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139 lines
4.8 KiB
139 lines
4.8 KiB
/* |
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* Basic general purpose allocator for managing special purpose |
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* memory, for example, memory that is not managed by the regular |
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* kmalloc/kfree interface. Uses for this includes on-device special |
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* memory, uncached memory etc. |
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* |
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* It is safe to use the allocator in NMI handlers and other special |
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* unblockable contexts that could otherwise deadlock on locks. This |
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* is implemented by using atomic operations and retries on any |
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* conflicts. The disadvantage is that there may be livelocks in |
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* extreme cases. For better scalability, one allocator can be used |
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* for each CPU. |
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* |
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* The lockless operation only works if there is enough memory |
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* available. If new memory is added to the pool a lock has to be |
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* still taken. So any user relying on locklessness has to ensure |
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* that sufficient memory is preallocated. |
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* |
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* The basic atomic operation of this allocator is cmpxchg on long. |
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* On architectures that don't have NMI-safe cmpxchg implementation, |
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* the allocator can NOT be used in NMI handler. So code uses the |
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* allocator in NMI handler should depend on |
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* CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. |
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* |
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* This source code is licensed under the GNU General Public License, |
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* Version 2. See the file COPYING for more details. |
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*/ |
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#ifndef __GENALLOC_H__ |
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#define __GENALLOC_H__ |
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#include <linux/spinlock_types.h> |
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struct device; |
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struct device_node; |
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/** |
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* Allocation callback function type definition |
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* @map: Pointer to bitmap |
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* @size: The bitmap size in bits |
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* @start: The bitnumber to start searching at |
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* @nr: The number of zeroed bits we're looking for |
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* @data: optional additional data used by @genpool_algo_t |
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*/ |
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typedef unsigned long (*genpool_algo_t)(unsigned long *map, |
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unsigned long size, |
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unsigned long start, |
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unsigned int nr, |
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void *data); |
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/* |
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* General purpose special memory pool descriptor. |
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*/ |
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struct gen_pool { |
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spinlock_t lock; |
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struct list_head chunks; /* list of chunks in this pool */ |
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int min_alloc_order; /* minimum allocation order */ |
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genpool_algo_t algo; /* allocation function */ |
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void *data; |
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const char *name; |
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}; |
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/* |
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* General purpose special memory pool chunk descriptor. |
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*/ |
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struct gen_pool_chunk { |
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struct list_head next_chunk; /* next chunk in pool */ |
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atomic_t avail; |
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phys_addr_t phys_addr; /* physical starting address of memory chunk */ |
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unsigned long start_addr; /* start address of memory chunk */ |
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unsigned long end_addr; /* end address of memory chunk (inclusive) */ |
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unsigned long bits[0]; /* bitmap for allocating memory chunk */ |
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}; |
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extern struct gen_pool *gen_pool_create(int, int); |
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extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long); |
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extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t, |
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size_t, int); |
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/** |
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* gen_pool_add - add a new chunk of special memory to the pool |
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* @pool: pool to add new memory chunk to |
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* @addr: starting address of memory chunk to add to pool |
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* @size: size in bytes of the memory chunk to add to pool |
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* @nid: node id of the node the chunk structure and bitmap should be |
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* allocated on, or -1 |
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* |
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* Add a new chunk of special memory to the specified pool. |
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* |
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* Returns 0 on success or a -ve errno on failure. |
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*/ |
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static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr, |
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size_t size, int nid) |
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{ |
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return gen_pool_add_virt(pool, addr, -1, size, nid); |
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} |
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extern void gen_pool_destroy(struct gen_pool *); |
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extern unsigned long gen_pool_alloc(struct gen_pool *, size_t); |
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extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, |
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dma_addr_t *dma); |
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extern void gen_pool_free(struct gen_pool *, unsigned long, size_t); |
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extern void gen_pool_for_each_chunk(struct gen_pool *, |
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void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *); |
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extern size_t gen_pool_avail(struct gen_pool *); |
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extern size_t gen_pool_size(struct gen_pool *); |
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extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, |
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void *data); |
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extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size, |
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unsigned long start, unsigned int nr, void *data); |
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extern unsigned long gen_pool_first_fit_order_align(unsigned long *map, |
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unsigned long size, unsigned long start, unsigned int nr, |
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void *data); |
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extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size, |
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unsigned long start, unsigned int nr, void *data); |
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extern struct gen_pool *devm_gen_pool_create(struct device *dev, |
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int min_alloc_order, int nid, const char *name); |
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extern struct gen_pool *gen_pool_get(struct device *dev, const char *name); |
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bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start, |
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size_t size); |
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#ifdef CONFIG_OF |
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extern struct gen_pool *of_gen_pool_get(struct device_node *np, |
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const char *propname, int index); |
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#else |
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static inline struct gen_pool *of_gen_pool_get(struct device_node *np, |
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const char *propname, int index) |
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{ |
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return NULL; |
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} |
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#endif |
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#endif /* __GENALLOC_H__ */
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