// SPDX-License-Identifier: GPL-2.0
/*
* drivers/staging/android/ion/ion.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_H
#define _ION_H
#include <linux/device.h>
#include <linux/dma-direction.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>
#include <linux/miscdevice.h>
#include "../uapi/ion.h"
/**
* struct ion_platform_heap - defines a heap in the given platform
* @type: type of the heap from ion_heap_type enum
* @id: unique identifier for heap. When allocating higher numb ers
* will be allocated from first. At allocation these are passed
* as a bit mask and therefore can not exceed ION_NUM_HEAP_IDS.
* @name: used for debug purposes
* @base: base address of heap in physical memory if applicable
* @size: size of the heap in bytes if applicable
* @priv: private info passed from the board file
*
* Provided by the board file.
*/
struct ion_platform_heap {
enum ion_heap_type type;
unsigned int id;
const char *name;
phys_addr_t base;
size_t size;
phys_addr_t align;
void *priv;
};
/**
* struct ion_buffer - metadata for a particular buffer
* @ref: reference 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
* @private_flags: internal buffer specific flags
* @size: size of the buffer
* @priv_virt: private data to the buffer representable as
* a void *
* @lock: protects the buffers cnt fields
* @kmap_cnt: number of times the buffer is mapped to the kernel
* @vaddr: the kernel mapping if kmap_cnt is not zero
* @sg_table: the sg table for the buffer if dmap_cnt is not zero
*/
struct ion_buffer {
union {
struct rb_node node;
struct list_head list;
};
struct ion_device *dev;
struct ion_heap *heap;
unsigned long flags;
unsigned long private_flags;
size_t size;
void *priv_virt;
struct mutex lock;
int kmap_cnt;
void *vaddr;
struct sg_table *sg_table;
struct list_head attachments;
};
void ion_buffer_destroy(struct ion_buffer *buffer);
/**
* struct ion_device - the metadata of the ion device node
* @dev: the actual misc device
* @buffers: an rb tree of all the existing buffers
* @buffer_lock: lock protecting the tree of buffers
* @lock: rwsem protecting the tree of heaps and clients
*/
struct ion_device {
struct miscdevice dev;
struct rb_root buffers;
struct mutex buffer_lock;
struct rw_semaphore lock;
struct plist_head heaps;
struct dentry *debug_root;
int heap_cnt;
};
/**
* struct ion_heap_ops - ops to operate on a given heap
* @allocate: allocate memory
* @free: free memory
* @map_kernel map memory to the kernel
* @unmap_kernel unmap memory to the kernel
* @map_user map memory to userspace
*
* allocate, phys, and map_user return 0 on success, -errno on error.
* map_dma and map_kernel return pointer on success, ERR_PTR on
* error. @free will be called with ION_PRIV_FLAG_SHRINKER_FREE set in
* the buffer's private_flags when called from a shrinker. In that
* case, the pages being free'd must be truly free'd back to the
* system, not put in a page pool or otherwise cached.
*/
struct ion_heap_ops {
int (*allocate)(struct ion_heap *heap,
struct ion_buffer *buffer, unsigned long len,
unsigned long flags);
void (*free)(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);
int (*shrink)(struct ion_heap *heap, gfp_t gfp_mask, int nr_to_scan);
};
/**
* heap flags - flags between the heaps and core ion code
*/
#define ION_HEAP_FLAG_DEFER_FREE BIT(0)
/**
* private flags - flags internal to ion
*/
/*
* Buffer is being freed from a shrinker function. Skip any possible
* heap-specific caching mechanism (e.g. page pools). Guarantees that
* any buffer storage that came from the system allocator will be
* returned to the system allocator.
*/
#define ION_PRIV_FLAG_SHRINKER_FREE BIT(0)
/**
* 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
* @flags: flags
* @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
* @shrinker: a shrinker for the heap
* @free_list: free list head if deferred free is used
* @free_list_size size of the deferred free list in bytes
* @lock: protects the free list
* @waitqueue: queue to wait on from deferred free thread
* @task: task struct of deferred free thread
* @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 plist_node node;
struct ion_device *dev;
enum ion_heap_type type;
struct ion_heap_ops *ops;
unsigned long flags;
unsigned int id;
const char *name;
struct shrinker shrinker;
struct list_head free_list;
size_t free_list_size;
spinlock_t free_lock;
wait_queue_head_t waitqueue;
struct task_struct *task;
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_add_heap - adds a heap to the ion device
* @heap: the heap to add
*/
void ion_device_add_heap(struct ion_heap *heap);
/**
* some helpers for common operations on buffers using the sg_table
* and vaddr fields
*/
void *ion_heap_map_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
void ion_heap_unmap_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
struct vm_area_struct *vma);
int ion_heap_buffer_zero(struct ion_buffer *buffer);
int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot);
int ion_alloc(size_t len,
unsigned int heap_id_mask,
unsigned int flags);
/**
* ion_heap_init_shrinker
* @heap: the heap
*
* If a heap sets the ION_HEAP_FLAG_DEFER_FREE flag or defines the shrink op
* this function will be called to setup a shrinker to shrink the freelists
* and call the heap's shrink op.
*/
void ion_heap_init_shrinker(struct ion_heap *heap);
/**
* ion_heap_init_deferred_free -- initialize deferred free functionality
* @heap: the heap
*
* If a heap sets the ION_HEAP_FLAG_DEFER_FREE flag this function will
* be called to setup deferred frees. Calls to free the buffer will
* return immediately and the actual free will occur some time later
*/
int ion_heap_init_deferred_free(struct ion_heap *heap);
/**
* ion_heap_freelist_add - add a buffer to the deferred free list
* @heap: the heap
* @buffer: the buffer
*
* Adds an item to the deferred freelist.
*/
void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer);
/**
* ion_heap_freelist_drain - drain the deferred free list
* @heap: the heap
* @size: amount of memory to drain in bytes
*
* Drains the indicated amount of memory from the deferred freelist immediately.
* Returns the total amount freed. The total freed may be higher depending
* on the size of the items in the list, or lower if there is insufficient
* total memory on the freelist.
*/
size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size);
/**
* ion_heap_freelist_shrink - drain the deferred free
* list, skipping any heap-specific
* pooling or caching mechanisms
*
* @heap: the heap
* @size: amount of memory to drain in bytes
*
* Drains the indicated amount of memory from the deferred freelist immediately.
* Returns the total amount freed. The total freed may be higher depending
* on the size of the items in the list, or lower if there is insufficient
* total memory on the freelist.
*
* Unlike with @ion_heap_freelist_drain, don't put any pages back into
* page pools or otherwise cache the pages. Everything must be
* genuinely free'd back to the system. If you're free'ing from a
* shrinker you probably want to use this. Note that this relies on
* the heap.ops.free callback honoring the ION_PRIV_FLAG_SHRINKER_FREE
* flag.
*/
size_t ion_heap_freelist_shrink(struct ion_heap *heap,
size_t size);
/**
* ion_heap_freelist_size - returns the size of the freelist in bytes
* @heap: the heap
*/
size_t ion_heap_freelist_size(struct ion_heap *heap);
/**
* 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 performance 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
* @mutex: lock protecting this struct and especially the count
* item list
* @gfp_mask: gfp_mask to use from alloc
* @order: order of pages in the pool
* @list: plist node for list of pools
* @cached: it's cached pool or not
*
* 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 performance benefit
* on many systems
*/
struct ion_page_pool {
int high_count;
int low_count;
bool cached;
struct list_head high_items;
struct list_head low_items;
struct mutex mutex;
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,
bool cached);
void ion_page_pool_destroy(struct ion_page_pool *pool);
struct page *ion_page_pool_alloc(struct ion_page_pool *pool);
void ion_page_pool_free(struct ion_page_pool *pool, struct page *page);
/** ion_page_pool_shrink - shrinks the size of the memory cached in the pool
* @pool: the pool
* @gfp_mask: the memory type to reclaim
* @nr_to_scan: number of items to shrink in pages
*
* returns the number of items freed in pages
*/
int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
int nr_to_scan);
long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
int ion_query_heaps(struct ion_heap_query *query);
#endif /* _ION_H */
