diff options
Diffstat (limited to 'drivers/media/video/videobuf2-dma-contig.c')
| -rw-r--r-- | drivers/media/video/videobuf2-dma-contig.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c new file mode 100644 index 000000000000..58205d596138 --- /dev/null +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -0,0 +1,185 @@ +/* + * 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/module.h> +#include <linux/slab.h> +#include <linux/dma-mapping.h> + +#include <media/videobuf2-core.h> +#include <media/videobuf2-memops.h> + +struct vb2_dc_conf { + struct device *dev; +}; + +struct vb2_dc_buf { + struct vb2_dc_conf *conf; + void *vaddr; + dma_addr_t paddr; + unsigned long size; + struct vm_area_struct *vma; + atomic_t refcount; + struct vb2_vmarea_handler handler; +}; + +static void vb2_dma_contig_put(void *buf_priv); + +static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size) +{ + struct vb2_dc_conf *conf = alloc_ctx; + struct vb2_dc_buf *buf; + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->paddr, + GFP_KERNEL); + if (!buf->vaddr) { + dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n", + buf->size); + kfree(buf); + return ERR_PTR(-ENOMEM); + } + + buf->conf = conf; + buf->size = size; + + buf->handler.refcount = &buf->refcount; + buf->handler.put = vb2_dma_contig_put; + buf->handler.arg = buf; + + atomic_inc(&buf->refcount); + + return buf; +} + +static void vb2_dma_contig_put(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + + if (atomic_dec_and_test(&buf->refcount)) { + dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr, + buf->paddr); + kfree(buf); + } +} + +static void *vb2_dma_contig_cookie(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + + return &buf->paddr; +} + +static void *vb2_dma_contig_vaddr(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + if (!buf) + return 0; + + return buf->vaddr; +} + +static unsigned int vb2_dma_contig_num_users(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + + return atomic_read(&buf->refcount); +} + +static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma) +{ + struct vb2_dc_buf *buf = buf_priv; + + if (!buf) { + printk(KERN_ERR "No buffer to map\n"); + return -EINVAL; + } + + return vb2_mmap_pfn_range(vma, buf->paddr, buf->size, + &vb2_common_vm_ops, &buf->handler); +} + +static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr, + unsigned long size, int write) +{ + struct vb2_dc_buf *buf; + struct vm_area_struct *vma; + dma_addr_t paddr = 0; + int ret; + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + ret = vb2_get_contig_userptr(vaddr, size, &vma, &paddr); + if (ret) { + printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n", + vaddr); + kfree(buf); + return ERR_PTR(ret); + } + + buf->size = size; + buf->paddr = paddr; + buf->vma = vma; + + return buf; +} + +static void vb2_dma_contig_put_userptr(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + + if (!buf) + return; + + vb2_put_vma(buf->vma); + kfree(buf); +} + +const struct vb2_mem_ops vb2_dma_contig_memops = { + .alloc = vb2_dma_contig_alloc, + .put = vb2_dma_contig_put, + .cookie = vb2_dma_contig_cookie, + .vaddr = vb2_dma_contig_vaddr, + .mmap = vb2_dma_contig_mmap, + .get_userptr = vb2_dma_contig_get_userptr, + .put_userptr = vb2_dma_contig_put_userptr, + .num_users = vb2_dma_contig_num_users, +}; +EXPORT_SYMBOL_GPL(vb2_dma_contig_memops); + +void *vb2_dma_contig_init_ctx(struct device *dev) +{ + struct vb2_dc_conf *conf; + + conf = kzalloc(sizeof *conf, GFP_KERNEL); + if (!conf) + return ERR_PTR(-ENOMEM); + + conf->dev = dev; + + return conf; +} +EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx); + +void vb2_dma_contig_cleanup_ctx(void *alloc_ctx) +{ + kfree(alloc_ctx); +} +EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx); + +MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2"); +MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); +MODULE_LICENSE("GPL"); |