RE: [PATCH V3 1/4] misc: vop: change the way of allocating vring and device page

[Sherry Sun <sherry.sun@nxp.com>]

Hi Christoph,

> 
> >  static int mic_dp_init(struct mic_device *mdev)  {
> > -	mdev->dp = kzalloc(MIC_DP_SIZE, GFP_KERNEL);
> > +	mdev->dp = dma_alloc_coherent(&mdev->pdev->dev, MIC_DP_SIZE,
> > +				      &mdev->dp_dma_addr, GFP_KERNEL);
> >  	if (!mdev->dp)
> >  		return -ENOMEM;
> >
> > -	mdev->dp_dma_addr = mic_map_single(mdev,
> > -		mdev->dp, MIC_DP_SIZE);
> > -	if (mic_map_error(mdev->dp_dma_addr)) {
> > -		kfree(mdev->dp);
> > -		dev_err(&mdev->pdev->dev, "%s %d err %d\n",
> > -			__func__, __LINE__, -ENOMEM);
> > -		return -ENOMEM;
> > -	}
> >  	mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev-
> >dp_dma_addr);
> >  	mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev-
> >dp_dma_addr >> 32);
> >  	return 0;
> > @@ -68,8 +62,7 @@ static int mic_dp_init(struct mic_device *mdev)
> >  /* Uninitialize the device page */
> >  static void mic_dp_uninit(struct mic_device *mdev)  {
> > -	mic_unmap_single(mdev, mdev->dp_dma_addr, MIC_DP_SIZE);
> > -	kfree(mdev->dp);
> > +	dma_free_coherent(&mdev->pdev->dev, MIC_DP_SIZE, mdev->dp,
> > +mdev->dp_dma_addr);
> >  }
> 
> This adds an over 80 char line.  Also please just kill mic_dp_init and
> mic_dp_uninit and inline those into the callers.

Okay, will fix them.
> 
> > +		vvr->buf = dma_alloc_coherent(vop_dev(vdev),
> VOP_INT_DMA_BUF_SIZE,
> > +					      &vvr->buf_da, GFP_KERNEL);
> 
> Another overly long line.
> 
> > @@ -1068,7 +1049,7 @@ vop_query_offset(struct vop_vdev *vdev,
> unsigned long offset,
> >  		struct vop_vringh *vvr = &vdev->vvr[i];
> >
> >  		if (offset == start) {
> > -			*pa = virt_to_phys(vvr->vring.va);
> > +			*pa = vqconfig[i].address;
> 
> vqconfig[i].address is a __le64, so this needs an endian swap.
> 
> But more importantly the caller of vop_query_offset, vop_mmap, uses
> remap_pfn_range and pa.  You cannot mix remap_pfn_range with DMA
> coherent allocations, it can only be mmaped using dma_mmap_coherent.

Will change to use dma_mmap_coherent in V4.

Best regards
Sherry