diff options
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-dma-contig.c')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-dma-contig.c | 785 |
1 files changed, 0 insertions, 785 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c deleted file mode 100644 index a9806ba6116d..000000000000 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ /dev/null @@ -1,785 +0,0 @@ -/* - * videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2 - * - * Copyright (C) 2010 Samsung Electronics - * - * Author: Pawel Osciak <pawel@osciak.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation. - */ - -#include <linux/dma-buf.h> -#include <linux/module.h> -#include <linux/refcount.h> -#include <linux/scatterlist.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/dma-mapping.h> - -#include <media/videobuf2-v4l2.h> -#include <media/videobuf2-dma-contig.h> -#include <media/videobuf2-memops.h> - -struct vb2_dc_buf { - struct device *dev; - void *vaddr; - unsigned long size; - void *cookie; - dma_addr_t dma_addr; - unsigned long attrs; - enum dma_data_direction dma_dir; - struct sg_table *dma_sgt; - struct frame_vector *vec; - - /* MMAP related */ - struct vb2_vmarea_handler handler; - refcount_t refcount; - struct sg_table *sgt_base; - - /* DMABUF related */ - struct dma_buf_attachment *db_attach; -}; - -/*********************************************/ -/* scatterlist table functions */ -/*********************************************/ - -static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) -{ - struct scatterlist *s; - dma_addr_t expected = sg_dma_address(sgt->sgl); - unsigned int i; - unsigned long size = 0; - - for_each_sg(sgt->sgl, s, sgt->nents, i) { - if (sg_dma_address(s) != expected) - break; - expected = sg_dma_address(s) + sg_dma_len(s); - size += sg_dma_len(s); - } - return size; -} - -/*********************************************/ -/* callbacks for all buffers */ -/*********************************************/ - -static void *vb2_dc_cookie(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - - return &buf->dma_addr; -} - -static void *vb2_dc_vaddr(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - - if (!buf->vaddr && buf->db_attach) - buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf); - - return buf->vaddr; -} - -static unsigned int vb2_dc_num_users(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - - return refcount_read(&buf->refcount); -} - -static void vb2_dc_prepare(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - struct sg_table *sgt = buf->dma_sgt; - - /* DMABUF exporter will flush the cache for us */ - if (!sgt || buf->db_attach) - return; - - dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir); -} - -static void vb2_dc_finish(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - struct sg_table *sgt = buf->dma_sgt; - - /* DMABUF exporter will flush the cache for us */ - if (!sgt || buf->db_attach) - return; - - dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); -} - -/*********************************************/ -/* callbacks for MMAP buffers */ -/*********************************************/ - -static void vb2_dc_put(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - - if (!refcount_dec_and_test(&buf->refcount)) - return; - - if (buf->sgt_base) { - sg_free_table(buf->sgt_base); - kfree(buf->sgt_base); - } - dma_free_attrs(buf->dev, buf->size, buf->cookie, buf->dma_addr, - buf->attrs); - put_device(buf->dev); - kfree(buf); -} - -static void *vb2_dc_alloc(struct device *dev, unsigned long attrs, - unsigned long size, enum dma_data_direction dma_dir, - gfp_t gfp_flags) -{ - struct vb2_dc_buf *buf; - - if (WARN_ON(!dev)) - return ERR_PTR(-EINVAL); - - buf = kzalloc(sizeof *buf, GFP_KERNEL); - if (!buf) - return ERR_PTR(-ENOMEM); - - if (attrs) - buf->attrs = attrs; - buf->cookie = dma_alloc_attrs(dev, size, &buf->dma_addr, - GFP_KERNEL | gfp_flags, buf->attrs); - if (!buf->cookie) { - dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size); - kfree(buf); - return ERR_PTR(-ENOMEM); - } - - if ((buf->attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0) - buf->vaddr = buf->cookie; - - /* Prevent the device from being released while the buffer is used */ - buf->dev = get_device(dev); - buf->size = size; - buf->dma_dir = dma_dir; - - buf->handler.refcount = &buf->refcount; - buf->handler.put = vb2_dc_put; - buf->handler.arg = buf; - - refcount_set(&buf->refcount, 1); - - return buf; -} - -static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) -{ - struct vb2_dc_buf *buf = buf_priv; - int ret; - - if (!buf) { - printk(KERN_ERR "No buffer to map\n"); - return -EINVAL; - } - - /* - * dma_mmap_* uses vm_pgoff as in-buffer offset, but we want to - * map whole buffer - */ - vma->vm_pgoff = 0; - - ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, - buf->dma_addr, buf->size, buf->attrs); - - if (ret) { - pr_err("Remapping memory failed, error: %d\n", ret); - return ret; - } - - vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; - vma->vm_private_data = &buf->handler; - vma->vm_ops = &vb2_common_vm_ops; - - vma->vm_ops->open(vma); - - pr_debug("%s: mapped dma addr 0x%08lx at 0x%08lx, size %ld\n", - __func__, (unsigned long)buf->dma_addr, vma->vm_start, - buf->size); - - return 0; -} - -/*********************************************/ -/* DMABUF ops for exporters */ -/*********************************************/ - -struct vb2_dc_attachment { - struct sg_table sgt; - enum dma_data_direction dma_dir; -}; - -static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev, - struct dma_buf_attachment *dbuf_attach) -{ - struct vb2_dc_attachment *attach; - unsigned int i; - struct scatterlist *rd, *wr; - struct sg_table *sgt; - struct vb2_dc_buf *buf = dbuf->priv; - int ret; - - attach = kzalloc(sizeof(*attach), GFP_KERNEL); - if (!attach) - return -ENOMEM; - - sgt = &attach->sgt; - /* Copy the buf->base_sgt scatter list to the attachment, as we can't - * map the same scatter list to multiple attachments at the same time. - */ - ret = sg_alloc_table(sgt, buf->sgt_base->orig_nents, GFP_KERNEL); - if (ret) { - kfree(attach); - return -ENOMEM; - } - - rd = buf->sgt_base->sgl; - wr = sgt->sgl; - for (i = 0; i < sgt->orig_nents; ++i) { - sg_set_page(wr, sg_page(rd), rd->length, rd->offset); - rd = sg_next(rd); - wr = sg_next(wr); - } - - attach->dma_dir = DMA_NONE; - dbuf_attach->priv = attach; - - return 0; -} - -static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf, - struct dma_buf_attachment *db_attach) -{ - struct vb2_dc_attachment *attach = db_attach->priv; - struct sg_table *sgt; - - if (!attach) - return; - - sgt = &attach->sgt; - - /* release the scatterlist cache */ - if (attach->dma_dir != DMA_NONE) - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); - sg_free_table(sgt); - kfree(attach); - db_attach->priv = NULL; -} - -static struct sg_table *vb2_dc_dmabuf_ops_map( - struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir) -{ - struct vb2_dc_attachment *attach = db_attach->priv; - /* stealing dmabuf mutex to serialize map/unmap operations */ - struct mutex *lock = &db_attach->dmabuf->lock; - struct sg_table *sgt; - - mutex_lock(lock); - - sgt = &attach->sgt; - /* return previously mapped sg table */ - if (attach->dma_dir == dma_dir) { - mutex_unlock(lock); - return sgt; - } - - /* release any previous cache */ - if (attach->dma_dir != DMA_NONE) { - dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - attach->dma_dir); - attach->dma_dir = DMA_NONE; - } - - /* mapping to the client with new direction */ - sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, - dma_dir); - if (!sgt->nents) { - pr_err("failed to map scatterlist\n"); - mutex_unlock(lock); - return ERR_PTR(-EIO); - } - - attach->dma_dir = dma_dir; - - mutex_unlock(lock); - - return sgt; -} - -static void vb2_dc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach, - struct sg_table *sgt, enum dma_data_direction dma_dir) -{ - /* nothing to be done here */ -} - -static void vb2_dc_dmabuf_ops_release(struct dma_buf *dbuf) -{ - /* drop reference obtained in vb2_dc_get_dmabuf */ - vb2_dc_put(dbuf->priv); -} - -static void *vb2_dc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum) -{ - struct vb2_dc_buf *buf = dbuf->priv; - - return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL; -} - -static void *vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf) -{ - struct vb2_dc_buf *buf = dbuf->priv; - - return buf->vaddr; -} - -static int vb2_dc_dmabuf_ops_mmap(struct dma_buf *dbuf, - struct vm_area_struct *vma) -{ - return vb2_dc_mmap(dbuf->priv, vma); -} - -static const struct dma_buf_ops vb2_dc_dmabuf_ops = { - .attach = vb2_dc_dmabuf_ops_attach, - .detach = vb2_dc_dmabuf_ops_detach, - .map_dma_buf = vb2_dc_dmabuf_ops_map, - .unmap_dma_buf = vb2_dc_dmabuf_ops_unmap, - .map = vb2_dc_dmabuf_ops_kmap, - .map_atomic = vb2_dc_dmabuf_ops_kmap, - .vmap = vb2_dc_dmabuf_ops_vmap, - .mmap = vb2_dc_dmabuf_ops_mmap, - .release = vb2_dc_dmabuf_ops_release, -}; - -static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf) -{ - int ret; - struct sg_table *sgt; - - sgt = kmalloc(sizeof(*sgt), GFP_KERNEL); - if (!sgt) { - dev_err(buf->dev, "failed to alloc sg table\n"); - return NULL; - } - - ret = dma_get_sgtable_attrs(buf->dev, sgt, buf->cookie, buf->dma_addr, - buf->size, buf->attrs); - if (ret < 0) { - dev_err(buf->dev, "failed to get scatterlist from DMA API\n"); - kfree(sgt); - return NULL; - } - - return sgt; -} - -static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags) -{ - struct vb2_dc_buf *buf = buf_priv; - struct dma_buf *dbuf; - DEFINE_DMA_BUF_EXPORT_INFO(exp_info); - - exp_info.ops = &vb2_dc_dmabuf_ops; - exp_info.size = buf->size; - exp_info.flags = flags; - exp_info.priv = buf; - - if (!buf->sgt_base) - buf->sgt_base = vb2_dc_get_base_sgt(buf); - - if (WARN_ON(!buf->sgt_base)) - return NULL; - - dbuf = dma_buf_export(&exp_info); - if (IS_ERR(dbuf)) - return NULL; - - /* dmabuf keeps reference to vb2 buffer */ - refcount_inc(&buf->refcount); - - return dbuf; -} - -/*********************************************/ -/* callbacks for USERPTR buffers */ -/*********************************************/ - -static void vb2_dc_put_userptr(void *buf_priv) -{ - struct vb2_dc_buf *buf = buf_priv; - struct sg_table *sgt = buf->dma_sgt; - int i; - struct page **pages; - - if (sgt) { - /* - * No need to sync to CPU, it's already synced to the CPU - * since the finish() memop will have been called before this. - */ - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - pages = frame_vector_pages(buf->vec); - /* sgt should exist only if vector contains pages... */ - BUG_ON(IS_ERR(pages)); - for (i = 0; i < frame_vector_count(buf->vec); i++) - set_page_dirty_lock(pages[i]); - sg_free_table(sgt); - kfree(sgt); - } - vb2_destroy_framevec(buf->vec); - kfree(buf); -} - -/* - * For some kind of reserved memory there might be no struct page available, - * so all that can be done to support such 'pages' is to try to convert - * pfn to dma address or at the last resort just assume that - * dma address == physical address (like it has been assumed in earlier version - * of videobuf2-dma-contig - */ - -#ifdef __arch_pfn_to_dma -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - return (dma_addr_t)__arch_pfn_to_dma(dev, pfn); -} -#elif defined(__pfn_to_bus) -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - return (dma_addr_t)__pfn_to_bus(pfn); -} -#elif defined(__pfn_to_phys) -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - return (dma_addr_t)__pfn_to_phys(pfn); -} -#else -static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn) -{ - /* really, we cannot do anything better at this point */ - return (dma_addr_t)(pfn) << PAGE_SHIFT; -} -#endif - -static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr, - unsigned long size, enum dma_data_direction dma_dir) -{ - struct vb2_dc_buf *buf; - struct frame_vector *vec; - unsigned int offset; - int n_pages, i; - int ret = 0; - struct sg_table *sgt; - unsigned long contig_size; - unsigned long dma_align = dma_get_cache_alignment(); - - /* Only cache aligned DMA transfers are reliable */ - if (!IS_ALIGNED(vaddr | size, dma_align)) { - pr_debug("user data must be aligned to %lu bytes\n", dma_align); - return ERR_PTR(-EINVAL); - } - - if (!size) { - pr_debug("size is zero\n"); - return ERR_PTR(-EINVAL); - } - - if (WARN_ON(!dev)) - return ERR_PTR(-EINVAL); - - buf = kzalloc(sizeof *buf, GFP_KERNEL); - if (!buf) - return ERR_PTR(-ENOMEM); - - buf->dev = dev; - buf->dma_dir = dma_dir; - - offset = lower_32_bits(offset_in_page(vaddr)); - vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE || - dma_dir == DMA_BIDIRECTIONAL); - if (IS_ERR(vec)) { - ret = PTR_ERR(vec); - goto fail_buf; - } - buf->vec = vec; - n_pages = frame_vector_count(vec); - ret = frame_vector_to_pages(vec); - if (ret < 0) { - unsigned long *nums = frame_vector_pfns(vec); - - /* - * Failed to convert to pages... Check the memory is physically - * contiguous and use direct mapping - */ - for (i = 1; i < n_pages; i++) - if (nums[i-1] + 1 != nums[i]) - goto fail_pfnvec; - buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]); - goto out; - } - - sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); - if (!sgt) { - pr_err("failed to allocate sg table\n"); - ret = -ENOMEM; - goto fail_pfnvec; - } - - ret = sg_alloc_table_from_pages(sgt, frame_vector_pages(vec), n_pages, - offset, size, GFP_KERNEL); - if (ret) { - pr_err("failed to initialize sg table\n"); - goto fail_sgt; - } - - /* - * No need to sync to the device, this will happen later when the - * prepare() memop is called. - */ - sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - if (sgt->nents <= 0) { - pr_err("failed to map scatterlist\n"); - ret = -EIO; - goto fail_sgt_init; - } - - contig_size = vb2_dc_get_contiguous_size(sgt); - if (contig_size < size) { - pr_err("contiguous mapping is too small %lu/%lu\n", - contig_size, size); - ret = -EFAULT; - goto fail_map_sg; - } - - buf->dma_addr = sg_dma_address(sgt->sgl); - buf->dma_sgt = sgt; -out: - buf->size = size; - - return buf; - -fail_map_sg: - dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, - buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); - -fail_sgt_init: - sg_free_table(sgt); - -fail_sgt: - kfree(sgt); - -fail_pfnvec: - vb2_destroy_framevec(vec); - -fail_buf: - kfree(buf); - - return ERR_PTR(ret); -} - -/*********************************************/ -/* callbacks for DMABUF buffers */ -/*********************************************/ - -static int vb2_dc_map_dmabuf(void *mem_priv) -{ - struct vb2_dc_buf *buf = mem_priv; - struct sg_table *sgt; - unsigned long contig_size; - - if (WARN_ON(!buf->db_attach)) { - pr_err("trying to pin a non attached buffer\n"); - return -EINVAL; - } - - if (WARN_ON(buf->dma_sgt)) { - pr_err("dmabuf buffer is already pinned\n"); - return 0; - } - - /* get the associated scatterlist for this buffer */ - sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir); - if (IS_ERR(sgt)) { - pr_err("Error getting dmabuf scatterlist\n"); - return -EINVAL; - } - - /* checking if dmabuf is big enough to store contiguous chunk */ - contig_size = vb2_dc_get_contiguous_size(sgt); - if (contig_size < buf->size) { - pr_err("contiguous chunk is too small %lu/%lu b\n", - contig_size, buf->size); - dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); - return -EFAULT; - } - - buf->dma_addr = sg_dma_address(sgt->sgl); - buf->dma_sgt = sgt; - buf->vaddr = NULL; - - return 0; -} - -static void vb2_dc_unmap_dmabuf(void *mem_priv) -{ - struct vb2_dc_buf *buf = mem_priv; - struct sg_table *sgt = buf->dma_sgt; - - if (WARN_ON(!buf->db_attach)) { - pr_err("trying to unpin a not attached buffer\n"); - return; - } - - if (WARN_ON(!sgt)) { - pr_err("dmabuf buffer is already unpinned\n"); - return; - } - - if (buf->vaddr) { - dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr); - buf->vaddr = NULL; - } - dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); - - buf->dma_addr = 0; - buf->dma_sgt = NULL; -} - -static void vb2_dc_detach_dmabuf(void *mem_priv) -{ - struct vb2_dc_buf *buf = mem_priv; - - /* if vb2 works correctly you should never detach mapped buffer */ - if (WARN_ON(buf->dma_addr)) - vb2_dc_unmap_dmabuf(buf); - - /* detach this attachment */ - dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); - kfree(buf); -} - -static void *vb2_dc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf, - unsigned long size, enum dma_data_direction dma_dir) -{ - struct vb2_dc_buf *buf; - struct dma_buf_attachment *dba; - - if (dbuf->size < size) - return ERR_PTR(-EFAULT); - - if (WARN_ON(!dev)) - return ERR_PTR(-EINVAL); - - buf = kzalloc(sizeof(*buf), GFP_KERNEL); - if (!buf) - return ERR_PTR(-ENOMEM); - - buf->dev = dev; - /* create attachment for the dmabuf with the user device */ - dba = dma_buf_attach(dbuf, buf->dev); - if (IS_ERR(dba)) { - pr_err("failed to attach dmabuf\n"); - kfree(buf); - return dba; - } - - buf->dma_dir = dma_dir; - buf->size = size; - buf->db_attach = dba; - - return buf; -} - -/*********************************************/ -/* DMA CONTIG exported functions */ -/*********************************************/ - -const struct vb2_mem_ops vb2_dma_contig_memops = { - .alloc = vb2_dc_alloc, - .put = vb2_dc_put, - .get_dmabuf = vb2_dc_get_dmabuf, - .cookie = vb2_dc_cookie, - .vaddr = vb2_dc_vaddr, - .mmap = vb2_dc_mmap, - .get_userptr = vb2_dc_get_userptr, - .put_userptr = vb2_dc_put_userptr, - .prepare = vb2_dc_prepare, - .finish = vb2_dc_finish, - .map_dmabuf = vb2_dc_map_dmabuf, - .unmap_dmabuf = vb2_dc_unmap_dmabuf, - .attach_dmabuf = vb2_dc_attach_dmabuf, - .detach_dmabuf = vb2_dc_detach_dmabuf, - .num_users = vb2_dc_num_users, -}; -EXPORT_SYMBOL_GPL(vb2_dma_contig_memops); - -/** - * vb2_dma_contig_set_max_seg_size() - configure DMA max segment size - * @dev: device for configuring DMA parameters - * @size: size of DMA max segment size to set - * - * To allow mapping the scatter-list into a single chunk in the DMA - * address space, the device is required to have the DMA max segment - * size parameter set to a value larger than the buffer size. Otherwise, - * the DMA-mapping subsystem will split the mapping into max segment - * size chunks. This function sets the DMA max segment size - * parameter to let DMA-mapping map a buffer as a single chunk in DMA - * address space. - * This code assumes that the DMA-mapping subsystem will merge all - * scatterlist segments if this is really possible (for example when - * an IOMMU is available and enabled). - * Ideally, this parameter should be set by the generic bus code, but it - * is left with the default 64KiB value due to historical litmiations in - * other subsystems (like limited USB host drivers) and there no good - * place to set it to the proper value. - * This function should be called from the drivers, which are known to - * operate on platforms with IOMMU and provide access to shared buffers - * (either USERPTR or DMABUF). This should be done before initializing - * videobuf2 queue. - */ -int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size) -{ - if (!dev->dma_parms) { - dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL); - if (!dev->dma_parms) - return -ENOMEM; - } - if (dma_get_max_seg_size(dev) < size) - return dma_set_max_seg_size(dev, size); - - return 0; -} -EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size); - -/* - * vb2_dma_contig_clear_max_seg_size() - release resources for DMA parameters - * @dev: device for configuring DMA parameters - * - * This function releases resources allocated to configure DMA parameters - * (see vb2_dma_contig_set_max_seg_size() function). It should be called from - * device drivers on driver remove. - */ -void vb2_dma_contig_clear_max_seg_size(struct device *dev) -{ - kfree(dev->dma_parms); - dev->dma_parms = NULL; -} -EXPORT_SYMBOL_GPL(vb2_dma_contig_clear_max_seg_size); - -MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2"); -MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); -MODULE_LICENSE("GPL"); |
