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From:   Robin Murphy <robin.murphy@arm.com>
To:     joro@8bytes.org
Cc:     will@kernel.org, iommu@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, baolu.lu@linux.intel.com,
        suravee.suthikulpanit@amd.com, vasant.hegde@amd.com,
        mjrosato@linux.ibm.com, gerald.schaefer@linux.ibm.com,
        schnelle@linux.ibm.com, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v3 15/15] iommu: Clean up bus_set_iommu()
Date:   Tue,  5 Jul 2022 18:08:38 +0100
Message-Id: <dc44a2269276e1d0fa6715d4530a51df4e7b781c.1657034828.git.robin.murphy@arm.com>
In-Reply-To: <cover.1657034827.git.robin.murphy@arm.com>
References: <cover.1657034827.git.robin.murphy@arm.com>
MIME-Version: 1.0
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Precedence: bulk

Clean up the remaining trivial bus_set_iommu() callsites along
with the implementation. Now drivers only have to know and care
about iommu_device instances, phew!

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

v3: Also catch Intel's cheeky open-coded assignment

 drivers/iommu/arm/arm-smmu/qcom_iommu.c |  4 ----
 drivers/iommu/fsl_pamu_domain.c         |  4 ----
 drivers/iommu/intel/iommu.c             |  2 --
 drivers/iommu/iommu.c                   | 24 ------------------------
 drivers/iommu/msm_iommu.c               |  2 --
 drivers/iommu/rockchip-iommu.c          |  2 --
 drivers/iommu/s390-iommu.c              |  6 ------
 drivers/iommu/sprd-iommu.c              |  5 -----
 drivers/iommu/sun50i-iommu.c            |  2 --
 include/linux/iommu.h                   |  1 -
 10 files changed, 52 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index 4c077c38fbd6..80af00f468b4 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -845,8 +845,6 @@ static int qcom_iommu_device_probe(struct platform_device *pdev)
 		goto err_pm_disable;
 	}
 
-	bus_set_iommu(&platform_bus_type, &qcom_iommu_ops);
-
 	if (qcom_iommu->local_base) {
 		pm_runtime_get_sync(dev);
 		writel_relaxed(0xffffffff, qcom_iommu->local_base + SMMU_INTR_SEL_NS);
@@ -864,8 +862,6 @@ static int qcom_iommu_device_remove(struct platform_device *pdev)
 {
 	struct qcom_iommu_dev *qcom_iommu = platform_get_drvdata(pdev);
 
-	bus_set_iommu(&platform_bus_type, NULL);
-
 	pm_runtime_force_suspend(&pdev->dev);
 	platform_set_drvdata(pdev, NULL);
 	iommu_device_sysfs_remove(&qcom_iommu->iommu);
diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 94b4589dc67c..09aa90c27723 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -481,11 +481,7 @@ int __init pamu_domain_init(void)
 	if (ret) {
 		iommu_device_sysfs_remove(&pamu_iommu);
 		pr_err("Can't register iommu device\n");
-		return ret;
 	}
 
-	bus_set_iommu(&platform_bus_type, &fsl_pamu_ops);
-	bus_set_iommu(&pci_bus_type, &fsl_pamu_ops);
-
 	return ret;
 }
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 3e02c08802a0..388dd0e22fb9 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4031,7 +4031,6 @@ static int __init probe_acpi_namespace_devices(void)
 					continue;
 				}
 
-				pn->dev->bus->iommu_ops = &intel_iommu_ops;
 				ret = iommu_probe_device(pn->dev);
 				if (ret)
 					break;
@@ -4153,7 +4152,6 @@ int __init intel_iommu_init(void)
 	}
 	up_read(&dmar_global_lock);
 
-	bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
 	if (si_domain && !hw_pass_through)
 		register_memory_notifier(&intel_iommu_memory_nb);
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index acb7b2ab0b79..c10ecb87fd9c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1834,30 +1834,6 @@ static int iommu_bus_init(struct bus_type *bus)
 	return err;
 }
 
-/**
- * bus_set_iommu - set iommu-callbacks for the bus
- * @bus: bus.
- * @ops: the callbacks provided by the iommu-driver
- *
- * This function is called by an iommu driver to set the iommu methods
- * used for a particular bus. Drivers for devices on that bus can use
- * the iommu-api after these ops are registered.
- * This special function is needed because IOMMUs are usually devices on
- * the bus itself, so the iommu drivers are not initialized when the bus
- * is set up. With this function the iommu-driver can set the iommu-ops
- * afterwards.
- */
-int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
-{
-	if (bus->iommu_ops && ops && bus->iommu_ops != ops)
-		return -EBUSY;
-
-	bus->iommu_ops = ops;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(bus_set_iommu);
-
 bool iommu_present(struct bus_type *bus)
 {
 	return bus->iommu_ops != NULL;
diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index f09aedfdd462..4a71989406dc 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -797,8 +797,6 @@ static int msm_iommu_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
-	bus_set_iommu(&platform_bus_type, &msm_iommu_ops);
-
 	pr_info("device mapped at %p, irq %d with %d ctx banks\n",
 		iommu->base, iommu->irq, iommu->ncb);
 
diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index ab57c4b8fade..a3fc59b814ab 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -1300,8 +1300,6 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	if (!dma_dev)
 		dma_dev = &pdev->dev;
 
-	bus_set_iommu(&platform_bus_type, &rk_iommu_ops);
-
 	pm_runtime_enable(dev);
 
 	for (i = 0; i < iommu->num_irq; i++) {
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index c898bcbbce11..dd957145fb81 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -385,9 +385,3 @@ static const struct iommu_ops s390_iommu_ops = {
 		.free		= s390_domain_free,
 	}
 };
-
-static int __init s390_iommu_init(void)
-{
-	return bus_set_iommu(&pci_bus_type, &s390_iommu_ops);
-}
-subsys_initcall(s390_iommu_init);
diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c
index bd409bab6286..6770e6a72283 100644
--- a/drivers/iommu/sprd-iommu.c
+++ b/drivers/iommu/sprd-iommu.c
@@ -507,9 +507,6 @@ static int sprd_iommu_probe(struct platform_device *pdev)
 	if (ret)
 		goto remove_sysfs;
 
-	if (!iommu_present(&platform_bus_type))
-		bus_set_iommu(&platform_bus_type, &sprd_iommu_ops);
-
 	ret = sprd_iommu_clk_enable(sdev);
 	if (ret)
 		goto unregister_iommu;
@@ -545,8 +542,6 @@ static int sprd_iommu_remove(struct platform_device *pdev)
 	iommu_group_put(sdev->group);
 	sdev->group = NULL;
 
-	bus_set_iommu(&platform_bus_type, NULL);
-
 	platform_set_drvdata(pdev, NULL);
 	iommu_device_sysfs_remove(&sdev->iommu);
 	iommu_device_unregister(&sdev->iommu);
diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
index c54ab477b8fd..e104543b78d9 100644
--- a/drivers/iommu/sun50i-iommu.c
+++ b/drivers/iommu/sun50i-iommu.c
@@ -968,8 +968,6 @@ static int sun50i_iommu_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto err_unregister;
 
-	bus_set_iommu(&platform_bus_type, &sun50i_iommu_ops);
-
 	return 0;
 
 err_unregister:
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 5e1afe169549..2cb05ff89f03 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -412,7 +412,6 @@ static inline const struct iommu_ops *dev_iommu_ops(struct device *dev)
 	return dev->iommu->iommu_dev->ops;
 }
 
-extern int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops);
 extern int bus_iommu_probe(struct bus_type *bus);
 extern bool iommu_present(struct bus_type *bus);
 extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
-- 
2.36.1.dirty