[1/2,v4] media: vb2: support userptr for PFN mappings.

  Some video devices need to use contiguous memory
which is not backed by pages as it happens with
vmalloc. This patch provides userptr handling for
those devices.

---
Changes since v3:
 - Remove vma_res variable.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
---
 drivers/media/video/videobuf2-vmalloc.c |   70 +++++++++++++++++++++----------
 1 files changed, 47 insertions(+), 23 deletions(-)
  

Hello,

On Wednesday, January 04, 2012 5:19 PM Javier Martin wrote:

> Some video devices need to use contiguous memory
> which is not backed by pages as it happens with
> vmalloc. This patch provides userptr handling for
> those devices.
> 
> ---
> Changes since v3:
>  - Remove vma_res variable.
> 
> Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>

Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

Do you plan to put a git tree with all your patches and send a pull request
to Mauro? If not I will take this patch and put it on my vb2 branch.

> ---
>  drivers/media/video/videobuf2-vmalloc.c |   70 +++++++++++++++++++++----------
>  1 files changed, 47 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c
> index 03aa62f..f9ff15f 100644
> --- a/drivers/media/video/videobuf2-vmalloc.c
> +++ b/drivers/media/video/videobuf2-vmalloc.c
> @@ -10,6 +10,7 @@
>   * the Free Software Foundation.
>   */
> 
> +#include <linux/io.h>
>  #include <linux/module.h>
>  #include <linux/mm.h>
>  #include <linux/sched.h>
> @@ -22,6 +23,7 @@
>  struct vb2_vmalloc_buf {
>  	void				*vaddr;
>  	struct page			**pages;
> +	struct vm_area_struct		*vma;
>  	int				write;
>  	unsigned long			size;
>  	unsigned int			n_pages;
> @@ -71,6 +73,8 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
>  	struct vb2_vmalloc_buf *buf;
>  	unsigned long first, last;
>  	int n_pages, offset;
> +	struct vm_area_struct *vma;
> +	dma_addr_t physp;
> 
>  	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
>  	if (!buf)
> @@ -80,23 +84,37 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
>  	offset = vaddr & ~PAGE_MASK;
>  	buf->size = size;
> 
> -	first = vaddr >> PAGE_SHIFT;
> -	last  = (vaddr + size - 1) >> PAGE_SHIFT;
> -	buf->n_pages = last - first + 1;
> -	buf->pages = kzalloc(buf->n_pages * sizeof(struct page *), GFP_KERNEL);
> -	if (!buf->pages)
> -		goto fail_pages_array_alloc;
> 
> -	/* current->mm->mmap_sem is taken by videobuf2 core */
> -	n_pages = get_user_pages(current, current->mm, vaddr & PAGE_MASK,
> -					buf->n_pages, write, 1, /* force */
> -					buf->pages, NULL);
> -	if (n_pages != buf->n_pages)
> -		goto fail_get_user_pages;
> -
> -	buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1, PAGE_KERNEL);
> -	if (!buf->vaddr)
> -		goto fail_get_user_pages;
> +	vma = find_vma(current->mm, vaddr);
> +	if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
> +		if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
> +			goto fail_pages_array_alloc;
> +		buf->vma = vma;
> +		buf->vaddr = ioremap_nocache(physp, size);
> +		if (!buf->vaddr)
> +			goto fail_pages_array_alloc;
> +	} else {
> +		first = vaddr >> PAGE_SHIFT;
> +		last  = (vaddr + size - 1) >> PAGE_SHIFT;
> +		buf->n_pages = last - first + 1;
> +		buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
> +				     GFP_KERNEL);
> +		if (!buf->pages)
> +			goto fail_pages_array_alloc;
> +
> +		/* current->mm->mmap_sem is taken by videobuf2 core */
> +		n_pages = get_user_pages(current, current->mm,
> +					 vaddr & PAGE_MASK, buf->n_pages,
> +					 write, 1, /* force */
> +					 buf->pages, NULL);
> +		if (n_pages != buf->n_pages)
> +			goto fail_get_user_pages;
> +
> +		buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
> +					PAGE_KERNEL);
> +		if (!buf->vaddr)
> +			goto fail_get_user_pages;
> +	}
> 
>  	buf->vaddr += offset;
>  	return buf;
> @@ -120,14 +138,20 @@ static void vb2_vmalloc_put_userptr(void *buf_priv)
>  	unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
>  	unsigned int i;
> 
> -	if (vaddr)
> -		vm_unmap_ram((void *)vaddr, buf->n_pages);
> -	for (i = 0; i < buf->n_pages; ++i) {
> -		if (buf->write)
> -			set_page_dirty_lock(buf->pages[i]);
> -		put_page(buf->pages[i]);
> +	if (buf->pages) {
> +		if (vaddr)
> +			vm_unmap_ram((void *)vaddr, buf->n_pages);
> +		for (i = 0; i < buf->n_pages; ++i) {
> +			if (buf->write)
> +				set_page_dirty_lock(buf->pages[i]);
> +			put_page(buf->pages[i]);
> +		}
> +		kfree(buf->pages);
> +	} else {
> +		if (buf->vma)
> +			vb2_put_vma(buf->vma);
> +		iounmap(buf->vaddr);
>  	}
> -	kfree(buf->pages);
>  	kfree(buf);
>  }
> 
> --


Best regards
  

Hi Marek,

On 9 January 2012 11:14, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
> Hello,
>
> On Wednesday, January 04, 2012 5:19 PM Javier Martin wrote:
>
>> Some video devices need to use contiguous memory
>> which is not backed by pages as it happens with
>> vmalloc. This patch provides userptr handling for
>> those devices.
>>
>> ---
>> Changes since v3:
>>  - Remove vma_res variable.
>>
>> Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
>
> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
>
> Do you plan to put a git tree with all your patches and send a pull request
> to Mauro? If not I will take this patch and put it on my vb2 branch.

Is this mandatory for Mauro to merge one's patches? Because I've sent
several patches in the patch and haven't received response yet.

Anyway, I prefer you to take this patch.

Thank you.