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Diffstat (limited to 'include/linux/dma-contiguous.h')
| -rw-r--r-- | include/linux/dma-contiguous.h | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h deleted file mode 100644 index 03f8e98e3bcc..000000000000 --- a/include/linux/dma-contiguous.h +++ /dev/null @@ -1,176 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -#ifndef __LINUX_CMA_H -#define __LINUX_CMA_H - -/* - * Contiguous Memory Allocator for DMA mapping framework - * Copyright (c) 2010-2011 by Samsung Electronics. - * Written by: - * Marek Szyprowski <m.szyprowski@samsung.com> - * Michal Nazarewicz <mina86@mina86.com> - */ - -/* - * Contiguous Memory Allocator - * - * The Contiguous Memory Allocator (CMA) makes it possible to - * allocate big contiguous chunks of memory after the system has - * booted. - * - * Why is it needed? - * - * Various devices on embedded systems have no scatter-getter and/or - * IO map support and require contiguous blocks of memory to - * operate. They include devices such as cameras, hardware video - * coders, etc. - * - * Such devices often require big memory buffers (a full HD frame - * is, for instance, more then 2 mega pixels large, i.e. more than 6 - * MB of memory), which makes mechanisms such as kmalloc() or - * alloc_page() ineffective. - * - * At the same time, a solution where a big memory region is - * reserved for a device is suboptimal since often more memory is - * reserved then strictly required and, moreover, the memory is - * inaccessible to page system even if device drivers don't use it. - * - * CMA tries to solve this issue by operating on memory regions - * where only movable pages can be allocated from. This way, kernel - * can use the memory for pagecache and when device driver requests - * it, allocated pages can be migrated. - * - * Driver usage - * - * CMA should not be used by the device drivers directly. It is - * only a helper framework for dma-mapping subsystem. - * - * For more information, see kernel-docs in kernel/dma/contiguous.c - */ - -#ifdef __KERNEL__ - -#include <linux/device.h> -#include <linux/mm.h> - -struct cma; -struct page; - -#ifdef CONFIG_DMA_CMA - -extern struct cma *dma_contiguous_default_area; - -static inline struct cma *dev_get_cma_area(struct device *dev) -{ - if (dev && dev->cma_area) - return dev->cma_area; - return dma_contiguous_default_area; -} - -static inline void dev_set_cma_area(struct device *dev, struct cma *cma) -{ - if (dev) - dev->cma_area = cma; -} - -static inline void dma_contiguous_set_default(struct cma *cma) -{ - dma_contiguous_default_area = cma; -} - -void dma_contiguous_reserve(phys_addr_t addr_limit); - -int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, - phys_addr_t limit, struct cma **res_cma, - bool fixed); - -/** - * dma_declare_contiguous() - reserve area for contiguous memory handling - * for particular device - * @dev: Pointer to device structure. - * @size: Size of the reserved memory. - * @base: Start address of the reserved memory (optional, 0 for any). - * @limit: End address of the reserved memory (optional, 0 for any). - * - * This function reserves memory for specified device. It should be - * called by board specific code when early allocator (memblock or bootmem) - * is still activate. - */ - -static inline int dma_declare_contiguous(struct device *dev, phys_addr_t size, - phys_addr_t base, phys_addr_t limit) -{ - struct cma *cma; - int ret; - ret = dma_contiguous_reserve_area(size, base, limit, &cma, true); - if (ret == 0) - dev_set_cma_area(dev, cma); - - return ret; -} - -struct page *dma_alloc_from_contiguous(struct device *dev, size_t count, - unsigned int order, bool no_warn); -bool dma_release_from_contiguous(struct device *dev, struct page *pages, - int count); -struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp); -void dma_free_contiguous(struct device *dev, struct page *page, size_t size); - -#else - -static inline struct cma *dev_get_cma_area(struct device *dev) -{ - return NULL; -} - -static inline void dev_set_cma_area(struct device *dev, struct cma *cma) { } - -static inline void dma_contiguous_set_default(struct cma *cma) { } - -static inline void dma_contiguous_reserve(phys_addr_t limit) { } - -static inline int dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, - phys_addr_t limit, struct cma **res_cma, - bool fixed) -{ - return -ENOSYS; -} - -static inline -int dma_declare_contiguous(struct device *dev, phys_addr_t size, - phys_addr_t base, phys_addr_t limit) -{ - return -ENOSYS; -} - -static inline -struct page *dma_alloc_from_contiguous(struct device *dev, size_t count, - unsigned int order, bool no_warn) -{ - return NULL; -} - -static inline -bool dma_release_from_contiguous(struct device *dev, struct page *pages, - int count) -{ - return false; -} - -/* Use fallback alloc() and free() when CONFIG_DMA_CMA=n */ -static inline struct page *dma_alloc_contiguous(struct device *dev, size_t size, - gfp_t gfp) -{ - return NULL; -} - -static inline void dma_free_contiguous(struct device *dev, struct page *page, - size_t size) -{ - __free_pages(page, get_order(size)); -} - -#endif - -#endif - -#endif |