/* SPDX-License-Identifier: GPL-2.0-only */ /* * Basic general purpose allocator for managing special purpose * memory, for example, memory that is not managed by the regular * kmalloc/kfree interface. Uses for this includes on-device special * memory, uncached memory etc. * * It is safe to use the allocator in NMI handlers and other special * unblockable contexts that could otherwise deadlock on locks. This * is implemented by using atomic operations and retries on any * conflicts. The disadvantage is that there may be livelocks in * extreme cases. For better scalability, one allocator can be used * for each CPU. * * The lockless operation only works if there is enough memory * available. If new memory is added to the pool a lock has to be * still taken. So any user relying on locklessness has to ensure * that sufficient memory is preallocated. * * The basic atomic operation of this allocator is cmpxchg on long. * On architectures that don't have NMI-safe cmpxchg implementation, * the allocator can NOT be used in NMI handler. So code uses the * allocator in NMI handler should depend on * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. */ #ifndef __GENALLOC_H__ #define __GENALLOC_H__ #include <linux/types.h> #include <linux/spinlock_types.h> #include <linux/atomic.h> struct device; struct device_node; struct gen_pool; /** * typedef genpool_algo_t: Allocation callback function type definition * @map: Pointer to bitmap * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @data: optional additional data used by the callback * @pool: the pool being allocated from */ genpool_algo_t; /* * General purpose special memory pool descriptor. */ struct gen_pool { … }; /* * General purpose special memory pool chunk descriptor. */ struct gen_pool_chunk { … }; /* * gen_pool data descriptor for gen_pool_first_fit_align. */ struct genpool_data_align { … }; /* * gen_pool data descriptor for gen_pool_fixed_alloc. */ struct genpool_data_fixed { … }; extern struct gen_pool *gen_pool_create(int, int); extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long); extern int gen_pool_add_owner(struct gen_pool *, unsigned long, phys_addr_t, size_t, int, void *); static inline int gen_pool_add_virt(struct gen_pool *pool, unsigned long addr, phys_addr_t phys, size_t size, int nid) { … } /** * gen_pool_add - add a new chunk of special memory to the pool * @pool: pool to add new memory chunk to * @addr: starting address of memory chunk to add to pool * @size: size in bytes of the memory chunk to add to pool * @nid: node id of the node the chunk structure and bitmap should be * allocated on, or -1 * * Add a new chunk of special memory to the specified pool. * * Returns 0 on success or a -ve errno on failure. */ static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size, int nid) { … } extern void gen_pool_destroy(struct gen_pool *); unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size, genpool_algo_t algo, void *data, void **owner); static inline unsigned long gen_pool_alloc_owner(struct gen_pool *pool, size_t size, void **owner) { … } static inline unsigned long gen_pool_alloc_algo(struct gen_pool *pool, size_t size, genpool_algo_t algo, void *data) { … } /** * gen_pool_alloc - allocate special memory from the pool * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * * Allocate the requested number of bytes from the specified pool. * Uses the pool allocation function (with first-fit algorithm by default). * Can not be used in NMI handler on architectures without * NMI-safe cmpxchg implementation. */ static inline unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size) { … } extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma); extern void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size, dma_addr_t *dma, genpool_algo_t algo, void *data); extern void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size, dma_addr_t *dma, int align); extern void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma); extern void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size, dma_addr_t *dma, genpool_algo_t algo, void *data); extern void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size, dma_addr_t *dma, int align); extern void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size, void **owner); static inline void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size) { … } extern void gen_pool_for_each_chunk(struct gen_pool *, void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *); extern size_t gen_pool_avail(struct gen_pool *); extern size_t gen_pool_size(struct gen_pool *); extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data); extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool, unsigned long start_addr); extern unsigned long gen_pool_fixed_alloc(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool, unsigned long start_addr); extern unsigned long gen_pool_first_fit_align(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool, unsigned long start_addr); extern unsigned long gen_pool_first_fit_order_align(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool, unsigned long start_addr); extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, void *data, struct gen_pool *pool, unsigned long start_addr); extern struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order, int nid, const char *name); extern struct gen_pool *gen_pool_get(struct device *dev, const char *name); extern bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start, size_t size); #ifdef CONFIG_OF extern struct gen_pool *of_gen_pool_get(struct device_node *np, const char *propname, int index); #else static inline struct gen_pool *of_gen_pool_get(struct device_node *np, const char *propname, int index) { return NULL; } #endif #endif /* __GENALLOC_H__ */
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