RE: [PATCH v3 10/13] remoteproc: modify vring allocation to support pre-registered region

[Loic PALLARDY <loic.pallardy@st.com>]

> -----Original Message-----
> From: Bjorn Andersson [mailto:bjorn.andersson@linaro.org]
> Sent: Thursday, May 10, 2018 2:59 AM
> To: Loic PALLARDY <loic.pallardy@st.com>
> Cc: ohad@wizery.com; linux-remoteproc@vger.kernel.org; linux-
> kernel@vger.kernel.org; Arnaud POULIQUEN <arnaud.pouliquen@st.com>;
> benjamin.gaignard@linaro.org
> Subject: Re: [PATCH v3 10/13] remoteproc: modify vring allocation to support
> pre-registered region
> 
> On Thu 01 Mar 08:23 PST 2018, Loic Pallardy wrote:
> [..]
> > @@ -265,23 +269,45 @@ int rproc_alloc_vring(struct rproc_vdev *rvdev,
> int i)
> >  	struct device *dev = &rproc->dev;
> >  	struct rproc_vring *rvring = &rvdev->vring[i];
> >  	struct fw_rsc_vdev *rsc;
> > -	dma_addr_t dma;
> > -	void *va;
> >  	int ret, size, notifyid;
> > +	struct fw_rsc_carveout rsc_carveout;
> > +	struct rproc_mem_entry *mem;
> >
> >  	/* actual size of vring (in bytes) */
> >  	size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
> >
> > -	/*
> > -	 * Allocate non-cacheable memory for the vring. In the future
> > -	 * this call will also configure the IOMMU for us
> > -	 */
> > -	va = dma_alloc_coherent(dev->parent, size, &dma, GFP_KERNEL);
> > -	if (!va) {
> > -		dev_err(dev->parent, "dma_alloc_coherent failed\n");
> > +	rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
> > +
> > +	/* Create virtual firmware carveout resource */
> > +	rsc_carveout.da = rsc->vring[i].da;
> > +	rsc_carveout.pa = FW_RSC_ADDR_ANY;
> > +	rsc_carveout.len = size;
> > +	rsc_carveout.flags = 0;
> > +	rsc_carveout.reserved = 0;
> > +	snprintf(rsc_carveout.name, sizeof(rsc_carveout.name),
> "vdev%dvring%d",
> > +		 rvdev->index, i);
> [..]
> > @@ -437,6 +460,7 @@ static int rproc_handle_vdev(struct rproc *rproc,
> struct fw_rsc_vdev *rsc,
> >
> >  	rvdev->id = rsc->id;
> >  	rvdev->rproc = rproc;
> > +	rvdev->index = index++;
> 
> This index isn't deterministic over multiple remoteproc instances and
> multiple restarts of the remoteproc. It probably needs to be based
> generated based on the ordering in the resource table.
Yes it was my intention, but static use make it wrong.
I'll revisit this point

Regards,
Loic
> 
> Regards,
> Bjorn