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-rw-r--r--include/linux/dma-contiguous.h176
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diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h
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index 03f8e98e3bcc..000000000000
--- a/include/linux/dma-contiguous.h
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-/* 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