[PATCH] x86_64 irq: Simplfy __assign_irq_vector

By precomputing old_mask I remove an extra if statement, remove an
indentation level and make the code slightly easier to read.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 8 deletions

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 950682f35766..357b354921c1 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -685,6 +685,7 @@ static int __assign_irq_vector(int irq, cpumask_t mask, cpumask_t *result)
          * 0x80, because int 0x80 is hm, kind of importantish. ;)
          */
         static int current_vector = FIRST_DEVICE_VECTOR, current_offset = 0;
+        cpumask_t old_mask = CPU_MASK_NONE;
         int old_vector = -1;
         int cpu;
 
@@ -699,11 +700,12 @@ static int __assign_irq_vector(int irq, cpumask_t mask, cpumask_t *result)
                 cpus_and(*result, irq_domain[irq], mask);
                 if (!cpus_empty(*result))
                         return old_vector;
+                cpus_and(old_mask, irq_domain[irq], cpu_online_map);
         }
 
         for_each_cpu_mask(cpu, mask) {
                 cpumask_t domain, new_mask;
-                int new_cpu;
+                int new_cpu, old_cpu;
                 int vector, offset;
 
                 domain = vector_allocation_domain(cpu);
@@ -728,13 +730,8 @@ next:
                 /* Found one! */
                 current_vector = vector;
                 current_offset = offset;
-                if (old_vector >= 0) {
-                        cpumask_t old_mask;
-                        int old_cpu;
-                        cpus_and(old_mask, irq_domain[irq], cpu_online_map);
-                        for_each_cpu_mask(old_cpu, old_mask)
-                                per_cpu(vector_irq, old_cpu)[old_vector] = -1;
-                }
+                for_each_cpu_mask(old_cpu, old_mask)
+                        per_cpu(vector_irq, old_cpu)[old_vector] = -1;
                 for_each_cpu_mask(new_cpu, new_mask)
                         per_cpu(vector_irq, new_cpu)[vector] = irq;
                 irq_vector[irq] = vector;