Re: [PATCH] iommu/arm-smmu: Report smmu type in dmesg

From: Aleksey Makarov
Date: Wed Mar 08 2017 - 10:25:38 EST




On 03/06/2017 02:58 PM, Robert Richter wrote:
The ARM SMMU detection especially depends from system firmware. For
better diagnostic, log the detected type in dmesg.

The smmu type's name is now stored in struct arm_smmu_type and ACPI
code is modified to use that struct too. Rename ARM_SMMU_MATCH_DATA()
macro to ARM_SMMU_TYPE() for better readability.

Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
---
drivers/iommu/arm-smmu.c | 61 ++++++++++++++++++++++++------------------------
1 file changed, 30 insertions(+), 31 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index abf6496843a6..5c793b3d3173 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -366,6 +366,7 @@ struct arm_smmu_device {
u32 options;
enum arm_smmu_arch_version version;
enum arm_smmu_implementation model;
+ const char *name;

u32 num_context_banks;
u32 num_s2_context_banks;
@@ -1955,19 +1956,20 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
return 0;
}

-struct arm_smmu_match_data {
+struct arm_smmu_type {
enum arm_smmu_arch_version version;
enum arm_smmu_implementation model;
+ const char *name;
};

-#define ARM_SMMU_MATCH_DATA(name, ver, imp) \
-static struct arm_smmu_match_data name = { .version = ver, .model = imp }
+#define ARM_SMMU_TYPE(var, ver, imp, _name) \
+static struct arm_smmu_type var = { .version = ver, .model = imp, .name = _name }

Can we infer the _name from the name of var?

#define ARM_SMMU_TYPE(var, ver, imp) \
static struct arm_smmu_type var = { .version = ver, .model = imp, .name = #var }

-ARM_SMMU_MATCH_DATA(smmu_generic_v1, ARM_SMMU_V1, GENERIC_SMMU);
-ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU);
-ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU);
-ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500);
-ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2);
+ARM_SMMU_TYPE(smmu_generic_v1, ARM_SMMU_V1, GENERIC_SMMU, "smmu-generic-v1");
+ARM_SMMU_TYPE(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU, "smmu-generic-v2");
+ARM_SMMU_TYPE(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU, "arm-mmu401");
+ARM_SMMU_TYPE(arm_mmu500, ARM_SMMU_V2, ARM_MMU500, "arm-mmu500");
+ARM_SMMU_TYPE(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2, "cavium-smmuv2");

So that this change will not be required?

Thank you
Aleksey Makarov

static const struct of_device_id arm_smmu_of_match[] = {
{ .compatible = "arm,smmu-v1", .data = &smmu_generic_v1 },
@@ -1981,29 +1983,19 @@ static const struct of_device_id arm_smmu_of_match[] = {
MODULE_DEVICE_TABLE(of, arm_smmu_of_match);

#ifdef CONFIG_ACPI
-static int acpi_smmu_get_data(u32 model, struct arm_smmu_device *smmu)
+static struct arm_smmu_type *acpi_smmu_get_type(u32 model)
{
- int ret = 0;
-
switch (model) {
case ACPI_IORT_SMMU_V1:
case ACPI_IORT_SMMU_CORELINK_MMU400:
- smmu->version = ARM_SMMU_V1;
- smmu->model = GENERIC_SMMU;
- break;
+ return &smmu_generic_v1;
case ACPI_IORT_SMMU_V2:
- smmu->version = ARM_SMMU_V2;
- smmu->model = GENERIC_SMMU;
- break;
+ return &smmu_generic_v2;
case ACPI_IORT_SMMU_CORELINK_MMU500:
- smmu->version = ARM_SMMU_V2;
- smmu->model = ARM_MMU500;
- break;
- default:
- ret = -ENODEV;
+ return &arm_mmu500;
}

- return ret;
+ return NULL;
}

static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
@@ -2013,14 +2005,18 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
struct acpi_iort_node *node =
*(struct acpi_iort_node **)dev_get_platdata(dev);
struct acpi_iort_smmu *iort_smmu;
- int ret;
+ struct arm_smmu_type *type;

/* Retrieve SMMU1/2 specific data */
iort_smmu = (struct acpi_iort_smmu *)node->node_data;

- ret = acpi_smmu_get_data(iort_smmu->model, smmu);
- if (ret < 0)
- return ret;
+ type = acpi_smmu_get_type(iort_smmu->model);
+ if (!type)
+ return -ENODEV;
+
+ smmu->version = type->version;
+ smmu->model = type->model;
+ smmu->name = type->name;

/* Ignore the configuration access interrupt */
smmu->num_global_irqs = 1;
@@ -2041,8 +2037,8 @@ static inline int arm_smmu_device_acpi_probe(struct platform_device *pdev,
static int arm_smmu_device_dt_probe(struct platform_device *pdev,
struct arm_smmu_device *smmu)
{
- const struct arm_smmu_match_data *data;
struct device *dev = &pdev->dev;
+ const struct arm_smmu_type *type;
bool legacy_binding;

if (of_property_read_u32(dev->of_node, "#global-interrupts",
@@ -2051,9 +2047,10 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
return -ENODEV;
}

- data = of_device_get_match_data(dev);
- smmu->version = data->version;
- smmu->model = data->model;
+ type = of_device_get_match_data(dev);
+ smmu->version = type->version;
+ smmu->model = type->model;
+ smmu->name = type->name;

parse_driver_options(smmu);

@@ -2098,6 +2095,8 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
if (err)
return err;

+ dev_notice(dev, "%s detected", smmu->name);
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ioaddr = res->start;
smmu->base = devm_ioremap_resource(dev, res);