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>

1 files changed, 50 insertions, 26 deletions

diff --git a/arch/x86/kernel/genapic_flat_64.c b/arch/x86/kernel/genapic_flat_64.c
index c0262791bda..50eebd0328f 100644
--- a/arch/x86/kernel/genapic_flat_64.c
+++ b/arch/x86/kernel/genapic_flat_64.c
@@ -30,12 +30,12 @@ static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
         return 1;
 }
 
-static cpumask_t flat_target_cpus(void)
+static const cpumask_t *flat_target_cpus(void)
 {
-        return cpu_online_map;
+        return &cpu_online_map;
 }
 
-static cpumask_t flat_vector_allocation_domain(int cpu)
+static void flat_vector_allocation_domain(int cpu, cpumask_t *retmask)
 {
         /* Careful. Some cpus do not strictly honor the set of cpus
          * specified in the interrupt destination when using lowest
@@ -45,8 +45,7 @@ static cpumask_t flat_vector_allocation_domain(int cpu)
          * deliver interrupts to the wrong hyperthread when only one
          * hyperthread was specified in the interrupt desitination.
          */
-        cpumask_t domain = { { [0] = APIC_ALL_CPUS, } };
-        return domain;
+        *retmask = (cpumask_t) { {[0] = APIC_ALL_CPUS, } };
 }
 
 /*
@@ -69,9 +68,8 @@ static void flat_init_apic_ldr(void)
         apic_write(APIC_LDR, val);
 }
 
-static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
+static inline void _flat_send_IPI_mask(unsigned long mask, int vector)
 {
-        unsigned long mask = cpus_addr(cpumask)[0];
         unsigned long flags;
 
         local_irq_save(flags);
@@ -79,20 +77,40 @@ static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
         local_irq_restore(flags);
 }
 
+static void flat_send_IPI_mask(const cpumask_t *cpumask, int vector)
+{
+        unsigned long mask = cpus_addr(*cpumask)[0];
+
+        _flat_send_IPI_mask(mask, vector);
+}
+
+static void flat_send_IPI_mask_allbutself(const cpumask_t *cpumask, int vector)
+{
+        unsigned long mask = cpus_addr(*cpumask)[0];
+        int cpu = smp_processor_id();
+
+        if (cpu < BITS_PER_LONG)
+                clear_bit(cpu, &mask);
+        _flat_send_IPI_mask(mask, vector);
+}
+
 static void flat_send_IPI_allbutself(int vector)
 {
+        int cpu = smp_processor_id();
 #ifdef  CONFIG_HOTPLUG_CPU
         int hotplug = 1;
 #else
         int hotplug = 0;
 #endif
         if (hotplug || vector == NMI_VECTOR) {
-                cpumask_t allbutme = cpu_online_map;
+                if (!cpus_equal(cpu_online_map, cpumask_of_cpu(cpu))) {
+                        unsigned long mask = cpus_addr(cpu_online_map)[0];
 
-                cpu_clear(smp_processor_id(), allbutme);
+                        if (cpu < BITS_PER_LONG)
+                                clear_bit(cpu, &mask);
 
-                if (!cpus_empty(allbutme))
-                        flat_send_IPI_mask(allbutme, vector);
+                        _flat_send_IPI_mask(mask, vector);
+                }
         } else if (num_online_cpus() > 1) {
                 __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL);
         }
@@ -101,7 +119,7 @@ static void flat_send_IPI_allbutself(int vector)
 static void flat_send_IPI_all(int vector)
 {
         if (vector == NMI_VECTOR)
-                flat_send_IPI_mask(cpu_online_map, vector);
+                flat_send_IPI_mask(&cpu_online_map, vector);
         else
                 __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
 }
@@ -135,9 +153,9 @@ static int flat_apic_id_registered(void)
         return physid_isset(read_xapic_id(), phys_cpu_present_map);
 }
 
-static unsigned int flat_cpu_mask_to_apicid(cpumask_t cpumask)
+static unsigned int flat_cpu_mask_to_apicid(const cpumask_t *cpumask)
 {
-        return cpus_addr(cpumask)[0] & APIC_ALL_CPUS;
+        return cpus_addr(*cpumask)[0] & APIC_ALL_CPUS;
 }
 
 static unsigned int phys_pkg_id(int index_msb)
@@ -157,6 +175,7 @@ struct genapic apic_flat =  {
         .send_IPI_all = flat_send_IPI_all,
         .send_IPI_allbutself = flat_send_IPI_allbutself,
         .send_IPI_mask = flat_send_IPI_mask,
+        .send_IPI_mask_allbutself = flat_send_IPI_mask_allbutself,
         .send_IPI_self = apic_send_IPI_self,
         .cpu_mask_to_apicid = flat_cpu_mask_to_apicid,
         .phys_pkg_id = phys_pkg_id,
@@ -188,35 +207,39 @@ static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
         return 0;
 }
 
-static cpumask_t physflat_target_cpus(void)
+static const cpumask_t *physflat_target_cpus(void)
 {
-        return cpu_online_map;
+        return &cpu_online_map;
 }
 
-static cpumask_t physflat_vector_allocation_domain(int cpu)
+static void physflat_vector_allocation_domain(int cpu, cpumask_t *retmask)
 {
-        return cpumask_of_cpu(cpu);
+        cpus_clear(*retmask);
+        cpu_set(cpu, *retmask);
 }
 
-static void physflat_send_IPI_mask(cpumask_t cpumask, int vector)
+static void physflat_send_IPI_mask(const cpumask_t *cpumask, int vector)
 {
         send_IPI_mask_sequence(cpumask, vector);
 }
 
-static void physflat_send_IPI_allbutself(int vector)
+static void physflat_send_IPI_mask_allbutself(const cpumask_t *cpumask,
+                                              int vector)
 {
-        cpumask_t allbutme = cpu_online_map;
+        send_IPI_mask_allbutself(cpumask, vector);
+}
 
-        cpu_clear(smp_processor_id(), allbutme);
-        physflat_send_IPI_mask(allbutme, vector);
+static void physflat_send_IPI_allbutself(int vector)
+{
+        send_IPI_mask_allbutself(&cpu_online_map, vector);
 }
 
 static void physflat_send_IPI_all(int vector)
 {
-        physflat_send_IPI_mask(cpu_online_map, vector);
+        physflat_send_IPI_mask(&cpu_online_map, vector);
 }
 
-static unsigned int physflat_cpu_mask_to_apicid(cpumask_t cpumask)
+static unsigned int physflat_cpu_mask_to_apicid(const cpumask_t *cpumask)
 {
         int cpu;
 
@@ -224,7 +247,7 @@ static unsigned int physflat_cpu_mask_to_apicid(cpumask_t cpumask)
          * We're using fixed IRQ delivery, can only return one phys APIC ID.
          * May as well be the first.
          */
-        cpu = first_cpu(cpumask);
+        cpu = first_cpu(*cpumask);
         if ((unsigned)cpu < nr_cpu_ids)
                 return per_cpu(x86_cpu_to_apicid, cpu);
         else
@@ -243,6 +266,7 @@ struct genapic apic_physflat =  {
         .send_IPI_all = physflat_send_IPI_all,
         .send_IPI_allbutself = physflat_send_IPI_allbutself,
         .send_IPI_mask = physflat_send_IPI_mask,
+        .send_IPI_mask_allbutself = physflat_send_IPI_mask_allbutself,
         .send_IPI_self = apic_send_IPI_self,
         .cpu_mask_to_apicid = physflat_cpu_mask_to_apicid,
         .phys_pkg_id = phys_pkg_id,