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irq_cpu_rmap_notify(struct irq_affinity_notify *notify, const cpumask_t *mask)// SPDX-License-Identifier: GPL-2.0-only/* * cpu_rmap.c: CPU affinity reverse-map support * Copyright 2011 Solarflare Communications Inc. *//* * These functions maintain a mapping from CPUs to some ordered set of * objects with CPU affinities. This can be seen as a reverse-map of * CPU affinity. However, we do not assume that the object affinities * cover all CPUs in the system. For those CPUs not directly covered * by object affinities, we attempt to find a nearest object based on * CPU topology. *//** * alloc_cpu_rmap - allocate CPU affinity reverse-map * @size: Number of objects to be mapped * @flags: Allocation flags e.g. %GFP_KERNEL */struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags){ struct cpu_rmap *rmap; unsigned int cpu; size_t obj_offset; /* This is a silly number of objects, and we use u16 indices. */ if (size > 0xffff) return NULL; /* Offset of object pointer array from base structure */ obj_offset = ALIGN(offsetof(struct cpu_rmap, near[nr_cpu_ids]), sizeof(void *)); rmap = kzalloc(obj_offset + size * sizeof(rmap->obj[0]), flags); if (!rmap) return NULL; kref_init(&rmap->refcount); rmap->obj = (void **)((char *)rmap + obj_offset); /* Initially assign CPUs to objects on a rota, since we have * no idea where the objects are. Use infinite distance, so * any object with known distance is preferable. Include the * CPUs that are not present/online, since we definitely want * any newly-hotplugged CPUs to have some object assigned. */ for_each_possible_cpu(cpu) { rmap->near[cpu].index = cpu % size; rmap->near[cpu].dist = CPU_RMAP_DIST_INF; } rmap->size = size; return rmap;}EXPORT_SYMBOL(alloc_cpu_rmap);/** * cpu_rmap_release - internal reclaiming helper called from kref_put * @ref: kref to struct cpu_rmap */static void cpu_rmap_release(struct kref *ref){ struct cpu_rmap *rmap = container_of(ref, struct cpu_rmap, refcount); kfree(rmap);}/** * cpu_rmap_get - internal helper to get new ref on a cpu_rmap * @rmap: reverse-map allocated with alloc_cpu_rmap() */static inline void cpu_rmap_get(struct cpu_rmap *rmap){ kref_get(&rmap->refcount);}/** * cpu_rmap_put - release ref on a cpu_rmap * @rmap: reverse-map allocated with alloc_cpu_rmap() */int cpu_rmap_put(struct cpu_rmap *rmap){ return kref_put(&rmap->refcount, cpu_rmap_release);}EXPORT_SYMBOL(cpu_rmap_put);/* Reevaluate nearest object for given CPU, comparing with the given * neighbours at the given distance.