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 04/15] iommu: Move bus setup to IOMMU device registration
Date: Tue, 5 Jul 2022 18:08:27 +0100 [thread overview]
Message-ID: <5b9b608af21b3c4353af042355973bac55397962.1657034828.git.robin.murphy@arm.com> (raw)
In-Reply-To: <cover.1657034827.git.robin.murphy@arm.com>
Move the bus setup to iommu_device_register(). This should allow
bus_iommu_probe() to be correctly replayed for multiple IOMMU instances,
and leaves bus_set_iommu() as a glorified no-op to be cleaned up next.
At this point we can also handle cleanup better than just rolling back
the most-recently-touched bus upon failure - which may release devices
owned by other already-registered instances, and still leave devices on
other buses with dangling pointers to the failed instance. Now it's easy
to clean up the exact footprint of a given instance, no more, no less.
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-By: Krishna Reddy <vdumpa@nvidia.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
v3: Have iommu_device_register() return -EBUSY for conflicting ops
rather than change that behaviour just yet.
drivers/iommu/iommu.c | 54 ++++++++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 24 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 514edc0eaa94..acb7b2ab0b79 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -180,6 +180,14 @@ static int __init iommu_subsys_init(void)
}
subsys_initcall(iommu_subsys_init);
+static int remove_iommu_group(struct device *dev, void *data)
+{
+ if (dev->iommu && dev->iommu->iommu_dev == data)
+ iommu_release_device(dev);
+
+ return 0;
+}
+
/**
* iommu_device_register() - Register an IOMMU hardware instance
* @iommu: IOMMU handle for the instance
@@ -202,12 +210,32 @@ int iommu_device_register(struct iommu_device *iommu,
spin_lock(&iommu_device_lock);
list_add_tail(&iommu->list, &iommu_device_list);
spin_unlock(&iommu_device_lock);
+
+ for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) {
+ struct bus_type *bus = iommu_buses[i];
+ int err;
+
+ if (bus->iommu_ops && bus->iommu_ops != ops) {
+ err = -EBUSY;
+ } else {
+ bus->iommu_ops = ops;
+ err = bus_iommu_probe(bus);
+ }
+ if (err) {
+ iommu_device_unregister(iommu);
+ return err;
+ }
+ }
+
return 0;
}
EXPORT_SYMBOL_GPL(iommu_device_register);
void iommu_device_unregister(struct iommu_device *iommu)
{
+ for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++)
+ bus_for_each_dev(iommu_buses[i], NULL, iommu, remove_iommu_group);
+
spin_lock(&iommu_device_lock);
list_del(&iommu->list);
spin_unlock(&iommu_device_lock);
@@ -1633,13 +1661,6 @@ static int probe_iommu_group(struct device *dev, void *data)
return ret;
}
-static int remove_iommu_group(struct device *dev, void *data)
-{
- iommu_release_device(dev);
-
- return 0;
-}
-
static int iommu_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
@@ -1828,27 +1849,12 @@ static int iommu_bus_init(struct bus_type *bus)
*/
int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
{
- int err;
-
- if (ops == NULL) {
- bus->iommu_ops = NULL;
- return 0;
- }
-
- if (bus->iommu_ops != NULL)
+ if (bus->iommu_ops && ops && bus->iommu_ops != ops)
return -EBUSY;
bus->iommu_ops = ops;
- /* Do IOMMU specific setup for this bus-type */
- err = bus_iommu_probe(bus);
- if (err) {
- /* Clean up */
- bus_for_each_dev(bus, NULL, NULL, remove_iommu_group);
- bus->iommu_ops = NULL;
- }
-
- return err;
+ return 0;
}
EXPORT_SYMBOL_GPL(bus_set_iommu);
--
2.36.1.dirty
next prev parent reply other threads:[~2022-07-05 17:08 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 17:08 [PATCH v3 00/15] iommu: Retire bus_set_iommu() Robin Murphy
2022-07-05 17:08 ` [PATCH v3 01/15] iommu/vt-d: Handle race between registration and device probe Robin Murphy
2022-07-06 1:39 ` Baolu Lu
2022-07-07 6:51 ` Tian, Kevin
2022-07-08 7:52 ` Baolu Lu
2022-07-15 12:37 ` Robin Murphy
2022-07-19 0:06 ` Lu Baolu
2022-07-05 17:08 ` [PATCH v3 02/15] iommu/amd: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 03/15] iommu: Always register bus notifiers Robin Murphy
2022-07-06 1:53 ` Baolu Lu
2022-07-06 13:43 ` Robin Murphy
2022-07-07 0:20 ` Baolu Lu
2022-07-07 6:34 ` Tian, Kevin
2022-07-07 9:38 ` Robin Murphy
2022-07-07 6:31 ` Tian, Kevin
2022-07-07 9:58 ` Robin Murphy
2022-07-08 5:50 ` Tian, Kevin
2022-07-05 17:08 ` Robin Murphy [this message]
2022-07-06 2:35 ` [PATCH v3 04/15] iommu: Move bus setup to IOMMU device registration Baolu Lu
2022-07-06 14:37 ` Robin Murphy
2022-07-07 1:19 ` Baolu Lu
2022-07-07 6:51 ` Tian, Kevin
2022-07-07 10:58 ` Robin Murphy
2022-07-08 5:52 ` Tian, Kevin
2022-07-05 17:08 ` [PATCH v3 05/15] iommu/amd: Clean up bus_set_iommu() Robin Murphy
2022-07-05 17:08 ` [PATCH v3 06/15] iommu/arm-smmu: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 07/15] iommu/arm-smmu-v3: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 08/15] iommu/dart: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 09/15] iommu/exynos: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 10/15] iommu/ipmmu-vmsa: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 11/15] iommu/mtk: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 12/15] iommu/omap: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 13/15] iommu/tegra-smmu: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 14/15] iommu/virtio: " Robin Murphy
2022-07-05 17:08 ` [PATCH v3 15/15] iommu: " Robin Murphy
2022-07-07 7:45 ` Tian, Kevin
2022-07-07 12:49 ` Matthew Rosato
2022-07-07 12:54 ` Matthew Rosato
2022-07-07 14:58 ` Robin Murphy
2022-07-07 16:42 ` Matthew Rosato
2022-07-08 8:14 ` [PATCH] iommu/s390: fail probe for non-pci device Niklas Schnelle
2022-07-08 8:17 ` [PATCH v3 00/15] iommu: Retire bus_set_iommu() Niklas Schnelle
2022-07-15 13:12 ` Robin Murphy
2022-07-21 7:17 ` Tian, Kevin
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