static int cpu_states_init(void) diff --git a/include/linux/smp.h b/include/linux/smp.h index 3f9a60043a97..0d5770c2e43a 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -21,6 +21,9 @@ struct call_single_data { u16 priv; }; +/* total number of cpus in this system (may exceed NR_CPUS) */ +extern unsigned int total_cpus; + #ifdef CONFIG_SMP #include