Messages in this thread Patch in this message | | | From | Robin Murphy <> | Subject | [PATCH 6/8] iommu: Retire bus ops | Date | Thu, 19 Jan 2023 19:18:24 +0000 |
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With the rest of the API internals converted, it's time to finally tackle probe_device and how we bootstrap the per-device ops association to begin with. This ends up being disappointingly straightforward, since fwspec users are already doing it in order to find their of_xlate callback, and it works out that we can easily do the equivalent for other drivers too. Then shuffle the remaining awareness of iommu_ops into the couple of core headers that still need it, and breathe a sigh of relief...
Ding dong the bus ops are gone!
CC: Rafael J. Wysocki <rafael.j.wysocki@intel.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Christoph Hellwig <hch@lst.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/iommu/iommu.c | 27 ++++++++++++++++----------- include/acpi/acpi_bus.h | 2 ++ include/linux/device.h | 1 - include/linux/device/bus.h | 5 ----- include/linux/dma-map-ops.h | 1 + 5 files changed, 19 insertions(+), 17 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 1a31d94adff5..8997b8f2e79f 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -218,13 +218,6 @@ int iommu_device_register(struct iommu_device *iommu, /* We need to be able to take module references appropriately */ if (WARN_ON(is_module_address((unsigned long)ops) && !ops->owner)) return -EINVAL; - /* - * Temporarily enforce global restriction to a single driver. This was - * already the de-facto behaviour, since any possible combination of - * existing drivers would compete for at least the PCI or platform bus. - */ - if (iommu_buses[0]->iommu_ops && iommu_buses[0]->iommu_ops != ops) - return -EBUSY; iommu->ops = ops; if (hwdev) @@ -234,10 +227,8 @@ int iommu_device_register(struct iommu_device *iommu, list_add_tail(&iommu->list, &iommu_device_list); spin_unlock(&iommu_device_lock); - for (int i = 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) { - iommu_buses[i]->iommu_ops = ops; + for (int i = 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) err = bus_iommu_probe(iommu_buses[i]); - } if (err) iommu_device_unregister(iommu); return err; @@ -303,12 +294,26 @@ static u32 dev_iommu_get_max_pasids(struct device *dev) static int __iommu_probe_device(struct device *dev, struct list_head *group_list) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + const struct iommu_ops *ops; struct iommu_device *iommu_dev; + struct iommu_fwspec *fwspec; struct iommu_group *group; static DEFINE_MUTEX(iommu_probe_device_lock); int ret; + /* + * For FDT-based systems and ACPI IORT/VIOT, drivers register IOMMU + * instances with non-NULL fwnodes, and client devices should have been + * identified with a fwspec by this point. For Intel/AMD/s390/PAMU we + * can assume a single active driver with global ops, and so grab those + * from any registered instance, cheekily co-opting the same mechanism. + */ + fwspec = dev_iommu_fwspec_get(dev); + if (fwspec && fwspec->ops) + ops = fwspec->ops; + else + ops = iommu_ops_from_fwnode(NULL); + if (!ops) return -ENODEV; /* diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index cd3b75e08ec3..067dde9291c9 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -614,6 +614,8 @@ struct acpi_pci_root { /* helper */ +struct iommu_ops; + bool acpi_dma_supported(const struct acpi_device *adev); enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev); int acpi_iommu_fwspec_init(struct device *dev, u32 id, diff --git a/include/linux/device.h b/include/linux/device.h index 44e3acae7b36..f7a7ecafedd3 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -41,7 +41,6 @@ struct class; struct subsys_private; struct device_node; struct fwnode_handle; -struct iommu_ops; struct iommu_group; struct dev_pin_info; struct dev_iommu; diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index d8b29ccd07e5..4ece3470112f 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -63,9 +63,6 @@ struct fwnode_handle; * this bus. * @pm: Power management operations of this bus, callback the specific * device driver's pm-ops. - * @iommu_ops: IOMMU specific operations for this bus, used to attach IOMMU - * driver implementations to a bus and allow the driver to do - * bus-specific setup * @p: The private data of the driver core, only the driver core can * touch this. * @lock_key: Lock class key for use by the lock validator @@ -109,8 +106,6 @@ struct bus_type { const struct dev_pm_ops *pm; - const struct iommu_ops *iommu_ops; - struct subsys_private *p; struct lock_class_key lock_key; diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index d678afeb8a13..e8ebf0bf611b 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -10,6 +10,7 @@ #include <linux/pgtable.h> struct cma; +struct iommu_ops; /* * Values for struct dma_map_ops.flags: -- 2.36.1.dirty
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