LCOV - code coverage report
Current view: top level - include/linux - genalloc.h (source / functions) Hit Total Coverage
Test: Real Lines: 4 4 100.0 %
Date: 2020-10-17 15:46:16 Functions: 0 0 -
Legend: Neither, QEMU, Real, Both Branches: 0 0 -

           Branch data     Line data    Source code
       1                 :            : /* SPDX-License-Identifier: GPL-2.0-only */
       2                 :            : /*
       3                 :            :  * Basic general purpose allocator for managing special purpose
       4                 :            :  * memory, for example, memory that is not managed by the regular
       5                 :            :  * kmalloc/kfree interface.  Uses for this includes on-device special
       6                 :            :  * memory, uncached memory etc.
       7                 :            :  *
       8                 :            :  * It is safe to use the allocator in NMI handlers and other special
       9                 :            :  * unblockable contexts that could otherwise deadlock on locks.  This
      10                 :            :  * is implemented by using atomic operations and retries on any
      11                 :            :  * conflicts.  The disadvantage is that there may be livelocks in
      12                 :            :  * extreme cases.  For better scalability, one allocator can be used
      13                 :            :  * for each CPU.
      14                 :            :  *
      15                 :            :  * The lockless operation only works if there is enough memory
      16                 :            :  * available.  If new memory is added to the pool a lock has to be
      17                 :            :  * still taken.  So any user relying on locklessness has to ensure
      18                 :            :  * that sufficient memory is preallocated.
      19                 :            :  *
      20                 :            :  * The basic atomic operation of this allocator is cmpxchg on long.
      21                 :            :  * On architectures that don't have NMI-safe cmpxchg implementation,
      22                 :            :  * the allocator can NOT be used in NMI handler.  So code uses the
      23                 :            :  * allocator in NMI handler should depend on
      24                 :            :  * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
      25                 :            :  */
      26                 :            : 
      27                 :            : 
      28                 :            : #ifndef __GENALLOC_H__
      29                 :            : #define __GENALLOC_H__
      30                 :            : 
      31                 :            : #include <linux/types.h>
      32                 :            : #include <linux/spinlock_types.h>
      33                 :            : #include <linux/atomic.h>
      34                 :            : 
      35                 :            : struct device;
      36                 :            : struct device_node;
      37                 :            : struct gen_pool;
      38                 :            : 
      39                 :            : /**
      40                 :            :  * typedef genpool_algo_t: Allocation callback function type definition
      41                 :            :  * @map: Pointer to bitmap
      42                 :            :  * @size: The bitmap size in bits
      43                 :            :  * @start: The bitnumber to start searching at
      44                 :            :  * @nr: The number of zeroed bits we're looking for
      45                 :            :  * @data: optional additional data used by the callback
      46                 :            :  * @pool: the pool being allocated from
      47                 :            :  */
      48                 :            : typedef unsigned long (*genpool_algo_t)(unsigned long *map,
      49                 :            :                         unsigned long size,
      50                 :            :                         unsigned long start,
      51                 :            :                         unsigned int nr,
      52                 :            :                         void *data, struct gen_pool *pool,
      53                 :            :                         unsigned long start_addr);
      54                 :            : 
      55                 :            : /*
      56                 :            :  *  General purpose special memory pool descriptor.
      57                 :            :  */
      58                 :            : struct gen_pool {
      59                 :            :         spinlock_t lock;
      60                 :            :         struct list_head chunks;        /* list of chunks in this pool */
      61                 :            :         int min_alloc_order;            /* minimum allocation order */
      62                 :            : 
      63                 :            :         genpool_algo_t algo;            /* allocation function */
      64                 :            :         void *data;
      65                 :            : 
      66                 :            :         const char *name;
      67                 :            : };
      68                 :            : 
      69                 :            : /*
      70                 :            :  *  General purpose special memory pool chunk descriptor.
      71                 :            :  */
      72                 :            : struct gen_pool_chunk {
      73                 :            :         struct list_head next_chunk;    /* next chunk in pool */
      74                 :            :         atomic_long_t avail;
      75                 :            :         phys_addr_t phys_addr;          /* physical starting address of memory chunk */
      76                 :            :         void *owner;                    /* private data to retrieve at alloc time */
      77                 :            :         unsigned long start_addr;       /* start address of memory chunk */
      78                 :            :         unsigned long end_addr;         /* end address of memory chunk (inclusive) */
      79                 :            :         unsigned long bits[0];          /* bitmap for allocating memory chunk */
      80                 :            : };
      81                 :            : 
      82                 :            : /*
      83                 :            :  *  gen_pool data descriptor for gen_pool_first_fit_align.
      84                 :            :  */
      85                 :            : struct genpool_data_align {
      86                 :            :         int align;              /* alignment by bytes for starting address */
      87                 :            : };
      88                 :            : 
      89                 :            : /*
      90                 :            :  *  gen_pool data descriptor for gen_pool_fixed_alloc.
      91                 :            :  */
      92                 :            : struct genpool_data_fixed {
      93                 :            :         unsigned long offset;           /* The offset of the specific region */
      94                 :            : };
      95                 :            : 
      96                 :            : extern struct gen_pool *gen_pool_create(int, int);
      97                 :            : extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
      98                 :            : extern int gen_pool_add_owner(struct gen_pool *, unsigned long, phys_addr_t,
      99                 :            :                              size_t, int, void *);
     100                 :            : 
     101                 :            : static inline int gen_pool_add_virt(struct gen_pool *pool, unsigned long addr,
     102                 :            :                 phys_addr_t phys, size_t size, int nid)
     103                 :            : {
     104                 :          3 :         return gen_pool_add_owner(pool, addr, phys, size, nid, NULL);
     105                 :            : }
     106                 :            : 
     107                 :            : /**
     108                 :            :  * gen_pool_add - add a new chunk of special memory to the pool
     109                 :            :  * @pool: pool to add new memory chunk to
     110                 :            :  * @addr: starting address of memory chunk to add to pool
     111                 :            :  * @size: size in bytes of the memory chunk to add to pool
     112                 :            :  * @nid: node id of the node the chunk structure and bitmap should be
     113                 :            :  *       allocated on, or -1
     114                 :            :  *
     115                 :            :  * Add a new chunk of special memory to the specified pool.
     116                 :            :  *
     117                 :            :  * Returns 0 on success or a -ve errno on failure.
     118                 :            :  */
     119                 :            : static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
     120                 :            :                                size_t size, int nid)
     121                 :            : {
     122                 :            :         return gen_pool_add_virt(pool, addr, -1, size, nid);
     123                 :            : }
     124                 :            : extern void gen_pool_destroy(struct gen_pool *);
     125                 :            : unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size,
     126                 :            :                 genpool_algo_t algo, void *data, void **owner);
     127                 :            : 
     128                 :            : static inline unsigned long gen_pool_alloc_owner(struct gen_pool *pool,
     129                 :            :                 size_t size, void **owner)
     130                 :            : {
     131                 :            :         return gen_pool_alloc_algo_owner(pool, size, pool->algo, pool->data,
     132                 :            :                         owner);
     133                 :            : }
     134                 :            : 
     135                 :            : static inline unsigned long gen_pool_alloc_algo(struct gen_pool *pool,
     136                 :            :                 size_t size, genpool_algo_t algo, void *data)
     137                 :            : {
     138                 :          3 :         return gen_pool_alloc_algo_owner(pool, size, algo, data, NULL);
     139                 :            : }
     140                 :            : 
     141                 :            : /**
     142                 :            :  * gen_pool_alloc - allocate special memory from the pool
     143                 :            :  * @pool: pool to allocate from
     144                 :            :  * @size: number of bytes to allocate from the pool
     145                 :            :  *
     146                 :            :  * Allocate the requested number of bytes from the specified pool.
     147                 :            :  * Uses the pool allocation function (with first-fit algorithm by default).
     148                 :            :  * Can not be used in NMI handler on architectures without
     149                 :            :  * NMI-safe cmpxchg implementation.
     150                 :            :  */
     151                 :            : static inline unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
     152                 :            : {
     153                 :          3 :         return gen_pool_alloc_algo(pool, size, pool->algo, pool->data);
     154                 :            : }
     155                 :            : 
     156                 :            : extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size,
     157                 :            :                 dma_addr_t *dma);
     158                 :            : extern void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size,
     159                 :            :                 dma_addr_t *dma, genpool_algo_t algo, void *data);
     160                 :            : extern void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size,
     161                 :            :                 dma_addr_t *dma, int align);
     162                 :            : extern void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma);
     163                 :            : extern void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size,
     164                 :            :                 dma_addr_t *dma, genpool_algo_t algo, void *data);
     165                 :            : extern void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size,
     166                 :            :                 dma_addr_t *dma, int align);
     167                 :            : extern void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr,
     168                 :            :                 size_t size, void **owner);
     169                 :            : static inline void gen_pool_free(struct gen_pool *pool, unsigned long addr,
     170                 :            :                 size_t size)
     171                 :            : {
     172                 :          3 :         gen_pool_free_owner(pool, addr, size, NULL);
     173                 :            : }
     174                 :            : 
     175                 :            : extern void gen_pool_for_each_chunk(struct gen_pool *,
     176                 :            :         void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
     177                 :            : extern size_t gen_pool_avail(struct gen_pool *);
     178                 :            : extern size_t gen_pool_size(struct gen_pool *);
     179                 :            : 
     180                 :            : extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo,
     181                 :            :                 void *data);
     182                 :            : 
     183                 :            : extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
     184                 :            :                 unsigned long start, unsigned int nr, void *data,
     185                 :            :                 struct gen_pool *pool, unsigned long start_addr);
     186                 :            : 
     187                 :            : extern unsigned long gen_pool_fixed_alloc(unsigned long *map,
     188                 :            :                 unsigned long size, unsigned long start, unsigned int nr,
     189                 :            :                 void *data, struct gen_pool *pool, unsigned long start_addr);
     190                 :            : 
     191                 :            : extern unsigned long gen_pool_first_fit_align(unsigned long *map,
     192                 :            :                 unsigned long size, unsigned long start, unsigned int nr,
     193                 :            :                 void *data, struct gen_pool *pool, unsigned long start_addr);
     194                 :            : 
     195                 :            : 
     196                 :            : extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,
     197                 :            :                 unsigned long size, unsigned long start, unsigned int nr,
     198                 :            :                 void *data, struct gen_pool *pool, unsigned long start_addr);
     199                 :            : 
     200                 :            : extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
     201                 :            :                 unsigned long start, unsigned int nr, void *data,
     202                 :            :                 struct gen_pool *pool, unsigned long start_addr);
     203                 :            : 
     204                 :            : 
     205                 :            : extern struct gen_pool *devm_gen_pool_create(struct device *dev,
     206                 :            :                 int min_alloc_order, int nid, const char *name);
     207                 :            : extern struct gen_pool *gen_pool_get(struct device *dev, const char *name);
     208                 :            : 
     209                 :            : bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
     210                 :            :                         size_t size);
     211                 :            : 
     212                 :            : #ifdef CONFIG_OF
     213                 :            : extern struct gen_pool *of_gen_pool_get(struct device_node *np,
     214                 :            :         const char *propname, int index);
     215                 :            : #else
     216                 :            : static inline struct gen_pool *of_gen_pool_get(struct device_node *np,
     217                 :            :         const char *propname, int index)
     218                 :            : {
     219                 :            :         return NULL;
     220                 :            : }
     221                 :            : #endif
     222                 :            : #endif /* __GENALLOC_H__ */
    

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