cpumask: accessors to manipulate possible/present/online/active maps

Since we are moving to const cpumask pointers for the maps, we need a
way to legitimately access them.  Simple accessors work well.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 include/linux/cpumask.h |    9 +++++++++
 kernel/cpu.c            |   40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff -r 10662b696ae5 include/linux/cpumask.h
--- a/include/linux/cpumask.h	Sun Sep 28 23:10:33 2008 +1000
+++ b/include/linux/cpumask.h	Mon Sep 29 00:08:01 2008 +1000
@@ -530,6 +530,15 @@ extern cpumask_t cpu_present_map;
 extern cpumask_t cpu_present_map;
 extern cpumask_t cpu_active_map;
 
+/* Wrappers to manipulate otherwise-constant masks. */
+void set_cpu_possible(unsigned int cpu, bool possible);
+void set_cpu_present(unsigned int cpu, bool present);
+void set_cpu_online(unsigned int cpu, bool online);
+void set_cpu_active(unsigned int cpu, bool active);
+void init_cpu_present(const struct cpumask *src);
+void init_cpu_possible(const struct cpumask *src);
+void init_cpu_online(const struct cpumask *src);
+
 #define cpu_is_offline(cpu)	unlikely(!cpu_online(cpu))
 
 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), &cpu_possible_map)
diff -r 10662b696ae5 kernel/cpu.c
--- a/kernel/cpu.c	Sun Sep 28 23:10:33 2008 +1000
+++ b/kernel/cpu.c	Mon Sep 29 00:08:01 2008 +1000
@@ -488,3 +488,43 @@ const struct cpumask cpu_mask_all = { {
 	} };
 EXPORT_SYMBOL(cpu_mask_all);
 
+void set_cpu_possible(unsigned int cpu, bool possible)
+{
+	if (possible)
+		cpumask_set_cpu(cpu, &cpu_possible_map);
+	else
+		cpumask_clear_cpu(cpu, &cpu_possible_map);
+}
+void set_cpu_present(unsigned int cpu, bool present)
+{
+	if (present)
+		cpumask_set_cpu(cpu, &cpu_present_map);
+	else
+		cpumask_clear_cpu(cpu, &cpu_present_map);
+}
+void set_cpu_online(unsigned int cpu, bool online)
+{
+	if (online)
+		cpumask_set_cpu(cpu, &cpu_online_map);
+	else
+		cpumask_clear_cpu(cpu, &cpu_online_map);
+}
+void set_cpu_active(unsigned int cpu, bool active)
+{
+	if (active)
+		cpumask_set_cpu(cpu, &cpu_active_map);
+	else
+		cpumask_clear_cpu(cpu, &cpu_active_map);
+}
+void init_cpu_present(const struct cpumask *src)
+{
+	cpumask_copy(&cpu_present_map, src);
+}
+void init_cpu_possible(const struct cpumask *src)
+{
+	cpumask_copy(&cpu_possible_map, src);
+}
+void init_cpu_online(const struct cpumask *src)
+{
+	cpumask_copy(&cpu_online_map, src);
+}