[PATCH v2] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

[PATCH v2] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

[Lorenzo Pieralisi]

Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
introduced a function (iort_node_get_id()) to retrieve ids for IORT
named components.

The iort_node_get_id() takes an index as input to refer to a specific
mapping entry in the named component IORT node mapping array.

For a mapping entry at a given index, iort_node_get_id() should return
the id value (through the id_out function parameter) and the IORT node
output_reference (through function return value) the given mapping entry
refers to.

Technically output_reference values may differ for different map
entries, (see diagram below - mapped id values may refer to different eg
IORT SMMU nodes; the kernel may not be able to handle different
output_reference values for a given named component but the IORT kernel
layer should still report the IORT mappings as reported by firmware) but
current code in iort_node_get_id() fails to use the index function
parameter to return the correct output_reference value (ie it always
returns the output_reference value of the first entry in the mapping
array whilst using the index correctly to retrieve the id value from the
respective entry).

	|----------------------|
	|     named component  |
	|----------------------|
	|      map entry[0]    |
	|----------------------|
	|       id value       |
	| output_reference----------------> eg SMMU 1
	|----------------------|
	|      map entry[1]    |
	|----------------------|
	|       id value       |
	| output_reference----------------> eg SMMU 2
	|----------------------|
		    .
		    .
		    .
	|----------------------|
	|      map entry[N]    |
	|----------------------|
	|       id value       |
	| output_reference----------------> eg SMMU 1
	|----------------------|

Consequently the iort_node_get_id() function always returns the IORT
node pointed at by the output_reference value of the first named
component mapping array entry, irrespective of the index parameter,
which is a bug.

Update the map array entry pointer computation in iort_node_get_id() to
take into account the index value, fixing the issue.

Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sinan Kaya <okaya@codeaurora.org>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Nate Watterson <nwatters@codeaurora.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
---
v1 -> v2:
	- Updated/improved commit log
	- Added review tags

 drivers/acpi/arm64/iort.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index e0d2e6e..ba156c5 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
 		return NULL;
 
 	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
-			   node->mapping_offset);
+			   node->mapping_offset + index * sizeof(*map));
 
 	/* Firmware bug! */
 	if (!map->output_reference) {
@@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
 	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
 		return NULL;
 
-	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
 		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
 		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
-			*id_out = map[index].output_base;
+			*id_out = map->output_base;
 			return parent;
 		}
 	}
-- 
2.10.0

Re: [PATCH v2] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

[Sinan Kaya]

On 1/10/2017 7:00 AM, Lorenzo Pieralisi wrote:
> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
> introduced a function (iort_node_get_id()) to retrieve ids for IORT
> named components.
> 
> The iort_node_get_id() takes an index as input to refer to a specific
> mapping entry in the named component IORT node mapping array.
> 
> For a mapping entry at a given index, iort_node_get_id() should return
> the id value (through the id_out function parameter) and the IORT node
> output_reference (through function return value) the given mapping entry
> refers to.
> 
> Technically output_reference values may differ for different map
> entries, (see diagram below - mapped id values may refer to different eg
> IORT SMMU nodes; the kernel may not be able to handle different
> output_reference values for a given named component but the IORT kernel
> layer should still report the IORT mappings as reported by firmware) but
> current code in iort_node_get_id() fails to use the index function
> parameter to return the correct output_reference value (ie it always
> returns the output_reference value of the first entry in the mapping
> array whilst using the index correctly to retrieve the id value from the
> respective entry).
> 
> 	|----------------------|
> 	|     named component  |
> 	|----------------------|
> 	|      map entry[0]    |
> 	|----------------------|
> 	|       id value       |
> 	| output_reference----------------> eg SMMU 1
> 	|----------------------|
> 	|      map entry[1]    |
> 	|----------------------|
> 	|       id value       |
> 	| output_reference----------------> eg SMMU 2
> 	|----------------------|
> 		    .
> 		    .
> 		    .
> 	|----------------------|
> 	|      map entry[N]    |
> 	|----------------------|
> 	|       id value       |
> 	| output_reference----------------> eg SMMU 1
> 	|----------------------|
> 
> Consequently the iort_node_get_id() function always returns the IORT
> node pointed at by the output_reference value of the first named
> component mapping array entry, irrespective of the index parameter,
> which is a bug.
> 
> Update the map array entry pointer computation in iort_node_get_id() to
> take into account the index value, fixing the issue.
> 
> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Sinan Kaya <okaya@codeaurora.org>
> Cc: Tomasz Nowicki <tn@semihalf.com>
> Cc: Nate Watterson <nwatters@codeaurora.org>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
> v1 -> v2:
> 	- Updated/improved commit log
> 	- Added review tags
> 
>  drivers/acpi/arm64/iort.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index e0d2e6e..ba156c5 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -333,7 +333,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  		return NULL;
>  
>  	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> -			   node->mapping_offset);
> +			   node->mapping_offset + index * sizeof(*map));
>  
>  	/* Firmware bug! */
>  	if (!map->output_reference) {
> @@ -348,10 +348,10 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
>  		return NULL;
>  
> -	if (map[index].flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>  		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>  		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> -			*id_out = map[index].output_base;
> +			*id_out = map->output_base;
>  			return parent;
>  		}
>  	}
> 

Tested on Qualcomm QDF2400 server with Hanjun's first 11 patches + my patch 
for (NC->SMMU->ITS) using HIDMA DMA Engine driver and MSI interrupts. 

No impacts to the existing functionality. Note that I do not have a topology
as described in this commit. I'm just stating that my existing functionality
is not impacted by this change.

Tested-by: Sinan Kaya <okaya@codeaurora.org>


-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH v2] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

[Hanjun Guo]

On 01/10/2017 08:00 PM, Lorenzo Pieralisi wrote:
> Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
> introduced a function (iort_node_get_id()) to retrieve ids for IORT
> named components.
>
> The iort_node_get_id() takes an index as input to refer to a specific
> mapping entry in the named component IORT node mapping array.
>
> For a mapping entry at a given index, iort_node_get_id() should return
> the id value (through the id_out function parameter) and the IORT node
> output_reference (through function return value) the given mapping entry
> refers to.
>
> Technically output_reference values may differ for different map
> entries, (see diagram below - mapped id values may refer to different eg
> IORT SMMU nodes; the kernel may not be able to handle different
> output_reference values for a given named component but the IORT kernel
> layer should still report the IORT mappings as reported by firmware) but
> current code in iort_node_get_id() fails to use the index function
> parameter to return the correct output_reference value (ie it always
> returns the output_reference value of the first entry in the mapping
> array whilst using the index correctly to retrieve the id value from the
> respective entry).
>
> 	|----------------------|
> 	|     named component  |
> 	|----------------------|
> 	|      map entry[0]    |
> 	|----------------------|
> 	|       id value       |
> 	| output_reference----------------> eg SMMU 1
> 	|----------------------|
> 	|      map entry[1]    |
> 	|----------------------|
> 	|       id value       |
> 	| output_reference----------------> eg SMMU 2
> 	|----------------------|
> 		    .
> 		    .
> 		    .
> 	|----------------------|
> 	|      map entry[N]    |
> 	|----------------------|
> 	|       id value       |
> 	| output_reference----------------> eg SMMU 1
> 	|----------------------|
>
> Consequently the iort_node_get_id() function always returns the IORT
> node pointed at by the output_reference value of the first named
> component mapping array entry, irrespective of the index parameter,
> which is a bug.
>
> Update the map array entry pointer computation in iort_node_get_id() to
> take into account the index value, fixing the issue.
>
> Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
> Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Hanjun Guo <hanjun.guo@linaro.org>
> Cc: Sinan Kaya <okaya@codeaurora.org>
> Cc: Tomasz Nowicki <tn@semihalf.com>
> Cc: Nate Watterson <nwatters@codeaurora.org>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> ---
> v1 -> v2:
> 	- Updated/improved commit log
> 	- Added review tags

Forgot to mention that I tested this patch on Hisilicon
D03,

Tested-by: Hanjun Guo <hanjun.guo@linaro.org>

BTW, Lorenzo, Rafael, since it's a bugfix, can this be merged into
4.10-rc7?

Thanks
Hanjun

Re: [PATCH v2] ACPI/IORT: Fix iort_node_get_id() mapping entries indexing

[Lorenzo Pieralisi]

On Fri, Feb 03, 2017 at 10:20:29AM +0800, Hanjun Guo wrote:
> On 01/10/2017 08:00 PM, Lorenzo Pieralisi wrote:
> >Commit 618f535a6062 ("ACPI/IORT: Add single mapping function")
> >introduced a function (iort_node_get_id()) to retrieve ids for IORT
> >named components.
> >
> >The iort_node_get_id() takes an index as input to refer to a specific
> >mapping entry in the named component IORT node mapping array.
> >
> >For a mapping entry at a given index, iort_node_get_id() should return
> >the id value (through the id_out function parameter) and the IORT node
> >output_reference (through function return value) the given mapping entry
> >refers to.
> >
> >Technically output_reference values may differ for different map
> >entries, (see diagram below - mapped id values may refer to different eg
> >IORT SMMU nodes; the kernel may not be able to handle different
> >output_reference values for a given named component but the IORT kernel
> >layer should still report the IORT mappings as reported by firmware) but
> >current code in iort_node_get_id() fails to use the index function
> >parameter to return the correct output_reference value (ie it always
> >returns the output_reference value of the first entry in the mapping
> >array whilst using the index correctly to retrieve the id value from the
> >respective entry).
> >
> >	|----------------------|
> >	|     named component  |
> >	|----------------------|
> >	|      map entry[0]    |
> >	|----------------------|
> >	|       id value       |
> >	| output_reference----------------> eg SMMU 1
> >	|----------------------|
> >	|      map entry[1]    |
> >	|----------------------|
> >	|       id value       |
> >	| output_reference----------------> eg SMMU 2
> >	|----------------------|
> >		    .
> >		    .
> >		    .
> >	|----------------------|
> >	|      map entry[N]    |
> >	|----------------------|
> >	|       id value       |
> >	| output_reference----------------> eg SMMU 1
> >	|----------------------|
> >
> >Consequently the iort_node_get_id() function always returns the IORT
> >node pointed at by the output_reference value of the first named
> >component mapping array entry, irrespective of the index parameter,
> >which is a bug.
> >
> >Update the map array entry pointer computation in iort_node_get_id() to
> >take into account the index value, fixing the issue.
> >
> >Fixes: 618f535a6062 ("ACPI/IORT: Add single mapping function")
> >Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
> >Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> >Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> >Cc: Hanjun Guo <hanjun.guo@linaro.org>
> >Cc: Sinan Kaya <okaya@codeaurora.org>
> >Cc: Tomasz Nowicki <tn@semihalf.com>
> >Cc: Nate Watterson <nwatters@codeaurora.org>
> >Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> >---
> >v1 -> v2:
> >	- Updated/improved commit log
> >	- Added review tags
> 
> Forgot to mention that I tested this patch on Hisilicon
> D03,
> 
> Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
> 
> BTW, Lorenzo, Rafael, since it's a bugfix, can this be merged into
> 4.10-rc7?

Yes, I thought Rafael picked it up already (I can't see it in
patchwork any longer).

This one from Dan:

https://patchwork.kernel.org/patch/9521003/

should get in -rc7 too, we should have both fixes in before v4.10
is released.

Rafael can you send them both for -rc7 please ?

Thanks,
Lorenzo