1
2
3
4
5
6
7
8
9
10
11
12
13#include <linux/io.h>
14#include <linux/module.h>
15#include <linux/mm.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19
20#include <media/videobuf2-core.h>
21#include <media/videobuf2-vmalloc.h>
22#include <media/videobuf2-memops.h>
23
24struct vb2_vmalloc_buf {
25 void *vaddr;
26 struct page **pages;
27 struct vm_area_struct *vma;
28 enum dma_data_direction dma_dir;
29 unsigned long size;
30 unsigned int n_pages;
31 atomic_t refcount;
32 struct vb2_vmarea_handler handler;
33 struct dma_buf *dbuf;
34};
35
36static void vb2_vmalloc_put(void *buf_priv);
37
38static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size,
39 enum dma_data_direction dma_dir, gfp_t gfp_flags)
40{
41 struct vb2_vmalloc_buf *buf;
42
43 buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
44 if (!buf)
45 return NULL;
46
47 buf->size = size;
48 buf->vaddr = vmalloc_user(buf->size);
49 buf->dma_dir = dma_dir;
50 buf->handler.refcount = &buf->refcount;
51 buf->handler.put = vb2_vmalloc_put;
52 buf->handler.arg = buf;
53
54 if (!buf->vaddr) {
55 pr_debug("vmalloc of size %ld failed\n", buf->size);
56 kfree(buf);
57 return NULL;
58 }
59
60 atomic_inc(&buf->refcount);
61 return buf;
62}
63
64static void vb2_vmalloc_put(void *buf_priv)
65{
66 struct vb2_vmalloc_buf *buf = buf_priv;
67
68 if (atomic_dec_and_test(&buf->refcount)) {
69 vfree(buf->vaddr);
70 kfree(buf);
71 }
72}
73
74static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
75 unsigned long size,
76 enum dma_data_direction dma_dir)
77{
78 struct vb2_vmalloc_buf *buf;
79 unsigned long first, last;
80 int n_pages, offset;
81 struct vm_area_struct *vma;
82 dma_addr_t physp;
83
84 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
85 if (!buf)
86 return NULL;
87
88 buf->dma_dir = dma_dir;
89 offset = vaddr & ~PAGE_MASK;
90 buf->size = size;
91
92
93 vma = find_vma(current->mm, vaddr);
94 if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
95 if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
96 goto fail_pages_array_alloc;
97 buf->vma = vma;
98 buf->vaddr = (__force void *)ioremap_nocache(physp, size);
99 if (!buf->vaddr)
100 goto fail_pages_array_alloc;
101 } else {
102 first = vaddr >> PAGE_SHIFT;
103 last = (vaddr + size - 1) >> PAGE_SHIFT;
104 buf->n_pages = last - first + 1;
105 buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
106 GFP_KERNEL);
107 if (!buf->pages)
108 goto fail_pages_array_alloc;
109
110
111 n_pages = get_user_pages(current, current->mm,
112 vaddr & PAGE_MASK, buf->n_pages,
113 dma_dir == DMA_FROM_DEVICE,
114 1,
115 buf->pages, NULL);
116 if (n_pages != buf->n_pages)
117 goto fail_get_user_pages;
118
119 buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
120 PAGE_KERNEL);
121 if (!buf->vaddr)
122 goto fail_get_user_pages;
123 }
124
125 buf->vaddr += offset;
126 return buf;
127
128fail_get_user_pages:
129 pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
130 buf->n_pages);
131 while (--n_pages >= 0)
132 put_page(buf->pages[n_pages]);
133 kfree(buf->pages);
134
135fail_pages_array_alloc:
136 kfree(buf);
137
138 return NULL;
139}
140
141static void vb2_vmalloc_put_userptr(void *buf_priv)
142{
143 struct vb2_vmalloc_buf *buf = buf_priv;
144 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
145 unsigned int i;
146
147 if (buf->pages) {
148 if (vaddr)
149 vm_unmap_ram((void *)vaddr, buf->n_pages);
150 for (i = 0; i < buf->n_pages; ++i) {
151 if (buf->dma_dir == DMA_FROM_DEVICE)
152 set_page_dirty_lock(buf->pages[i]);
153 put_page(buf->pages[i]);
154 }
155 kfree(buf->pages);
156 } else {
157 vb2_put_vma(buf->vma);
158 iounmap((__force void __iomem *)buf->vaddr);
159 }
160 kfree(buf);
161}
162
163static void *vb2_vmalloc_vaddr(void *buf_priv)
164{
165 struct vb2_vmalloc_buf *buf = buf_priv;
166
167 if (!buf->vaddr) {
168 pr_err("Address of an unallocated plane requested "
169 "or cannot map user pointer\n");
170 return NULL;
171 }
172
173 return buf->vaddr;
174}
175
176static unsigned int vb2_vmalloc_num_users(void *buf_priv)
177{
178 struct vb2_vmalloc_buf *buf = buf_priv;
179 return atomic_read(&buf->refcount);
180}
181
182static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
183{
184 struct vb2_vmalloc_buf *buf = buf_priv;
185 int ret;
186
187 if (!buf) {
188 pr_err("No memory to map\n");
189 return -EINVAL;
190 }
191
192 ret = remap_vmalloc_range(vma, buf->vaddr, 0);
193 if (ret) {
194 pr_err("Remapping vmalloc memory, error: %d\n", ret);
195 return ret;
196 }
197
198
199
200
201 vma->vm_flags |= VM_DONTEXPAND;
202
203
204
205
206 vma->vm_private_data = &buf->handler;
207 vma->vm_ops = &vb2_common_vm_ops;
208
209 vma->vm_ops->open(vma);
210
211 return 0;
212}
213
214#ifdef CONFIG_HAS_DMA
215
216
217
218
219struct vb2_vmalloc_attachment {
220 struct sg_table sgt;
221 enum dma_data_direction dma_dir;
222};
223
224static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
225 struct dma_buf_attachment *dbuf_attach)
226{
227 struct vb2_vmalloc_attachment *attach;
228 struct vb2_vmalloc_buf *buf = dbuf->priv;
229 int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE;
230 struct sg_table *sgt;
231 struct scatterlist *sg;
232 void *vaddr = buf->vaddr;
233 int ret;
234 int i;
235
236 attach = kzalloc(sizeof(*attach), GFP_KERNEL);
237 if (!attach)
238 return -ENOMEM;
239
240 sgt = &attach->sgt;
241 ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
242 if (ret) {
243 kfree(attach);
244 return ret;
245 }
246 for_each_sg(sgt->sgl, sg, sgt->nents, i) {
247 struct page *page = vmalloc_to_page(vaddr);
248
249 if (!page) {
250 sg_free_table(sgt);
251 kfree(attach);
252 return -ENOMEM;
253 }
254 sg_set_page(sg, page, PAGE_SIZE, 0);
255 vaddr += PAGE_SIZE;
256 }
257
258 attach->dma_dir = DMA_NONE;
259 dbuf_attach->priv = attach;
260 return 0;
261}
262
263static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
264 struct dma_buf_attachment *db_attach)
265{
266 struct vb2_vmalloc_attachment *attach = db_attach->priv;
267 struct sg_table *sgt;
268
269 if (!attach)
270 return;
271
272 sgt = &attach->sgt;
273
274
275 if (attach->dma_dir != DMA_NONE)
276 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
277 attach->dma_dir);
278 sg_free_table(sgt);
279 kfree(attach);
280 db_attach->priv = NULL;
281}
282
283static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
284 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
285{
286 struct vb2_vmalloc_attachment *attach = db_attach->priv;
287
288 struct mutex *lock = &db_attach->dmabuf->lock;
289 struct sg_table *sgt;
290 int ret;
291
292 mutex_lock(lock);
293
294 sgt = &attach->sgt;
295
296 if (attach->dma_dir == dma_dir) {
297 mutex_unlock(lock);
298 return sgt;
299 }
300
301
302 if (attach->dma_dir != DMA_NONE) {
303 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
304 attach->dma_dir);
305 attach->dma_dir = DMA_NONE;
306 }
307
308
309 ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dma_dir);
310 if (ret <= 0) {
311 pr_err("failed to map scatterlist\n");
312 mutex_unlock(lock);
313 return ERR_PTR(-EIO);
314 }
315
316 attach->dma_dir = dma_dir;
317
318 mutex_unlock(lock);
319
320 return sgt;
321}
322
323static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
324 struct sg_table *sgt, enum dma_data_direction dma_dir)
325{
326
327}
328
329static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
330{
331
332 vb2_vmalloc_put(dbuf->priv);
333}
334
335static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
336{
337 struct vb2_vmalloc_buf *buf = dbuf->priv;
338
339 return buf->vaddr + pgnum * PAGE_SIZE;
340}
341
342static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
343{
344 struct vb2_vmalloc_buf *buf = dbuf->priv;
345
346 return buf->vaddr;
347}
348
349static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
350 struct vm_area_struct *vma)
351{
352 return vb2_vmalloc_mmap(dbuf->priv, vma);
353}
354
355static struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
356 .attach = vb2_vmalloc_dmabuf_ops_attach,
357 .detach = vb2_vmalloc_dmabuf_ops_detach,
358 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
359 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
360 .kmap = vb2_vmalloc_dmabuf_ops_kmap,
361 .kmap_atomic = vb2_vmalloc_dmabuf_ops_kmap,
362 .vmap = vb2_vmalloc_dmabuf_ops_vmap,
363 .mmap = vb2_vmalloc_dmabuf_ops_mmap,
364 .release = vb2_vmalloc_dmabuf_ops_release,
365};
366
367static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
368{
369 struct vb2_vmalloc_buf *buf = buf_priv;
370 struct dma_buf *dbuf;
371
372 if (WARN_ON(!buf->vaddr))
373 return NULL;
374
375 dbuf = dma_buf_export(buf, &vb2_vmalloc_dmabuf_ops, buf->size, flags, NULL);
376 if (IS_ERR(dbuf))
377 return NULL;
378
379
380 atomic_inc(&buf->refcount);
381
382 return dbuf;
383}
384#endif
385
386
387
388
389
390
391static int vb2_vmalloc_map_dmabuf(void *mem_priv)
392{
393 struct vb2_vmalloc_buf *buf = mem_priv;
394
395 buf->vaddr = dma_buf_vmap(buf->dbuf);
396
397 return buf->vaddr ? 0 : -EFAULT;
398}
399
400static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
401{
402 struct vb2_vmalloc_buf *buf = mem_priv;
403
404 dma_buf_vunmap(buf->dbuf, buf->vaddr);
405 buf->vaddr = NULL;
406}
407
408static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
409{
410 struct vb2_vmalloc_buf *buf = mem_priv;
411
412 if (buf->vaddr)
413 dma_buf_vunmap(buf->dbuf, buf->vaddr);
414
415 kfree(buf);
416}
417
418static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
419 unsigned long size, enum dma_data_direction dma_dir)
420{
421 struct vb2_vmalloc_buf *buf;
422
423 if (dbuf->size < size)
424 return ERR_PTR(-EFAULT);
425
426 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
427 if (!buf)
428 return ERR_PTR(-ENOMEM);
429
430 buf->dbuf = dbuf;
431 buf->dma_dir = dma_dir;
432 buf->size = size;
433
434 return buf;
435}
436
437
438const struct vb2_mem_ops vb2_vmalloc_memops = {
439 .alloc = vb2_vmalloc_alloc,
440 .put = vb2_vmalloc_put,
441 .get_userptr = vb2_vmalloc_get_userptr,
442 .put_userptr = vb2_vmalloc_put_userptr,
443#ifdef CONFIG_HAS_DMA
444 .get_dmabuf = vb2_vmalloc_get_dmabuf,
445#endif
446 .map_dmabuf = vb2_vmalloc_map_dmabuf,
447 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf,
448 .attach_dmabuf = vb2_vmalloc_attach_dmabuf,
449 .detach_dmabuf = vb2_vmalloc_detach_dmabuf,
450 .vaddr = vb2_vmalloc_vaddr,
451 .mmap = vb2_vmalloc_mmap,
452 .num_users = vb2_vmalloc_num_users,
453};
454EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
455
456MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
457MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
458MODULE_LICENSE("GPL");
459
