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