2 * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
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.
14 #include <linux/module.h>
16 #include <linux/refcount.h>
17 #include <linux/sched.h>
18 #include <linux/slab.h>
19 #include <linux/vmalloc.h>
21 #include <media/videobuf2-v4l2.h>
22 #include <media/videobuf2-vmalloc.h>
23 #include <media/videobuf2-memops.h>
25 struct vb2_vmalloc_buf {
27 struct frame_vector *vec;
28 enum dma_data_direction dma_dir;
31 struct vb2_vmarea_handler handler;
35 static void vb2_vmalloc_put(void *buf_priv);
37 static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs,
38 unsigned long size, enum dma_data_direction dma_dir,
41 struct vb2_vmalloc_buf *buf;
43 buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
45 return ERR_PTR(-ENOMEM);
48 buf->vaddr = vmalloc_user(buf->size);
50 pr_debug("vmalloc of size %ld failed\n", buf->size);
52 return ERR_PTR(-ENOMEM);
55 buf->dma_dir = dma_dir;
56 buf->handler.refcount = &buf->refcount;
57 buf->handler.put = vb2_vmalloc_put;
58 buf->handler.arg = buf;
60 refcount_set(&buf->refcount, 1);
64 static void vb2_vmalloc_put(void *buf_priv)
66 struct vb2_vmalloc_buf *buf = buf_priv;
68 if (refcount_dec_and_test(&buf->refcount)) {
74 static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr,
76 enum dma_data_direction dma_dir)
78 struct vb2_vmalloc_buf *buf;
79 struct frame_vector *vec;
80 int n_pages, offset, i;
83 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
85 return ERR_PTR(-ENOMEM);
87 buf->dma_dir = dma_dir;
88 offset = vaddr & ~PAGE_MASK;
90 vec = vb2_create_framevec(vaddr, size);
93 goto fail_pfnvec_create;
96 n_pages = frame_vector_count(vec);
97 if (frame_vector_to_pages(vec) < 0) {
98 unsigned long *nums = frame_vector_pfns(vec);
101 * We cannot get page pointers for these pfns. Check memory is
102 * physically contiguous and use direct mapping.
104 for (i = 1; i < n_pages; i++)
105 if (nums[i-1] + 1 != nums[i])
107 buf->vaddr = (__force void *)
108 ioremap(__pfn_to_phys(nums[0]), size + offset);
110 buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1);
115 buf->vaddr += offset;
119 vb2_destroy_framevec(vec);
126 static void vb2_vmalloc_put_userptr(void *buf_priv)
128 struct vb2_vmalloc_buf *buf = buf_priv;
129 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
132 unsigned int n_pages;
134 if (!buf->vec->is_pfns) {
135 n_pages = frame_vector_count(buf->vec);
136 pages = frame_vector_pages(buf->vec);
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]);
144 iounmap((__force void __iomem *)buf->vaddr);
146 vb2_destroy_framevec(buf->vec);
150 static void *vb2_vmalloc_vaddr(void *buf_priv)
152 struct vb2_vmalloc_buf *buf = buf_priv;
155 pr_err("Address of an unallocated plane requested or cannot map user pointer\n");
162 static unsigned int vb2_vmalloc_num_users(void *buf_priv)
164 struct vb2_vmalloc_buf *buf = buf_priv;
165 return refcount_read(&buf->refcount);
168 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
170 struct vb2_vmalloc_buf *buf = buf_priv;
174 pr_err("No memory to map\n");
178 ret = remap_vmalloc_range(vma, buf->vaddr, 0);
180 pr_err("Remapping vmalloc memory, error: %d\n", ret);
185 * Make sure that vm_areas for 2 buffers won't be merged together
187 vma->vm_flags |= VM_DONTEXPAND;
190 * Use common vm_area operations to track buffer refcount.
192 vma->vm_private_data = &buf->handler;
193 vma->vm_ops = &vb2_common_vm_ops;
195 vma->vm_ops->open(vma);
200 #ifdef CONFIG_HAS_DMA
201 /*********************************************/
202 /* DMABUF ops for exporters */
203 /*********************************************/
205 struct vb2_vmalloc_attachment {
207 enum dma_data_direction dma_dir;
210 static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf,
211 struct dma_buf_attachment *dbuf_attach)
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;
222 attach = kzalloc(sizeof(*attach), GFP_KERNEL);
227 ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
232 for_each_sg(sgt->sgl, sg, sgt->nents, i) {
233 struct page *page = vmalloc_to_page(vaddr);
240 sg_set_page(sg, page, PAGE_SIZE, 0);
244 attach->dma_dir = DMA_NONE;
245 dbuf_attach->priv = attach;
249 static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
250 struct dma_buf_attachment *db_attach)
252 struct vb2_vmalloc_attachment *attach = db_attach->priv;
253 struct sg_table *sgt;
260 /* release the scatterlist cache */
261 if (attach->dma_dir != DMA_NONE)
262 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
266 db_attach->priv = NULL;
269 static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
270 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
272 struct vb2_vmalloc_attachment *attach = db_attach->priv;
273 /* stealing dmabuf mutex to serialize map/unmap operations */
274 struct mutex *lock = &db_attach->dmabuf->lock;
275 struct sg_table *sgt;
280 /* return previously mapped sg table */
281 if (attach->dma_dir == dma_dir) {
286 /* release any previous cache */
287 if (attach->dma_dir != DMA_NONE) {
288 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
290 attach->dma_dir = DMA_NONE;
293 /* mapping to the client with new direction */
294 sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
297 pr_err("failed to map scatterlist\n");
299 return ERR_PTR(-EIO);
302 attach->dma_dir = dma_dir;
309 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
310 struct sg_table *sgt, enum dma_data_direction dma_dir)
312 /* nothing to be done here */
315 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
317 /* drop reference obtained in vb2_vmalloc_get_dmabuf */
318 vb2_vmalloc_put(dbuf->priv);
321 static int vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map)
323 struct vb2_vmalloc_buf *buf = dbuf->priv;
325 dma_buf_map_set_vaddr(map, buf->vaddr);
330 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
331 struct vm_area_struct *vma)
333 return vb2_vmalloc_mmap(dbuf->priv, vma);
336 static const struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
337 .attach = vb2_vmalloc_dmabuf_ops_attach,
338 .detach = vb2_vmalloc_dmabuf_ops_detach,
339 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
340 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
341 .vmap = vb2_vmalloc_dmabuf_ops_vmap,
342 .mmap = vb2_vmalloc_dmabuf_ops_mmap,
343 .release = vb2_vmalloc_dmabuf_ops_release,
346 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
348 struct vb2_vmalloc_buf *buf = buf_priv;
349 struct dma_buf *dbuf;
350 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
352 exp_info.ops = &vb2_vmalloc_dmabuf_ops;
353 exp_info.size = buf->size;
354 exp_info.flags = flags;
357 if (WARN_ON(!buf->vaddr))
360 dbuf = dma_buf_export(&exp_info);
364 /* dmabuf keeps reference to vb2 buffer */
365 refcount_inc(&buf->refcount);
369 #endif /* CONFIG_HAS_DMA */
372 /*********************************************/
373 /* callbacks for DMABUF buffers */
374 /*********************************************/
376 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
378 struct vb2_vmalloc_buf *buf = mem_priv;
379 struct dma_buf_map map;
382 ret = dma_buf_vmap(buf->dbuf, &map);
385 buf->vaddr = map.vaddr;
390 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
392 struct vb2_vmalloc_buf *buf = mem_priv;
393 struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(buf->vaddr);
395 dma_buf_vunmap(buf->dbuf, &map);
399 static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
401 struct vb2_vmalloc_buf *buf = mem_priv;
402 struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(buf->vaddr);
405 dma_buf_vunmap(buf->dbuf, &map);
410 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
411 unsigned long size, enum dma_data_direction dma_dir)
413 struct vb2_vmalloc_buf *buf;
415 if (dbuf->size < size)
416 return ERR_PTR(-EFAULT);
418 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
420 return ERR_PTR(-ENOMEM);
423 buf->dma_dir = dma_dir;
430 const struct vb2_mem_ops vb2_vmalloc_memops = {
431 .alloc = vb2_vmalloc_alloc,
432 .put = vb2_vmalloc_put,
433 .get_userptr = vb2_vmalloc_get_userptr,
434 .put_userptr = vb2_vmalloc_put_userptr,
435 #ifdef CONFIG_HAS_DMA
436 .get_dmabuf = vb2_vmalloc_get_dmabuf,
438 .map_dmabuf = vb2_vmalloc_map_dmabuf,
439 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf,
440 .attach_dmabuf = vb2_vmalloc_attach_dmabuf,
441 .detach_dmabuf = vb2_vmalloc_detach_dmabuf,
442 .vaddr = vb2_vmalloc_vaddr,
443 .mmap = vb2_vmalloc_mmap,
444 .num_users = vb2_vmalloc_num_users,
446 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
448 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
449 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
450 MODULE_LICENSE("GPL");