1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2015 MediaTek Inc.
  4 */
  5
  6#include <linux/dma-buf.h>
  7
  8#include <drm/drm.h>
  9#include <drm/drm_device.h>
 10#include <drm/drm_gem.h>
 11#include <drm/drm_gem_dma_helper.h>
 12#include <drm/drm_prime.h>
 13
 14#include "mtk_drm_drv.h"
 15#include "mtk_drm_gem.h"
 16
 17static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 18
 19static const struct vm_operations_struct vm_ops = {
 20	.open = drm_gem_vm_open,
 21	.close = drm_gem_vm_close,
 22};
 23
 24static const struct drm_gem_object_funcs mtk_drm_gem_object_funcs = {
 25	.free = mtk_drm_gem_free_object,
 26	.get_sg_table = mtk_gem_prime_get_sg_table,
 27	.vmap = mtk_drm_gem_prime_vmap,
 28	.vunmap = mtk_drm_gem_prime_vunmap,
 29	.mmap = mtk_drm_gem_object_mmap,
 30	.vm_ops = &vm_ops,
 31};
 32
 33static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
 34						unsigned long size)
 35{
 36	struct mtk_drm_gem_obj *mtk_gem_obj;
 37	int ret;
 38
 39	size = round_up(size, PAGE_SIZE);
 40
 41	mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
 42	if (!mtk_gem_obj)
 43		return ERR_PTR(-ENOMEM);
 44
 45	mtk_gem_obj->base.funcs = &mtk_drm_gem_object_funcs;
 46
 47	ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
 48	if (ret < 0) {
 49		DRM_ERROR("failed to initialize gem object\n");
 50		kfree(mtk_gem_obj);
 51		return ERR_PTR(ret);
 52	}
 53
 54	return mtk_gem_obj;
 55}
 56
 57struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
 58					   size_t size, bool alloc_kmap)
 59{
 60	struct mtk_drm_private *priv = dev->dev_private;
 61	struct mtk_drm_gem_obj *mtk_gem;
 62	struct drm_gem_object *obj;
 63	int ret;
 64
 65	mtk_gem = mtk_drm_gem_init(dev, size);
 66	if (IS_ERR(mtk_gem))
 67		return ERR_CAST(mtk_gem);
 68
 69	obj = &mtk_gem->base;
 70
 71	mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
 72
 73	if (!alloc_kmap)
 74		mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
 75
 76	mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
 77					  &mtk_gem->dma_addr, GFP_KERNEL,
 78					  mtk_gem->dma_attrs);
 79	if (!mtk_gem->cookie) {
 80		DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
 81		ret = -ENOMEM;
 82		goto err_gem_free;
 83	}
 84
 85	if (alloc_kmap)
 86		mtk_gem->kvaddr = mtk_gem->cookie;
 87
 88	DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
 89			 mtk_gem->cookie, &mtk_gem->dma_addr,
 90			 size);
 91
 92	return mtk_gem;
 93
 94err_gem_free:
 95	drm_gem_object_release(obj);
 96	kfree(mtk_gem);
 97	return ERR_PTR(ret);
 98}
 99
100void mtk_drm_gem_free_object(struct drm_gem_object *obj)
101{
102	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
103	struct mtk_drm_private *priv = obj->dev->dev_private;
104
105	if (mtk_gem->sg)
106		drm_prime_gem_destroy(obj, mtk_gem->sg);
107	else
108		dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
109			       mtk_gem->dma_addr, mtk_gem->dma_attrs);
110
111	/* release file pointer to gem object. */
112	drm_gem_object_release(obj);
113
114	kfree(mtk_gem);
115}
116
117int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
118			    struct drm_mode_create_dumb *args)
119{
120	struct mtk_drm_gem_obj *mtk_gem;
121	int ret;
122
123	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
124
125	/*
126	 * Multiply 2 variables of different types,
127	 * for example: args->size = args->spacing * args->height;
128	 * may cause coverity issue with unintentional overflow.
129	 */
130	args->size = args->pitch;
131	args->size *= args->height;
132
133	mtk_gem = mtk_drm_gem_create(dev, args->size, false);
134	if (IS_ERR(mtk_gem))
135		return PTR_ERR(mtk_gem);
136
137	/*
138	 * allocate a id of idr table where the obj is registered
139	 * and handle has the id what user can see.
140	 */
141	ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
142	if (ret)
143		goto err_handle_create;
144
145	/* drop reference from allocate - handle holds it now. */
146	drm_gem_object_put(&mtk_gem->base);
147
148	return 0;
149
150err_handle_create:
151	mtk_drm_gem_free_object(&mtk_gem->base);
152	return ret;
153}
154
155static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj,
156				   struct vm_area_struct *vma)
157
158{
159	int ret;
160	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
161	struct mtk_drm_private *priv = obj->dev->dev_private;
162
163	/*
164	 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
165	 * whole buffer from the start.
166	 */
167	vma->vm_pgoff = 0;
168
169	/*
170	 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
171	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
172	 */
173	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
174	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
175	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
176
177	ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
178			     mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
179
180	return ret;
181}
182
183/*
184 * Allocate a sg_table for this GEM object.
185 * Note: Both the table's contents, and the sg_table itself must be freed by
186 *       the caller.
187 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
188 */
189struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
190{
191	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
192	struct mtk_drm_private *priv = obj->dev->dev_private;
193	struct sg_table *sgt;
194	int ret;
195
196	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
197	if (!sgt)
198		return ERR_PTR(-ENOMEM);
199
200	ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
201				    mtk_gem->dma_addr, obj->size,
202				    mtk_gem->dma_attrs);
203	if (ret) {
204		DRM_ERROR("failed to allocate sgt, %d\n", ret);
205		kfree(sgt);
206		return ERR_PTR(ret);
207	}
208
209	return sgt;
210}
211
212struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
213			struct dma_buf_attachment *attach, struct sg_table *sg)
214{
215	struct mtk_drm_gem_obj *mtk_gem;
216
217	/* check if the entries in the sg_table are contiguous */
218	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
219		DRM_ERROR("sg_table is not contiguous");
220		return ERR_PTR(-EINVAL);
221	}
222
223	mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
224	if (IS_ERR(mtk_gem))
225		return ERR_CAST(mtk_gem);
226
227	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
228	mtk_gem->sg = sg;
229
230	return &mtk_gem->base;
231}
232
233int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
234{
235	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
236	struct sg_table *sgt = NULL;
237	unsigned int npages;
238
239	if (mtk_gem->kvaddr)
240		goto out;
241
242	sgt = mtk_gem_prime_get_sg_table(obj);
243	if (IS_ERR(sgt))
244		return PTR_ERR(sgt);
245
246	npages = obj->size >> PAGE_SHIFT;
247	mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
248	if (!mtk_gem->pages) {
249		sg_free_table(sgt);
250		kfree(sgt);
251		return -ENOMEM;
252	}
253
254	drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
255
256	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
257			       pgprot_writecombine(PAGE_KERNEL));
258	if (!mtk_gem->kvaddr) {
259		sg_free_table(sgt);
260		kfree(sgt);
261		kfree(mtk_gem->pages);
262		return -ENOMEM;
263	}
264	sg_free_table(sgt);
265	kfree(sgt);
266
267out:
268	iosys_map_set_vaddr(map, mtk_gem->kvaddr);
269
270	return 0;
271}
272
273void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
274			      struct iosys_map *map)
275{
276	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
277	void *vaddr = map->vaddr;
278
279	if (!mtk_gem->pages)
280		return;
281
282	vunmap(vaddr);
283	mtk_gem->kvaddr = NULL;
284	kfree(mtk_gem->pages);
285}