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	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
 53static 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 */
 68struct 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
 88static int
 89v3d_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
126struct 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
144free_obj:
145	drm_gem_shmem_free(shmem_obj);
146	return ERR_PTR(ret);
147}
148
149struct drm_gem_object *
150v3d_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
170int 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
194int 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
217int 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}