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SubjectRE: [PATCH v2 05/16] remoteproc: modify rproc_handle_carveout to support preallocated region
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> -----Original Message-----
> From: Bjorn Andersson [mailto:bjorn.andersson@linaro.org]
> Sent: Thursday, December 14, 2017 1:59 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 v2 05/16] remoteproc: modify rproc_handle_carveout to
> support preallocated region
>
> On Thu 30 Nov 08:46 PST 2017, Loic Pallardy wrote:
>
> > In current version rproc_handle_carveout function support only dynamic
> > region allocation.
> > This patch extends rproc_handle_carveout function to support different
> carveout
> > configurations:
> > - fixed DA and fixed PA: check if already part of pre-registered carveouts
> > (platform driver). If no, return error.
> > - fixed DA and any PA: check if already part of pre-allocated carveouts
> > (platform driver). If not found and rproc supports iommu, continue with
> > dynamic allocation (DA will be used for iommu programming), else return
> > error as no way to force DA.
> > - any DA and any PA: use original dynamic allocation
> >
> > Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
> > ---
> > drivers/remoteproc/remoteproc_core.c | 40
> ++++++++++++++++++++++++++++++++++++
> > 1 file changed, 40 insertions(+)
> >
> > diff --git a/drivers/remoteproc/remoteproc_core.c
> b/drivers/remoteproc/remoteproc_core.c
> > index 78525d1..515a17a 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -184,6 +184,10 @@ void *rproc_da_to_va(struct rproc *rproc, u64 da,
> int len)
> > struct rproc_mem_entry *carveout;
> > void *ptr = NULL;
> >
> > + /*
> > + * da_to_va platform driver is deprecated. Driver should register
> > + * carveout thanks to rproc_add_carveout function
> > + */
>
> I think this comment is unrelated to the rest of this patch. I also
> think that at the end of the carveout-rework we should have a patch
> removing this ops.

I'll remove this comment and add a da_to_va clean-up patch at the end of the series

>
> > if (rproc->ops->da_to_va) {
> > ptr = rproc->ops->da_to_va(rproc, da, len);
> > if (ptr)
> > @@ -677,6 +681,7 @@ static int rproc_handle_carveout(struct rproc
> *rproc,
> > struct rproc_mem_entry *carveout, *mapping;
> > struct device *dev = &rproc->dev;
> > dma_addr_t dma;
> > + phys_addr_t pa;
> > void *va;
> > int ret;
> >
> > @@ -698,6 +703,41 @@ static int rproc_handle_carveout(struct rproc
> *rproc,
> > if (!carveout)
> > return -ENOMEM;
> >
> > + /* Check carveout rsc already part of a registered carveout */
> > + if (rsc->da != FW_RSC_ADDR_ANY) {
>
> As mentioned before, I consider it perfectly viable for rsc->da to be
> ANY and the driver providing a fixed carveout.

Yes I'll change sequence to lookup by name first and then verify exact parameters matching , not only da definition.

>
> > + va = rproc_find_carveout_by_da(rproc, rsc->da, rsc->len);
> > +
> > + if (va) {
>
> In a system with an iommu it's possible that rsc->len is larger than
> some carveout->len and va is NULL here so we fall through, allocate some
> memory and remap a segment of the carveout. (Or hopefully fails
> attempting).
>
> > + /* Registered region found */
> > + pa = rproc_va_to_pa(va);
> > + if (rsc->pa != FW_RSC_ADDR_ANY && rsc->pa !=
> (u32)pa) {
> > + /* Carveout doesn't match request */
> > + dev_err(dev->parent,
> > + "Failed to find carveout fitting da and
> pa\n");
> > + return -ENOMEM;
> > + }
> > +
> > + /* Update rsc table with physical address */
> > + rsc->pa = (u32)pa;
> > +
> > + /* Update carveouts list */
> > + carveout->va = va;
> > + carveout->len = rsc->len;
> > + carveout->da = rsc->da;
> > + carveout->priv = (void *)CARVEOUT_RSC;
> > +
> > + list_add_tail(&carveout->node, &rproc->carveouts);
>
> rproc_find_carveout_by_da() will return a reference into a carveout, now
> we add another overlapping carveout into the same list.
>
>
> I think it would be saner to not allow the resource table to describe
> subsets of carveouts registered by the driver.
>
> In which case this would better find a carveout by name or exact da,
> then check that the pa, da, len and rsc->flags are adequate.

Agree
/Loic
>
> > +
> > + return 0;
> > + }
> > +
> > + if (!rproc->domain) {
>
> Currently this function ignore invalid values of da when !domain, so I
> think it would be good you can submit this sanity check in it's own
> patch so that anyone bisecting this would know why their broken firmware
> suddenly isn't loadable.
>
> > + dev_err(dev->parent,
> > + "Bad carveout rsc configuration\n");
> > + return -ENOMEM;
> > + }
> > + }
> > +
>
> Regards,
> Bjorn

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