1 files changed, 56 insertions, 0 deletions
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
new file mode 100644
index 0000000000..9638b25fd5
--- /dev/null
+++ b/block/blk-mq-cpumap.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CPU <-> hardware queue mapping helpers
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ */
+#include <linux/kernel.h>
+#include <linux/threads.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/group_cpus.h>
+
+#include "blk.h"
+#include "blk-mq.h"
+
+void blk_mq_map_queues(struct blk_mq_queue_map *qmap)
+{
+	const struct cpumask *masks;
+	unsigned int queue, cpu;
+
+	masks = group_cpus_evenly(qmap->nr_queues);
+	if (!masks) {
+		for_each_possible_cpu(cpu)
+			qmap->mq_map[cpu] = qmap->queue_offset;
+		return;
+	}
+
+	for (queue = 0; queue < qmap->nr_queues; queue++) {
+		for_each_cpu(cpu, &masks[queue])
+			qmap->mq_map[cpu] = qmap->queue_offset + queue;
+	}
+	kfree(masks);
+}
+EXPORT_SYMBOL_GPL(blk_mq_map_queues);
+
+/**
+ * blk_mq_hw_queue_to_node - Look up the memory node for a hardware queue index
+ * @qmap: CPU to hardware queue map.
+ * @index: hardware queue index.
+ *
+ * We have no quick way of doing reverse lookups. This is only used at
+ * queue init time, so runtime isn't important.
+ */
+int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		if (index == qmap->mq_map[i])
+			return cpu_to_node(i);
+	}
+
+	return NUMA_NO_NODE;
+}