cpumask: arch_send_call_function_ipi_mask: arm

We're weaning the core code off handing cpumask's around on-stack.
This introduces arch_send_call_function_ipi_mask().

This change goes a little deeper than a simple macro to ensure we
actually use the new for_each_cpu() iterator.  This is because only
the lower nr_cpumask_bits bits of the cpumask arg are going to be
valid once we remove the hack in kernel/smp.c.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 arch/arm/include/asm/smp.h |    3 ++-
 arch/arm/kernel/smp.c      |   11 ++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
--- a/arch/arm/include/asm/smp.h
+++ b/arch/arm/include/asm/smp.h
@@ -102,7 +102,8 @@ extern void platform_cpu_enable(unsigned
 extern void platform_cpu_enable(unsigned int cpu);
 
 extern void arch_send_call_function_single_ipi(int cpu);
-extern void arch_send_call_function_ipi(cpumask_t mask);
+extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
+#define arch_send_call_function_ipi_mask arch_send_call_function_ipi_mask
 
 /*
  * Local timer interrupt handling function (can be IPI'ed).
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -324,14 +324,15 @@ void __init smp_prepare_boot_cpu(void)
 	per_cpu(cpu_data, cpu).idle = current;
 }
 
-static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)
+static void send_ipi_message(const struct cpumask *callmap,
+			     enum ipi_msg_type msg)
 {
 	unsigned long flags;
 	unsigned int cpu;
 
 	local_irq_save(flags);
 
-	for_each_cpu_mask(cpu, callmap) {
+	for_each_cpu(cpu, callmap) {
 		struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
 
 		spin_lock(&ipi->lock);
@@ -342,19 +343,19 @@ static void send_ipi_message(cpumask_t c
 	/*
 	 * Call the platform specific cross-CPU call function.
 	 */
-	smp_cross_call(callmap);
+	smp_cross_call(*callmap);
 
 	local_irq_restore(flags);
 }
 
-void arch_send_call_function_ipi(cpumask_t mask)
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 {
 	send_ipi_message(mask, IPI_CALL_FUNC);
 }
 
 void arch_send_call_function_single_ipi(int cpu)
 {
-	send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
+	send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
 }
 
 void show_ipi_list(struct seq_file *p)