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-rw-r--r--drivers/base/cpu.c44
-rw-r--r--include/linux/smp.h3
2 files changed, 47 insertions, 0 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 4259072f5bd..2aef96f20b3 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 3f9a60043a9..0d5770c2e43 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 <linux/preempt.h>