Marek Szyprowski wrote:
2010/11/20 Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>:
> From: Pawel Osciak <p.osciak@xxxxxxxxxxx>
>
> Add support for the CMA contiguous memory allocator to videobuf2.
>
> Signed-off-by: Pawel Osciak <p.osciak@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> CC: Pawel Osciak <pawel@xxxxxxxxxx>
> ---
Hi Marek,
<snip>
> +static void *vb2_cma_get_userptr(unsigned long vaddr, unsigned long size)
static void *vb2_cma_get_userptr(unsigned long vaddr, unsigned long size,
const struct vb2_alloc_ctx
*alloc_ctx)
alloc_ctx can be useful for many cases.
> +{
> + struct vb2_cma_buf *buf;
> + unsigned long paddr = 0;
> + int ret;
> +
> + buf = kzalloc(sizeof *buf, GFP_KERNEL);
> + if (!buf)
> + return ERR_PTR(-ENOMEM);
> +
> + buf->vma = vb2_get_userptr(vaddr);
vb2_get_vma looks good instead of vb2_get_userptr.
How do you think about this ?
> + if (!buf->vma) {
> + printk(KERN_ERR "Failed acquiring VMA for vaddr
0x%08lx\n",
> + vaddr);
> + ret = -EINVAL;
> + goto done;
> + }
> +
> + ret = vb2_contig_verify_userptr(buf->vma, vaddr, size, &paddr);
> + if (ret) {
> + vb2_put_userptr(buf->vma);
> + goto done;
> + }
> +
In vb2_contig_verify_userptr, vma is re-found via find_vma although it has
been checked after vb2_get_userptr.
Why double checking is needed ?
> + buf->size = size;
> + buf->paddr = paddr;
> +
> + return buf;
> +
> +done:
> + kfree(buf);
> + return ERR_PTR(ret);
> +}
> +
<snip>
BRs,
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