Re: [RFC PATCH 4/4] ACPI: IORT: Add SMMUv3 MSI support

Lorenzo Pieralisi
2017-08-15T17:15:30Z

On Fri, Aug 11, 2017 at 09:56:31PM +0800, Hanjun Guo wrote:
> Hi Lorenzo,
>
> On 11 August 2017 at 17:33, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote:
> > On Wed, Aug 09, 2017 at 06:53:37PM +0800, Hanjun Guo wrote:
> >> From: Hanjun Guo <hanjun.guo@linaro.org>
> >>
> >> Since we have a mapping index for SMMUv3 MSI, we can
> >> directly use that index to get the map entry, then
> >> retrieve dev ID and ITS parent to add SMMUv3 MSI
> >> support.
> >>
> >> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> >> ---
> >> drivers/acpi/arm64/iort.c | 46 ++++++++++++++++++++++++++++++++++++----------
> >> 1 file changed, 36 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> >> index 9439f02..ce03298 100644
> >> --- a/drivers/acpi/arm64/iort.c
> >> +++ b/drivers/acpi/arm64/iort.c
> >> @@ -313,7 +313,8 @@ static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
> >> /* Single mapping does not care for input id */
> >> if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> >> if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> >> - type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> >> + type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX ||
> >> + type == ACPI_IORT_NODE_SMMU_V3) {
> >> *rid_out = map->output_base;
> >> return 0;
> >> }
> >> @@ -357,7 +358,8 @@ 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;
> >> }
> >> @@ -549,9 +551,21 @@ int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> >> 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))
> >> + if (node->type == ACPI_IORT_NODE_SMMU_V3) {
> >> + u32 index;
> >> +
> >> + if (iort_get_smmu_v3_id_mapping_index(node, &index))
> >> + return -ENODEV;
> >> +
> >> + if (iort_node_map_platform_id(node, dev_id, IORT_MSI_TYPE,
> >> + 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;
> >> @@ -626,20 +640,30 @@ static struct irq_domain *iort_get_platform_device_domain(struct device *dev)
> >> struct acpi_iort_node *node, *msi_parent;
> >> struct fwnode_handle *iort_fwnode;
> >> struct acpi_iort_its_group *its;
> >> - int i;
> >>
> >> /* find its associated iort node */
> >> - node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> >> - iort_match_node_callback, dev);
> >> + node = iort_find_dev_node(dev);
> >> if (!node)
> >> return NULL;
> >>
> >> /* then find its msi parent node */
> >> - for (i = 0; i < node->mapping_count; i++) {
> >> + if (node->type == ACPI_IORT_NODE_SMMU_V3) {
> >> + u32 index;
> >> +
> >> + if (iort_get_smmu_v3_id_mapping_index(node, &index))
> >> + return NULL;
> >> +
> >> msi_parent = iort_node_map_platform_id(node, NULL,
> >> + IORT_MSI_TYPE, index);
> >> + } else {
> >> + int i;
> >> +
> >> + for (i = 0; i < node->mapping_count; i++) {
> >> + msi_parent = iort_node_map_platform_id(node, NULL,
> >> IORT_MSI_TYPE, i);
> >> - if (msi_parent)
> >> - break;
> >> + if (msi_parent)
> >> + break;
> >> + }
> >> }
> >>
> >> if (!msi_parent)
> >> @@ -1233,6 +1257,8 @@ static int __init iort_add_smmu_platform_device(struct acpi_iort_node *node)
> >> /* Configure DMA for the page table walker */
> >> acpi_dma_configure(&pdev->dev, attr);
> >>
> >> + acpi_configure_pmsi_domain(&pdev->dev);
> >
> > I think this is just overkill. There are two separate things to solve
> > here:
> >
> > 1) Make single mappings valid for SMMUv3 (and PMCG); that's fair enough
> > and goes with the logic to skip the ITS DeviceID index for "normal"
> > mappings, I can live with that
> > 2) Find the MSI domain for an SMMUv3 (or any other IORT table node); I
> > do not think you need all this complexity to do it via
> > acpi_configure_pmsi_domain(), it can be done in a easier way with
> > an ad-hoc stub (it does not even have to be SMMUv3 specific)
> >
> > My worry is that we are peppering the generic IORT mapping code with
> > node types specific kludges and it is becoming a mess.
>
> Agreed.
>
> >
> > I can rework the patch to show you what I have in mind, please let
> > me know.
>
> Please, thank you very much for doing so.

Here, untested just to get your opinion, please let me know.

Thanks,
Lorenzo

-- >8 --
Subject: [PATCH 4/4] ACPI/IORT: IORT nodes MSI handling

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
drivers/acpi/arm64/iort.c | 76 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 63 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 24678c3..21a0aab 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -366,7 +366,7 @@ struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
return NULL;
}

-static int iort_get_smmu_v3_id_mapping_index(struct acpi_iort_node *node,
+static int iort_get_id_mapping_index(struct acpi_iort_node *node,
u32 *index)
{
struct acpi_iort_smmu_v3 *smmu;
@@ -378,20 +378,25 @@ static int iort_get_smmu_v3_id_mapping_index(struct acpi_iort_node *node,
if (node->revision < 1)
return -EINVAL;

- smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
- /* if any of the gsi for control interrupts is not 0, ignore the MSI */
- if (smmu->event_gsiv || smmu->pri_gsiv || smmu->gerr_gsiv
- || smmu->sync_gsiv)
- return -EINVAL;
+ switch (node->type) {
+ case ACPI_IORT_NODE_SMMU_V3:
+ smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
+ /* if any of the gsi for control interrupts is not 0, ignore the MSI */
+ 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;
+ }

- 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);
+ *index = smmu->id_mapping_index;
+ return 0;
+ default:
return -EINVAL;
}
-
- *index = smmu->id_mapping_index;
- return 0;
}

static struct acpi_iort_node *iort_node_map_id(struct acpi_iort_node *node,
@@ -431,7 +436,7 @@ static struct acpi_iort_node *iort_node_map_id(struct acpi_iort_node *node,
* associated ID map for single mapping cases.
*/
if (node->type == ACPI_IORT_NODE_SMMU_V3)
- ret = iort_get_smmu_v3_id_mapping_index(node, &index);
+ ret = iort_get_id_mapping_index(node, &index);

/* Do the ID translation */
for (i = 0; i < node->mapping_count; i++, map++) {
@@ -620,6 +625,49 @@ struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id)
return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
}

+static void iort_set_device_domain(struct device *dev,
+ struct acpi_iort_node *node)
+{
+ struct acpi_iort_its_group *its;
+ struct acpi_iort_node *msi_parent;
+ struct acpi_iort_id_mapping *map;
+ struct fwnode_handle *iort_fwnode;
+ struct irq_domain *domain;
+ int ret, index;
+
+ ret = iort_get_id_mapping_index(node, &index);
+ if (ret < 0)
+ return;
+
+ map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+ node->mapping_offset + index * sizeof(*map));
+
+ /* Firmware bug! */
+ if (!map->output_reference ||
+ !(map->flags & ACPI_IORT_ID_SINGLE_MAPPING)) {
+ pr_err(FW_BUG "[node %p type %d] Invalid MSI mapping\n",
+ node, node->type);
+ return;
+ }
+
+ msi_parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+ map->output_reference);
+
+ if (!msi_parent || msi_parent->type != ACPI_IORT_NODE_ITS_GROUP)
+ return;
+
+ /* Move to ITS specific data */
+ its = (struct acpi_iort_its_group *)msi_parent->node_data;
+
+ iort_fwnode = iort_find_domain_token(its->identifiers[0]);
+ if (!iort_fwnode)
+ return;
+
+ domain = irq_find_matching_fwnode(iort_fwnode, DOMAIN_BUS_PLATFORM_MSI);
+ if (domain)
+ dev_set_msi_domain(dev, domain);
+}
+
/**
* iort_get_platform_device_domain() - Find MSI domain related to a
* platform device
@@ -1159,6 +1207,8 @@ static int __init iort_add_smmu_platform_device(struct acpi_iort_node *node)
/* Configure DMA for the page table walker */
acpi_dma_configure(&pdev->dev, attr);

+ iort_set_device_domain(&pdev->dev, node);
+
ret = platform_device_add(pdev);
if (ret)
goto dma_deconfigure;
--
2.10.0