linux-stable/include/linux/cpu_rmap.h
Eli Cohen 9821d8d462 lib: cpu_rmap: Use allocator for rmap entries
Use a proper allocator for rmap entries using a naive for loop. The
allocator relies on whether an entry is NULL to be considered free.
Remove the used field of rmap which is not needed.

Also, avoid crashing the kernel if an entry is not available.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
2023-03-24 16:04:10 -07:00

65 lines
1.6 KiB
C

/* 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
* @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;
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 */