Re: [PATCH v2] ACPI/IORT: Fix PMCG node always look for a single ID mapping.

[Robin Murphy]

On 2020-05-13 4:16 am, Hanjun Guo wrote:
> On 2020/5/13 7:56, Tuan Phan wrote:
> > PMCG node can have zero ID mapping if its overflow interrupt
> > is wire based. The code to parse PMCG node can not assume it will
> > have a single ID mapping.
> >
> > Signed-off-by: Tuan Phan <tuanphan@xxxxxxxxxxxxxxxxxxxxxx>
>
> It's better to add
>
> Fixes: 24e516049360 ("ACPI/IORT: Add support for PMCG")
>
> > ---
> > Changes in v2:
> > - Used pmcg node to detect wired base overflow interrupt.
> > Â drivers/acpi/arm64/iort.c | 5 +++++
> > Â 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index ed3d2d1..11a4e8e 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -414,6 +414,7 @@ static struct acpi_iort_node 
> > *iort_node_get_id(struct acpi_iort_node *node,
> > Â static int iort_get_id_mapping_index(struct acpi_iort_node *node)
> > Â {
> > ÂÂÂÂÂ struct acpi_iort_smmu_v3 *smmu;
> > +ÂÂÂ struct acpi_iort_pmcg *pmcg;
> > ÂÂÂÂÂ switch (node->type) {
> > ÂÂÂÂÂ case ACPI_IORT_NODE_SMMU_V3:
> > @@ -441,6 +442,10 @@ static int iort_get_id_mapping_index(struct 
> > acpi_iort_node *node)
> > ÂÂÂÂÂÂÂÂÂ return smmu->id_mapping_index;
> > ÂÂÂÂÂ case ACPI_IORT_NODE_PMCG:
> > +ÂÂÂÂÂÂÂ pmcg = (struct acpi_iort_pmcg *)node->node_data;
> > +ÂÂÂÂÂÂÂ if (pmcg->overflow_gsiv)

	if (pmcg->overflow_gsiv || node->mapping_count == 0)

...if there is no GSIV, we should still *also* check that index 0 is 
valid before we return it.

Robin.

> > +ÂÂÂÂÂÂÂÂÂÂÂ return -EINVAL;
> > +
> > ÂÂÂÂÂÂÂÂÂ return 0;
> > ÂÂÂÂÂ default:
> > ÂÂÂÂÂÂÂÂÂ return -EINVAL;
>
> With my comments addressed,
>
> Reviewed-by: Hanjun Guo <guoahanjun@xxxxxxxxxx>
>
>
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