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 <[email protected]>
> Reviewed-by: Hanjun Guo <[email protected]>
> Signed-off-by: Lorenzo Pieralisi <[email protected]>
> Cc: Hanjun Guo <[email protected]>
> Cc: Sinan Kaya <[email protected]>
> Cc: Tomasz Nowicki <[email protected]>
> Cc: Nate Watterson <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
> ---
> 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 <[email protected]>
--
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.
