1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (C) 2015-2018 Broadcom */
3 
4 /**
5  * DOC: V3D GEM BO management support
6  *
7  * Compared to VC4 (V3D 2.x), V3D 3.3 introduces an MMU between the
8  * GPU and the bus, allowing us to use shmem objects for our storage
9  * instead of CMA.
10  *
11  * Physically contiguous objects may still be imported to V3D, but the
12  * driver doesn't allocate physically contiguous objects on its own.
13  * Display engines requiring physically contiguous allocations should
14  * look into Mesa's "renderonly" support (as used by the Mesa pl111
15  * driver) for an example of how to integrate with V3D.
16  *
17  * Long term, we should support evicting pages from the MMU when under
18  * memory pressure (thus the v3d_bo_get_pages() refcounting), but
19  * that's not a high priority since our systems tend to not have swap.
20  */
21 
22 #include <linux/dma-buf.h>
23 #include <linux/pfn_t.h>
24 
25 #include "v3d_drv.h"
26 #include "uapi/drm/v3d_drm.h"
27 
28 /* Called DRM core on the last userspace/kernel unreference of the
29  * BO.
30  */
v3d_free_object(struct drm_gem_object * obj)31 void v3d_free_object(struct drm_gem_object *obj)
32 {
33 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
34 	struct v3d_bo *bo = to_v3d_bo(obj);
35 
36 	v3d_mmu_remove_ptes(bo);
37 
38 	mutex_lock(&v3d->bo_lock);
39 	v3d->bo_stats.num_allocated--;
40 	v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
41 	mutex_unlock(&v3d->bo_lock);
42 
43 	spin_lock(&v3d->mm_lock);
44 	drm_mm_remove_node(&bo->node);
45 	spin_unlock(&v3d->mm_lock);
46 
47 	/* GPU execution may have dirtied any pages in the BO. */
48 	bo->base.pages_mark_dirty_on_put = true;
49 
50 	drm_gem_shmem_free(&bo->base);
51 }
52 
53 static const struct drm_gem_object_funcs v3d_gem_funcs = {
54 	.free = v3d_free_object,
55 	.print_info = drm_gem_shmem_object_print_info,
56 	.pin = drm_gem_shmem_object_pin,
57 	.unpin = drm_gem_shmem_object_unpin,
58 	.get_sg_table = drm_gem_shmem_object_get_sg_table,
59 	.vmap = drm_gem_shmem_object_vmap,
60 	.vunmap = drm_gem_shmem_object_vunmap,
61 	.mmap = drm_gem_shmem_object_mmap,
62 	.vm_ops = &drm_gem_shmem_vm_ops,
63 };
64 
65 /* gem_create_object function for allocating a BO struct and doing
66  * early setup.
67  */
v3d_create_object(struct drm_device * dev,size_t size)68 struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size)
69 {
70 	struct v3d_bo *bo;
71 	struct drm_gem_object *obj;
72 
73 	if (size == 0)
74 		return ERR_PTR(-EINVAL);
75 
76 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
77 	if (!bo)
78 		return ERR_PTR(-ENOMEM);
79 	obj = &bo->base.base;
80 
81 	obj->funcs = &v3d_gem_funcs;
82 	bo->base.map_wc = true;
83 	INIT_LIST_HEAD(&bo->unref_head);
84 
85 	return &bo->base.base;
86 }
87 
88 static int
v3d_bo_create_finish(struct drm_gem_object * obj)89 v3d_bo_create_finish(struct drm_gem_object *obj)
90 {
91 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
92 	struct v3d_bo *bo = to_v3d_bo(obj);
93 	struct sg_table *sgt;
94 	int ret;
95 
96 	/* So far we pin the BO in the MMU for its lifetime, so use
97 	 * shmem's helper for getting a lifetime sgt.
98 	 */
99 	sgt = drm_gem_shmem_get_pages_sgt(&bo->base);
100 	if (IS_ERR(sgt))
101 		return PTR_ERR(sgt);
102 
103 	spin_lock(&v3d->mm_lock);
104 	/* Allocate the object's space in the GPU's page tables.
105 	 * Inserting PTEs will happen later, but the offset is for the
106 	 * lifetime of the BO.
107 	 */
108 	ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
109 					 obj->size >> PAGE_SHIFT,
110 					 GMP_GRANULARITY >> PAGE_SHIFT, 0, 0);
111 	spin_unlock(&v3d->mm_lock);
112 	if (ret)
113 		return ret;
114 
115 	/* Track stats for /debug/dri/n/bo_stats. */
116 	mutex_lock(&v3d->bo_lock);
117 	v3d->bo_stats.num_allocated++;
118 	v3d->bo_stats.pages_allocated += obj->size >> PAGE_SHIFT;
119 	mutex_unlock(&v3d->bo_lock);
120 
121 	v3d_mmu_insert_ptes(bo);
122 
123 	return 0;
124 }
125 
v3d_bo_create(struct drm_device * dev,struct drm_file * file_priv,size_t unaligned_size)126 struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
127 			     size_t unaligned_size)
128 {
129 	struct drm_gem_shmem_object *shmem_obj;
130 	struct v3d_bo *bo;
131 	int ret;
132 
133 	shmem_obj = drm_gem_shmem_create(dev, unaligned_size);
134 	if (IS_ERR(shmem_obj))
135 		return ERR_CAST(shmem_obj);
136 	bo = to_v3d_bo(&shmem_obj->base);
137 
138 	ret = v3d_bo_create_finish(&shmem_obj->base);
139 	if (ret)
140 		goto free_obj;
141 
142 	return bo;
143 
144 free_obj:
145 	drm_gem_shmem_free(shmem_obj);
146 	return ERR_PTR(ret);
147 }
148 
149 struct drm_gem_object *
v3d_prime_import_sg_table(struct drm_device * dev,struct dma_buf_attachment * attach,struct sg_table * sgt)150 v3d_prime_import_sg_table(struct drm_device *dev,
151 			  struct dma_buf_attachment *attach,
152 			  struct sg_table *sgt)
153 {
154 	struct drm_gem_object *obj;
155 	int ret;
156 
157 	obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
158 	if (IS_ERR(obj))
159 		return obj;
160 
161 	ret = v3d_bo_create_finish(obj);
162 	if (ret) {
163 		drm_gem_shmem_free(&to_v3d_bo(obj)->base);
164 		return ERR_PTR(ret);
165 	}
166 
167 	return obj;
168 }
169 
v3d_create_bo_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)170 int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
171 			struct drm_file *file_priv)
172 {
173 	struct drm_v3d_create_bo *args = data;
174 	struct v3d_bo *bo = NULL;
175 	int ret;
176 
177 	if (args->flags != 0) {
178 		DRM_INFO("unknown create_bo flags: %d\n", args->flags);
179 		return -EINVAL;
180 	}
181 
182 	bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
183 	if (IS_ERR(bo))
184 		return PTR_ERR(bo);
185 
186 	args->offset = bo->node.start << PAGE_SHIFT;
187 
188 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
189 	drm_gem_object_put(&bo->base.base);
190 
191 	return ret;
192 }
193 
v3d_mmap_bo_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)194 int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
195 		      struct drm_file *file_priv)
196 {
197 	struct drm_v3d_mmap_bo *args = data;
198 	struct drm_gem_object *gem_obj;
199 
200 	if (args->flags != 0) {
201 		DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
202 		return -EINVAL;
203 	}
204 
205 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
206 	if (!gem_obj) {
207 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
208 		return -ENOENT;
209 	}
210 
211 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
212 	drm_gem_object_put(gem_obj);
213 
214 	return 0;
215 }
216 
v3d_get_bo_offset_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)217 int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
218 			    struct drm_file *file_priv)
219 {
220 	struct drm_v3d_get_bo_offset *args = data;
221 	struct drm_gem_object *gem_obj;
222 	struct v3d_bo *bo;
223 
224 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
225 	if (!gem_obj) {
226 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
227 		return -ENOENT;
228 	}
229 	bo = to_v3d_bo(gem_obj);
230 
231 	args->offset = bo->node.start << PAGE_SHIFT;
232 
233 	drm_gem_object_put(gem_obj);
234 	return 0;
235 }
236