Re: [PATCH v3 1/3] acpi: arm64: add iort support for PMCG

From: Robin Murphy
Date: Thu Oct 04 2018 - 13:35:25 EST


On 04/10/18 17:43, Lorenzo Pieralisi wrote:
On Fri, Sep 21, 2018 at 04:08:01PM +0100, Shameer Kolothum wrote:
From: Neil Leeder <nleeder@xxxxxxxxxxxxxx>

Add support for the SMMU Performance Monitor Counter Group
information from ACPI. This is in preparation for its use
in the SMMUv3 PMU driver.

Signed-off-by: Neil Leeder <nleeder@xxxxxxxxxxxxxx>
Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/acpi/arm64/iort.c | 78 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 66 insertions(+), 12 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 08f26db..b979c86 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -356,7 +356,8 @@ static 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_SMMU_V3) {
+ node->type == ACPI_IORT_NODE_SMMU_V3 ||
+ node->type == ACPI_IORT_NODE_PMCG) {
*id_out = map->output_base;
return parent;
}
@@ -394,6 +395,8 @@ static int iort_get_id_mapping_index(struct acpi_iort_node *node)
}
return smmu->id_mapping_index;
+ case ACPI_IORT_NODE_PMCG:
+ return 0;
default:
return -EINVAL;
}
@@ -1309,6 +1312,50 @@ static bool __init arm_smmu_is_coherent(struct acpi_iort_node *node)
return smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK;
}
+static void __init arm_smmu_common_dma_configure(struct device *dev,
+ enum dev_dma_attr attr)
+{
+ /* We expect the dma masks to be equivalent for all SMMUs set-ups */
+ dev->dma_mask = &dev->coherent_dma_mask;
+
+ /* Configure DMA for the page table walker */
+ acpi_dma_configure(dev, attr);
+}

It looks like we can't get rid of this acpi_dma_configure() call
given that the platform device we create has no ACPI companion
(and I am not looking forward to fabricating one to make the
code homogeneous :)).

Yeah, given that this is essentially only for SMMUs, the alternatives all end up looking like too much bother to be worthwhile.

Still, having two methods per IORT node type (dev_is_coherent() and
dev_dma_configure()) does not make much sense, we can merge it into one
I think.

Good point - looks the attr from dev_is_coherent is only ever passed through dev_dma_configure, so we may as well just have per-SMMU-type dev_dma_configure methods which retrieve their own relevant coherency directly. FWIW, on v2 I was tempted to suggest just wrapping the DMA setup in "if (node->type != ACPI_IORT_NODE_PMCG)..." rather than messing with more callbacks, but that clearly wouldn't fit well with the local style here.

Robin.


Thanks,
Lorenzo

+static int __init arm_smmu_v3_pmcg_count_resources(struct acpi_iort_node *node)
+{
+ struct acpi_iort_pmcg *pmcg;
+
+ /* Retrieve PMCG specific data */
+ pmcg = (struct acpi_iort_pmcg *)node->node_data;
+
+ /*
+ * There are always 2 memory resources.
+ * If the overflow_gsiv is present then add that for a total of 3.
+ */
+ return pmcg->overflow_gsiv ? 3 : 2;
+}
+
+static void __init arm_smmu_v3_pmcg_init_resources(struct resource *res,
+ struct acpi_iort_node *node)
+{
+ struct acpi_iort_pmcg *pmcg;
+
+ /* Retrieve PMCG specific data */
+ pmcg = (struct acpi_iort_pmcg *)node->node_data;
+
+ res[0].start = pmcg->page0_base_address;
+ res[0].end = pmcg->page0_base_address + SZ_4K - 1;
+ res[0].flags = IORESOURCE_MEM;
+ res[1].start = pmcg->page1_base_address;
+ res[1].end = pmcg->page1_base_address + SZ_4K - 1;
+ res[1].flags = IORESOURCE_MEM;
+
+ if (pmcg->overflow_gsiv)
+ acpi_iort_register_irq(pmcg->overflow_gsiv, "overflow",
+ ACPI_EDGE_SENSITIVE, &res[2]);
+}
+
struct iort_dev_config {
const char *name;
int (*dev_init)(struct acpi_iort_node *node);
@@ -1318,6 +1365,8 @@ struct iort_dev_config {
struct acpi_iort_node *node);
void (*dev_set_proximity)(struct device *dev,
struct acpi_iort_node *node);
+ void (*dev_dma_configure)(struct device *dev,
+ enum dev_dma_attr attr);
};
static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {
@@ -1326,23 +1375,34 @@ static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {
.dev_count_resources = arm_smmu_v3_count_resources,
.dev_init_resources = arm_smmu_v3_init_resources,
.dev_set_proximity = arm_smmu_v3_set_proximity,
+ .dev_dma_configure = arm_smmu_common_dma_configure,
};
static const struct iort_dev_config iort_arm_smmu_cfg __initconst = {
.name = "arm-smmu",
.dev_is_coherent = arm_smmu_is_coherent,
.dev_count_resources = arm_smmu_count_resources,
- .dev_init_resources = arm_smmu_init_resources
+ .dev_init_resources = arm_smmu_init_resources,
+ .dev_dma_configure = arm_smmu_common_dma_configure,
+};
+
+static const struct iort_dev_config iort_arm_smmu_v3_pmcg_cfg __initconst = {
+ .name = "arm-smmu-v3-pmu",
+ .dev_count_resources = arm_smmu_v3_pmcg_count_resources,
+ .dev_init_resources = arm_smmu_v3_pmcg_init_resources,
};
static __init const struct iort_dev_config *iort_get_dev_cfg(
struct acpi_iort_node *node)
{
+
switch (node->type) {
case ACPI_IORT_NODE_SMMU_V3:
return &iort_arm_smmu_v3_cfg;
case ACPI_IORT_NODE_SMMU:
return &iort_arm_smmu_cfg;
+ case ACPI_IORT_NODE_PMCG:
+ return &iort_arm_smmu_v3_pmcg_cfg;
default:
return NULL;
}
@@ -1398,12 +1458,6 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,
if (ret)
goto dev_put;
- /*
- * We expect the dma masks to be equivalent for
- * all SMMUs set-ups
- */
- pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
-
fwnode = iort_get_fwnode(node);
if (!fwnode) {
@@ -1413,11 +1467,11 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,
pdev->dev.fwnode = fwnode;
- attr = ops->dev_is_coherent && ops->dev_is_coherent(node) ?
+ if (ops->dev_dma_configure) {
+ attr = ops->dev_is_coherent && ops->dev_is_coherent(node) ?
DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
-
- /* Configure DMA for the page table walker */
- acpi_dma_configure(&pdev->dev, attr);
+ ops->dev_dma_configure(&pdev->dev, attr);
+ }
iort_set_device_domain(&pdev->dev, node);
--
2.7.4