[PATCH v5] ACPI/IORT: Fix PMCG node single ID mapping handling

[PATCH v5] ACPI/IORT: Fix PMCG node single ID mapping handling

[Tuan Phan]

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")

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Hanjun Guo <guoahanjun@huawei.com>
Signed-off-by: Tuan Phan <tuanphan@os.amperecomputing.com>
---
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.

v4 -> v5:
- Remove period in the title and commit references.

 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

Re: [PATCH v5] ACPI/IORT: Fix PMCG node single ID mapping handling

[Lorenzo Pieralisi]

On Wed, May 20, 2020 at 10:13:07AM -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")
> 
> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Reviewed-by: Hanjun Guo <guoahanjun@huawei.com>
> Signed-off-by: Tuan Phan <tuanphan@os.amperecomputing.com>
> ---
> 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.
> 
> v4 -> v5:
> - Remove period in the title and commit references.
> 
>  drivers/acpi/arm64/iort.c | 5 +++++

Hi Will,

is there a chance we can get this patch into v5.8 ? I understand
we are very late in the cycle but I wanted to ask (it applies cleanly
to for-next/acpi).

Thanks !
Lorenzo

>  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
> 

Re: [PATCH v5] ACPI/IORT: Fix PMCG node single ID mapping handling

[Will Deacon]

On Wed, May 20, 2020 at 06:27:36PM +0100, Lorenzo Pieralisi wrote:
> On Wed, May 20, 2020 at 10:13:07AM -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")
> > 
> > Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Reviewed-by: Hanjun Guo <guoahanjun@huawei.com>
> > Signed-off-by: Tuan Phan <tuanphan@os.amperecomputing.com>
> > ---
> > 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.
> > 
> > v4 -> v5:
> > - Remove period in the title and commit references.
> > 
> >  drivers/acpi/arm64/iort.c | 5 +++++
> 
> Hi Will,
> 
> is there a chance we can get this patch into v5.8 ? I understand
> we are very late in the cycle but I wanted to ask (it applies cleanly
> to for-next/acpi).

Sorry, Lorenzo -- I didn't notice that this had been Acked already. I was
waiting for somebody to chime in! I'll queue it ASAP for 5.8.

Will

Re: [PATCH v5] ACPI/IORT: Fix PMCG node single ID mapping handling

[Will Deacon]

On Wed, 20 May 2020 10:13:07 -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.
> 
> [...]

Applied to arm64 (for-next/acpi), thanks!

[1/1] ACPI/IORT: Fix PMCG node single ID mapping handling
      https://git.kernel.org/arm64/c/50c8ab8d9fbf

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev