1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef __DRM_GEM_SHMEM_HELPER_H__
4 #define __DRM_GEM_SHMEM_HELPER_H__
5 
6 #include <linux/fs.h>
7 #include <linux/mm.h>
8 #include <linux/mutex.h>
9 
10 #include <drm/drm_file.h>
11 #include <drm/drm_gem.h>
12 #include <drm/drm_ioctl.h>
13 #include <drm/drm_prime.h>
14 
15 struct dma_buf_attachment;
16 struct drm_mode_create_dumb;
17 struct drm_printer;
18 struct sg_table;
19 
20 /**
21  * struct drm_gem_shmem_object - GEM object backed by shmem
22  */
23 struct drm_gem_shmem_object {
24 	/**
25 	 * @base: Base GEM object
26 	 */
27 	struct drm_gem_object base;
28 
29 	/**
30 	 * @pages_lock: Protects the page table and use count
31 	 */
32 	struct mutex pages_lock;
33 
34 	/**
35 	 * @pages: Page table
36 	 */
37 	struct page **pages;
38 
39 	/**
40 	 * @pages_use_count:
41 	 *
42 	 * Reference count on the pages table.
43 	 * The pages are put when the count reaches zero.
44 	 */
45 	unsigned int pages_use_count;
46 
47 	/**
48 	 * @madv: State for madvise
49 	 *
50 	 * 0 is active/inuse.
51 	 * A negative value is the object is purged.
52 	 * Positive values are driver specific and not used by the helpers.
53 	 */
54 	int madv;
55 
56 	/**
57 	 * @madv_list: List entry for madvise tracking
58 	 *
59 	 * Typically used by drivers to track purgeable objects
60 	 */
61 	struct list_head madv_list;
62 
63 	/**
64 	 * @pages_mark_dirty_on_put:
65 	 *
66 	 * Mark pages as dirty when they are put.
67 	 */
68 	unsigned int pages_mark_dirty_on_put    : 1;
69 
70 	/**
71 	 * @pages_mark_accessed_on_put:
72 	 *
73 	 * Mark pages as accessed when they are put.
74 	 */
75 	unsigned int pages_mark_accessed_on_put : 1;
76 
77 	/**
78 	 * @sgt: Scatter/gather table for imported PRIME buffers
79 	 */
80 	struct sg_table *sgt;
81 
82 	/**
83 	 * @vmap_lock: Protects the vmap address and use count
84 	 */
85 	struct mutex vmap_lock;
86 
87 	/**
88 	 * @vaddr: Kernel virtual address of the backing memory
89 	 */
90 	void *vaddr;
91 
92 	/**
93 	 * @vmap_use_count:
94 	 *
95 	 * Reference count on the virtual address.
96 	 * The address are un-mapped when the count reaches zero.
97 	 */
98 	unsigned int vmap_use_count;
99 
100 	/**
101 	 * @map_cached: map object cached (instead of using writecombine).
102 	 */
103 	bool map_cached;
104 };
105 
106 #define to_drm_gem_shmem_obj(obj) \
107 	container_of(obj, struct drm_gem_shmem_object, base)
108 
109 struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
110 void drm_gem_shmem_free_object(struct drm_gem_object *obj);
111 
112 int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
113 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
114 int drm_gem_shmem_pin(struct drm_gem_object *obj);
115 void drm_gem_shmem_unpin(struct drm_gem_object *obj);
116 void *drm_gem_shmem_vmap(struct drm_gem_object *obj);
117 void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr);
118 
119 int drm_gem_shmem_madvise(struct drm_gem_object *obj, int madv);
120 
121 static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
122 {
123 	return (shmem->madv > 0) &&
124 		!shmem->vmap_use_count && shmem->sgt &&
125 		!shmem->base.dma_buf && !shmem->base.import_attach;
126 }
127 
128 void drm_gem_shmem_purge_locked(struct drm_gem_object *obj);
129 bool drm_gem_shmem_purge(struct drm_gem_object *obj);
130 
131 struct drm_gem_shmem_object *
132 drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
133 				 struct drm_device *dev, size_t size,
134 				 uint32_t *handle);
135 int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
136 			      struct drm_mode_create_dumb *args);
137 
138 int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
139 
140 void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent,
141 			      const struct drm_gem_object *obj);
142 
143 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj);
144 struct drm_gem_object *
145 drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
146 				    struct dma_buf_attachment *attach,
147 				    struct sg_table *sgt);
148 
149 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj);
150 
151 /**
152  * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations
153  *
154  * This macro provides a shortcut for setting the shmem GEM operations in
155  * the &drm_driver structure.
156  */
157 #define DRM_GEM_SHMEM_DRIVER_OPS \
158 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd, \
159 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle, \
160 	.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \
161 	.gem_prime_mmap		= drm_gem_prime_mmap, \
162 	.dumb_create		= drm_gem_shmem_dumb_create
163 
164 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */
165