On Mon, Apr 23, 2018 at 08:55:57AM +0000, Loic PALLARDY wrote: > > > > -----Original Message----- > > From: [email protected] [mailto:linux-remoteproc- > > [email protected]] On Behalf Of Anup Patel > > Sent: Sunday, April 22, 2018 6:08 AM > > To: Michael S. Tsirkin <[email protected]> > > Cc: [email protected]; Ohad Ben-Cohen > > <[email protected]>; Bjorn Andersson <[email protected]>; > > [email protected] > > Subject: Re: virtio remoteproc device > > > > On Fri, Apr 20, 2018 at 10:23 PM, Michael S. Tsirkin <[email protected]> > > 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 => rproc => platform-dev. > > > */ > > > if (!vdev->dev.parent || !vdev->dev.parent->parent) > > > goto free_buf; > > > buf->dev = vdev->dev.parent->parent; > > > > > > /* Increase device refcnt to avoid freeing it */ > > > get_device(buf->dev); > > > buf->buf = dma_alloc_coherent(buf->dev, buf_size, > > > &buf->dma, > > > GFP_KERNEL); > > > } > > > > > > Added here: > > > commit 1b6370463e88b0c1c317de16d7b962acc1dab4f2 > > > Author: Sjur Brændeland <[email protected]> > > > 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/ > > Hi Anup and Michael, > > I pushed a series to modify virtio device allocation in remoteproc. Please > see [1]. > It allows to remove allocation based on "grand-parent" device in the case of > virtio device allocated by remoteproc. > Virto_console patch missing, only virtio_rpmsg modification proposed. I can > add it in next version. > > Regards, > Loic > > [1] https://lkml.org/lkml/2018/3/1/644
Thanks! Based on that patch, can remoteproc force VIRTIO_F_IOMMU_PLATFORM in features and then drop special-casing of dma completely? > > > > Regards, > > Anup > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-remoteproc" > > in > > the body of a message to [email protected] > > More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
