Re: [PATCH v4] ACPI/IORT: Fix PMCG node single ID mapping handling.

[Lorenzo Pieralisi]

On Fri, May 15, 2020 at 12:24:46PM -0700, Tuan Phan wrote:
> An IORT PMCG node can have no ID mapping if its overflow interrupt is
> wire based therefore the code that parses the PMCG node can not assume
> the node will always have a single mapping present at index 0.
> 
> Fix iort_get_id_mapping_index() by checking for an overflow interrupt
> and mapping count.
> 
> Fixes: 24e516049360 ("ACPI/IORT: Add support for PMCG").

Remove these periods in the $SUBJECT and commit references, I
don't know why you keep adding them.

Anyway - I don't know if it is too late for v5.8 but this patch
is ready to be merged (minus the nits I have just mentioned).

Lorenzo

> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Reviewed-by: Hanjun Guo <guoahanjun@xxxxxxxxxx>
> Signed-off-by: Tuan Phan <tuanphan@xxxxxxxxxxxxxxxxxxxxxx>
> ---
> v1 -> v2:
> - Use pmcg node to detect wired base overflow interrupt.
> 
> v2 -> v3:
> - Address Hanjun and Robin's comments.
> 
> v3 -> v4:
> - Update the title and description as mentioned by Lorenzo.
> 
>  drivers/acpi/arm64/iort.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index ed3d2d1..12bb70e 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,
>  static int iort_get_id_mapping_index(struct acpi_iort_node *node)
>  {
>  	struct acpi_iort_smmu_v3 *smmu;
> +	struct acpi_iort_pmcg *pmcg;
>  
>  	switch (node->type) {
>  	case ACPI_IORT_NODE_SMMU_V3:
> @@ -441,6 +442,10 @@ static int iort_get_id_mapping_index(struct acpi_iort_node *node)
>  
>  		return smmu->id_mapping_index;
>  	case ACPI_IORT_NODE_PMCG:
> +		pmcg = (struct acpi_iort_pmcg *)node->node_data;
> +		if (pmcg->overflow_gsiv || node->mapping_count == 0)
> +			return -EINVAL;
> +
>  		return 0;
>  	default:
>  		return -EINVAL;
> -- 
> 2.7.4
>