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