1 files changed, 16 insertions, 7 deletions

diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 30cc217b8631..1698e77645ac 100644
--- a/kernel/irq/matrix.c
+++ b/kernel/irq/matrix.c
@@ -280,12 +280,13 @@ void irq_matrix_remove_managed(struct irq_matrix *m, const struct cpumask *msk)
 /**
  * irq_matrix_alloc_managed - Allocate a managed interrupt in a CPU map
  * @m:		Matrix pointer
- * @cpu:	On which CPU the interrupt should be allocated
+ * @msk:	Which CPUs to search in
+ * @mapped_cpu:	Pointer to store the CPU for which the irq was allocated
  */
 int irq_matrix_alloc_managed(struct irq_matrix *m, const struct cpumask *msk,
 			     unsigned int *mapped_cpu)
 {
-	unsigned int bit, cpu, end = m->alloc_end;
+	unsigned int bit, cpu, end;
 	struct cpumap *cm;
 
 	if (cpumask_empty(msk))
@@ -337,15 +338,14 @@ void irq_matrix_assign(struct irq_matrix *m, unsigned int bit)
  * irq_matrix_reserve - Reserve interrupts
  * @m:		Matrix pointer
  *
- * This is merily a book keeping call. It increments the number of globally
+ * This is merely a book keeping call. It increments the number of globally
  * reserved interrupt bits w/o actually allocating them. This allows to
  * setup interrupt descriptors w/o assigning low level resources to it.
  * The actual allocation happens when the interrupt gets activated.
  */
 void irq_matrix_reserve(struct irq_matrix *m)
 {
-	if (m->global_reserved <= m->global_available &&
-	    m->global_reserved + 1 > m->global_available)
+	if (m->global_reserved == m->global_available)
 		pr_warn("Interrupt reservation exceeds available resources\n");
 
 	m->global_reserved++;
@@ -356,7 +356,7 @@ void irq_matrix_reserve(struct irq_matrix *m)
  * irq_matrix_remove_reserved - Remove interrupt reservation
  * @m:		Matrix pointer
  *
- * This is merily a book keeping call. It decrements the number of globally
+ * This is merely a book keeping call. It decrements the number of globally
  * reserved interrupt bits. This is used to undo irq_matrix_reserve() when the
  * interrupt was never in use and a real vector allocated, which undid the
  * reservation.
@@ -380,6 +380,13 @@ int irq_matrix_alloc(struct irq_matrix *m, const struct cpumask *msk,
 	unsigned int cpu, bit;
 	struct cpumap *cm;
 
+	/*
+	 * Not required in theory, but matrix_find_best_cpu() uses
+	 * for_each_cpu() which ignores the cpumask on UP .
+	 */
+	if (cpumask_empty(msk))
+		return -EINVAL;
+
 	cpu = matrix_find_best_cpu(m, msk);
 	if (cpu == UINT_MAX)
 		return -ENOSPC;
@@ -416,7 +423,9 @@ void irq_matrix_free(struct irq_matrix *m, unsigned int cpu,
 	if (WARN_ON_ONCE(bit < m->alloc_start || bit >= m->alloc_end))
 		return;
 
-	clear_bit(bit, cm->alloc_map);
+	if (WARN_ON_ONCE(!test_and_clear_bit(bit, cm->alloc_map)))
+		return;
+
 	cm->allocated--;
 	if(managed)
 		cm->managed_allocated--;