[PATCH v2 3/7] iommufd/device: Make iommufd_device_is_attached non-static

Nicolin Chen
2025-10-15T00:31:24Z

A new SET_OPTION will reuse this helper for a sanity check before setting
a per-idev property.

Given that the attach handle can be NULL if device is not attached, add a
pointer check prior to the xa_load(). This is not a problem currently, as
the only caller iommufd_device_do_replace() verifies the attach handle.

Also, add lockdep_assert_held on igroup's mutex;

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/iommufd/iommufd_private.h | 1 +
drivers/iommu/iommufd/device.c | 7 ++++---
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index cc758610b9f7c..c458ab16736b6 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -502,6 +502,7 @@ iommufd_get_device(struct iommufd_ucmd *ucmd, u32 id)

void iommufd_device_pre_destroy(struct iommufd_object *obj);
void iommufd_device_destroy(struct iommufd_object *obj);
+bool iommufd_device_is_attached(struct iommufd_device *idev, ioasid_t pasid);
int iommufd_get_hw_info(struct iommufd_ucmd *ucmd);

struct iommufd_access {
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 2a816533dc10e..45a1d1603c009 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -436,13 +436,14 @@ iommufd_device_attach_reserved_iova(struct iommufd_device *idev,

/* The device attach/detach/replace helpers for attach_handle */

-static bool iommufd_device_is_attached(struct iommufd_device *idev,
- ioasid_t pasid)
+bool iommufd_device_is_attached(struct iommufd_device *idev, ioasid_t pasid)
{
struct iommufd_attach *attach;

+ lockdep_assert_held(&idev->igroup->lock);
+
attach = xa_load(&idev->igroup->pasid_attach, pasid);
- return xa_load(&attach->device_array, idev->obj.id);
+ return attach && xa_load(&attach->device_array, idev->obj.id);
}

static int iommufd_hwpt_pasid_compat(struct iommufd_hw_pagetable *hwpt,
--
2.43.0