Messages in this thread | | | Subject | Re: [PATCH v4 01/17] remoteproc: configure IOMMU only if device address requested | From | Suman Anna <> | Date | Tue, 23 Oct 2018 12:25:49 -0500 |
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Hi Loic,
On 7/27/18 8:14 AM, Loic Pallardy wrote: > If there is no IOMMU associate to remote processor device, > remoteproc_core won't be able to satisfy device address requested > in firmware resource table. > Return an error as configuration won't be coherent. > > Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
This patch is breaking my Davinci platforms. It is not really required that you _should_ have IOMMUs when a valid DA is mentioned. Please see the existing description (paras 4 and 5) on the fw_rsc_carveout kerneldoc in remoteproc.h file.
We do have platforms where we have some internal sub-modules within the remote processor sub-system that provides some linear address-translation (most common case with 32-bit processors supporting 64-bit addresses). Also, we have some upcoming SoCs where we have an MMU but is not programmable by Linux.
There is one comment there, but I don't think this is actually handled in the current remoteproc core. "If @da is set to * FW_RSC_ADDR_ANY, then the host will dynamically allocate it, and then * overwrite @da with the dynamically allocated address."
regards Suman
> --- > drivers/remoteproc/remoteproc_core.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c > index 4cd1a8e..437fabf 100644 > --- a/drivers/remoteproc/remoteproc_core.c > +++ b/drivers/remoteproc/remoteproc_core.c > @@ -657,7 +657,15 @@ static int rproc_handle_carveout(struct rproc *rproc, > * to use the iommu-based DMA API: we expect 'dma' to contain the > * physical address in this case. > */ > - if (rproc->domain) { > + > + if (rsc->da != FW_RSC_ADDR_ANY && !rproc->domain) { > + dev_err(dev->parent, > + "Bad carveout rsc configuration\n"); > + ret = -ENOMEM; > + goto dma_free; > + } > + > + if (rsc->da != FW_RSC_ADDR_ANY && rproc->domain) { > mapping = kzalloc(sizeof(*mapping), GFP_KERNEL); > if (!mapping) { > ret = -ENOMEM; >
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