1/*
  2 * Copyright (c) 2015 MediaTek Inc.
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License version 2 as
  6 * published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful,
  9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11 * GNU General Public License for more details.
 12 */
 13
 14#include <drm/drmP.h>
 15#include <drm/drm_gem.h>
 16#include <linux/dma-buf.h>
 17
 18#include "mtk_drm_drv.h"
 19#include "mtk_drm_gem.h"
 20
 21static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
 22						unsigned long size)
 23{
 24	struct mtk_drm_gem_obj *mtk_gem_obj;
 25	int ret;
 26
 27	size = round_up(size, PAGE_SIZE);
 28
 29	mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
 30	if (!mtk_gem_obj)
 31		return ERR_PTR(-ENOMEM);
 32
 33	ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
 34	if (ret < 0) {
 35		DRM_ERROR("failed to initialize gem object\n");
 36		kfree(mtk_gem_obj);
 37		return ERR_PTR(ret);
 38	}
 39
 40	return mtk_gem_obj;
 41}
 42
 43struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
 44					   size_t size, bool alloc_kmap)
 45{
 46	struct mtk_drm_private *priv = dev->dev_private;
 47	struct mtk_drm_gem_obj *mtk_gem;
 48	struct drm_gem_object *obj;
 49	int ret;
 50
 51	mtk_gem = mtk_drm_gem_init(dev, size);
 52	if (IS_ERR(mtk_gem))
 53		return ERR_CAST(mtk_gem);
 54
 55	obj = &mtk_gem->base;
 56
 57	mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
 58
 59	if (!alloc_kmap)
 60		mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
 61
 62	mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
 63					  &mtk_gem->dma_addr, GFP_KERNEL,
 64					  mtk_gem->dma_attrs);
 65	if (!mtk_gem->cookie) {
 66		DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
 67		ret = -ENOMEM;
 68		goto err_gem_free;
 69	}
 70
 71	if (alloc_kmap)
 72		mtk_gem->kvaddr = mtk_gem->cookie;
 73
 74	DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
 75			 mtk_gem->cookie, &mtk_gem->dma_addr,
 76			 size);
 77
 78	return mtk_gem;
 79
 80err_gem_free:
 81	drm_gem_object_release(obj);
 82	kfree(mtk_gem);
 83	return ERR_PTR(ret);
 84}
 85
 86void mtk_drm_gem_free_object(struct drm_gem_object *obj)
 87{
 88	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
 89	struct mtk_drm_private *priv = obj->dev->dev_private;
 90
 91	if (mtk_gem->sg)
 92		drm_prime_gem_destroy(obj, mtk_gem->sg);
 93	else
 94		dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
 95			       mtk_gem->dma_addr, mtk_gem->dma_attrs);
 96
 97	/* release file pointer to gem object. */
 98	drm_gem_object_release(obj);
 99
100	kfree(mtk_gem);
101}
102
103int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
104			    struct drm_mode_create_dumb *args)
105{
106	struct mtk_drm_gem_obj *mtk_gem;
107	int ret;
108
109	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
110	args->size = args->pitch * args->height;
111
112	mtk_gem = mtk_drm_gem_create(dev, args->size, false);
113	if (IS_ERR(mtk_gem))
114		return PTR_ERR(mtk_gem);
115
116	/*
117	 * allocate a id of idr table where the obj is registered
118	 * and handle has the id what user can see.
119	 */
120	ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
121	if (ret)
122		goto err_handle_create;
123
124	/* drop reference from allocate - handle holds it now. */
125	drm_gem_object_put_unlocked(&mtk_gem->base);
126
127	return 0;
128
129err_handle_create:
130	mtk_drm_gem_free_object(&mtk_gem->base);
131	return ret;
132}
133
134static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj,
135				   struct vm_area_struct *vma)
136
137{
138	int ret;
139	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
140	struct mtk_drm_private *priv = obj->dev->dev_private;
141
142	/*
143	 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
144	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
145	 */
146	vma->vm_flags &= ~VM_PFNMAP;
147	vma->vm_pgoff = 0;
148
149	ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
150			     mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
151	if (ret)
152		drm_gem_vm_close(vma);
153
154	return ret;
155}
156
157int mtk_drm_gem_mmap_buf(struct drm_gem_object *obj, struct vm_area_struct *vma)
158{
159	int ret;
160
161	ret = drm_gem_mmap_obj(obj, obj->size, vma);
162	if (ret)
163		return ret;
164
165	return mtk_drm_gem_object_mmap(obj, vma);
166}
167
168int mtk_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
169{
170	struct drm_gem_object *obj;
171	int ret;
172
173	ret = drm_gem_mmap(filp, vma);
174	if (ret)
175		return ret;
176
177	obj = vma->vm_private_data;
178
179	return mtk_drm_gem_object_mmap(obj, vma);
180}
181
182/*
183 * Allocate a sg_table for this GEM object.
184 * Note: Both the table's contents, and the sg_table itself must be freed by
185 *       the caller.
186 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
187 */
188struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
189{
190	struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
191	struct mtk_drm_private *priv = obj->dev->dev_private;
192	struct sg_table *sgt;
193	int ret;
194
195	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
196	if (!sgt)
197		return ERR_PTR(-ENOMEM);
198
199	ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
200				    mtk_gem->dma_addr, obj->size,
201				    mtk_gem->dma_attrs);
202	if (ret) {
203		DRM_ERROR("failed to allocate sgt, %d\n", ret);
204		kfree(sgt);
205		return ERR_PTR(ret);
206	}
207
208	return sgt;
209}
210
211struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
212			struct dma_buf_attachment *attach, struct sg_table *sg)
213{
214	struct mtk_drm_gem_obj *mtk_gem;
215	int ret;
216	struct scatterlist *s;
217	unsigned int i;
218	dma_addr_t expected;
219
220	mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
221
222	if (IS_ERR(mtk_gem))
223		return ERR_PTR(PTR_ERR(mtk_gem));
224
225	expected = sg_dma_address(sg->sgl);
226	for_each_sg(sg->sgl, s, sg->nents, i) {
227		if (sg_dma_address(s) != expected) {
228			DRM_ERROR("sg_table is not contiguous");
229			ret = -EINVAL;
230			goto err_gem_free;
231		}
232		expected = sg_dma_address(s) + sg_dma_len(s);
233	}
234
235	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
236	mtk_gem->sg = sg;
237
238	return &mtk_gem->base;
239
240err_gem_free:
241	kfree(mtk_gem);
242	return ERR_PTR(ret);
243}