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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Copyright (c) 2019, The Linux Foundation. All rights reserved.
- */
- #ifndef _ION_KERNEL_H
- #define _ION_KERNEL_H
- #include <linux/dma-buf.h>
- #include <linux/err.h>
- #include <linux/device.h>
- #include <linux/dma-direction.h>
- #include <linux/kref.h>
- #include <linux/mm_types.h>
- #include <linux/module.h>
- #include <linux/mutex.h>
- #include <linux/rbtree.h>
- #include <linux/sched.h>
- #include <linux/shrinker.h>
- #include <linux/types.h>
- #include <uapi/linux/ion.h>
- /**
- * struct ion_buffer - metadata for a particular buffer
- * @list: element in list of deferred freeable buffers
- * @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
- * @attachments: list of devices attached to this buffer
- */
- struct ion_buffer {
- struct list_head list;
- 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;
- };
- /**
- * struct ion_heap_ops - ops to operate on a given heap
- * @allocate: allocate memory
- * @free: free memory
- * @get_pool_size: get pool size in pages
- *
- * allocate returns 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);
- int (*shrink)(struct ion_heap *heap, gfp_t gfp_mask, int nr_to_scan);
- long (*get_pool_size)(struct ion_heap *heap);
- };
- /**
- * 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
- * @type: type of heap
- * @ops: ops struct as above
- * @buf_ops: dma_buf ops specific to the heap implementation.
- * @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
- * @owner: kernel module that implements this heap
- * @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
- * @num_of_buffers the number of currently allocated buffers
- * @num_of_alloc_bytes the number of allocated bytes
- * @alloc_bytes_wm the number of allocated bytes watermark
- *
- * 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;
- enum ion_heap_type type;
- struct ion_heap_ops *ops;
- struct dma_buf_ops buf_ops;
- unsigned long flags;
- unsigned int id;
- const char *name;
- struct module *owner;
- /* deferred free support */
- 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;
- /* heap statistics */
- u64 num_of_buffers;
- u64 num_of_alloc_bytes;
- u64 alloc_bytes_wm;
- /* protect heap statistics */
- spinlock_t stat_lock;
- /* heap's debugfs root */
- struct dentry *debugfs_dir;
- };
- #define ion_device_add_heap(heap) __ion_device_add_heap(heap, THIS_MODULE)
- /**
- * struct ion_dma_buf_attachment - hold device-table attachment data for buffer
- * @dev: device attached to the buffer.
- * @table: cached mapping.
- * @list: list of ion_dma_buf_attachment.
- */
- struct ion_dma_buf_attachment {
- struct device *dev;
- struct sg_table *table;
- struct list_head list;
- bool mapped:1;
- };
- #ifdef CONFIG_ION
- /**
- * __ion_device_add_heap - adds a heap to the ion device
- *
- * @heap: the heap to add
- *
- * Returns 0 on success, negative error otherwise.
- */
- int __ion_device_add_heap(struct ion_heap *heap, struct module *owner);
- /**
- * ion_device_remove_heap - removes a heap from ion device
- *
- * @heap: pointer to the heap to be removed
- */
- void ion_device_remove_heap(struct ion_heap *heap);
- /**
- * 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.
- */
- int 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);
- /**
- * ion_heap_map_kernel - map the ion_buffer in kernel virtual address space.
- *
- * @heap: the heap
- * @buffer: buffer to be mapped
- *
- * Maps the buffer using vmap(). The function respects cache flags for the
- * buffer and creates the page table entries accordingly. Returns virtual
- * address at the beginning of the buffer or ERR_PTR.
- */
- void *ion_heap_map_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
- /**
- * ion_heap_unmap_kernel - unmap ion_buffer
- *
- * @buffer: buffer to be unmapped
- *
- * ION wrapper for vunmap() of the ion buffer.
- */
- void ion_heap_unmap_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
- /**
- * ion_heap_map_user - map given ion buffer in provided vma
- *
- * @heap: the heap this buffer belongs to
- * @buffer: Ion buffer to be mapped
- * @vma: vma of the process where buffer should be mapped.
- *
- * Maps the buffer using remap_pfn_range() into specific process's vma starting
- * with vma->vm_start. The vma size is expected to be >= ion buffer size.
- * If not, a partial buffer mapping may be created. Returns 0 on success.
- */
- int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
- struct vm_area_struct *vma);
- /* ion_buffer_zero - zeroes out an ion buffer respecting the ION_FLAGs.
- *
- * @buffer: ion_buffer to zero
- *
- * Returns 0 on success, negative error otherwise.
- */
- int ion_buffer_zero(struct ion_buffer *buffer);
- /**
- * ion_buffer_prep_noncached - flush cache before non-cached mapping
- *
- * @buffer: ion_buffer to flush
- *
- * The memory allocated by the heap could be in the CPU cache. To map
- * this memory as non-cached, we need to flush the associated cache
- * first. Without the flush, it is possible for stale dirty cache lines
- * to be evicted after the ION client started writing into this buffer,
- * leading to data corruption.
- */
- void ion_buffer_prep_noncached(struct ion_buffer *buffer);
- /**
- * ion_alloc - Allocates an ion buffer of given size from given heap
- *
- * @len: size of the buffer to be allocated.
- * @heap_id_mask: a bitwise maks of heap ids to allocate from
- * @flags: ION_BUFFER_XXXX flags for the new buffer.
- *
- * The function exports a dma_buf object for the new ion buffer internally
- * and returns that to the caller. So, the buffer is ready to be used by other
- * drivers immediately. Returns ERR_PTR in case of failure.
- */
- struct dma_buf *ion_alloc(size_t len, unsigned int heap_id_mask,
- unsigned int flags);
- /**
- * ion_free - Releases the ion buffer.
- *
- * @buffer: ion buffer to be released
- */
- int ion_free(struct ion_buffer *buffer);
- /**
- * ion_query_heaps_kernel - Returns information about available heaps to
- * in-kernel clients.
- *
- * @hdata: pointer to array of struct ion_heap_data.
- * @size: size of @hdata array.
- *
- * Returns the number of available heaps and populates @hdata with information
- * regarding the same. When invoked with @size as 0, the function with return
- * the number of available heaps without modifying @hdata. When the number of
- * available heaps is higher than @size, @size is returned instead of the
- * actual number of available heaps.
- */
- size_t ion_query_heaps_kernel(struct ion_heap_data *hdata, size_t size);
- #else
- static inline int __ion_device_add_heap(struct ion_heap *heap,
- struct module *owner)
- {
- return -ENODEV;
- }
- static inline int ion_heap_init_shrinker(struct ion_heap *heap)
- {
- return -ENODEV;
- }
- static inline int ion_heap_init_deferred_free(struct ion_heap *heap)
- {
- return -ENODEV;
- }
- static inline void ion_heap_freelist_add(struct ion_heap *heap,
- struct ion_buffer *buffer) {}
- static inline size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size)
- {
- return -ENODEV;
- }
- static inline size_t ion_heap_freelist_shrink(struct ion_heap *heap,
- size_t size)
- {
- return -ENODEV;
- }
- static inline size_t ion_heap_freelist_size(struct ion_heap *heap)
- {
- return -ENODEV;
- }
- static inline void *ion_heap_map_kernel(struct ion_heap *heap,
- struct ion_buffer *buffer)
- {
- return ERR_PTR(-ENODEV);
- }
- static inline void ion_heap_unmap_kernel(struct ion_heap *heap,
- struct ion_buffer *buffer) {}
- static inline int ion_heap_map_user(struct ion_heap *heap,
- struct ion_buffer *buffer,
- struct vm_area_struct *vma)
- {
- return -ENODEV;
- }
- static inline int ion_buffer_zero(struct ion_buffer *buffer)
- {
- return -EINVAL;
- }
- static inline void ion_buffer_prep_noncached(struct ion_buffer *buffer) {}
- static inline struct dma_buf *ion_alloc(size_t len, unsigned int heap_id_mask,
- unsigned int flags)
- {
- return ERR_PTR(-ENOMEM);
- }
- static inline int ion_free(struct ion_buffer *buffer)
- {
- return 0;
- }
- static inline size_t ion_query_heaps_kernel(struct ion_heap_data *hdata,
- size_t size)
- {
- return 0;
- }
- #endif /* CONFIG_ION */
- #endif /* _ION_KERNEL_H */
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