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_object(obj);
 51}
 52
 53static const struct drm_gem_object_funcs v3d_gem_funcs = {
 54	.free = v3d_free_object,
 55	.print_info = drm_gem_shmem_print_info,
 56	.pin = drm_gem_shmem_pin,
 57	.unpin = drm_gem_shmem_unpin,
 58	.get_sg_table = drm_gem_shmem_get_sg_table,
 59	.vmap = drm_gem_shmem_vmap,
 60	.vunmap = drm_gem_shmem_vunmap,
 61	.vm_ops = &drm_gem_shmem_vm_ops,
 62};
 63
 64/* gem_create_object function for allocating a BO struct and doing
 65 * early setup.
 66 */
 67struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size)
 68{
 69	struct v3d_bo *bo;
 70	struct drm_gem_object *obj;
 71
 72	if (size == 0)
 73		return NULL;
 74
 75	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
 76	if (!bo)
 77		return NULL;
 78	obj = &bo->base.base;
 79
 80	obj->funcs = &v3d_gem_funcs;
 81
 82	INIT_LIST_HEAD(&bo->unref_head);
 83
 84	return &bo->base.base;
 85}
 86
 87static int
 88v3d_bo_create_finish(struct drm_gem_object *obj)
 89{
 90	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
 91	struct v3d_bo *bo = to_v3d_bo(obj);
 92	struct sg_table *sgt;
 93	int ret;
 94
 95	/* So far we pin the BO in the MMU for its lifetime, so use
 96	 * shmem's helper for getting a lifetime sgt.
 97	 */
 98	sgt = drm_gem_shmem_get_pages_sgt(&bo->base.base);
 99	if (IS_ERR(sgt))
100		return PTR_ERR(sgt);
101
102	spin_lock(&v3d->mm_lock);
103	/* Allocate the object's space in the GPU's page tables.
104	 * Inserting PTEs will happen later, but the offset is for the
105	 * lifetime of the BO.
106	 */
107	ret = drm_mm_insert_node_generic(&v3d->mm, &bo->node,
108					 obj->size >> PAGE_SHIFT,
109					 GMP_GRANULARITY >> PAGE_SHIFT, 0, 0);
110	spin_unlock(&v3d->mm_lock);
111	if (ret)
112		return ret;
113
114	/* Track stats for /debug/dri/n/bo_stats. */
115	mutex_lock(&v3d->bo_lock);
116	v3d->bo_stats.num_allocated++;
117	v3d->bo_stats.pages_allocated += obj->size >> PAGE_SHIFT;
118	mutex_unlock(&v3d->bo_lock);
119
120	v3d_mmu_insert_ptes(bo);
121
122	return 0;
123}
124
125struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
126			     size_t unaligned_size)
127{
128	struct drm_gem_shmem_object *shmem_obj;
129	struct v3d_bo *bo;
130	int ret;
131
132	shmem_obj = drm_gem_shmem_create(dev, unaligned_size);
133	if (IS_ERR(shmem_obj))
134		return ERR_CAST(shmem_obj);
135	bo = to_v3d_bo(&shmem_obj->base);
136
137	ret = v3d_bo_create_finish(&shmem_obj->base);
138	if (ret)
139		goto free_obj;
140
141	return bo;
142
143free_obj:
144	drm_gem_shmem_free_object(&shmem_obj->base);
145	return ERR_PTR(ret);
146}
147
148struct drm_gem_object *
149v3d_prime_import_sg_table(struct drm_device *dev,
150			  struct dma_buf_attachment *attach,
151			  struct sg_table *sgt)
152{
153	struct drm_gem_object *obj;
154	int ret;
155
156	obj = drm_gem_shmem_prime_import_sg_table(dev, attach, sgt);
157	if (IS_ERR(obj))
158		return obj;
159
160	ret = v3d_bo_create_finish(obj);
161	if (ret) {
162		drm_gem_shmem_free_object(obj);
163		return ERR_PTR(ret);
164	}
165
166	return obj;
167}
168
169int v3d_create_bo_ioctl(struct drm_device *dev, void *data,
170			struct drm_file *file_priv)
171{
172	struct drm_v3d_create_bo *args = data;
173	struct v3d_bo *bo = NULL;
174	int ret;
175
176	if (args->flags != 0) {
177		DRM_INFO("unknown create_bo flags: %d\n", args->flags);
178		return -EINVAL;
179	}
180
181	bo = v3d_bo_create(dev, file_priv, PAGE_ALIGN(args->size));
182	if (IS_ERR(bo))
183		return PTR_ERR(bo);
184
185	args->offset = bo->node.start << PAGE_SHIFT;
186
187	ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
188	drm_gem_object_put_unlocked(&bo->base.base);
189
190	return ret;
191}
192
193int v3d_mmap_bo_ioctl(struct drm_device *dev, void *data,
194		      struct drm_file *file_priv)
195{
196	struct drm_v3d_mmap_bo *args = data;
197	struct drm_gem_object *gem_obj;
198
199	if (args->flags != 0) {
200		DRM_INFO("unknown mmap_bo flags: %d\n", args->flags);
201		return -EINVAL;
202	}
203
204	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
205	if (!gem_obj) {
206		DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
207		return -ENOENT;
208	}
209
210	args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
211	drm_gem_object_put_unlocked(gem_obj);
212
213	return 0;
214}
215
216int v3d_get_bo_offset_ioctl(struct drm_device *dev, void *data,
217			    struct drm_file *file_priv)
218{
219	struct drm_v3d_get_bo_offset *args = data;
220	struct drm_gem_object *gem_obj;
221	struct v3d_bo *bo;
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	bo = to_v3d_bo(gem_obj);
229
230	args->offset = bo->node.start << PAGE_SHIFT;
231
232	drm_gem_object_put_unlocked(gem_obj);
233	return 0;
234}