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); + cpu = matrix_find_best_cpu(m, msk); + if (cpu == UINT_MAX) + return -ENOSPC; - if (!cm->online || cm->available <= maxavl) - continue; + 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; - best_cpu = cpu; - maxavl = cm->available; - } - - 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; } /**