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_cma_helper.h>
 12#include <drm/drm_prime.h>
 13
 14#include "mtk_drm_drv.h"
 15#include "mtk_drm_gem.h"
 16
 17static const struct drm_gem_object_funcs mtk_drm_gem_object_funcs = {
 18	.free = mtk_drm_gem_free_object,
 19	.get_sg_table = mtk_gem_prime_get_sg_table,
 20	.vmap = mtk_drm_gem_prime_vmap,
 21	.vunmap = mtk_drm_gem_prime_vunmap,
 22	.vm_ops = &drm_gem_cma_vm_ops,
 23};
 24
 25static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
 26						unsigned long size)
 27{
 28	struct mtk_drm_gem_obj *mtk_gem_obj;
 29	int ret;
 30
 31	size = round_up(size, PAGE_SIZE);
 32
 33	mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
 34	if (!mtk_gem_obj)
 35		return ERR_PTR(-ENOMEM);
 36
 37	mtk_gem_obj->base.funcs = &mtk_drm_gem_object_funcs;
 38
 39	ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
 40	if (ret < 0) {
 41		DRM_ERROR("failed to initialize gem object\n");
 42		kfree(mtk_gem_obj);
 43		return ERR_PTR(ret);
 44	}
 45
 46	return mtk_gem_obj;
 47}
 48
 49struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
 50					   size_t size, bool alloc_kmap)
 51{
 52	struct mtk_drm_private *priv = dev->dev_private;
 53	struct mtk_drm_gem_obj *mtk_gem;
 54	struct drm_gem_object *obj;
 55	int ret;
 56
 57	mtk_gem = mtk_drm_gem_init(dev, size);
 58	if (IS_ERR(mtk_gem))
 59		return ERR_CAST(mtk_gem);
 60
 61	obj = &mtk_gem->base;
 62
 63	mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
 64
 65	if (!alloc_kmap)
 66		mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
 67
 68	mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
 69					  &mtk_gem->dma_addr, GFP_KERNEL,
 70					  mtk_gem->dma_attrs);
 71	if (!mtk_gem->cookie) {
 72		DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
 73		ret = -ENOMEM;
 74		goto err_gem_free;
 75	}
 76
 77	if (alloc_kmap)
 78		mtk_gem->kvaddr = mtk_gem->cookie;
 79
 80	DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
 81			 mtk_gem->cookie, &mtk_gem->dma_addr,
 82			 size);
 83
 84	return mtk_gem;
 85
 86err_gem_free:
 87	drm_gem_object_release(obj);
 88	kfree(mtk_gem);
 89	return ERR_PTR(ret);
 90}
 91
 92void mtk_drm_gem_free_object(struct drm_gem_object *obj)
 93{
 94	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
 95	struct mtk_drm_private *priv = obj->dev->dev_private;
 96
 97	if (mtk_gem->sg)
 98		drm_prime_gem_destroy(obj, mtk_gem->sg);
 99	else
100		dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
101			       mtk_gem->dma_addr, mtk_gem->dma_attrs);
102
103	/* release file pointer to gem object. */
104	drm_gem_object_release(obj);
105
106	kfree(mtk_gem);
107}
108
109int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
110			    struct drm_mode_create_dumb *args)
111{
112	struct mtk_drm_gem_obj *mtk_gem;
113	int ret;
114
115	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
116	args->size = args->pitch * args->height;
117
118	mtk_gem = mtk_drm_gem_create(dev, args->size, false);
119	if (IS_ERR(mtk_gem))
120		return PTR_ERR(mtk_gem);
121
122	/*
123	 * allocate a id of idr table where the obj is registered
124	 * and handle has the id what user can see.
125	 */
126	ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
127	if (ret)
128		goto err_handle_create;
129
130	/* drop reference from allocate - handle holds it now. */
131	drm_gem_object_put(&mtk_gem->base);
132
133	return 0;
134
135err_handle_create:
136	mtk_drm_gem_free_object(&mtk_gem->base);
137	return ret;
138}
139
140static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj,
141				   struct vm_area_struct *vma)
142
143{
144	int ret;
145	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
146	struct mtk_drm_private *priv = obj->dev->dev_private;
147
148	/*
149	 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
150	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
151	 */
152	vma->vm_flags &= ~VM_PFNMAP;
153
154	ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
155			     mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
156	if (ret)
157		drm_gem_vm_close(vma);
158
159	return ret;
160}
161
162int mtk_drm_gem_mmap_buf(struct drm_gem_object *obj, struct vm_area_struct *vma)
163{
164	int ret;
165
166	ret = drm_gem_mmap_obj(obj, obj->size, vma);
167	if (ret)
168		return ret;
169
170	return mtk_drm_gem_object_mmap(obj, vma);
171}
172
173int mtk_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
174{
175	struct drm_gem_object *obj;
176	int ret;
177
178	ret = drm_gem_mmap(filp, vma);
179	if (ret)
180		return ret;
181
182	obj = vma->vm_private_data;
183
184	/*
185	 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
186	 * whole buffer from the start.
187	 */
188	vma->vm_pgoff = 0;
189
190	return mtk_drm_gem_object_mmap(obj, vma);
191}
192
193/*
194 * Allocate a sg_table for this GEM object.
195 * Note: Both the table's contents, and the sg_table itself must be freed by
196 *       the caller.
197 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
198 */
199struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
200{
201	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
202	struct mtk_drm_private *priv = obj->dev->dev_private;
203	struct sg_table *sgt;
204	int ret;
205
206	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
207	if (!sgt)
208		return ERR_PTR(-ENOMEM);
209
210	ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
211				    mtk_gem->dma_addr, obj->size,
212				    mtk_gem->dma_attrs);
213	if (ret) {
214		DRM_ERROR("failed to allocate sgt, %d\n", ret);
215		kfree(sgt);
216		return ERR_PTR(ret);
217	}
218
219	return sgt;
220}
221
222struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
223			struct dma_buf_attachment *attach, struct sg_table *sg)
224{
225	struct mtk_drm_gem_obj *mtk_gem;
226
227	/* check if the entries in the sg_table are contiguous */
228	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
229		DRM_ERROR("sg_table is not contiguous");
230		return ERR_PTR(-EINVAL);
231	}
232
233	mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
234	if (IS_ERR(mtk_gem))
235		return ERR_CAST(mtk_gem);
236
237	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
238	mtk_gem->sg = sg;
239
240	return &mtk_gem->base;
241}
242
243int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
244{
245	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
246	struct sg_table *sgt = NULL;
247	unsigned int npages;
248
249	if (mtk_gem->kvaddr)
250		goto out;
251
252	sgt = mtk_gem_prime_get_sg_table(obj);
253	if (IS_ERR(sgt))
254		return PTR_ERR(sgt);
255
256	npages = obj->size >> PAGE_SHIFT;
257	mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
258	if (!mtk_gem->pages) {
259		kfree(sgt);
260		return -ENOMEM;
261	}
262
263	drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
264
265	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
266			       pgprot_writecombine(PAGE_KERNEL));
267
268out:
269	kfree(sgt);
270	dma_buf_map_set_vaddr(map, mtk_gem->kvaddr);
271
272	return 0;
273}
274
275void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
276{
277	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
278	void *vaddr = map->vaddr;
279
280	if (!mtk_gem->pages)
281		return;
282
283	vunmap(vaddr);
284	mtk_gem->kvaddr = 0;
285	kfree(mtk_gem->pages);
286}