1 /*
2 * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
3 *
4 * Copyright (C) 2010 Samsung Electronics
5 *
6 * Author: Pawel Osciak <pawel@osciak.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation.
11 */
12
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/mm.h>
16 #include <linux/refcount.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/vmalloc.h>
20
21 #include <media/videobuf2-v4l2.h>
22 #include <media/videobuf2-vmalloc.h>
23 #include <media/videobuf2-memops.h>
24
25 struct vb2_vmalloc_buf {
26 void *vaddr;
27 struct frame_vector *vec;
28 enum dma_data_direction dma_dir;
29 unsigned long size;
30 refcount_t refcount;
31 struct vb2_vmarea_handler handler;
32 struct dma_buf *dbuf;
33 };
34
35 static void vb2_vmalloc_put(void *buf_priv);
36
vb2_vmalloc_alloc(struct vb2_buffer * vb,struct device * dev,unsigned long size)37 static void *vb2_vmalloc_alloc(struct vb2_buffer *vb, struct device *dev,
38 unsigned long size)
39 {
40 struct vb2_vmalloc_buf *buf;
41
42 buf = kzalloc(sizeof(*buf), GFP_KERNEL | vb->vb2_queue->gfp_flags);
43 if (!buf)
44 return ERR_PTR(-ENOMEM);
45
46 buf->size = size;
47 buf->vaddr = vmalloc_user(buf->size);
48 if (!buf->vaddr) {
49 pr_debug("vmalloc of size %ld failed\n", buf->size);
50 kfree(buf);
51 return ERR_PTR(-ENOMEM);
52 }
53
54 buf->dma_dir = vb->vb2_queue->dma_dir;
55 buf->handler.refcount = &buf->refcount;
56 buf->handler.put = vb2_vmalloc_put;
57 buf->handler.arg = buf;
58
59 refcount_set(&buf->refcount, 1);
60 return buf;
61 }
62
vb2_vmalloc_put(void * buf_priv)63 static void vb2_vmalloc_put(void *buf_priv)
64 {
65 struct vb2_vmalloc_buf *buf = buf_priv;
66
67 if (refcount_dec_and_test(&buf->refcount)) {
68 vfree(buf->vaddr);
69 kfree(buf);
70 }
71 }
72
vb2_vmalloc_get_userptr(struct vb2_buffer * vb,struct device * dev,unsigned long vaddr,unsigned long size)73 static void *vb2_vmalloc_get_userptr(struct vb2_buffer *vb, struct device *dev,
74 unsigned long vaddr, unsigned long size)
75 {
76 struct vb2_vmalloc_buf *buf;
77 struct frame_vector *vec;
78 int n_pages, offset, i;
79 int ret = -ENOMEM;
80
81 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
82 if (!buf)
83 return ERR_PTR(-ENOMEM);
84
85 buf->dma_dir = vb->vb2_queue->dma_dir;
86 offset = vaddr & ~PAGE_MASK;
87 buf->size = size;
88 vec = vb2_create_framevec(vaddr, size,
89 buf->dma_dir == DMA_FROM_DEVICE ||
90 buf->dma_dir == DMA_BIDIRECTIONAL);
91 if (IS_ERR(vec)) {
92 ret = PTR_ERR(vec);
93 goto fail_pfnvec_create;
94 }
95 buf->vec = vec;
96 n_pages = frame_vector_count(vec);
97 if (frame_vector_to_pages(vec) < 0) {
98 unsigned long *nums = frame_vector_pfns(vec);
99
100 /*
101 * We cannot get page pointers for these pfns. Check memory is
102 * physically contiguous and use direct mapping.
103 */
104 for (i = 1; i < n_pages; i++)
105 if (nums[i-1] + 1 != nums[i])
106 goto fail_map;
107 buf->vaddr = (__force void *)
108 ioremap(__pfn_to_phys(nums[0]), size + offset);
109 } else {
110 buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1);
111 }
112
113 if (!buf->vaddr)
114 goto fail_map;
115 buf->vaddr += offset;
116 return buf;
117
118 fail_map:
119 vb2_destroy_framevec(vec);
120 fail_pfnvec_create:
121 kfree(buf);
122
123 return ERR_PTR(ret);
124 }
125
vb2_vmalloc_put_userptr(void * buf_priv)126 static void vb2_vmalloc_put_userptr(void *buf_priv)
127 {
128 struct vb2_vmalloc_buf *buf = buf_priv;
129 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
130 unsigned int i;
131 struct page **pages;
132 unsigned int n_pages;
133
134 if (!buf->vec->is_pfns) {
135 n_pages = frame_vector_count(buf->vec);
136 pages = frame_vector_pages(buf->vec);
137 if (vaddr)
138 vm_unmap_ram((void *)vaddr, n_pages);
139 if (buf->dma_dir == DMA_FROM_DEVICE ||
140 buf->dma_dir == DMA_BIDIRECTIONAL)
141 for (i = 0; i < n_pages; i++)
142 set_page_dirty_lock(pages[i]);
143 } else {
144 iounmap((__force void __iomem *)buf->vaddr);
145 }
146 vb2_destroy_framevec(buf->vec);
147 kfree(buf);
148 }
149
vb2_vmalloc_vaddr(struct vb2_buffer * vb,void * buf_priv)150 static void *vb2_vmalloc_vaddr(struct vb2_buffer *vb, void *buf_priv)
151 {
152 struct vb2_vmalloc_buf *buf = buf_priv;
153
154 if (!buf->vaddr) {
155 pr_err("Address of an unallocated plane requested or cannot map user pointer\n");
156 return NULL;
157 }
158
159 return buf->vaddr;
160 }
161
vb2_vmalloc_num_users(void * buf_priv)162 static unsigned int vb2_vmalloc_num_users(void *buf_priv)
163 {
164 struct vb2_vmalloc_buf *buf = buf_priv;
165 return refcount_read(&buf->refcount);
166 }
167
vb2_vmalloc_mmap(void * buf_priv,struct vm_area_struct * vma)168 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
169 {
170 struct vb2_vmalloc_buf *buf = buf_priv;
171 int ret;
172
173 if (!buf) {
174 pr_err("No memory to map\n");
175 return -EINVAL;
176 }
177
178 ret = remap_vmalloc_range(vma, buf->vaddr, 0);
179 if (ret) {
180 pr_err("Remapping vmalloc memory, error: %d\n", ret);
181 return ret;
182 }
183
184 /*
185 * Make sure that vm_areas for 2 buffers won't be merged together
186 */
187 vm_flags_set(vma, VM_DONTEXPAND);
188
189 /*
190 * Use common vm_area operations to track buffer refcount.
191 */
192 vma->vm_private_data = &buf->handler;
193 vma->vm_ops = &vb2_common_vm_ops;
194
195 vma->vm_ops->open(vma);
196
197 return 0;
198 }
199
200 #ifdef CONFIG_HAS_DMA
201 /*********************************************/
202 /* DMABUF ops for exporters */
203 /*********************************************/
204
205 struct vb2_vmalloc_attachment {
206 struct sg_table sgt;
207 enum dma_data_direction dma_dir;
208 };
209
vb2_vmalloc_dmabuf_ops_attach(struct dma_buf * dbuf,struct dma_buf_attachment * dbuf_attach)210 static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf,
211 struct dma_buf_attachment *dbuf_attach)
212 {
213 struct vb2_vmalloc_attachment *attach;
214 struct vb2_vmalloc_buf *buf = dbuf->priv;
215 int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE;
216 struct sg_table *sgt;
217 struct scatterlist *sg;
218 void *vaddr = buf->vaddr;
219 int ret;
220 int i;
221
222 attach = kzalloc(sizeof(*attach), GFP_KERNEL);
223 if (!attach)
224 return -ENOMEM;
225
226 sgt = &attach->sgt;
227 ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
228 if (ret) {
229 kfree(attach);
230 return ret;
231 }
232 for_each_sgtable_sg(sgt, sg, i) {
233 struct page *page = vmalloc_to_page(vaddr);
234
235 if (!page) {
236 sg_free_table(sgt);
237 kfree(attach);
238 return -ENOMEM;
239 }
240 sg_set_page(sg, page, PAGE_SIZE, 0);
241 vaddr += PAGE_SIZE;
242 }
243
244 attach->dma_dir = DMA_NONE;
245 dbuf_attach->priv = attach;
246 return 0;
247 }
248
vb2_vmalloc_dmabuf_ops_detach(struct dma_buf * dbuf,struct dma_buf_attachment * db_attach)249 static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
250 struct dma_buf_attachment *db_attach)
251 {
252 struct vb2_vmalloc_attachment *attach = db_attach->priv;
253 struct sg_table *sgt;
254
255 if (!attach)
256 return;
257
258 sgt = &attach->sgt;
259
260 /* release the scatterlist cache */
261 if (attach->dma_dir != DMA_NONE)
262 dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
263 sg_free_table(sgt);
264 kfree(attach);
265 db_attach->priv = NULL;
266 }
267
vb2_vmalloc_dmabuf_ops_map(struct dma_buf_attachment * db_attach,enum dma_data_direction dma_dir)268 static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
269 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
270 {
271 struct vb2_vmalloc_attachment *attach = db_attach->priv;
272 struct sg_table *sgt;
273
274 sgt = &attach->sgt;
275 /* return previously mapped sg table */
276 if (attach->dma_dir == dma_dir)
277 return sgt;
278
279 /* release any previous cache */
280 if (attach->dma_dir != DMA_NONE) {
281 dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
282 attach->dma_dir = DMA_NONE;
283 }
284
285 /* mapping to the client with new direction */
286 if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
287 pr_err("failed to map scatterlist\n");
288 return ERR_PTR(-EIO);
289 }
290
291 attach->dma_dir = dma_dir;
292
293 return sgt;
294 }
295
vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment * db_attach,struct sg_table * sgt,enum dma_data_direction dma_dir)296 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
297 struct sg_table *sgt, enum dma_data_direction dma_dir)
298 {
299 /* nothing to be done here */
300 }
301
vb2_vmalloc_dmabuf_ops_release(struct dma_buf * dbuf)302 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
303 {
304 /* drop reference obtained in vb2_vmalloc_get_dmabuf */
305 vb2_vmalloc_put(dbuf->priv);
306 }
307
vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf * dbuf,struct iosys_map * map)308 static int vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf,
309 struct iosys_map *map)
310 {
311 struct vb2_vmalloc_buf *buf = dbuf->priv;
312
313 iosys_map_set_vaddr(map, buf->vaddr);
314
315 return 0;
316 }
317
vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf * dbuf,struct vm_area_struct * vma)318 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
319 struct vm_area_struct *vma)
320 {
321 return vb2_vmalloc_mmap(dbuf->priv, vma);
322 }
323
324 static const struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
325 .attach = vb2_vmalloc_dmabuf_ops_attach,
326 .detach = vb2_vmalloc_dmabuf_ops_detach,
327 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
328 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
329 .vmap = vb2_vmalloc_dmabuf_ops_vmap,
330 .mmap = vb2_vmalloc_dmabuf_ops_mmap,
331 .release = vb2_vmalloc_dmabuf_ops_release,
332 };
333
vb2_vmalloc_get_dmabuf(struct vb2_buffer * vb,void * buf_priv,unsigned long flags)334 static struct dma_buf *vb2_vmalloc_get_dmabuf(struct vb2_buffer *vb,
335 void *buf_priv,
336 unsigned long flags)
337 {
338 struct vb2_vmalloc_buf *buf = buf_priv;
339 struct dma_buf *dbuf;
340 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
341
342 exp_info.ops = &vb2_vmalloc_dmabuf_ops;
343 exp_info.size = buf->size;
344 exp_info.flags = flags;
345 exp_info.priv = buf;
346
347 if (WARN_ON(!buf->vaddr))
348 return NULL;
349
350 dbuf = dma_buf_export(&exp_info);
351 if (IS_ERR(dbuf))
352 return NULL;
353
354 /* dmabuf keeps reference to vb2 buffer */
355 refcount_inc(&buf->refcount);
356
357 return dbuf;
358 }
359 #endif /* CONFIG_HAS_DMA */
360
361
362 /*********************************************/
363 /* callbacks for DMABUF buffers */
364 /*********************************************/
365
vb2_vmalloc_map_dmabuf(void * mem_priv)366 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
367 {
368 struct vb2_vmalloc_buf *buf = mem_priv;
369 struct iosys_map map;
370 int ret;
371
372 ret = dma_buf_vmap_unlocked(buf->dbuf, &map);
373 if (ret)
374 return -EFAULT;
375 buf->vaddr = map.vaddr;
376
377 return 0;
378 }
379
vb2_vmalloc_unmap_dmabuf(void * mem_priv)380 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
381 {
382 struct vb2_vmalloc_buf *buf = mem_priv;
383 struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
384
385 dma_buf_vunmap_unlocked(buf->dbuf, &map);
386 buf->vaddr = NULL;
387 }
388
vb2_vmalloc_detach_dmabuf(void * mem_priv)389 static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
390 {
391 struct vb2_vmalloc_buf *buf = mem_priv;
392 struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
393
394 if (buf->vaddr)
395 dma_buf_vunmap_unlocked(buf->dbuf, &map);
396
397 kfree(buf);
398 }
399
vb2_vmalloc_attach_dmabuf(struct vb2_buffer * vb,struct device * dev,struct dma_buf * dbuf,unsigned long size)400 static void *vb2_vmalloc_attach_dmabuf(struct vb2_buffer *vb,
401 struct device *dev,
402 struct dma_buf *dbuf,
403 unsigned long size)
404 {
405 struct vb2_vmalloc_buf *buf;
406
407 if (dbuf->size < size)
408 return ERR_PTR(-EFAULT);
409
410 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
411 if (!buf)
412 return ERR_PTR(-ENOMEM);
413
414 buf->dbuf = dbuf;
415 buf->dma_dir = vb->vb2_queue->dma_dir;
416 buf->size = size;
417
418 return buf;
419 }
420
421
422 const struct vb2_mem_ops vb2_vmalloc_memops = {
423 .alloc = vb2_vmalloc_alloc,
424 .put = vb2_vmalloc_put,
425 .get_userptr = vb2_vmalloc_get_userptr,
426 .put_userptr = vb2_vmalloc_put_userptr,
427 #ifdef CONFIG_HAS_DMA
428 .get_dmabuf = vb2_vmalloc_get_dmabuf,
429 #endif
430 .map_dmabuf = vb2_vmalloc_map_dmabuf,
431 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf,
432 .attach_dmabuf = vb2_vmalloc_attach_dmabuf,
433 .detach_dmabuf = vb2_vmalloc_detach_dmabuf,
434 .vaddr = vb2_vmalloc_vaddr,
435 .mmap = vb2_vmalloc_mmap,
436 .num_users = vb2_vmalloc_num_users,
437 };
438 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
439
440 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
441 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
442 MODULE_LICENSE("GPL");
443 MODULE_IMPORT_NS(DMA_BUF);
444