/*
 * drivers/gpu/ion/ion_priv.h
 *
 * Copyright (C) 2011 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#ifndef _ION_PRIV_H
#define _ION_PRIV_H

#include <linux/ion.h>
#include <linux/kref.h>
#include <linux/mm_types.h>
#include <linux/mutex.h>
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/shrinker.h>
#include <linux/types.h>

struct ion_buffer *ion_handle_buffer(struct ion_handle *handle);

/**
 * struct ion_buffer - metadata for a particular buffer
 * @ref:		refernce count
 * @node:		node in the ion_device buffers tree
 * @dev:		back pointer to the ion_device
 * @heap:		back pointer to the heap the buffer came from
 * @flags:		buffer specific flags
 * @size:		size of the buffer
 * @priv_virt:		private data to the buffer representable as
 *			a void *
 * @priv_phys:		private data to the buffer representable as
 *			an ion_phys_addr_t (and someday a phys_addr_t)
 * @lock:		protects the buffers cnt fields
 * @kmap_cnt:		number of times the buffer is mapped to the kernel
 * @vaddr:		the kenrel mapping if kmap_cnt is not zero
 * @dmap_cnt:		number of times the buffer is mapped for dma
 * @sg_table:		the sg table for the buffer if dmap_cnt is not zero
 * @dirty:		bitmask representing which pages of this buffer have
 *			been dirtied by the cpu and need cache maintenance
 *			before dma
 * @vmas:		list of vma's mapping this buffer
 * @handle_count:	count of handles referencing this buffer
 * @task_comm:		taskcomm of last client to reference this buffer in a
 *			handle, used for debugging
 * @pid:		pid of last client to reference this buffer in a
 *			handle, used for debugging
*/
struct ion_buffer {
	struct kref ref;
	struct rb_node node;
	struct ion_device *dev;
	struct ion_heap *heap;
	unsigned long flags;
	size_t size;
	union {
		void *priv_virt;
		ion_phys_addr_t priv_phys;
	};
	struct mutex lock;
	int kmap_cnt;
	void *vaddr;
	int dmap_cnt;
	struct sg_table *sg_table;
	unsigned long *dirty;
	struct list_head vmas;
	/* used to track orphaned buffers */
	int handle_count;
	char task_comm[TASK_COMM_LEN];
	pid_t pid;
};

/**
 * struct ion_heap_ops - ops to operate on a given heap
 * @allocate:		allocate memory
 * @free:		free memory
 * @phys		get physical address of a buffer (only define on
 *			physically contiguous heaps)
 * @map_dma		map the memory for dma to a scatterlist
 * @unmap_dma		unmap the memory for dma
 * @map_kernel		map memory to the kernel
 * @unmap_kernel	unmap memory to the kernel
 * @map_user		map memory to userspace
 */
struct ion_heap_ops {
	int (*allocate) (struct ion_heap *heap,
			 struct ion_buffer *buffer, unsigned long len,
			 unsigned long align, unsigned long flags);
	void (*free) (struct ion_buffer *buffer);
	int (*phys) (struct ion_heap *heap, struct ion_buffer *buffer,
		     ion_phys_addr_t *addr, size_t *len);
	struct sg_table *(*map_dma) (struct ion_heap *heap,
					struct ion_buffer *buffer);
	void (*unmap_dma) (struct ion_heap *heap, struct ion_buffer *buffer);
	void * (*map_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
	void (*unmap_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
	int (*map_user) (struct ion_heap *mapper, struct ion_buffer *buffer,
			 struct vm_area_struct *vma);
};

/**
 * struct ion_heap - represents a heap in the system
 * @node:		rb node to put the heap on the device's tree of heaps
 * @dev:		back pointer to the ion_device
 * @type:		type of heap
 * @ops:		ops struct as above
 * @id:			id of heap, also indicates priority of this heap when
 *			allocating.  These are specified by platform data and
 *			MUST be unique
 * @name:		used for debugging
 * @debug_show:		called when heap debug file is read to add any
 *			heap specific debug info to output
 *
 * Represents a pool of memory from which buffers can be made.  In some
 * systems the only heap is regular system memory allocated via vmalloc.
 * On others, some blocks might require large physically contiguous buffers
 * that are allocated from a specially reserved heap.
 */
struct ion_heap {
	struct rb_node node;
	struct ion_device *dev;
	enum ion_heap_type type;
	struct ion_heap_ops *ops;
	int id;
	const char *name;
	int (*debug_show)(struct ion_heap *heap, struct seq_file *, void *);
};

/**
 * ion_buffer_cached - this ion buffer is cached
 * @buffer:		buffer
 *
 * indicates whether this ion buffer is cached
 */
bool ion_buffer_cached(struct ion_buffer *buffer);

/**
 * ion_buffer_fault_user_mappings - fault in user mappings of this buffer
 * @buffer:		buffer
 *
 * indicates whether userspace mappings of this buffer will be faulted
 * in, this can affect how buffers are allocated from the heap.
 */
bool ion_buffer_fault_user_mappings(struct ion_buffer *buffer);

/**
 * ion_device_create - allocates and returns an ion device
 * @custom_ioctl:	arch specific ioctl function if applicable
 *
 * returns a valid device or -PTR_ERR
 */
struct ion_device *ion_device_create(long (*custom_ioctl)
				     (struct ion_client *client,
				      unsigned int cmd,
				      unsigned long arg));

/**
 * ion_device_destroy - free and device and it's resource
 * @dev:		the device
 */
void ion_device_destroy(struct ion_device *dev);

/**
 * ion_device_add_heap - adds a heap to the ion device
 * @dev:		the device
 * @heap:		the heap to add
 */
void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap);

/**
 * functions for creating and destroying the built in ion heaps.
 * architectures can add their own custom architecture specific
 * heaps as appropriate.
 */

struct ion_heap *ion_heap_create(struct ion_platform_heap *);
void ion_heap_destroy(struct ion_heap *);

struct ion_heap *ion_system_heap_create(struct ion_platform_heap *);
void ion_system_heap_destroy(struct ion_heap *);

struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *);
void ion_system_contig_heap_destroy(struct ion_heap *);

struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *);
void ion_carveout_heap_destroy(struct ion_heap *);
/**
 * kernel api to allocate/free from carveout -- used when carveout is
 * used to back an architecture specific custom heap
 */
ion_phys_addr_t ion_carveout_allocate(struct ion_heap *heap, unsigned long size,
				      unsigned long align);
void ion_carveout_free(struct ion_heap *heap, ion_phys_addr_t addr,
		       unsigned long size);
/**
 * The carveout heap returns physical addresses, since 0 may be a valid
 * physical address, this is used to indicate allocation failed
 */
#define ION_CARVEOUT_ALLOCATE_FAIL -1

/**
 * functions for creating and destroying a heap pool -- allows you
 * to keep a pool of pre allocated memory to use from your heap.  Keeping
 * a pool of memory that is ready for dma, ie any cached mapping have been
 * invalidated from the cache, provides a significant peformance benefit on
 * many systems */

/**
 * struct ion_page_pool - pagepool struct
 * @high_count:		number of highmem items in the pool
 * @low_count:		number of lowmem items in the pool
 * @high_items:		list of highmem items
 * @low_items:		list of lowmem items
 * @shrinker:		a shrinker for the items
 * @mutex:		lock protecting this struct and especially the count
 *			item list
 * @alloc:		function to be used to allocate pageory when the pool
 *			is empty
 * @free:		function to be used to free pageory back to the system
 *			when the shrinker fires
 * @gfp_mask:		gfp_mask to use from alloc
 * @order:		order of pages in the pool
 * @list:		plist node for list of pools
 *
 * Allows you to keep a pool of pre allocated pages to use from your heap.
 * Keeping a pool of pages that is ready for dma, ie any cached mapping have
 * been invalidated from the cache, provides a significant peformance benefit
 * on many systems
 */
struct ion_page_pool {
	int high_count;
	int low_count;
	struct list_head high_items;
	struct list_head low_items;
	struct mutex mutex;
	void *(*alloc)(struct ion_page_pool *pool);
	void (*free)(struct ion_page_pool *pool, struct page *page);
	gfp_t gfp_mask;
	unsigned int order;
	struct plist_node list;
};

struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order);
void ion_page_pool_destroy(struct ion_page_pool *);
void *ion_page_pool_alloc(struct ion_page_pool *);
void ion_page_pool_free(struct ion_page_pool *, struct page *);

#endif /* _ION_PRIV_H */