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authorJason Gunthorpe <jgg@nvidia.com>2023-08-22 13:15:57 -0300
committerJoerg Roedel <jroedel@suse.de>2023-09-25 11:45:29 +0200
commite8f52d84cf0b6d1862ab62f7ed705f78690d11b2 (patch)
tree5fba4306a231fc6d6a49f3f22aee870098d3085b /drivers
parente946f8e3e62bf05da21a14658f8cb05e2a616260 (diff)
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iommu: Add generic_single_device_group()
This implements the common pattern seen in drivers of a single iommu_group for the entire iommu driver instance. Implement this in core code so the drivers that want this can select it from their ops. Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/2-v1-c869a95191f2+5e8-iommu_single_grp_jgg@nvidia.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/iommu.c28
1 files changed, 27 insertions, 1 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6483d6e19a5e..03202314322b 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -292,6 +292,10 @@ void iommu_device_unregister(struct iommu_device *iommu)
spin_lock(&iommu_device_lock);
list_del(&iommu->list);
spin_unlock(&iommu_device_lock);
+
+ /* Pairs with the alloc in generic_single_device_group() */
+ iommu_group_put(iommu->singleton_group);
+ iommu->singleton_group = NULL;
}
EXPORT_SYMBOL_GPL(iommu_device_unregister);
@@ -406,6 +410,7 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops)
ret = PTR_ERR(iommu_dev);
goto err_module_put;
}
+ dev->iommu->iommu_dev = iommu_dev;
ret = iommu_device_link(iommu_dev, dev);
if (ret)
@@ -420,7 +425,6 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops)
}
dev->iommu_group = group;
- dev->iommu->iommu_dev = iommu_dev;
dev->iommu->max_pasids = dev_iommu_get_max_pasids(dev);
if (ops->is_attach_deferred)
dev->iommu->attach_deferred = ops->is_attach_deferred(dev);
@@ -434,6 +438,7 @@ err_release:
err_module_put:
module_put(ops->owner);
err_free:
+ dev->iommu->iommu_dev = NULL;
dev_iommu_free(dev);
return ret;
}
@@ -1638,6 +1643,27 @@ struct iommu_group *generic_device_group(struct device *dev)
EXPORT_SYMBOL_GPL(generic_device_group);
/*
+ * Generic device_group call-back function. It just allocates one
+ * iommu-group per iommu driver instance shared by every device
+ * probed by that iommu driver.
+ */
+struct iommu_group *generic_single_device_group(struct device *dev)
+{
+ struct iommu_device *iommu = dev->iommu->iommu_dev;
+
+ if (!iommu->singleton_group) {
+ struct iommu_group *group;
+
+ group = iommu_group_alloc();
+ if (IS_ERR(group))
+ return group;
+ iommu->singleton_group = group;
+ }
+ return iommu_group_ref_get(iommu->singleton_group);
+}
+EXPORT_SYMBOL_GPL(generic_single_device_group);
+
+/*
* Use standard PCI bus topology, isolation features, and DMA alias quirks
* to find or create an IOMMU group for a device.
*/