cpumask: convert c1e_mask in arch/x86/kernel/process.c to cpumask_var_t.

Impact: reduce kernel size when CONFIG_CPUMASK_OFFSTACK=y

Simple conversion.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 6afa523..cad5431 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -474,12 +474,12 @@
 	return 1;
 }
 
-static cpumask_t c1e_mask = CPU_MASK_NONE;
+static cpumask_var_t c1e_mask;
 static int c1e_detected;
 
 void c1e_remove_cpu(int cpu)
 {
-	cpu_clear(cpu, c1e_mask);
+	cpumask_clear_cpu(cpu, c1e_mask);
 }
 
 /*
@@ -508,8 +508,8 @@
 	if (c1e_detected) {
 		int cpu = smp_processor_id();
 
-		if (!cpu_isset(cpu, c1e_mask)) {
-			cpu_set(cpu, c1e_mask);
+		if (!cpumask_test_cpu(cpu, c1e_mask)) {
+			cpumask_set_cpu(cpu, c1e_mask);
 			/*
 			 * Force broadcast so ACPI can not interfere. Needs
 			 * to run with interrupts enabled as it uses
@@ -556,6 +556,8 @@
 		pm_idle = mwait_idle;
 	} else if (check_c1e_idle(c)) {
 		printk(KERN_INFO "using C1E aware idle routine\n");
+		alloc_cpumask_var(&c1e_mask, GFP_KERNEL);
+		cpumask_clear(c1e_mask);
 		pm_idle = c1e_idle;
 	} else
 		pm_idle = default_idle;