/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* DMA BUF PagePool implementation
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* Based on earlier ION code by Google
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*
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* Copyright (C) 2011 Google, Inc.
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* Copyright (C) 2020 Linaro Ltd.
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*/
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#ifndef _DMABUF_PAGE_POOL_H
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#define _DMABUF_PAGE_POOL_H
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#include <linux/device.h>
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#include <linux/kref.h>
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#include <linux/mm_types.h>
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#include <linux/mutex.h>
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#include <linux/shrinker.h>
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#include <linux/types.h>
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/* page types we track in the pool */
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enum {
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POOL_LOWPAGE, /* Clean lowmem pages */
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POOL_HIGHPAGE, /* Clean highmem pages */
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POOL_TYPE_SIZE,
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};
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/**
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* struct dmabuf_page_pool - pagepool struct
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* @count[]: array of number of pages of that type in the pool
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* @items[]: array of list of pages of the specific type
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* @mutex: lock protecting this struct and especially the count
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* item list
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* @gfp_mask: gfp_mask to use from alloc
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* @order: order of pages in the pool
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* @list: list node for list of pools
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*
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* Allows you to keep a pool of pre allocated pages to use
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*/
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struct dmabuf_page_pool {
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int count[POOL_TYPE_SIZE];
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struct list_head items[POOL_TYPE_SIZE];
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struct mutex mutex; /* No longer used! */
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gfp_t gfp_mask;
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unsigned int order;
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struct list_head list;
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};
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struct dmabuf_page_pool *dmabuf_page_pool_create(gfp_t gfp_mask,
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unsigned int order);
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void dmabuf_page_pool_destroy(struct dmabuf_page_pool *pool);
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struct page *dmabuf_page_pool_alloc(struct dmabuf_page_pool *pool);
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void dmabuf_page_pool_free(struct dmabuf_page_pool *pool, struct page *page);
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#endif /* _DMABUF_PAGE_POOL_H */
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