xref: /linux/drivers/gpu/drm/v3d/v3d_bo.c (revision 2fe3c78a2c26dd5ee811024a1b7d6cfb4d654319)
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 /* Called DRM core on the last userspace/kernel unreference of the
30  * BO.
31  */
32 void v3d_free_object(struct drm_gem_object *obj)
33 {
34 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
35 	struct v3d_bo *bo = to_v3d_bo(obj);
36 
37 	if (bo->vaddr)
38 		v3d_put_bo_vaddr(bo);
39 
40 	v3d_mmu_remove_ptes(bo);
41 
42 	mutex_lock(&v3d->bo_lock);
43 	v3d->bo_stats.num_allocated--;
44 	v3d->bo_stats.pages_allocated -= obj->size >> V3D_MMU_PAGE_SHIFT;
45 	mutex_unlock(&v3d->bo_lock);
46 
47 	spin_lock(&v3d->mm_lock);
48 	drm_mm_remove_node(&bo->node);
49 	spin_unlock(&v3d->mm_lock);
50 
51 	/* GPU execution may have dirtied any pages in the BO. */
52 	bo->base.pages_mark_dirty_on_put = true;
53 
54 	drm_gem_shmem_free(&bo->base);
55 }
56 
57 static const struct drm_gem_object_funcs v3d_gem_funcs = {
58 	.free = v3d_free_object,
59 	.print_info = drm_gem_shmem_object_print_info,
60 	.pin = drm_gem_shmem_object_pin,
61 	.unpin = drm_gem_shmem_object_unpin,
62 	.get_sg_table = drm_gem_shmem_object_get_sg_table,
63 	.vmap = drm_gem_shmem_object_vmap,
64 	.vunmap = drm_gem_shmem_object_vunmap,
65 	.mmap = drm_gem_shmem_object_mmap,
66 	.vm_ops = &drm_gem_shmem_vm_ops,
67 };
68 
69 /* gem_create_object function for allocating a BO struct and doing
70  * early setup.
71  */
72 struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size)
73 {
74 	struct v3d_bo *bo;
75 	struct drm_gem_object *obj;
76 
77 	if (size == 0)
78 		return ERR_PTR(-EINVAL);
79 
80 	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
81 	if (!bo)
82 		return ERR_PTR(-ENOMEM);
83 	obj = &bo->base.base;
84 
85 	obj->funcs = &v3d_gem_funcs;
86 	bo->base.map_wc = true;
87 	INIT_LIST_HEAD(&bo->unref_head);
88 
89 	return &bo->base.base;
90 }
91 
92 static int
93 v3d_bo_create_finish(struct drm_gem_object *obj)
94 {
95 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
96 	struct v3d_bo *bo = to_v3d_bo(obj);
97 	struct sg_table *sgt;
98 	int ret;
99 
100 	/* So far we pin the BO in the MMU for its lifetime, so use
101 	 * shmem's helper for getting a lifetime sgt.
102 	 */
103 	sgt = drm_gem_shmem_get_pages_sgt(&bo->base);
104 	if (IS_ERR(sgt))
105 		return PTR_ERR(sgt);
106 
107 	spin_lock(&v3d->mm_lock);
108 	/* Allocate the object's space in the GPU's page tables.
109 	 * Inserting PTEs will happen later, but the offset is for the
110 	 * lifetime of the BO.
111 	 */
112 	ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
113 					 obj->size >> V3D_MMU_PAGE_SHIFT,
114 					 GMP_GRANULARITY >> V3D_MMU_PAGE_SHIFT, 0, 0);
115 	spin_unlock(&v3d->mm_lock);
116 	if (ret)
117 		return ret;
118 
119 	/* Track stats for /debug/dri/n/bo_stats. */
120 	mutex_lock(&v3d->bo_lock);
121 	v3d->bo_stats.num_allocated++;
122 	v3d->bo_stats.pages_allocated += obj->size >> V3D_MMU_PAGE_SHIFT;
123 	mutex_unlock(&v3d->bo_lock);
124 
125 	v3d_mmu_insert_ptes(bo);
126 
127 	return 0;
128 }
129 
130 struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
131 			     size_t unaligned_size)
132 {
133 	struct drm_gem_shmem_object *shmem_obj;
134 	struct v3d_bo *bo;
135 	int ret;
136 
137 	shmem_obj = drm_gem_shmem_create(dev, unaligned_size);
138 	if (IS_ERR(shmem_obj))
139 		return ERR_CAST(shmem_obj);
140 	bo = to_v3d_bo(&shmem_obj->base);
141 	bo->vaddr = NULL;
142 
143 	ret = v3d_bo_create_finish(&shmem_obj->base);
144 	if (ret)
145 		goto free_obj;
146 
147 	return bo;
148 
149 free_obj:
150 	drm_gem_shmem_free(shmem_obj);
151 	return ERR_PTR(ret);
152 }
153 
154 struct drm_gem_object *
155 v3d_prime_import_sg_table(struct drm_device *dev,
156 			  struct dma_buf_attachment *attach,
157 			  struct sg_table *sgt)
158 {
159 	struct drm_gem_object *obj;
160 	int ret;
161 
162 	obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
163 	if (IS_ERR(obj))
164 		return obj;
165 
166 	ret = v3d_bo_create_finish(obj);
167 	if (ret) {
168 		drm_gem_shmem_free(&to_v3d_bo(obj)->base);
169 		return ERR_PTR(ret);
170 	}
171 
172 	return obj;
173 }
174 
175 void v3d_get_bo_vaddr(struct v3d_bo *bo)
176 {
177 	struct drm_gem_shmem_object *obj = &bo->base;
178 
179 	bo->vaddr = vmap(obj->pages, obj->base.size >> PAGE_SHIFT, VM_MAP,
180 			 pgprot_writecombine(PAGE_KERNEL));
181 }
182 
183 void v3d_put_bo_vaddr(struct v3d_bo *bo)
184 {
185 	vunmap(bo->vaddr);
186 	bo->vaddr = NULL;
187 }
188 
189 int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
190 			struct drm_file *file_priv)
191 {
192 	struct drm_v3d_create_bo *args = data;
193 	struct v3d_bo *bo = NULL;
194 	int ret;
195 
196 	if (args->flags != 0) {
197 		DRM_INFO("unknown create_bo flags: %d\n", args->flags);
198 		return -EINVAL;
199 	}
200 
201 	bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
202 	if (IS_ERR(bo))
203 		return PTR_ERR(bo);
204 
205 	args->offset = bo->node.start << V3D_MMU_PAGE_SHIFT;
206 
207 	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
208 	drm_gem_object_put(&bo->base.base);
209 
210 	return ret;
211 }
212 
213 int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
214 		      struct drm_file *file_priv)
215 {
216 	struct drm_v3d_mmap_bo *args = data;
217 	struct drm_gem_object *gem_obj;
218 
219 	if (args->flags != 0) {
220 		DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
221 		return -EINVAL;
222 	}
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 
230 	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
231 	drm_gem_object_put(gem_obj);
232 
233 	return 0;
234 }
235 
236 int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
237 			    struct drm_file *file_priv)
238 {
239 	struct drm_v3d_get_bo_offset *args = data;
240 	struct drm_gem_object *gem_obj;
241 	struct v3d_bo *bo;
242 
243 	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
244 	if (!gem_obj) {
245 		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
246 		return -ENOENT;
247 	}
248 	bo = to_v3d_bo(gem_obj);
249 
250 	args->offset = bo->node.start << V3D_MMU_PAGE_SHIFT;
251 
252 	drm_gem_object_put(gem_obj);
253 	return 0;
254 }
255 
256 int
257 v3d_wait_bo_ioctl(struct drm_device *dev, void *data,
258 		  struct drm_file *file_priv)
259 {
260 	int ret;
261 	struct drm_v3d_wait_bo *args = data;
262 	ktime_t start = ktime_get();
263 	u64 delta_ns;
264 	unsigned long timeout_jiffies =
265 		nsecs_to_jiffies_timeout(args->timeout_ns);
266 
267 	if (args->pad != 0)
268 		return -EINVAL;
269 
270 	ret = drm_gem_dma_resv_wait(file_priv, args->handle,
271 				    true, timeout_jiffies);
272 
273 	/* Decrement the user's timeout, in case we got interrupted
274 	 * such that the ioctl will be restarted.
275 	 */
276 	delta_ns = ktime_to_ns(ktime_sub(ktime_get(), start));
277 	if (delta_ns < args->timeout_ns)
278 		args->timeout_ns -= delta_ns;
279 	else
280 		args->timeout_ns = 0;
281 
282 	/* Asked to wait beyond the jiffy/scheduler precision? */
283 	if (ret == -ETIME && args->timeout_ns)
284 		ret = -EAGAIN;
285 
286 	return ret;
287 }
288