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