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