// 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. * * Copyright 2005 (C) Jes Sorensen <[email protected]> */ #include <linux/slab.h> #include <linux/export.h> #include <linux/bitmap.h> #include <linux/rculist.h> #include <linux/interrupt.h> #include <linux/genalloc.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/vmalloc.h> static inline size_t chunk_size(const struct gen_pool_chunk *chunk) { … } static inline int set_bits_ll(unsigned long *addr, unsigned long mask_to_set) { … } static inline int clear_bits_ll(unsigned long *addr, unsigned long mask_to_clear) { … } /* * bitmap_set_ll - set the specified number of bits at the specified position * @map: pointer to a bitmap * @start: a bit position in @map * @nr: number of bits to set * * Set @nr bits start from @start in @map lock-lessly. Several users * can set/clear the same bitmap simultaneously without lock. If two * users set the same bit, one user will return remain bits, otherwise * return 0. */ static unsigned long bitmap_set_ll(unsigned long *map, unsigned long start, unsigned long nr) { … } /* * bitmap_clear_ll - clear the specified number of bits at the specified position * @map: pointer to a bitmap * @start: a bit position in @map * @nr: number of bits to set * * Clear @nr bits start from @start in @map lock-lessly. Several users * can set/clear the same bitmap simultaneously without lock. If two * users clear the same bit, one user will return remain bits, * otherwise return 0. */ static unsigned long bitmap_clear_ll(unsigned long *map, unsigned long start, unsigned long nr) { … } /** * gen_pool_create - create a new special memory pool * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents * @nid: node id of the node the pool structure should be allocated on, or -1 * * Create a new special memory pool that can be used to manage special purpose * memory not managed by the regular kmalloc/kfree interface. */ struct gen_pool *gen_pool_create(int min_alloc_order, int nid) { … } EXPORT_SYMBOL(…); /** * gen_pool_add_owner- add a new chunk of special memory to the pool * @pool: pool to add new memory chunk to * @virt: virtual starting address of memory chunk to add to pool * @phys: physical 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 * @owner: private data the publisher would like to recall at alloc time * * Add a new chunk of special memory to the specified pool. * * Returns 0 on success or a -ve errno on failure. */ int gen_pool_add_owner(struct gen_pool *pool, unsigned long virt, phys_addr_t phys, size_t size, int nid, void *owner) { … } EXPORT_SYMBOL(…); /** * gen_pool_virt_to_phys - return the physical address of memory * @pool: pool to allocate from * @addr: starting address of memory * * Returns the physical address on success, or -1 on error. */ phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long addr) { … } EXPORT_SYMBOL(…); /** * gen_pool_destroy - destroy a special memory pool * @pool: pool to destroy * * Destroy the specified special memory pool. Verifies that there are no * outstanding allocations. */ void gen_pool_destroy(struct gen_pool *pool) { … } EXPORT_SYMBOL(…); /** * gen_pool_alloc_algo_owner - allocate special memory from the pool * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @algo: algorithm passed from caller * @data: data passed to algorithm * @owner: optionally retrieve the chunk owner * * 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. */ unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size, genpool_algo_t algo, void *data, void **owner) { … } EXPORT_SYMBOL(…); /** * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @dma: dma-view physical address return value. Use %NULL if unneeded. * * 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. * * Return: virtual address of the allocated memory, or %NULL on failure */ void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma) { … } EXPORT_SYMBOL(…); /** * gen_pool_dma_alloc_algo - allocate special memory from the pool for DMA * usage with the given pool algorithm * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @dma: DMA-view physical address return value. Use %NULL if unneeded. * @algo: algorithm passed from caller * @data: data passed to algorithm * * Allocate the requested number of bytes from the specified pool. Uses the * given pool allocation function. Can not be used in NMI handler on * architectures without NMI-safe cmpxchg implementation. * * Return: virtual address of the allocated memory, or %NULL on failure */ void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size, dma_addr_t *dma, genpool_algo_t algo, void *data) { … } EXPORT_SYMBOL(…); /** * gen_pool_dma_alloc_align - allocate special memory from the pool for DMA * usage with the given alignment * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @dma: DMA-view physical address return value. Use %NULL if unneeded. * @align: alignment in bytes for starting address * * Allocate the requested number bytes from the specified pool, with the given * alignment restriction. Can not be used in NMI handler on architectures * without NMI-safe cmpxchg implementation. * * Return: virtual address of the allocated memory, or %NULL on failure */ void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size, dma_addr_t *dma, int align) { … } EXPORT_SYMBOL(…); /** * gen_pool_dma_zalloc - allocate special zeroed memory from the pool for * DMA usage * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @dma: dma-view physical address return value. Use %NULL if unneeded. * * Allocate the requested number of zeroed 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. * * Return: virtual address of the allocated zeroed memory, or %NULL on failure */ void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma) { … } EXPORT_SYMBOL(…); /** * gen_pool_dma_zalloc_algo - allocate special zeroed memory from the pool for * DMA usage with the given pool algorithm * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @dma: DMA-view physical address return value. Use %NULL if unneeded. * @algo: algorithm passed from caller * @data: data passed to algorithm * * Allocate the requested number of zeroed bytes from the specified pool. Uses * the given pool allocation function. Can not be used in NMI handler on * architectures without NMI-safe cmpxchg implementation. * * Return: virtual address of the allocated zeroed memory, or %NULL on failure */ void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size, dma_addr_t *dma, genpool_algo_t algo, void *data) { … } EXPORT_SYMBOL(…); /** * gen_pool_dma_zalloc_align - allocate special zeroed memory from the pool for * DMA usage with the given alignment * @pool: pool to allocate from * @size: number of bytes to allocate from the pool * @dma: DMA-view physical address return value. Use %NULL if unneeded. * @align: alignment in bytes for starting address * * Allocate the requested number of zeroed bytes from the specified pool, * with the given alignment restriction. Can not be used in NMI handler on * architectures without NMI-safe cmpxchg implementation. * * Return: virtual address of the allocated zeroed memory, or %NULL on failure */ void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size, dma_addr_t *dma, int align) { … } EXPORT_SYMBOL(…); /** * gen_pool_free_owner - free allocated special memory back to the pool * @pool: pool to free to * @addr: starting address of memory to free back to pool * @size: size in bytes of memory to free * @owner: private data stashed at gen_pool_add() time * * Free previously allocated special memory back to the specified * pool. Can not be used in NMI handler on architectures without * NMI-safe cmpxchg implementation. */ void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, size_t size, void **owner) { … } EXPORT_SYMBOL(…); /** * gen_pool_for_each_chunk - call func for every chunk of generic memory pool * @pool: the generic memory pool * @func: func to call * @data: additional data used by @func * * Call @func for every chunk of generic memory pool. The @func is * called with rcu_read_lock held. */ void gen_pool_for_each_chunk(struct gen_pool *pool, void (*func)(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data), void *data) { … } EXPORT_SYMBOL(…); /** * gen_pool_has_addr - checks if an address falls within the range of a pool * @pool: the generic memory pool * @start: start address * @size: size of the region * * Check if the range of addresses falls within the specified pool. Returns * true if the entire range is contained in the pool and false otherwise. */ bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start, size_t size) { … } EXPORT_SYMBOL(…); /** * gen_pool_avail - get available free space of the pool * @pool: pool to get available free space * * Return available free space of the specified pool. */ size_t gen_pool_avail(struct gen_pool *pool) { … } EXPORT_SYMBOL_GPL(…); /** * gen_pool_size - get size in bytes of memory managed by the pool * @pool: pool to get size * * Return size in bytes of memory managed by the pool. */ size_t gen_pool_size(struct gen_pool *pool) { … } EXPORT_SYMBOL_GPL(…); /** * gen_pool_set_algo - set the allocation algorithm * @pool: pool to change allocation algorithm * @algo: custom algorithm function * @data: additional data used by @algo * * Call @algo for each memory allocation in the pool. * If @algo is NULL use gen_pool_first_fit as default * memory allocation function. */ void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, void *data) { … } EXPORT_SYMBOL(…); /** * gen_pool_first_fit - find the first available region * of memory matching the size requirement (no alignment constraint) * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @data: additional data - unused * @pool: pool to find the fit region memory from * @start_addr: not used in this function */ 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) { … } EXPORT_SYMBOL(…); /** * gen_pool_first_fit_align - find the first available region * of memory matching the size requirement (alignment constraint) * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @data: data for alignment * @pool: pool to get order from * @start_addr: start addr of alloction chunk */ 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) { … } EXPORT_SYMBOL(…); /** * gen_pool_fixed_alloc - reserve a specific region * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @data: data for alignment * @pool: pool to get order from * @start_addr: not used in this function */ 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) { … } EXPORT_SYMBOL(…); /** * gen_pool_first_fit_order_align - find the first available region * of memory matching the size requirement. The region will be aligned * to the order of the size specified. * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @data: additional data - unused * @pool: pool to find the fit region memory from * @start_addr: not used in this function */ 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) { … } EXPORT_SYMBOL(…); /** * gen_pool_best_fit - find the best fitting region of memory * matching the size requirement (no alignment constraint) * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @data: additional data - unused * @pool: pool to find the fit region memory from * @start_addr: not used in this function * * Iterate over the bitmap to find the smallest free region * which we can allocate the memory. */ 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) { … } EXPORT_SYMBOL(…); static void devm_gen_pool_release(struct device *dev, void *res) { … } static int devm_gen_pool_match(struct device *dev, void *res, void *data) { … } /** * gen_pool_get - Obtain the gen_pool (if any) for a device * @dev: device to retrieve the gen_pool from * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device * * Returns the gen_pool for the device if one is present, or NULL. */ struct gen_pool *gen_pool_get(struct device *dev, const char *name) { … } EXPORT_SYMBOL_GPL(…); /** * devm_gen_pool_create - managed gen_pool_create * @dev: device that provides the gen_pool * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents * @nid: node selector for allocated gen_pool, %NUMA_NO_NODE for all nodes * @name: name of a gen_pool or NULL, identifies a particular gen_pool on device * * Create a new special memory pool that can be used to manage special purpose * memory not managed by the regular kmalloc/kfree interface. The pool will be * automatically destroyed by the device management code. */ struct gen_pool *devm_gen_pool_create(struct device *dev, int min_alloc_order, int nid, const char *name) { … } EXPORT_SYMBOL(…); #ifdef CONFIG_OF /** * of_gen_pool_get - find a pool by phandle property * @np: device node * @propname: property name containing phandle(s) * @index: index into the phandle array * * Returns the pool that contains the chunk starting at the physical * address of the device tree node pointed at by the phandle property, * or NULL if not found. */ struct gen_pool *of_gen_pool_get(struct device_node *np, const char *propname, int index) { … } EXPORT_SYMBOL_GPL(…); #endif /* CONFIG_OF */
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