genirq/affinity: Pass affinity managed mask array to irq_build_affinity_masks

Pass affinity managed mask array to irq_build_affinity_masks() so that the
index of the first affinity managed vector is always zero.

This allows to simplify the implementation a bit.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>                                                                                                                                                                                                    
Link: https://lore.kernel.org/r/20221227022905.352674-3-ming.lei@redhat.com

kernel/irq/affinity.c

@@ -246,14 +246,13 @@ static void alloc_nodes_vectors(unsigned int numvecs,
 
 static int __irq_build_affinity_masks(unsigned int startvec,
 				      unsigned int numvecs,
-				      unsigned int firstvec,
 				      cpumask_var_t *node_to_cpumask,
 				      const struct cpumask *cpu_mask,
 				      struct cpumask *nmsk,
 				      struct irq_affinity_desc *masks)
 {
 	unsigned int i, n, nodes, cpus_per_vec, extra_vecs, done = 0;
-	unsigned int last_affv = firstvec + numvecs;
+	unsigned int last_affv = numvecs;
 	unsigned int curvec = startvec;
 	nodemask_t nodemsk = NODE_MASK_NONE;
 	struct node_vectors *node_vectors;
@@ -273,7 +272,7 @@ static int __irq_build_affinity_masks(unsigned int startvec,
 			cpumask_and(nmsk, cpu_mask, node_to_cpumask[n]);
 			cpumask_or(&masks[curvec].mask, &masks[curvec].mask, nmsk);
 			if (++curvec == last_affv)
-				curvec = firstvec;
+				curvec = 0;
 		}
 		return numvecs;
 	}
@@ -321,7 +320,7 @@ static int __irq_build_affinity_masks(unsigned int startvec,
 			 * may start anywhere
 			 */
 			if (curvec >= last_affv)
-				curvec = firstvec;
+				curvec = 0;
 			irq_spread_init_one(&masks[curvec].mask, nmsk,
 						cpus_per_vec);
 		}
@@ -336,11 +335,10 @@ static int __irq_build_affinity_masks(unsigned int startvec,
  *	1) spread present CPU on these vectors
  *	2) spread other possible CPUs on these vectors
  */
-static int irq_build_affinity_masks(unsigned int startvec, unsigned int numvecs,
+static int irq_build_affinity_masks(unsigned int numvecs,
 				    struct irq_affinity_desc *masks)
 {
-	unsigned int curvec = startvec, nr_present = 0, nr_others = 0;
-	unsigned int firstvec = startvec;
+	unsigned int curvec = 0, nr_present = 0, nr_others = 0;
 	cpumask_var_t *node_to_cpumask;
 	cpumask_var_t nmsk, npresmsk;
 	int ret = -ENOMEM;
@@ -360,9 +358,8 @@ static int irq_build_affinity_masks(unsigned int startvec, unsigned int numvecs,
 	build_node_to_cpumask(node_to_cpumask);
 
 	/* Spread on present CPUs starting from affd->pre_vectors */
-	ret = __irq_build_affinity_masks(curvec, numvecs, firstvec,
-					 node_to_cpumask, cpu_present_mask,
-					 nmsk, masks);
+	ret = __irq_build_affinity_masks(curvec, numvecs, node_to_cpumask,
+					 cpu_present_mask, nmsk, masks);
 	if (ret < 0)
 		goto fail_build_affinity;
 	nr_present = ret;
@@ -374,13 +371,12 @@ static int irq_build_affinity_masks(unsigned int startvec, unsigned int numvecs,
 	 * out vectors.
 	 */
 	if (nr_present >= numvecs)
-		curvec = firstvec;
+		curvec = 0;
 	else
-		curvec = firstvec + nr_present;
+		curvec = nr_present;
 	cpumask_andnot(npresmsk, cpu_possible_mask, cpu_present_mask);
-	ret = __irq_build_affinity_masks(curvec, numvecs, firstvec,
-					 node_to_cpumask, npresmsk, nmsk,
-					 masks);
+	ret = __irq_build_affinity_masks(curvec, numvecs, node_to_cpumask,
+					 npresmsk, nmsk, masks);
 	if (ret >= 0)
 		nr_others = ret;
 
@@ -463,7 +459,7 @@ irq_create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd)
 		unsigned int this_vecs = affd->set_size[i];
 		int ret;
 
-		ret = irq_build_affinity_masks(curvec, this_vecs, masks);
+		ret = irq_build_affinity_masks(this_vecs, &masks[curvec]);
 		if (ret) {
 			kfree(masks);
 			return NULL;