xref: /linux/drivers/gpu/drm/v3d/v3d_bo.c (revision 663269cebc7157e487400c4aeee1f765546a9c98)
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 #include <linux/vmalloc.h>
25 
26 #include "v3d_drv.h"
27 #include "uapi/drm/v3d_drm.h"
28 
29 static enum drm_gem_object_status v3d_gem_status(struct drm_gem_object *obj)
30 {
31 	struct v3d_bo *bo = to_v3d_bo(obj);
32 	enum drm_gem_object_status res = 0;
33 
34 	if (bo->base.pages)
35 		res |= DRM_GEM_OBJECT_RESIDENT;
36 
37 	return res;
38 }
39 
40 /* Called DRM core on the last userspace/kernel unreference of the
41  * BO.
42  */
43 void v3d_free_object(struct drm_gem_object *obj)
44 {
45 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
46 	struct v3d_bo *bo = to_v3d_bo(obj);
47 
48 	if (bo->vaddr)
49 		v3d_put_bo_vaddr(bo);
50 
51 	v3d_mmu_remove_ptes(bo);
52 
53 	mutex_lock(&v3d->bo_lock);
54 	v3d->bo_stats.num_allocated--;
55 	v3d->bo_stats.pages_allocated -= obj->size >> V3D_MMU_PAGE_SHIFT;
56 	mutex_unlock(&v3d->bo_lock);
57 
58 	spin_lock(&v3d->mm_lock);
59 	drm_mm_remove_node(&bo->node);
60 	spin_unlock(&v3d->mm_lock);
61 
62 	/* GPU execution may have dirtied any pages in the BO. */
63 	bo->base.pages_mark_dirty_on_put = true;
64 
65 	drm_gem_shmem_free(&bo->base);
66 }
67 
68 static const struct drm_gem_object_funcs v3d_gem_funcs = {
69 	.free = v3d_free_object,
70 	.print_info = drm_gem_shmem_object_print_info,
71 	.pin = drm_gem_shmem_object_pin,
72 	.unpin = drm_gem_shmem_object_unpin,
73 	.get_sg_table = drm_gem_shmem_object_get_sg_table,
74 	.vmap = drm_gem_shmem_object_vmap,
75 	.vunmap = drm_gem_shmem_object_vunmap,
76 	.mmap = drm_gem_shmem_object_mmap,
77 	.status = v3d_gem_status,
78 	.vm_ops = &drm_gem_shmem_vm_ops,
79 };
80 
81 /* gem_create_object function for allocating a BO struct and doing
82  * early setup.
83  */
84 struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size)
85 {
86 	struct v3d_bo *bo;
87 	struct drm_gem_object *obj;
88 
89 	if (size == 0)
90 		return ERR_PTR(-EINVAL);
91 
92 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
93 	if (!bo)
94 		return ERR_PTR(-ENOMEM);
95 	obj = &bo->base.base;
96 
97 	obj->funcs = &v3d_gem_funcs;
98 	bo->base.map_wc = true;
99 	INIT_LIST_HEAD(&bo->unref_head);
100 
101 	return &bo->base.base;
102 }
103 
104 static int
105 v3d_bo_create_finish(struct drm_gem_object *obj)
106 {
107 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
108 	struct v3d_bo *bo = to_v3d_bo(obj);
109 	struct sg_table *sgt;
110 	u64 align;
111 	int ret;
112 
113 	/* So far we pin the BO in the MMU for its lifetime, so use
114 	 * shmem's helper for getting a lifetime sgt.
115 	 */
116 	sgt = drm_gem_shmem_get_pages_sgt(&bo->base);
117 	if (IS_ERR(sgt))
118 		return PTR_ERR(sgt);
119 
120 	if (!v3d->gemfs)
121 		align = SZ_4K;
122 	else if (obj->size >= SZ_1M)
123 		align = SZ_1M;
124 	else if (obj->size >= SZ_64K)
125 		align = SZ_64K;
126 	else
127 		align = SZ_4K;
128 
129 	spin_lock(&v3d->mm_lock);
130 	/* Allocate the object's space in the GPU's page tables.
131 	 * Inserting PTEs will happen later, but the offset is for the
132 	 * lifetime of the BO.
133 	 */
134 	ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
135 					 obj->size >> V3D_MMU_PAGE_SHIFT,
136 					 align >> V3D_MMU_PAGE_SHIFT, 0, 0);
137 	spin_unlock(&v3d->mm_lock);
138 	if (ret)
139 		return ret;
140 
141 	/* Track stats for /debug/dri/n/bo_stats. */
142 	mutex_lock(&v3d->bo_lock);
143 	v3d->bo_stats.num_allocated++;
144 	v3d->bo_stats.pages_allocated += obj->size >> V3D_MMU_PAGE_SHIFT;
145 	mutex_unlock(&v3d->bo_lock);
146 
147 	v3d_mmu_insert_ptes(bo);
148 
149 	return 0;
150 }
151 
152 struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
153 			     size_t unaligned_size)
154 {
155 	struct drm_gem_shmem_object *shmem_obj;
156 	struct v3d_dev *v3d = to_v3d_dev(dev);
157 	struct v3d_bo *bo;
158 	int ret;
159 
160 	/* Let the user opt out of allocating the BOs with THP */
161 	if (v3d->gemfs)
162 		shmem_obj = drm_gem_shmem_create_with_mnt(dev, unaligned_size,
163 							  v3d->gemfs);
164 	else
165 		shmem_obj = drm_gem_shmem_create(dev, unaligned_size);
166 
167 	if (IS_ERR(shmem_obj))
168 		return ERR_CAST(shmem_obj);
169 	bo = to_v3d_bo(&shmem_obj->base);
170 	bo->vaddr = NULL;
171 
172 	ret = v3d_bo_create_finish(&shmem_obj->base);
173 	if (ret)
174 		goto free_obj;
175 
176 	return bo;
177 
178 free_obj:
179 	drm_gem_shmem_free(shmem_obj);
180 	return ERR_PTR(ret);
181 }
182 
183 struct drm_gem_object *
184 v3d_prime_import_sg_table(struct drm_device *dev,
185 			  struct dma_buf_attachment *attach,
186 			  struct sg_table *sgt)
187 {
188 	struct drm_gem_object *obj;
189 	int ret;
190 
191 	obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
192 	if (IS_ERR(obj))
193 		return obj;
194 
195 	ret = v3d_bo_create_finish(obj);
196 	if (ret) {
197 		drm_gem_shmem_free(&to_v3d_bo(obj)->base);
198 		return ERR_PTR(ret);
199 	}
200 
201 	return obj;
202 }
203 
204 void v3d_get_bo_vaddr(struct v3d_bo *bo)
205 {
206 	struct drm_gem_shmem_object *obj = &bo->base;
207 
208 	bo->vaddr = vmap(obj->pages, obj->base.size >> PAGE_SHIFT, VM_MAP,
209 			 pgprot_writecombine(PAGE_KERNEL));
210 }
211 
212 void v3d_put_bo_vaddr(struct v3d_bo *bo)
213 {
214 	vunmap(bo->vaddr);
215 	bo->vaddr = NULL;
216 }
217 
218 int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
219 			struct drm_file *file_priv)
220 {
221 	struct drm_v3d_create_bo *args = data;
222 	struct v3d_bo *bo = NULL;
223 	int ret;
224 
225 	if (args->flags != 0) {
226 		DRM_INFO("unknown create_bo flags: %d\n", args->flags);
227 		return -EINVAL;
228 	}
229 
230 	bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
231 	if (IS_ERR(bo))
232 		return PTR_ERR(bo);
233 
234 	args->offset = bo->node.start << V3D_MMU_PAGE_SHIFT;
235 
236 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
237 	drm_gem_object_put(&bo->base.base);
238 
239 	return ret;
240 }
241 
242 int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
243 		      struct drm_file *file_priv)
244 {
245 	struct drm_v3d_mmap_bo *args = data;
246 	struct drm_gem_object *gem_obj;
247 
248 	if (args->flags != 0) {
249 		DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
250 		return -EINVAL;
251 	}
252 
253 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
254 	if (!gem_obj) {
255 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
256 		return -ENOENT;
257 	}
258 
259 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
260 	drm_gem_object_put(gem_obj);
261 
262 	return 0;
263 }
264 
265 int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
266 			    struct drm_file *file_priv)
267 {
268 	struct drm_v3d_get_bo_offset *args = data;
269 	struct drm_gem_object *gem_obj;
270 	struct v3d_bo *bo;
271 
272 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
273 	if (!gem_obj) {
274 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
275 		return -ENOENT;
276 	}
277 	bo = to_v3d_bo(gem_obj);
278 
279 	args->offset = bo->node.start << V3D_MMU_PAGE_SHIFT;
280 
281 	drm_gem_object_put(gem_obj);
282 	return 0;
283 }
284 
285 int
286 v3d_wait_bo_ioctl(struct drm_device *dev, void *data,
287 		  struct drm_file *file_priv)
288 {
289 	int ret;
290 	struct drm_v3d_wait_bo *args = data;
291 	ktime_t start = ktime_get();
292 	u64 delta_ns;
293 	unsigned long timeout_jiffies =
294 		nsecs_to_jiffies_timeout(args->timeout_ns);
295 
296 	if (args->pad != 0)
297 		return -EINVAL;
298 
299 	ret = drm_gem_dma_resv_wait(file_priv, args->handle,
300 				    true, timeout_jiffies);
301 
302 	/* Decrement the user's timeout, in case we got interrupted
303 	 * such that the ioctl will be restarted.
304 	 */
305 	delta_ns = ktime_to_ns(ktime_sub(ktime_get(), start));
306 	if (delta_ns < args->timeout_ns)
307 		args->timeout_ns -= delta_ns;
308 	else
309 		args->timeout_ns = 0;
310 
311 	/* Asked to wait beyond the jiffie/scheduler precision? */
312 	if (ret == -ETIME && args->timeout_ns)
313 		ret = -EAGAIN;
314 
315 	return ret;
316 }
317