linux-4.4.1/vb2_dc_mmap()

参照元†

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説明†

パス: linux-4.4.1/drivers/media/v4l2-core/videobuf2-dma-contig.c

FIXME: これは何？
- 説明

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引数†

void *buf_priv
struct vm_area_struct *vma
- linux-4.4.1/vm_area_struct

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返り値†

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参考†

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実装†

static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
{
        struct vb2_dc_buf *buf = buf_priv;
        int ret;

- linux-4.4.1/vb2_dc_buf

        if (!buf) {
                printk(KERN_ERR "No buffer to map\n");
                return -EINVAL;
        }

- linux-4.4.1/printk()

        /*
         * dma_mmap_* uses vm_pgoff as in-buffer offset, but we want to
         * map whole buffer
         */
        vma->vm_pgoff = 0;

        ret = dma_mmap_coherent(buf->dev, vma, buf->vaddr,
                buf->dma_addr, buf->size);

        if (ret) {
                pr_err("Remapping memory failed, error: %d\n", ret);
                return ret;
        }

- linux-4.4.1/dma_mmap_coherent()
- linux-4.4.1/pr_err()

        vma->vm_flags           |= VM_DONTEXPAND | VM_DONTDUMP;
        vma->vm_private_data    = &buf->handler;
        vma->vm_ops             = &vb2_common_vm_ops;

- linux-4.4.1/vb2_common_vm_ops(global)

        vma->vm_ops->open(vma);

- vma->vm_ops は struct vm_operations_struct * 型
- linux-4.4.1/vm_operations_struct

        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);