xref: /linux/drivers/gpu/drm/v3d/v3d_bo.c (revision 74ba587f402d5501af2c85e50cf1e4044263b6ca)
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 
18 #include <linux/dma-buf.h>
19 #include <linux/vmalloc.h>
20 
21 #include <drm/drm_print.h>
22 
23 #include "v3d_drv.h"
24 #include "uapi/drm/v3d_drm.h"
25 
26 static enum drm_gem_object_status v3d_gem_status(struct drm_gem_object *obj)
27 {
28 	struct v3d_bo *bo = to_v3d_bo(obj);
29 	enum drm_gem_object_status res = 0;
30 
31 	if (bo->base.pages)
32 		res |= DRM_GEM_OBJECT_RESIDENT;
33 
34 	return res;
35 }
36 
37 /* Called DRM core on the last userspace/kernel unreference of the
38  * BO.
39  */
40 void v3d_free_object(struct drm_gem_object *obj)
41 {
42 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
43 	struct v3d_bo *bo = to_v3d_bo(obj);
44 
45 	if (bo->vaddr)
46 		v3d_put_bo_vaddr(bo);
47 
48 	v3d_mmu_remove_ptes(bo);
49 
50 	mutex_lock(&v3d->bo_lock);
51 	v3d->bo_stats.num_allocated--;
52 	v3d->bo_stats.pages_allocated -= obj->size >> V3D_MMU_PAGE_SHIFT;
53 	mutex_unlock(&v3d->bo_lock);
54 
55 	spin_lock(&v3d->mm_lock);
56 	drm_mm_remove_node(&bo->node);
57 	spin_unlock(&v3d->mm_lock);
58 
59 	/* GPU execution may have dirtied any pages in the BO. */
60 	bo->base.pages_mark_dirty_on_put = true;
61 
62 	drm_gem_shmem_free(&bo->base);
63 }
64 
65 static const struct drm_gem_object_funcs v3d_gem_funcs = {
66 	.free = v3d_free_object,
67 	.print_info = drm_gem_shmem_object_print_info,
68 	.pin = drm_gem_shmem_object_pin,
69 	.unpin = drm_gem_shmem_object_unpin,
70 	.get_sg_table = drm_gem_shmem_object_get_sg_table,
71 	.vmap = drm_gem_shmem_object_vmap,
72 	.vunmap = drm_gem_shmem_object_vunmap,
73 	.mmap = drm_gem_shmem_object_mmap,
74 	.status = v3d_gem_status,
75 	.vm_ops = &drm_gem_shmem_vm_ops,
76 };
77 
78 /* gem_create_object function for allocating a BO struct and doing
79  * early setup.
80  */
81 struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size)
82 {
83 	struct v3d_bo *bo;
84 	struct drm_gem_object *obj;
85 
86 	if (size == 0)
87 		return ERR_PTR(-EINVAL);
88 
89 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
90 	if (!bo)
91 		return ERR_PTR(-ENOMEM);
92 	obj = &bo->base.base;
93 
94 	obj->funcs = &v3d_gem_funcs;
95 	bo->base.map_wc = true;
96 	INIT_LIST_HEAD(&bo->unref_head);
97 
98 	return &bo->base.base;
99 }
100 
101 static int
102 v3d_bo_create_finish(struct drm_gem_object *obj)
103 {
104 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
105 	struct v3d_bo *bo = to_v3d_bo(obj);
106 	struct sg_table *sgt;
107 	u64 align;
108 	int ret;
109 
110 	/* So far we pin the BO in the MMU for its lifetime, so use
111 	 * shmem's helper for getting a lifetime sgt.
112 	 */
113 	sgt = drm_gem_shmem_get_pages_sgt(&bo->base);
114 	if (IS_ERR(sgt))
115 		return PTR_ERR(sgt);
116 
117 	if (!v3d->gemfs)
118 		align = SZ_4K;
119 	else if (obj->size >= SZ_1M)
120 		align = SZ_1M;
121 	else if (obj->size >= SZ_64K)
122 		align = SZ_64K;
123 	else
124 		align = SZ_4K;
125 
126 	spin_lock(&v3d->mm_lock);
127 	/* Allocate the object's space in the GPU's page tables.
128 	 * Inserting PTEs will happen later, but the offset is for the
129 	 * lifetime of the BO.
130 	 */
131 	ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
132 					 obj->size >> V3D_MMU_PAGE_SHIFT,
133 					 align >> V3D_MMU_PAGE_SHIFT, 0, 0);
134 	spin_unlock(&v3d->mm_lock);
135 	if (ret)
136 		return ret;
137 
138 	/* Track stats for /debug/dri/n/bo_stats. */
139 	mutex_lock(&v3d->bo_lock);
140 	v3d->bo_stats.num_allocated++;
141 	v3d->bo_stats.pages_allocated += obj->size >> V3D_MMU_PAGE_SHIFT;
142 	mutex_unlock(&v3d->bo_lock);
143 
144 	v3d_mmu_insert_ptes(bo);
145 
146 	return 0;
147 }
148 
149 struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
150 			     size_t unaligned_size)
151 {
152 	struct drm_gem_shmem_object *shmem_obj;
153 	struct v3d_dev *v3d = to_v3d_dev(dev);
154 	struct v3d_bo *bo;
155 	int ret;
156 
157 	shmem_obj = drm_gem_shmem_create_with_mnt(dev, unaligned_size,
158 						  v3d->gemfs);
159 	if (IS_ERR(shmem_obj))
160 		return ERR_CAST(shmem_obj);
161 	bo = to_v3d_bo(&shmem_obj->base);
162 	bo->vaddr = NULL;
163 
164 	ret = v3d_bo_create_finish(&shmem_obj->base);
165 	if (ret)
166 		goto free_obj;
167 
168 	return bo;
169 
170 free_obj:
171 	drm_gem_shmem_free(shmem_obj);
172 	return ERR_PTR(ret);
173 }
174 
175 struct drm_gem_object *
176 v3d_prime_import_sg_table(struct drm_device *dev,
177 			  struct dma_buf_attachment *attach,
178 			  struct sg_table *sgt)
179 {
180 	struct drm_gem_object *obj;
181 	int ret;
182 
183 	obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
184 	if (IS_ERR(obj))
185 		return obj;
186 
187 	ret = v3d_bo_create_finish(obj);
188 	if (ret) {
189 		drm_gem_shmem_free(&to_v3d_bo(obj)->base);
190 		return ERR_PTR(ret);
191 	}
192 
193 	return obj;
194 }
195 
196 void v3d_get_bo_vaddr(struct v3d_bo *bo)
197 {
198 	struct drm_gem_shmem_object *obj = &bo->base;
199 
200 	bo->vaddr = vmap(obj->pages, obj->base.size >> PAGE_SHIFT, VM_MAP,
201 			 pgprot_writecombine(PAGE_KERNEL));
202 }
203 
204 void v3d_put_bo_vaddr(struct v3d_bo *bo)
205 {
206 	vunmap(bo->vaddr);
207 	bo->vaddr = NULL;
208 }
209 
210 int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
211 			struct drm_file *file_priv)
212 {
213 	struct drm_v3d_create_bo *args = data;
214 	struct v3d_bo *bo = NULL;
215 	int ret;
216 
217 	if (args->flags != 0) {
218 		DRM_INFO("unknown create_bo flags: %d\n", args->flags);
219 		return -EINVAL;
220 	}
221 
222 	bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
223 	if (IS_ERR(bo))
224 		return PTR_ERR(bo);
225 
226 	args->offset = bo->node.start << V3D_MMU_PAGE_SHIFT;
227 
228 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
229 	drm_gem_object_put(&bo->base.base);
230 
231 	return ret;
232 }
233 
234 int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
235 		      struct drm_file *file_priv)
236 {
237 	struct drm_v3d_mmap_bo *args = data;
238 	struct drm_gem_object *gem_obj;
239 
240 	if (args->flags != 0) {
241 		DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
242 		return -EINVAL;
243 	}
244 
245 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
246 	if (!gem_obj) {
247 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
248 		return -ENOENT;
249 	}
250 
251 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
252 	drm_gem_object_put(gem_obj);
253 
254 	return 0;
255 }
256 
257 int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
258 			    struct drm_file *file_priv)
259 {
260 	struct drm_v3d_get_bo_offset *args = data;
261 	struct drm_gem_object *gem_obj;
262 	struct v3d_bo *bo;
263 
264 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
265 	if (!gem_obj) {
266 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
267 		return -ENOENT;
268 	}
269 	bo = to_v3d_bo(gem_obj);
270 
271 	args->offset = bo->node.start << V3D_MMU_PAGE_SHIFT;
272 
273 	drm_gem_object_put(gem_obj);
274 	return 0;
275 }
276 
277 int
278 v3d_wait_bo_ioctl(struct drm_device *dev, void *data,
279 		  struct drm_file *file_priv)
280 {
281 	int ret;
282 	struct drm_v3d_wait_bo *args = data;
283 	ktime_t start = ktime_get();
284 	u64 delta_ns;
285 	unsigned long timeout_jiffies =
286 		nsecs_to_jiffies_timeout(args->timeout_ns);
287 
288 	if (args->pad != 0)
289 		return -EINVAL;
290 
291 	ret = drm_gem_dma_resv_wait(file_priv, args->handle,
292 				    true, timeout_jiffies);
293 
294 	/* Decrement the user's timeout, in case we got interrupted
295 	 * such that the ioctl will be restarted.
296 	 */
297 	delta_ns = ktime_to_ns(ktime_sub(ktime_get(), start));
298 	if (delta_ns < args->timeout_ns)
299 		args->timeout_ns -= delta_ns;
300 	else
301 		args->timeout_ns = 0;
302 
303 	/* Asked to wait beyond the jiffy/scheduler precision? */
304 	if (ret == -ETIME && args->timeout_ns)
305 		ret = -EAGAIN;
306 
307 	return ret;
308 }
309