x86 smp: modify send_IPI_mask interface to accept cpumask_t pointers

Impact: cleanup, change parameter passing

  * Change genapic interfaces to accept cpumask_t pointers where possible.

  * Modify external callers to use cpumask_t pointers in function calls.

  * Create new send_IPI_mask_allbutself which is the same as the
    send_IPI_mask functions but removes smp_processor_id() from list.
    This removes another common need for a temporary cpumask_t variable.

  * Functions that used a temp cpumask_t variable for:

	cpumask_t allbutme = cpu_online_map;

	cpu_clear(smp_processor_id(), allbutme);
	if (!cpus_empty(allbutme))
		...

    become:

	if (!cpus_equal(cpu_online_map, cpumask_of_cpu(cpu)))
		...

  * Other minor code optimizations (like using cpus_clear instead of
    CPU_MASK_NONE, etc.)

Applies to linux-2.6.tip/master.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/ipi.c b/arch/x86/kernel/ipi.c
index f1c688e..86aa50f 100644
--- a/arch/x86/kernel/ipi.c
+++ b/arch/x86/kernel/ipi.c
@@ -116,9 +116,9 @@
 /*
  * This is only used on smaller machines.
  */
-void send_IPI_mask_bitmask(cpumask_t cpumask, int vector)
+void send_IPI_mask_bitmask(const cpumask_t *cpumask, int vector)
 {
-	unsigned long mask = cpus_addr(cpumask)[0];
+	unsigned long mask = cpus_addr(*cpumask)[0];
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -127,7 +127,7 @@
 	local_irq_restore(flags);
 }
 
-void send_IPI_mask_sequence(cpumask_t mask, int vector)
+void send_IPI_mask_sequence(const cpumask_t *mask, int vector)
 {
 	unsigned long flags;
 	unsigned int query_cpu;
@@ -139,12 +139,24 @@
 	 */
 
 	local_irq_save(flags);
-	for_each_possible_cpu(query_cpu) {
-		if (cpu_isset(query_cpu, mask)) {
+	for_each_cpu_mask_nr(query_cpu, *mask)
+		__send_IPI_dest_field(cpu_to_logical_apicid(query_cpu), vector);
+	local_irq_restore(flags);
+}
+
+void send_IPI_mask_allbutself(const cpumask_t *mask, int vector)
+{
+	unsigned long flags;
+	unsigned int query_cpu;
+	unsigned int this_cpu = smp_processor_id();
+
+	/* See Hack comment above */
+
+	local_irq_save(flags);
+	for_each_cpu_mask_nr(query_cpu, *mask)
+		if (query_cpu != this_cpu)
 			__send_IPI_dest_field(cpu_to_logical_apicid(query_cpu),
 					      vector);
-		}
-	}
 	local_irq_restore(flags);
 }