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            |   42 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 50 insertions(+), 1 deletion(-)

diff -r 9ef23dff7889 include/linux/cpumask.h
--- a/include/linux/cpumask.h	Sun Oct 05 15:11:10 2008 +1100
+++ b/include/linux/cpumask.h	Sun Oct 05 15:33:34 2008 +1100
@@ -565,6 +565,15 @@ extern cpumask_t cpu_active_map;
 #define cpu_active(cpu)		((cpu) == 0)
 #endif
 
+/* 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 9ef23dff7889 kernel/cpu.c
--- a/kernel/cpu.c	Sun Oct 05 15:11:10 2008 +1100
+++ b/kernel/cpu.c	Sun Oct 05 15:33:34 2008 +1100
@@ -470,7 +470,6 @@ out:
 #define MASK_DECLARE_8(x)	MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
 
 const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
-
 	MASK_DECLARE_8(0),	MASK_DECLARE_8(8),
 	MASK_DECLARE_8(16),	MASK_DECLARE_8(24),
 #if BITS_PER_LONG > 32
@@ -479,3 +478,44 @@ const unsigned long cpu_bit_bitmap[BITS_
 #endif
 };
 EXPORT_SYMBOL_GPL(cpu_bit_bitmap);
+
+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);
+}