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_sgtable_sg(sgt, sg, 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_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
265 db_attach->priv = NULL;
268 static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
269 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
271 struct vb2_vmalloc_attachment *attach = db_attach->priv;
272 /* stealing dmabuf mutex to serialize map/unmap operations */
273 struct mutex *lock = &db_attach->dmabuf->lock;
274 struct sg_table *sgt;
279 /* return previously mapped sg table */
280 if (attach->dma_dir == dma_dir) {
285 /* release any previous cache */
286 if (attach->dma_dir != DMA_NONE) {
287 dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir, 0);
288 attach->dma_dir = DMA_NONE;
291 /* mapping to the client with new direction */
292 if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
293 pr_err("failed to map scatterlist\n");
295 return ERR_PTR(-EIO);
298 attach->dma_dir = dma_dir;
305 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
306 struct sg_table *sgt, enum dma_data_direction dma_dir)
308 /* nothing to be done here */
311 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
313 /* drop reference obtained in vb2_vmalloc_get_dmabuf */
314 vb2_vmalloc_put(dbuf->priv);
317 static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
319 struct vb2_vmalloc_buf *buf = dbuf->priv;
324 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
325 struct vm_area_struct *vma)
327 return vb2_vmalloc_mmap(dbuf->priv, vma);
330 static const struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
331 .attach = vb2_vmalloc_dmabuf_ops_attach,
332 .detach = vb2_vmalloc_dmabuf_ops_detach,
333 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
334 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
335 .vmap = vb2_vmalloc_dmabuf_ops_vmap,
336 .mmap = vb2_vmalloc_dmabuf_ops_mmap,
337 .release = vb2_vmalloc_dmabuf_ops_release,
340 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
342 struct vb2_vmalloc_buf *buf = buf_priv;
343 struct dma_buf *dbuf;
344 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
346 exp_info.ops = &vb2_vmalloc_dmabuf_ops;
347 exp_info.size = buf->size;
348 exp_info.flags = flags;
351 if (WARN_ON(!buf->vaddr))
354 dbuf = dma_buf_export(&exp_info);
358 /* dmabuf keeps reference to vb2 buffer */
359 refcount_inc(&buf->refcount);
363 #endif /* CONFIG_HAS_DMA */
366 /*********************************************/
367 /* callbacks for DMABUF buffers */
368 /*********************************************/
370 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
372 struct vb2_vmalloc_buf *buf = mem_priv;
374 buf->vaddr = dma_buf_vmap(buf->dbuf);
376 return buf->vaddr ? 0 : -EFAULT;
379 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
381 struct vb2_vmalloc_buf *buf = mem_priv;
383 dma_buf_vunmap(buf->dbuf, buf->vaddr);
387 static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
389 struct vb2_vmalloc_buf *buf = mem_priv;
392 dma_buf_vunmap(buf->dbuf, buf->vaddr);
397 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
398 unsigned long size, enum dma_data_direction dma_dir)
400 struct vb2_vmalloc_buf *buf;
402 if (dbuf->size < size)
403 return ERR_PTR(-EFAULT);
405 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
407 return ERR_PTR(-ENOMEM);
410 buf->dma_dir = dma_dir;
417 const struct vb2_mem_ops vb2_vmalloc_memops = {
418 .alloc = vb2_vmalloc_alloc,
419 .put = vb2_vmalloc_put,
420 .get_userptr = vb2_vmalloc_get_userptr,
421 .put_userptr = vb2_vmalloc_put_userptr,
422 #ifdef CONFIG_HAS_DMA
423 .get_dmabuf = vb2_vmalloc_get_dmabuf,
425 .map_dmabuf = vb2_vmalloc_map_dmabuf,
426 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf,
427 .attach_dmabuf = vb2_vmalloc_attach_dmabuf,
428 .detach_dmabuf = vb2_vmalloc_detach_dmabuf,
429 .vaddr = vb2_vmalloc_vaddr,
430 .mmap = vb2_vmalloc_mmap,
431 .num_users = vb2_vmalloc_num_users,
433 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
435 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
436 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
437 MODULE_LICENSE("GPL");