[RFC 03/13] v4l: vb2-dma-contig: let mmap method to use dma_mmap_coherent call

[Laurent Pinchart]

Hi Tomasz,

Thanks for the patch.

On Tuesday 10 April 2012 15:10:37 Tomasz Stanislawski wrote:
> From: Marek Szyprowski 
> 
> Let mmap method to use dma_mmap_coherent call.  This patch depends on DMA
> mapping redesign patches because the usage of dma_mmap_coherent breaks
> dma-contig allocator for architectures other than ARM and AVR.
> 
> Signed-off-by: Marek Szyprowski 
> ---
>  drivers/media/video/videobuf2-dma-contig.c |   28 +++--
>  1 files changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/video/videobuf2-dma-contig.c
> b/drivers/media/video/videobuf2-dma-contig.c index 6329483..f4df9e2 100644
> --- a/drivers/media/video/videobuf2-dma-contig.c
> +++ b/drivers/media/video/videobuf2-dma-contig.c
> @@ -224,14 +224,38 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned
> long size) 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;
>   }
> 
> - return vb2_mmap_pfn_range(vma, buf->dma_addr, buf->size,
> -   _common_vm_ops, >handler);

This was the only vb2_mmap_pfn_range() if I'm not mistaken. Should the 
function be removed ?

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

Is it safe to set vma->vm_pgoff to 0 here behind memory core's back ?

> + ret = dma_mmap_coherent(buf->dev, vma, buf->vaddr,
> + buf->dma_addr, buf->size);
> +
> + if (ret) {
> + printk(KERN_ERR "Remapping memory failed, error: %d\n", ret);
> + return ret;
> + }
> +
> + vma->vm_flags   |= VM_DONTEXPAND | VM_RESERVED;
> + vma->vm_private_data= >handler;
> + vma->vm_ops = _common_vm_ops;
> +
> + vma->vm_ops->open(vma);
> +
> + printk(KERN_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;
>  }
> 
>  /*/
-- 
Regards,

Laurent Pinchart

Re: [RFC 03/13] v4l: vb2-dma-contig: let mmap method to use dma_mmap_coherent call

[Laurent Pinchart]

Hi Tomasz,

Thanks for the patch.

On Tuesday 10 April 2012 15:10:37 Tomasz Stanislawski wrote:
 From: Marek Szyprowski m.szyprow...@samsung.com
 
 Let mmap method to use dma_mmap_coherent call.  This patch depends on DMA
 mapping redesign patches because the usage of dma_mmap_coherent breaks
 dma-contig allocator for architectures other than ARM and AVR.
 
 Signed-off-by: Marek Szyprowski m.szyprow...@samsung.com
 ---
  drivers/media/video/videobuf2-dma-contig.c |   28 +++--
  1 files changed, 26 insertions(+), 2 deletions(-)
 
 diff --git a/drivers/media/video/videobuf2-dma-contig.c
 b/drivers/media/video/videobuf2-dma-contig.c index 6329483..f4df9e2 100644
 --- a/drivers/media/video/videobuf2-dma-contig.c
 +++ b/drivers/media/video/videobuf2-dma-contig.c
 @@ -224,14 +224,38 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned
 long size) 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;
   }
 
 - return vb2_mmap_pfn_range(vma, buf-dma_addr, buf-size,
 -   vb2_common_vm_ops, buf-handler);

This was the only vb2_mmap_pfn_range() if I'm not mistaken. Should the 
function be removed ?

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

Is it safe to set vma-vm_pgoff to 0 here behind memory core's back ?

 + ret = dma_mmap_coherent(buf-dev, vma, buf-vaddr,
 + buf-dma_addr, buf-size);
 +
 + if (ret) {
 + printk(KERN_ERR Remapping memory failed, error: %d\n, ret);
 + return ret;
 + }
 +
 + vma-vm_flags   |= VM_DONTEXPAND | VM_RESERVED;
 + vma-vm_private_data= buf-handler;
 + vma-vm_ops = vb2_common_vm_ops;
 +
 + vma-vm_ops-open(vma);
 +
 + printk(KERN_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;
  }
 
  /*/
-- 
Regards,

Laurent Pinchart

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[RFC 03/13] v4l: vb2-dma-contig: let mmap method to use dma_mmap_coherent call

[Tomasz Stanislawski]

From: Marek Szyprowski 

Let mmap method to use dma_mmap_coherent call.  This patch depends on DMA
mapping redesign patches because the usage of dma_mmap_coherent breaks
dma-contig allocator for architectures other than ARM and AVR.

Signed-off-by: Marek Szyprowski 
---
 drivers/media/video/videobuf2-dma-contig.c |   28 ++--
 1 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c 
b/drivers/media/video/videobuf2-dma-contig.c
index 6329483..f4df9e2 100644
--- a/drivers/media/video/videobuf2-dma-contig.c
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -224,14 +224,38 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long 
size)
 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;
}

-   return vb2_mmap_pfn_range(vma, buf->dma_addr, buf->size,
- _common_vm_ops, >handler);
+   /*
+* 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) {
+   printk(KERN_ERR "Remapping memory failed, error: %d\n", ret);
+   return ret;
+   }
+
+   vma->vm_flags   |= VM_DONTEXPAND | VM_RESERVED;
+   vma->vm_private_data= >handler;
+   vma->vm_ops = _common_vm_ops;
+
+   vma->vm_ops->open(vma);
+
+   printk(KERN_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;
 }

 /*/
-- 
1.7.5.4