[PATCH v3 06/15] iommu/arm-smmu: Clean up bus_set_iommu()

Robin Murphy
2022-07-05T17:08:58Z

Stop calling bus_set_iommu() since it's now unnecessary. With device
probes now replayed for every IOMMU instance registration, the whole
sorry ordering workaround for legacy DT bindings goes too, hooray!

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

v3: No change

drivers/iommu/arm/arm-smmu/arm-smmu.c | 84 +--------------------------
1 file changed, 2 insertions(+), 82 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 2ed3594f384e..83c9f2144541 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -37,7 +37,6 @@
#include <linux/ratelimit.h>
#include <linux/slab.h>

-#include <linux/amba/bus.h>
#include <linux/fsl/mc.h>

#include "arm-smmu.h"
@@ -93,8 +92,6 @@ static struct platform_driver arm_smmu_driver;
static struct iommu_ops arm_smmu_ops;

#ifdef CONFIG_ARM_SMMU_LEGACY_DT_BINDINGS
-static int arm_smmu_bus_init(struct iommu_ops *ops);
-
static struct device_node *dev_get_dev_node(struct device *dev)
{
if (dev_is_pci(dev)) {
@@ -180,20 +177,6 @@ static int arm_smmu_register_legacy_master(struct device *dev,
kfree(sids);
return err;
}
-
-/*
- * With the legacy DT binding in play, 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 probe_device() calls get missed.
- */
-static int arm_smmu_legacy_bus_init(void)
-{
- if (using_legacy_binding)
- return arm_smmu_bus_init(&arm_smmu_ops);
- return 0;
-}
-device_initcall_sync(arm_smmu_legacy_bus_init);
#else
static int arm_smmu_register_legacy_master(struct device *dev,
struct arm_smmu_device **smmu)
@@ -2025,52 +2008,6 @@ static int arm_smmu_device_dt_probe(struct arm_smmu_device *smmu,
return 0;
}

-static int arm_smmu_bus_init(struct iommu_ops *ops)
-{
- int err;
-
- /* Oh, for a proper bus abstraction */
- if (!iommu_present(&platform_bus_type)) {
- err = bus_set_iommu(&platform_bus_type, ops);
- if (err)
- return err;
- }
-#ifdef CONFIG_ARM_AMBA
- if (!iommu_present(&amba_bustype)) {
- err = bus_set_iommu(&amba_bustype, ops);
- if (err)
- goto err_reset_platform_ops;
- }
-#endif
-#ifdef CONFIG_PCI
- if (!iommu_present(&pci_bus_type)) {
- err = bus_set_iommu(&pci_bus_type, ops);
- if (err)
- goto err_reset_amba_ops;
- }
-#endif
-#ifdef CONFIG_FSL_MC_BUS
- if (!iommu_present(&fsl_mc_bus_type)) {
- err = bus_set_iommu(&fsl_mc_bus_type, ops);
- if (err)
- goto err_reset_pci_ops;
- }
-#endif
- return 0;
-
-err_reset_pci_ops: __maybe_unused;
-#ifdef CONFIG_PCI
- bus_set_iommu(&pci_bus_type, NULL);
-#endif
-err_reset_amba_ops: __maybe_unused;
-#ifdef CONFIG_ARM_AMBA
- bus_set_iommu(&amba_bustype, NULL);
-#endif
-err_reset_platform_ops: __maybe_unused;
- bus_set_iommu(&platform_bus_type, NULL);
- return err;
-}
-
static int arm_smmu_device_probe(struct platform_device *pdev)
{
struct resource *res;
@@ -2187,7 +2124,8 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
err = iommu_device_register(&smmu->iommu, &arm_smmu_ops, dev);
if (err) {
dev_err(dev, "Failed to register iommu\n");
- goto err_sysfs_remove;
+ iommu_device_sysfs_remove(&smmu->iommu);
+ return err;
}

platform_set_drvdata(pdev, smmu);
@@ -2205,24 +2143,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
pm_runtime_enable(dev);
}

- /*
- * 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) {
- err = arm_smmu_bus_init(&arm_smmu_ops);
- if (err)
- goto err_unregister_device;
- }
-
return 0;
-
-err_unregister_device:
- iommu_device_unregister(&smmu->iommu);
-err_sysfs_remove:
- iommu_device_sysfs_remove(&smmu->iommu);
- return err;
}

static int arm_smmu_device_remove(struct platform_device *pdev)
@@ -2235,7 +2156,6 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
if (!bitmap_empty(smmu->context_map, ARM_SMMU_MAX_CBS))
dev_notice(&pdev->dev, "disabling translation\n");

- arm_smmu_bus_init(NULL);
iommu_device_unregister(&smmu->iommu);
iommu_device_sysfs_remove(&smmu->iommu);

--
2.36.1.dirty