[PATCH V10 11/12] iommu/arm-smmu: Clean up early-probing workarounds

From: Sricharan R
Date: Tue Apr 04 2017 - 06:21:16 EST


From: Robin Murphy <robin.murphy@xxxxxxx>

Now that the appropriate ordering is enforced via probe-deferral of
masters in core code, rip it all out and bask in the simplicity.

Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
[Sricharan: Rebased on top of ACPI IORT SMMU series]
Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx>
---
drivers/iommu/arm-smmu-v3.c | 46 +-----------------
drivers/iommu/arm-smmu.c | 110 +++++++++++++++++++-------------------------
2 files changed, 49 insertions(+), 107 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 591bb96..4362139 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2761,51 +2761,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
.probe = arm_smmu_device_probe,
.remove = arm_smmu_device_remove,
};
+module_platform_driver(arm_smmu_driver);

-static int __init arm_smmu_init(void)
-{
- static bool registered;
- int ret = 0;
-
- if (!registered) {
- ret = platform_driver_register(&arm_smmu_driver);
- registered = !ret;
- }
- return ret;
-}
-
-static void __exit arm_smmu_exit(void)
-{
- return platform_driver_unregister(&arm_smmu_driver);
-}
-
-subsys_initcall(arm_smmu_init);
-module_exit(arm_smmu_exit);
-
-static int __init arm_smmu_of_init(struct device_node *np)
-{
- int ret = arm_smmu_init();
-
- if (ret)
- return ret;
-
- if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
- return -ENODEV;
-
- return 0;
-}
-IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
-
-#ifdef CONFIG_ACPI
-static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
-{
- if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
- return arm_smmu_init();
-
- return 0;
-}
-IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
-#endif
+IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);

MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
MODULE_AUTHOR("Will Deacon <will.deacon@xxxxxxx>");
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index b493c99..792fe7d 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -2075,6 +2075,23 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
return 0;
}

+static void arm_smmu_bus_init(void)
+{
+ /* Oh, for a proper bus abstraction */
+ if (!iommu_present(&platform_bus_type))
+ bus_set_iommu(&platform_bus_type, &arm_smmu_ops);
+#ifdef CONFIG_ARM_AMBA
+ if (!iommu_present(&amba_bustype))
+ bus_set_iommu(&amba_bustype, &arm_smmu_ops);
+#endif
+#ifdef CONFIG_PCI
+ if (!iommu_present(&pci_bus_type)) {
+ pci_request_acs();
+ bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
+ }
+#endif
+}
+
static int arm_smmu_device_probe(struct platform_device *pdev)
{
struct resource *res;
@@ -2180,21 +2197,30 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
arm_smmu_device_reset(smmu);
arm_smmu_test_smr_masks(smmu);

- /* Oh, for a proper bus abstraction */
- if (!iommu_present(&platform_bus_type))
- bus_set_iommu(&platform_bus_type, &arm_smmu_ops);
-#ifdef CONFIG_ARM_AMBA
- if (!iommu_present(&amba_bustype))
- bus_set_iommu(&amba_bustype, &arm_smmu_ops);
-#endif
-#ifdef CONFIG_PCI
- if (!iommu_present(&pci_bus_type)) {
- pci_request_acs();
- bus_set_iommu(&pci_bus_type, &arm_smmu_ops);
- }
-#endif
+ /*
+ * For ACPI and generic DT bindings, an SMMU will be probed before
+ * any device which might need it, so we want the bus ops in place
+ * ready to handle default domain setup as soon as any SMMU exists.
+ */
+ if (!using_legacy_binding)
+ arm_smmu_bus_init();
+
+ return 0;
+}
+
+/*
+ * With the legacy DT binding in play, though, we have no guarantees about
+ * probe order, but then we're also not doing default domains, so we can
+ * delay setting bus ops until we're sure every possible SMMU is ready,
+ * and that way ensure that no add_device() calls get missed.
+ */
+static int arm_smmu_legacy_bus_init(void)
+{
+ if (using_legacy_binding)
+ arm_smmu_bus_init();
return 0;
}
+device_initcall_sync(arm_smmu_legacy_bus_init);

static int arm_smmu_device_remove(struct platform_device *pdev)
{
@@ -2219,56 +2245,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
.probe = arm_smmu_device_probe,
.remove = arm_smmu_device_remove,
};
-
-static int __init arm_smmu_init(void)
-{
- static bool registered;
- int ret = 0;
-
- if (!registered) {
- ret = platform_driver_register(&arm_smmu_driver);
- registered = !ret;
- }
- return ret;
-}
-
-static void __exit arm_smmu_exit(void)
-{
- return platform_driver_unregister(&arm_smmu_driver);
-}
-
-subsys_initcall(arm_smmu_init);
-module_exit(arm_smmu_exit);
-
-static int __init arm_smmu_of_init(struct device_node *np)
-{
- int ret = arm_smmu_init();
-
- if (ret)
- return ret;
-
- if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
- return -ENODEV;
-
- return 0;
-}
-IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
-IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
-
-#ifdef CONFIG_ACPI
-static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
-{
- if (iort_node_match(ACPI_IORT_NODE_SMMU))
- return arm_smmu_init();
-
- return 0;
-}
-IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
-#endif
+module_platform_driver(arm_smmu_driver);
+
+IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
+IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
+IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
+IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
+IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
+IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);

MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
MODULE_AUTHOR("Will Deacon <will.deacon@xxxxxxx>");
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation