irq/apic: Use config_enabled(CONFIG_SMP) checks to clean up irq_set_affinity() for UP

Move the ->irq_set_affinity() routines out of the #ifdef CONFIG_SMP
sections and use config_enabled(CONFIG_SMP) checks inside those
routines. Thus making those routines simple null stubs for
!CONFIG_SMP and retaining those routines with no additional
runtime overhead for CONFIG_SMP kernels.

Cleans up the ifdef CONFIG_SMP in and around routines related to
irq_set_affinity in io_apic and irq_remapping subsystems.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: torvalds@linux-foundation.org
Cc: joerg.roedel@amd.com
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1339723729.3475.63.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 5 insertions, 9 deletions

diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 853902a1b7db..e0b18f3ae9a8 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -902,7 +902,6 @@ static int intel_setup_ioapic_entry(int irq,
         return 0;
 }
 
-#ifdef CONFIG_SMP
 /*
  * Migrate the IO-APIC irq in the presence of intr-remapping.
  *
@@ -926,6 +925,9 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
         struct irte irte;
         int err;
 
+        if (!config_enabled(CONFIG_SMP))
+                return -EINVAL;
+
         if (!cpumask_intersects(mask, cpu_online_mask))
                 return -EINVAL;
 
@@ -963,7 +965,6 @@ intel_ioapic_set_affinity(struct irq_data *data, const struct cpumask *mask,
         cpumask_copy(data->affinity, mask);
         return 0;
 }
-#endif
 
 static void intel_compose_msi_msg(struct pci_dev *pdev,
                                   unsigned int irq, unsigned int dest,
@@ -1065,9 +1066,7 @@ struct irq_remap_ops intel_irq_remap_ops = {
         .reenable               = reenable_irq_remapping,
         .enable_faulting        = enable_drhd_fault_handling,
         .setup_ioapic_entry     = intel_setup_ioapic_entry,
-#ifdef CONFIG_SMP
         .set_affinity           = intel_ioapic_set_affinity,
-#endif
         .free_irq               = free_irte,
         .compose_msi_msg        = intel_compose_msi_msg,
         .msi_alloc_irq          = intel_msi_alloc_irq,
diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index 40cda8e98d87..1d29b1c66e72 100644
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -111,16 +111,15 @@ int setup_ioapic_remapped_entry(int irq,
                                              vector, attr);
 }
 
-#ifdef CONFIG_SMP
 int set_remapped_irq_affinity(struct irq_data *data, const struct cpumask *mask,
                               bool force)
 {
-        if (!remap_ops || !remap_ops->set_affinity)
+        if (!config_enabled(CONFIG_SMP) || !remap_ops ||
+            !remap_ops->set_affinity)
                 return 0;
 
         return remap_ops->set_affinity(data, mask, force);
 }
-#endif
 
 void free_remapped_irq(int irq)
 {
diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h
index be9d72950c51..b12974cc1dfe 100644
--- a/drivers/iommu/irq_remapping.h
+++ b/drivers/iommu/irq_remapping.h
@@ -59,11 +59,9 @@ struct irq_remap_ops {
                                   unsigned int, int,
                                   struct io_apic_irq_attr *);
 
-#ifdef CONFIG_SMP
         /* Set the CPU affinity of a remapped interrupt */
         int (*set_affinity)(struct irq_data *data, const struct cpumask *mask,
                             bool force);
-#endif
 
         /* Free an IRQ */
         int (*free_irq)(int);