674470d979
In struct gen_pool_chunk, end_addr means the end address of memory chunk (inclusive), but in the implementation it is treated as address + size of memory chunk (exclusive), so it points to the address plus one instead of correct ending address. The ending address of memory chunk plus one will cause overflow on the memory chunk including the last address of memory map, e.g. when starting address is 0xFFF00000 and size is 0x100000 on 32bit machine, ending address will be 0x100000000. Use correct ending address like starting address + size - 1. [akpm@linux-foundation.org: add comment to struct gen_pool_chunk:end_addr] Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
127 lines
4.4 KiB
C
127 lines
4.4 KiB
C
/*
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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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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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};
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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_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_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);
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extern struct gen_pool *dev_get_gen_pool(struct device *dev);
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#ifdef CONFIG_OF
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extern struct gen_pool *of_get_named_gen_pool(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_get_named_gen_pool(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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