diff mbox series

[v2,31/60,SRU,OEM-5.6] iommu: Export bus_iommu_probe() and make is safe for re-probing

Message ID 20200602074421.1742802-32-vicamo.yang@canonical.com
State New
Headers show
Series Fix can't find root device on VMD when secureboot enabled | expand

Commit Message

You-Sheng Yang June 2, 2020, 7:43 a.m. UTC 
From: Joerg Roedel <jroedel@suse.de>

BugLink: https://bugs.launchpad.net/bugs/1876707

Add a check to the bus_iommu_probe() call-path to make sure it ignores
devices which have already been successfully probed. Then export the
bus_iommu_probe() function so it can be used by IOMMU drivers.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20200429133712.31431-14-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
(cherry picked from commit 5012c3968537e2ffecbdb2eba3479bf9fb9e5597
linux-next)
Signed-off-by: You-Sheng Yang <vicamo.yang@canonical.com>
---
 drivers/iommu/iommu.c | 10 +++++++++-
 include/linux/iommu.h |  1 +
 2 files changed, 10 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6c03bd0e77c0..45507260d5c7 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1620,11 +1620,19 @@  static int probe_iommu_group(struct device *dev, void *data)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 	struct list_head *group_list = data;
+	struct iommu_group *group;
 	int ret;
 
 	if (!dev_iommu_get(dev))
 		return -ENOMEM;
 
+	/* Device is probed already if in a group */
+	group = iommu_group_get(dev);
+	if (group) {
+		iommu_group_put(group);
+		return 0;
+	}
+
 	if (!try_module_get(ops->owner)) {
 		ret = -EINVAL;
 		goto err_free_dev_iommu;
@@ -1793,7 +1801,7 @@  static int iommu_group_create_direct_mappings(struct iommu_group *group)
 					  iommu_do_create_direct_mappings);
 }
 
-static int bus_iommu_probe(struct bus_type *bus)
+int bus_iommu_probe(struct bus_type *bus)
 {
 	const struct iommu_ops *ops = bus->iommu_ops;
 	int ret;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 30170d191e5e..fea1622408ad 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -445,6 +445,7 @@  static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather)
 #define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER	6 /* Post Driver unbind */
 
 extern int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops);
+extern int bus_iommu_probe(struct bus_type *bus);
 extern bool iommu_present(struct bus_type *bus);
 extern bool iommu_capable(struct bus_type *bus, enum iommu_cap cap);
 extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);