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From:   Sherry Sun <sherry.sun@nxp.com>
To:     Christoph Hellwig <hch@infradead.org>
CC:     "sudeep.dutt@intel.com" <sudeep.dutt@intel.com>,
        "ashutosh.dixit@intel.com" <ashutosh.dixit@intel.com>,
        "arnd@arndb.de" <arnd@arndb.de>,
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        "kishon@ti.com" <kishon@ti.com>,
        "lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        dl-linux-imx <linux-imx@nxp.com>
Subject: RE: [PATCH V3 1/4] misc: vop: change the way of allocating vring and
 device page
Thread-Topic: [PATCH V3 1/4] misc: vop: change the way of allocating vring and
 device page
Thread-Index: AQHWqDFPY7Z3VR772U+S1nPW/DeV8Kmk7HwAgARJSyA=
Date:   Mon, 26 Oct 2020 02:54:43 +0000
Message-ID: <VI1PR04MB4960119E6D56CF64E8FD2E4492190@VI1PR04MB4960.eurprd04.prod.outlook.com>
References: <20201022050638.29641-1-sherry.sun@nxp.com>
 <20201022050638.29641-2-sherry.sun@nxp.com>
 <20201023092524.GA29066@infradead.org>
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Hi Christoph,

>=20
> >  static int mic_dp_init(struct mic_device *mdev)  {
> > -	mdev->dp =3D kzalloc(MIC_DP_SIZE, GFP_KERNEL);
> > +	mdev->dp =3D dma_alloc_coherent(&mdev->pdev->dev, MIC_DP_SIZE,
> > +				      &mdev->dp_dma_addr, GFP_KERNEL);
> >  	if (!mdev->dp)
> >  		return -ENOMEM;
> >
> > -	mdev->dp_dma_addr =3D 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);
> >  }
>=20
> 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.
>=20
> > +		vvr->buf =3D dma_alloc_coherent(vop_dev(vdev),
> VOP_INT_DMA_BUF_SIZE,
> > +					      &vvr->buf_da, GFP_KERNEL);
>=20
> Another overly long line.
>=20
> > @@ -1068,7 +1049,7 @@ vop_query_offset(struct vop_vdev *vdev,
> unsigned long offset,
> >  		struct vop_vringh *vvr =3D &vdev->vvr[i];
> >
> >  		if (offset =3D=3D start) {
> > -			*pa =3D virt_to_phys(vvr->vring.va);
> > +			*pa =3D vqconfig[i].address;
>=20
> vqconfig[i].address is a __le64, so this needs an endian swap.
>=20
> 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=20