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 	int madv;
48 	struct list_head madv_list;
49 
50 	/**
51 	 * @pages_mark_dirty_on_put:
52 	 *
53 	 * Mark pages as dirty when they are put.
54 	 */
55 	unsigned int pages_mark_dirty_on_put    : 1;
56 
57 	/**
58 	 * @pages_mark_accessed_on_put:
59 	 *
60 	 * Mark pages as accessed when they are put.
61 	 */
62 	unsigned int pages_mark_accessed_on_put : 1;
63 
64 	/**
65 	 * @sgt: Scatter/gather table for imported PRIME buffers
66 	 */
67 	struct sg_table *sgt;
68 
69 	/**
70 	 * @vmap_lock: Protects the vmap address and use count
71 	 */
72 	struct mutex vmap_lock;
73 
74 	/**
75 	 * @vaddr: Kernel virtual address of the backing memory
76 	 */
77 	void *vaddr;
78 
79 	/**
80 	 * @vmap_use_count:
81 	 *
82 	 * Reference count on the virtual address.
83 	 * The address are un-mapped when the count reaches zero.
84 	 */
85 	unsigned int vmap_use_count;
86 };
87 
88 #define to_drm_gem_shmem_obj(obj) \
89 	container_of(obj, struct drm_gem_shmem_object, base)
90 
91 /**
92  * DEFINE_DRM_GEM_SHMEM_FOPS() - Macro to generate file operations for shmem drivers
93  * @name: name for the generated structure
94  *
95  * This macro autogenerates a suitable &struct file_operations for shmem based
96  * drivers, which can be assigned to &drm_driver.fops. Note that this structure
97  * cannot be shared between drivers, because it contains a reference to the
98  * current module using THIS_MODULE.
99  *
100  * Note that the declaration is already marked as static - if you need a
101  * non-static version of this you're probably doing it wrong and will break the
102  * THIS_MODULE reference by accident.
103  */
104 #define DEFINE_DRM_GEM_SHMEM_FOPS(name) \
105 	static const struct file_operations name = {\
106 		.owner		= THIS_MODULE,\
107 		.open		= drm_open,\
108 		.release	= drm_release,\
109 		.unlocked_ioctl	= drm_ioctl,\
110 		.compat_ioctl	= drm_compat_ioctl,\
111 		.poll		= drm_poll,\
112 		.read		= drm_read,\
113 		.llseek		= noop_llseek,\
114 		.mmap		= drm_gem_shmem_mmap, \
115 	}
116 
117 struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
118 void drm_gem_shmem_free_object(struct drm_gem_object *obj);
119 
120 int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
121 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
122 int drm_gem_shmem_pin(struct drm_gem_object *obj);
123 void drm_gem_shmem_unpin(struct drm_gem_object *obj);
124 void *drm_gem_shmem_vmap(struct drm_gem_object *obj);
125 void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr);
126 
127 int drm_gem_shmem_madvise(struct drm_gem_object *obj, int madv);
128 
129 static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
130 {
131 	return (shmem->madv > 0) &&
132 		!shmem->vmap_use_count && shmem->sgt &&
133 		!shmem->base.dma_buf && !shmem->base.import_attach;
134 }
135 
136 void drm_gem_shmem_purge_locked(struct drm_gem_object *obj);
137 bool drm_gem_shmem_purge(struct drm_gem_object *obj);
138 
139 struct drm_gem_shmem_object *
140 drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
141 				 struct drm_device *dev, size_t size,
142 				 uint32_t *handle);
143 int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
144 			      struct drm_mode_create_dumb *args);
145 
146 int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma);
147 
148 extern const struct vm_operations_struct drm_gem_shmem_vm_ops;
149 
150 void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent,
151 			      const struct drm_gem_object *obj);
152 
153 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj);
154 struct drm_gem_object *
155 drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
156 				    struct dma_buf_attachment *attach,
157 				    struct sg_table *sgt);
158 
159 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_object *obj);
160 
161 /**
162  * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations
163  *
164  * This macro provides a shortcut for setting the shmem GEM operations in
165  * the &drm_driver structure.
166  */
167 #define DRM_GEM_SHMEM_DRIVER_OPS \
168 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd, \
169 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle, \
170 	.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \
171 	.gem_prime_mmap		= drm_gem_prime_mmap, \
172 	.dumb_create		= drm_gem_shmem_dumb_create
173 
174 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */
175