Hi Hanjun,
On Wed, Sep 27, 2017 at 09:20:14AM +0800, Hanjun Guo wrote:
> IORT revision C introduced SMMUv3 MSI support which adding a
> device ID mapping index in SMMUv3 sub table, to get the SMMUv3
> device ID mapping for the output ID (dev ID for ITS) and the
> link to which ITS.
>
> So if a platform supports SMMUv3 MSI for control interrupt,
> there will be a additional single map entry under SMMU, this
> will not introduce any difference for devices just use one
> step map to get its output ID and parent (ITS or SMMU), such
> as PCI/NC/PMCG ---> ITS or PCI/NC ---> SMMU, but we need to
> do the special handling for two steps map case such as
> PCI/NC--->SMMUv3--->ITS.
>
> Take a PCI hostbridge for example,
>
> |----------------------|
> | Root Complex Node |
> |----------------------|
> | map entry[x] |
> |----------------------|
> | id value |
> | output_reference |
> |---|------------------|
> |
> | |----------------------|
> |-->| SMMUv3 |
> |----------------------|
> | SMMU dev ID |
> | mapping index 0 |
> |----------------------|
> | map entry[0] |
> |----------------------|
> | id value |
> | output_reference-----------> ITS 1 (SMMU MSI domain)
> |----------------------|
> | map entry[1] |
> |----------------------|
> | id value |
> | output_reference-----------> ITS 2 (PCI MSI domain)
> |----------------------|
>
> When the SMMU dev ID mapping index is 0, there is entry[0]
> to map to a ITS, we need to skip that map entry for PCI
> or NC (named component), or we may get the wrong ITS parent.
Is this actually true ? I think that currently we would simply skip
the entry and print an error log but we can't get a wrong ITS parent.
I am rewriting this commit (I will probably split it), it is doing the
right thing but the commit log is stale (probably caused by code
reshuffling).
Thanks,
Lorenzo
> Introduce iort_get_id_mapping_index() to get the index then
> skip the map entry in iort_node_map_id(), also to get the
> dev ID directly for iort_pmsi_get_dev_id() for ITS platform
> MSI preparation.
>
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> ---
> drivers/acpi/arm64/iort.c | 64 +++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 59 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index db71d7f..1c1160e 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -357,7 +357,8 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>
> if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> - node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> + node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX ||
> + node->type == ACPI_IORT_NODE_SMMU_V3) {
> *id_out = map->output_base;
> return parent;
> }
> @@ -366,6 +367,40 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
> return NULL;
> }
>
> +static int iort_get_id_mapping_index(struct acpi_iort_node *node)
> +{
> + struct acpi_iort_smmu_v3 *smmu;
> +
> + switch (node->type) {
> + case ACPI_IORT_NODE_SMMU_V3:
> + /*
> + * SMMUv3 dev ID mapping index was introdueced in revision 1
> + * table, not available in revision 0
> + */
> + if (node->revision < 1)
> + return -EINVAL;
> +
> + smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
> + /*
> + * ID mapping index is only ignored if all interrupts are
> + * GSIV based
> + */
> + if (smmu->event_gsiv && smmu->pri_gsiv && smmu->gerr_gsiv
> + && smmu->sync_gsiv)
> + return -EINVAL;
> +
> + if (smmu->id_mapping_index >= node->mapping_count) {
> + pr_err(FW_BUG "[node %p type %d] ID mapping index overflows valid mappings\n",
> + node, node->type);
> + return -EINVAL;
> + }
> +
> + return smmu->id_mapping_index;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static struct acpi_iort_node *iort_node_map_id(struct acpi_iort_node *node,
> u32 id_in, u32 *id_out,
> u8 type_mask)
> @@ -375,7 +410,7 @@ static struct acpi_iort_node *iort_node_map_id(struct acpi_iort_node *node,
> /* Parse the ID mapping tree to find specified node type */
> while (node) {
> struct acpi_iort_id_mapping *map;
> - int i;
> + int i, index;
>
> if (IORT_TYPE_MASK(node->type) & type_mask) {
> if (id_out)
> @@ -396,8 +431,19 @@ static struct acpi_iort_node *iort_node_map_id(struct acpi_iort_node *node,
> goto fail_map;
> }
>
> + /*
> + * we need to get SMMUv3 dev ID mapping index and skip its
> + * associated ID map for single mapping cases, error value
> + * returned for index will be an invalid value in practical.
> + */
> + index = iort_get_id_mapping_index(node);
> +
> /* Do the ID translation */
> for (i = 0; i < node->mapping_count; i++, map++) {
> + /* if it's a SMMUv3 device id mapping index, skip it */
> + if (i == index)
> + continue;
> +
> if (!iort_id_map(map, node->type, id, &id))
> break;
> }
> @@ -507,16 +553,24 @@ u32 iort_msi_map_rid(struct device *dev, u32 req_id)
> */
> int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> {
> - int i;
> + int i, index;
> struct acpi_iort_node *node;
>
> node = iort_find_dev_node(dev);
> if (!node)
> return -ENODEV;
>
> - for (i = 0; i < node->mapping_count; i++) {
> - if (iort_node_map_platform_id(node, dev_id, IORT_MSI_TYPE, i))
> + index = iort_get_id_mapping_index(node);
> + /* if there is a valid index, go get the dev_id directly */
> + if (index >= 0) {
> + if (iort_node_get_id(node, dev_id, index))
> return 0;
> + } else {
> + for (i = 0; i < node->mapping_count; i++) {
> + if (iort_node_map_platform_id(node, dev_id,
> + IORT_MSI_TYPE, i))
> + return 0;
> + }
> }
>
> return -ENODEV;
> --
> 1.9.1
>
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