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-rw-r--r--kernel/irq/matrix.c65
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;
}
/**
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