cregit-Linux how code gets into the kernel

Release 4.7 include/linux/genalloc.h

Directory: include/linux
/*
 * 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.
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */


#ifndef __GENALLOC_H__

#define __GENALLOC_H__

#include <linux/types.h>
#include <linux/spinlock_types.h>

struct device;
struct device_node;
struct gen_pool;

/**
 * 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 @genpool_algo_t
 */

typedef unsigned long (*genpool_algo_t)(unsigned long *map,
			unsigned long size,
			unsigned long start,
			unsigned int nr,
			void *data, struct gen_pool *pool);

/*
 *  General purpose special memory pool descriptor.
 */

struct gen_pool {
	
spinlock_t lock;
	
struct list_head chunks;	/* list of chunks in this pool */
	
int min_alloc_order;		/* minimum allocation order */

	
genpool_algo_t algo;		/* allocation function */
	
void *data;

	
const char *name;
};

/*
 *  General purpose special memory pool chunk descriptor.
 */

struct gen_pool_chunk {
	
struct list_head next_chunk;	/* next chunk in pool */
	
atomic_t avail;
	
phys_addr_t phys_addr;		/* physical starting address of memory chunk */
	
unsigned long start_addr;	/* start address of memory chunk */
	
unsigned long end_addr;		/* end address of memory chunk (inclusive) */
	
unsigned long bits[0];		/* bitmap for allocating memory chunk */
};

/*
 *  gen_pool data descriptor for gen_pool_first_fit_align.
 */

struct genpool_data_align {
	
int align;		/* alignment by bytes for starting address */
};

/*
 *  gen_pool data descriptor for gen_pool_fixed_alloc.
 */

struct genpool_data_fixed {
	
unsigned long offset;		/* The offset of the specific region */
};

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_virt(struct gen_pool *, unsigned long, phys_addr_t,
			     size_t, int);
/**
 * 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) { return gen_pool_add_virt(pool, addr, -1, size, nid); }

Contributors

PersonTokensPropCommitsCommitProp
jean-christophe plagniol-villardjean-christophe plagniol-villard37100.00%1100.00%
Total37100.00%1100.00%

extern void gen_pool_destroy(struct gen_pool *); extern unsigned long gen_pool_alloc(struct gen_pool *, size_t); extern unsigned long gen_pool_alloc_algo(struct gen_pool *, size_t, genpool_algo_t algo, void *data); extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma); extern void gen_pool_free(struct gen_pool *, unsigned long, size_t); 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); 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); 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); 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); 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); 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); bool addr_in_gen_pool(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; }

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PersonTokensPropCommitsCommitProp
philipp zabelphilipp zabel2496.00%150.00%
vladimir zapolskiyvladimir zapolskiy14.00%150.00%
Total25100.00%2100.00%

#endif #endif /* __GENALLOC_H__ */

Overall Contributors

PersonTokensPropCommitsCommitProp
zhao qiangzhao qiang13020.54%210.53%
benjamin gaignardbenjamin gaignard11017.38%15.26%
philipp zabelphilipp zabel8513.43%15.26%
jean-christophe plagniol-villardjean-christophe plagniol-villard6710.58%210.53%
dean nelsondean nelson538.37%15.26%
huang yinghuang ying528.21%15.26%
jes sorensenjes sorensen436.79%15.26%
laura abbottlaura abbott436.79%210.53%
vladimir zapolskiyvladimir zapolskiy182.84%421.05%
nicolin chennicolin chen182.84%15.26%
steve wisesteve wise91.42%15.26%
shawn guoshawn guo30.47%15.26%
joonyoung shimjoonyoung shim20.32%15.26%
Total633100.00%19100.00%
Directory: include/linux
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