cpumask: add show cpu map functions

  * Add cpu_sysdev_class functions to display the following maps
    with cpulist_scnprintf().

	cpu_online_map
	cpu_present_map
	cpu_possible_map

  * Small change to include/linux/sysdev.h to allow the attribute
    name and label to be different (to avoid collision with the
    "attr_online" entry for bringing cpus on- and off-line.)

Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 59 insertions, 6 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 499b003f9278..2c76afff3b15 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -103,6 +103,51 @@ static SYSDEV_ATTR(crash_notes, 0400, show_crash_notes, NULL);
 #endif
 
 /*
+ * Print cpu online, possible, present, and system maps
+ */
+static ssize_t print_cpus_map(char *buf, cpumask_t *map)
+{
+        int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *map);
+
+        buf[n++] = '\n';
+        buf[n] = '\0';
+        return n;
+}
+
+#define print_cpus_func(type) \
+static ssize_t print_cpus_##type(struct sysdev_class *class, char *buf) \
+{                                                                       \
+        return print_cpus_map(buf, &cpu_##type##_map);                  \
+}                                                                       \
+struct sysdev_class_attribute attr_##type##_map =                       \
+        _SYSDEV_CLASS_ATTR(type, 0444, print_cpus_##type, NULL)
+
+print_cpus_func(online);
+print_cpus_func(possible);
+print_cpus_func(present);
+
+struct sysdev_class_attribute *cpu_state_attr[] = {
+        &attr_online_map,
+        &attr_possible_map,
+        &attr_present_map,
+};
+
+static int cpu_states_init(void)
+{
+        int i;
+        int err = 0;
+
+        for (i = 0;  i < ARRAY_SIZE(cpu_state_attr); i++) {
+                int ret;
+                ret = sysdev_class_create_file(&cpu_sysdev_class,
+                                                cpu_state_attr[i]);
+                if (!err)
+                        err = ret;
+        }
+        return err;
+}
+
+/*
  * register_cpu - Setup a sysfs device for a CPU.
  * @cpu - cpu->hotpluggable field set to 1 will generate a control file in
  *        sysfs for this CPU.
@@ -147,6 +192,9 @@ int __init cpu_dev_init(void)
         int err;
 
         err = sysdev_class_register(&cpu_sysdev_class);
+        if (!err)
+                err = cpu_states_init();
+
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
         if (!err)
                 err = sched_create_sysfs_power_savings_entries(&cpu_sysdev_class);
diff --git a/include/linux/sysdev.h b/include/linux/sysdev.h
index f752e73bf977..f2767bc6b735 100644
--- a/include/linux/sysdev.h
+++ b/include/linux/sysdev.h
@@ -45,12 +45,16 @@ struct sysdev_class_attribute {
         ssize_t (*store)(struct sysdev_class *, const char *, size_t);
 };
 
-#define SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)             \
-struct sysdev_class_attribute attr_##_name = {                  \
+#define _SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)            \
+{                                                               \
         .attr = {.name = __stringify(_name), .mode = _mode },   \
         .show   = _show,                                        \
         .store  = _store,                                       \
-};
+}
+
+#define SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)             \
+        struct sysdev_class_attribute attr_##_name =            \
+                _SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)
 
 
 extern int sysdev_class_register(struct sysdev_class *);
@@ -100,15 +104,16 @@ struct sysdev_attribute {
 };
 
 
-#define _SYSDEV_ATTR(_name,_mode,_show,_store)                  \
+#define _SYSDEV_ATTR(_name, _mode, _show, _store)               \
 {                                                               \
         .attr = { .name = __stringify(_name), .mode = _mode },  \
         .show   = _show,                                        \
         .store  = _store,                                       \
 }
 
-#define SYSDEV_ATTR(_name,_mode,_show,_store)           \
-struct sysdev_attribute attr_##_name = _SYSDEV_ATTR(_name,_mode,_show,_store);
+#define SYSDEV_ATTR(_name, _mode, _show, _store)                \
+        struct sysdev_attribute attr_##_name =                  \
+                _SYSDEV_ATTR(_name, _mode, _show, _store);
 
 extern int sysdev_create_file(struct sys_device *, struct sysdev_attribute *);
 extern void sysdev_remove_file(struct sys_device *, struct sysdev_attribute *);