From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: <20180420194321-mutt-send-email-mst@kernel.org> References: <20180420194321-mutt-send-email-mst@kernel.org> From: Anup Patel Date: Sun, 22 Apr 2018 09:38:10 +0530 Message-ID: Subject: Re: virtio remoteproc device Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable To: "Michael S. Tsirkin" Cc: linux-remoteproc@vger.kernel.org, Ohad Ben-Cohen , Bjorn Andersson , virtualization@lists.linux-foundation.org List-ID: On Fri, Apr 20, 2018 at 10:23 PM, Michael S. Tsirkin wrote= : > Hello! > I note the following in the serial console: > > if (is_rproc_serial(vdev)) { > /* > * Allocate DMA memory from ancestor. When a virtio > * device is created by remoteproc, the DMA memory is > * associated with the grandparent device: > * vdev =3D> rproc =3D> platform-dev. > */ > if (!vdev->dev.parent || !vdev->dev.parent->parent) > goto free_buf; > buf->dev =3D vdev->dev.parent->parent; > > /* Increase device refcnt to avoid freeing it */ > get_device(buf->dev); > buf->buf =3D dma_alloc_coherent(buf->dev, buf_size, &buf-= >dma, > GFP_KERNEL); > } > > Added here: > commit 1b6370463e88b0c1c317de16d7b962acc1dab4f2 > Author: Sjur Br=C3=A6ndeland > Date: Fri Dec 14 14:40:51 2012 +1030 > > virtio_console: Add support for remoteproc serial > > > I am not familiar with rproc so I have a question: > why is it required to use coherent memory here, > and why through a grandparent device? I faced similar issue when I tried VirtIO RPMSG bus over VirtIO MMIO transport. Here's my fix for VirtIO RPMSG bus driver: https://patchwork.kernel.org/patch/10155145/ Regards, Anup From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anup Patel Subject: Re: virtio remoteproc device Date: Sun, 22 Apr 2018 09:38:10 +0530 Message-ID: References: <20180420194321-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20180420194321-mutt-send-email-mst@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: "Michael S. Tsirkin" Cc: Ohad Ben-Cohen , virtualization@lists.linux-foundation.org, linux-remoteproc@vger.kernel.org, Bjorn Andersson List-Id: virtualization@lists.linuxfoundation.org T24gRnJpLCBBcHIgMjAsIDIwMTggYXQgMTA6MjMgUE0sIE1pY2hhZWwgUy4gVHNpcmtpbiA8bXN0 QHJlZGhhdC5jb20+IHdyb3RlOgo+IEhlbGxvIQo+IEkgbm90ZSB0aGUgZm9sbG93aW5nIGluIHRo ZSBzZXJpYWwgY29uc29sZToKPgo+ICAgICAgIGlmIChpc19ycHJvY19zZXJpYWwodmRldikpIHsK PiAgICAgICAgICAgICAgICAgLyoKPiAgICAgICAgICAgICAgICAgICogQWxsb2NhdGUgRE1BIG1l bW9yeSBmcm9tIGFuY2VzdG9yLiBXaGVuIGEgdmlydGlvCj4gICAgICAgICAgICAgICAgICAqIGRl dmljZSBpcyBjcmVhdGVkIGJ5IHJlbW90ZXByb2MsIHRoZSBETUEgbWVtb3J5IGlzCj4gICAgICAg ICAgICAgICAgICAqIGFzc29jaWF0ZWQgd2l0aCB0aGUgZ3JhbmRwYXJlbnQgZGV2aWNlOgo+ICAg ICAgICAgICAgICAgICAgKiB2ZGV2ID0+IHJwcm9jID0+IHBsYXRmb3JtLWRldi4KPiAgICAgICAg ICAgICAgICAgICovCj4gICAgICAgICAgICAgICAgIGlmICghdmRldi0+ZGV2LnBhcmVudCB8fCAh dmRldi0+ZGV2LnBhcmVudC0+cGFyZW50KQo+ICAgICAgICAgICAgICAgICAgICAgICAgIGdvdG8g ZnJlZV9idWY7Cj4gICAgICAgICAgICAgICAgIGJ1Zi0+ZGV2ID0gdmRldi0+ZGV2LnBhcmVudC0+ cGFyZW50Owo+Cj4gICAgICAgICAgICAgICAgIC8qIEluY3JlYXNlIGRldmljZSByZWZjbnQgdG8g YXZvaWQgZnJlZWluZyBpdCAqLwo+ICAgICAgICAgICAgICAgICBnZXRfZGV2aWNlKGJ1Zi0+ZGV2 KTsKPiAgICAgICAgICAgICAgICAgYnVmLT5idWYgPSBkbWFfYWxsb2NfY29oZXJlbnQoYnVmLT5k ZXYsIGJ1Zl9zaXplLCAmYnVmLT5kbWEsCj4gICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ICAgICAgICAgICAgICAgIEdGUF9LRVJORUwpOwo+ICAgICAgICAgfQo+Cj4gQWRkZWQgaGVyZToK PiAgICAgICAgIGNvbW1pdCAxYjYzNzA0NjNlODhiMGMxYzMxN2RlMTZkN2I5NjJhY2MxZGFiNGYy Cj4gICAgICAgICBBdXRob3I6IFNqdXIgQnLDpm5kZWxhbmQgPHNqdXIuYnJhbmRlbGFuZEBzdGVy aWNzc29uLmNvbT4KPiAgICAgICAgIERhdGU6ICAgRnJpIERlYyAxNCAxNDo0MDo1MSAyMDEyICsx MDMwCj4KPiAgICAgdmlydGlvX2NvbnNvbGU6IEFkZCBzdXBwb3J0IGZvciByZW1vdGVwcm9jIHNl cmlhbAo+Cj4KPiBJIGFtIG5vdCBmYW1pbGlhciB3aXRoIHJwcm9jIHNvIEkgaGF2ZSBhIHF1ZXN0 aW9uOgo+IHdoeSBpcyBpdCByZXF1aXJlZCB0byB1c2UgY29oZXJlbnQgbWVtb3J5IGhlcmUsCj4g YW5kIHdoeSB0aHJvdWdoIGEgZ3JhbmRwYXJlbnQgZGV2aWNlPwoKSSBmYWNlZCBzaW1pbGFyIGlz c3VlIHdoZW4gSSB0cmllZCBWaXJ0SU8gUlBNU0cgYnVzIG92ZXIKVmlydElPIE1NSU8gdHJhbnNw b3J0LgoKSGVyZSdzIG15IGZpeCBmb3IgVmlydElPIFJQTVNHIGJ1cyBkcml2ZXI6Cmh0dHBzOi8v cGF0Y2h3b3JrLmtlcm5lbC5vcmcvcGF0Y2gvMTAxNTUxNDUvCgpSZWdhcmRzLApBbnVwCl9fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClZpcnR1YWxpemF0aW9u IG1haWxpbmcgbGlzdApWaXJ0dWFsaXphdGlvbkBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZwpo dHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby92aXJ0dWFs aXphdGlvbg==