1 files changed, 38 insertions, 27 deletions

diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 5092494bf261..67768bbe736e 100644
--- a/kernel/irq/matrix.c
+++ b/kernel/irq/matrix.c
@@ -124,6 +124,27 @@ static unsigned int matrix_alloc_area(struct irq_matrix *m, struct cpumap *cm,
         return area;
 }
 
+/* Find the best CPU which has the lowest vector allocation count */
+static unsigned int matrix_find_best_cpu(struct irq_matrix *m,
+                                        const struct cpumask *msk)
+{
+        unsigned int cpu, best_cpu, maxavl = 0;
+        struct cpumap *cm;
+
+        best_cpu = UINT_MAX;
+
+        for_each_cpu(cpu, msk) {
+                cm = per_cpu_ptr(m->maps, cpu);
+
+                if (!cm->online || cm->available <= maxavl)
+                        continue;
+
+                best_cpu = cpu;
+                maxavl = cm->available;
+        }
+        return best_cpu;
+}
+
 /**
  * irq_matrix_assign_system - Assign system wide entry in the matrix
  * @m:          Matrix pointer
@@ -322,37 +343,27 @@ void irq_matrix_remove_reserved(struct irq_matrix *m)
 int irq_matrix_alloc(struct irq_matrix *m, const struct cpumask *msk,
                      bool reserved, unsigned int *mapped_cpu)
 {
-        unsigned int cpu, best_cpu, maxavl = 0;
+        unsigned int cpu, bit;
         struct cpumap *cm;
-        unsigned int bit;
 
-        best_cpu = UINT_MAX;
-        for_each_cpu(cpu, msk) {
-                cm = per_cpu_ptr(m->maps, cpu);
-
-                if (!cm->online || cm->available <= maxavl)
-                        continue;
+        cpu = matrix_find_best_cpu(m, msk);
+        if (cpu == UINT_MAX)
+                return -ENOSPC;
 
-                best_cpu = cpu;
-                maxavl = cm->available;
-        }
+        cm = per_cpu_ptr(m->maps, cpu);
+        bit = matrix_alloc_area(m, cm, 1, false);
+        if (bit >= m->alloc_end)
+                return -ENOSPC;
+        cm->allocated++;
+        cm->available--;
+        m->total_allocated++;
+        m->global_available--;
+        if (reserved)
+                m->global_reserved--;
+        *mapped_cpu = cpu;
+        trace_irq_matrix_alloc(bit, cpu, m, cm);
+        return bit;
 
-        if (maxavl) {
-                cm = per_cpu_ptr(m->maps, best_cpu);
-                bit = matrix_alloc_area(m, cm, 1, false);
-                if (bit < m->alloc_end) {
-                        cm->allocated++;
-                        cm->available--;
-                        m->total_allocated++;
-                        m->global_available--;
-                        if (reserved)
-                                m->global_reserved--;
-                        *mapped_cpu = best_cpu;
-                        trace_irq_matrix_alloc(bit, best_cpu, m, cm);
-                        return bit;
-                }
-        }
-        return -ENOSPC;
 }
 
 /**