1 files changed, 66 insertions, 0 deletions
diff --git a/include/linux/cpu_rmap.h b/include/linux/cpu_rmap.h
new file mode 100644
index 000000000..be8aea04d
--- /dev/null
+++ b/include/linux/cpu_rmap.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __LINUX_CPU_RMAP_H
+#define __LINUX_CPU_RMAP_H
+
+/*
+ * cpu_rmap.c: CPU affinity reverse-map support
+ * Copyright 2011 Solarflare Communications Inc.
+ */
+
+#include <linux/cpumask.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/kref.h>
+
+/**
+ * struct cpu_rmap - CPU affinity reverse-map
+ * @refcount: kref for object
+ * @size: Number of objects to be reverse-mapped
+ * @used: Number of objects added
+ * @obj: Pointer to array of object pointers
+ * @near: For each CPU, the index and distance to the nearest object,
+ *      based on affinity masks
+ */
+struct cpu_rmap {
+	struct kref	refcount;
+	u16		size, used;
+	void		**obj;
+	struct {
+		u16	index;
+		u16	dist;
+	}		near[];
+};
+#define CPU_RMAP_DIST_INF 0xffff
+
+extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
+extern int cpu_rmap_put(struct cpu_rmap *rmap);
+
+extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
+extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
+			   const struct cpumask *affinity);
+
+static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
+{
+	return rmap->near[cpu].index;
+}
+
+static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
+{
+	return rmap->obj[rmap->near[cpu].index];
+}
+
+/**
+ * alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
+ * @size: Number of objects to be mapped
+ *
+ * Must be called in process context.
+ */
+static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
+{
+	return alloc_cpu_rmap(size, GFP_KERNEL);
+}
+extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
+
+extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
+
+#endif /* __LINUX_CPU_RMAP_H */