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Message-ID: <50cece73-a499-eba3-7018-9e92e0791c88@collabora.com>
Date:   Sun, 13 Nov 2022 19:35:20 +0300
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Subject: Re: [PATCH v2] udmabuf: add vmap method to udmabuf_ops
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To:     Lukasz Wiecaszek <lukasz.wiecaszek@googlemail.com>,
        Gerd Hoffmann <kraxel@redhat.com>
Cc:     Lukasz Wiecaszek <lukasz.wiecaszek@gmail.com>,
        kernel test robot <lkp@intel.com>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org,
        linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org
References: <20221113150511.8878-1-lukasz.wiecaszek@gmail.com>
From:   Dmitry Osipenko <dmitry.osipenko@collabora.com>
In-Reply-To: <20221113150511.8878-1-lukasz.wiecaszek@gmail.com>
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On 11/13/22 18:05, Lukasz Wiecaszek wrote:
> +static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map)
> +{
> +	struct udmabuf *ubuf = buf->priv;
> +
> +	if (!ubuf->vaddr) {
> +		ubuf->vaddr = vm_map_ram(ubuf->pages, ubuf->pagecount, -1);
> +		if (!ubuf->vaddr)
> +			return -EINVAL;
> +	}

Create a new mapping on each vmap_udmabuf() and add the corresponding
vunmap.

Otherwise persistent vmapping shall be released together with udmabuf.
It doesn't look that persistent vmapping is needed for udmabufs.

-- 
Best regards,
Dmitry