lkml.org 
[lkml]   [2019]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v4 06/16] iommu/of: Take a ref to the IOMMU driver during ->of_xlate()
Date
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>
---
drivers/iommu/of_iommu.c | 18 ++++++++++++------
1 file 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 {
--
2.24.1.735.g03f4e72817-goog
\
 
 \ /
  Last update: 2019-12-19 13:04    [W:0.177 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site