1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2015 MediaTek Inc.
  4 */
  5
  6#include <linux/dma-buf.h>
  7#include <linux/vmalloc.h>
  8
  9#include <drm/drm.h>
 10#include <drm/drm_device.h>
 11#include <drm/drm_gem.h>
 12#include <drm/drm_gem_dma_helper.h>
 13#include <drm/drm_prime.h>
 14
 15#include "mtk_drm_drv.h"
 16#include "mtk_gem.h"
 17
 18static int mtk_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 19
 20static const struct vm_operations_struct vm_ops = {
 21	.open = drm_gem_vm_open,
 22	.close = drm_gem_vm_close,
 23};
 24
 25static const struct drm_gem_object_funcs mtk_gem_object_funcs = {
 26	.free = mtk_gem_free_object,
 27	.get_sg_table = mtk_gem_prime_get_sg_table,
 28	.vmap = mtk_gem_prime_vmap,
 29	.vunmap = mtk_gem_prime_vunmap,
 30	.mmap = mtk_gem_object_mmap,
 31	.vm_ops = &vm_ops,
 32};
 33
 34static struct mtk_gem_obj *mtk_gem_init(struct drm_device *dev,
 35					unsigned long size)
 36{
 37	struct mtk_gem_obj *mtk_gem_obj;
 38	int ret;
 39
 40	size = round_up(size, PAGE_SIZE);
 41
 42	if (size == 0)
 43		return ERR_PTR(-EINVAL);
 44
 45	mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
 46	if (!mtk_gem_obj)
 47		return ERR_PTR(-ENOMEM);
 48
 49	mtk_gem_obj->base.funcs = &mtk_gem_object_funcs;
 50
 51	ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
 52	if (ret < 0) {
 53		DRM_ERROR("failed to initialize gem object\n");
 54		kfree(mtk_gem_obj);
 55		return ERR_PTR(ret);
 56	}
 57
 58	return mtk_gem_obj;
 59}
 60
 61struct mtk_gem_obj *mtk_gem_create(struct drm_device *dev,
 62				   size_t size, bool alloc_kmap)
 63{
 64	struct mtk_drm_private *priv = dev->dev_private;
 65	struct mtk_gem_obj *mtk_gem;
 66	struct drm_gem_object *obj;
 67	int ret;
 68
 69	mtk_gem = mtk_gem_init(dev, size);
 70	if (IS_ERR(mtk_gem))
 71		return ERR_CAST(mtk_gem);
 72
 73	obj = &mtk_gem->base;
 74
 75	mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
 76
 77	if (!alloc_kmap)
 78		mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
 79
 80	mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
 81					  &mtk_gem->dma_addr, GFP_KERNEL,
 82					  mtk_gem->dma_attrs);
 83	if (!mtk_gem->cookie) {
 84		DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
 85		ret = -ENOMEM;
 86		goto err_gem_free;
 87	}
 88
 89	if (alloc_kmap)
 90		mtk_gem->kvaddr = mtk_gem->cookie;
 91
 92	DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
 93			 mtk_gem->cookie, &mtk_gem->dma_addr,
 94			 size);
 95
 96	return mtk_gem;
 97
 98err_gem_free:
 99	drm_gem_object_release(obj);
100	kfree(mtk_gem);
101	return ERR_PTR(ret);
102}
103
104void mtk_gem_free_object(struct drm_gem_object *obj)
105{
106	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
107	struct mtk_drm_private *priv = obj->dev->dev_private;
108
109	if (mtk_gem->sg)
110		drm_prime_gem_destroy(obj, mtk_gem->sg);
111	else
112		dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
113			       mtk_gem->dma_addr, mtk_gem->dma_attrs);
114
115	/* release file pointer to gem object. */
116	drm_gem_object_release(obj);
117
118	kfree(mtk_gem);
119}
120
121int mtk_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
122			struct drm_mode_create_dumb *args)
123{
124	struct mtk_gem_obj *mtk_gem;
125	int ret;
126
127	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
128
129	/*
130	 * Multiply 2 variables of different types,
131	 * for example: args->size = args->spacing * args->height;
132	 * may cause coverity issue with unintentional overflow.
133	 */
134	args->size = args->pitch;
135	args->size *= args->height;
136
137	mtk_gem = mtk_gem_create(dev, args->size, false);
138	if (IS_ERR(mtk_gem))
139		return PTR_ERR(mtk_gem);
140
141	/*
142	 * allocate a id of idr table where the obj is registered
143	 * and handle has the id what user can see.
144	 */
145	ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
146	if (ret)
147		goto err_handle_create;
148
149	/* drop reference from allocate - handle holds it now. */
150	drm_gem_object_put(&mtk_gem->base);
151
152	return 0;
153
154err_handle_create:
155	mtk_gem_free_object(&mtk_gem->base);
156	return ret;
157}
158
159static int mtk_gem_object_mmap(struct drm_gem_object *obj,
160			       struct vm_area_struct *vma)
161
162{
163	int ret;
164	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
165	struct mtk_drm_private *priv = obj->dev->dev_private;
166
167	/*
168	 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
169	 * whole buffer from the start.
170	 */
171	vma->vm_pgoff = 0;
172
173	/*
174	 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
175	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
176	 */
177	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
178	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
179	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
180
181	ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
182			     mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
183
184	return ret;
185}
186
187/*
188 * Allocate a sg_table for this GEM object.
189 * Note: Both the table's contents, and the sg_table itself must be freed by
190 *       the caller.
191 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
192 */
193struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
194{
195	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
196	struct mtk_drm_private *priv = obj->dev->dev_private;
197	struct sg_table *sgt;
198	int ret;
199
200	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
201	if (!sgt)
202		return ERR_PTR(-ENOMEM);
203
204	ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
205				    mtk_gem->dma_addr, obj->size,
206				    mtk_gem->dma_attrs);
207	if (ret) {
208		DRM_ERROR("failed to allocate sgt, %d\n", ret);
209		kfree(sgt);
210		return ERR_PTR(ret);
211	}
212
213	return sgt;
214}
215
216struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
217			struct dma_buf_attachment *attach, struct sg_table *sg)
218{
219	struct mtk_gem_obj *mtk_gem;
220
221	/* check if the entries in the sg_table are contiguous */
222	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
223		DRM_ERROR("sg_table is not contiguous");
224		return ERR_PTR(-EINVAL);
225	}
226
227	mtk_gem = mtk_gem_init(dev, attach->dmabuf->size);
228	if (IS_ERR(mtk_gem))
229		return ERR_CAST(mtk_gem);
230
231	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
232	mtk_gem->sg = sg;
233
234	return &mtk_gem->base;
235}
236
237int mtk_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
238{
239	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
240	struct sg_table *sgt = NULL;
241	unsigned int npages;
242
243	if (mtk_gem->kvaddr)
244		goto out;
245
246	sgt = mtk_gem_prime_get_sg_table(obj);
247	if (IS_ERR(sgt))
248		return PTR_ERR(sgt);
249
250	npages = obj->size >> PAGE_SHIFT;
251	mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
252	if (!mtk_gem->pages) {
253		sg_free_table(sgt);
254		kfree(sgt);
255		return -ENOMEM;
256	}
257
258	drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
259
260	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
261			       pgprot_writecombine(PAGE_KERNEL));
262	if (!mtk_gem->kvaddr) {
263		sg_free_table(sgt);
264		kfree(sgt);
265		kfree(mtk_gem->pages);
266		return -ENOMEM;
267	}
268	sg_free_table(sgt);
269	kfree(sgt);
270
271out:
272	iosys_map_set_vaddr(map, mtk_gem->kvaddr);
273
274	return 0;
275}
276
277void mtk_gem_prime_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
278{
279	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
280	void *vaddr = map->vaddr;
281
282	if (!mtk_gem->pages)
283		return;
284
285	vunmap(vaddr);
286	mtk_gem->kvaddr = NULL;
287	kfree(mtk_gem->pages);
288}