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authorWill Deacon <will@kernel.org>2019-12-19 12:03:42 +0000
committerJoerg Roedel <jroedel@suse.de>2019-12-23 14:06:05 +0100
commit386dce2788eef626aaaa6a3ca32809ea7904581b (patch)
treedce51da68a4423561611270829eacf67e7ac4c09
parent25f003de987aed630db265ceae9cd978537a3f80 (diff)
iommu/of: Take a ref to the IOMMU driver during ->of_xlate()
Ensure that we hold a reference to the IOMMU driver module while calling the '->of_xlate()' callback during early device probing. Signed-off-by: Will Deacon <will@kernel.org> Tested-by: John Garry <john.garry@huawei.com> # smmu v3 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--drivers/iommu/of_iommu.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 4d2f02132e7a..e7bc8b721947 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -8,11 +8,12 @@
#include <linux/export.h>
#include <linux/iommu.h>
#include <linux/limits.h>
-#include <linux/pci.h>
+#include <linux/module.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
#include <linux/of_pci.h>
+#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/fsl/mc.h>
@@ -91,16 +92,16 @@ static int of_iommu_xlate(struct device *dev,
{
const struct iommu_ops *ops;
struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
- int err;
+ int ret;
ops = iommu_ops_from_fwnode(fwnode);
if ((ops && !ops->of_xlate) ||
!of_device_is_available(iommu_spec->np))
return NO_IOMMU;
- err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
- if (err)
- return err;
+ ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
+ if (ret)
+ return ret;
/*
* The otherwise-empty fwspec handily serves to indicate the specific
* IOMMU device we're waiting for, which will be useful if we ever get
@@ -109,7 +110,12 @@ static int of_iommu_xlate(struct device *dev,
if (!ops)
return driver_deferred_probe_check_state(dev);
- return ops->of_xlate(dev, iommu_spec);
+ if (!try_module_get(ops->owner))
+ return -ENODEV;
+
+ ret = ops->of_xlate(dev, iommu_spec);
+ module_put(ops->owner);
+ return ret;
}
struct of_pci_iommu_alias_info {