[PATCH v3 06/23] iommufd/driver: Add iommufd_struct_destroy to revert iommufd_viommu_alloc
From: Nicolin Chen <hidden>
Date: 2025-05-01 23:02:04
Also in:
linux-doc, linux-iommu, linux-kselftest, linux-patches, linux-tegra, lkml
Subsystem:
iommu subsystem, iommufd, the rest · Maintainers:
Joerg Roedel, Will Deacon, Jason Gunthorpe, Kevin Tian, Linus Torvalds
An IOMMU driver that allocated a vIOMMU may want to revert the allocation,
if it encounters an internal error after the allocation. So, there needs a
destroy helper for drivers to use. For instance:
static my_viommu_alloc()
{
...
my_viommu = iommufd_viommu_alloc(viomm, struct my_viommu, core);
...
ret = init_my_viommu();
if (ret) {
/* Need to destroy the my_viommu->core */
return ERR_PTR(ret);
}
return &my_viommu->core;
}
Move iommufd_object_abort() to the driver.c file and the public header, to
introduce common iommufd_struct_destroy() helper that will abort all kinds
of driver structures, not confined to iommufd_viommu but also the new ones
being added in the future.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Nicolin Chen <redacted>
---
drivers/iommu/iommufd/iommufd_private.h | 1 -
include/linux/iommufd.h | 16 ++++++++++++++++
drivers/iommu/iommufd/driver.c | 14 ++++++++++++++
drivers/iommu/iommufd/main.c | 13 -------------
4 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 5c69ac05c029..8d96aa514033 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h@@ -180,7 +180,6 @@ static inline void iommufd_put_object(struct iommufd_ctx *ictx, wake_up_interruptible_all(&ictx->destroy_wait); } -void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj); void iommufd_object_abort_and_destroy(struct iommufd_ctx *ictx, struct iommufd_object *obj); void iommufd_object_finalize(struct iommufd_ctx *ictx,
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index dc6535e848df..f6f333eaaae3 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h@@ -213,6 +213,7 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx) struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size, enum iommufd_object_type type); +void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj); struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id); int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu,
@@ -228,6 +229,11 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size, return ERR_PTR(-EOPNOTSUPP); } +static inline void iommufd_object_abort(struct iommufd_ctx *ictx, + struct iommufd_object *obj) +{ +} + static inline struct device * iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id) {
@@ -285,4 +291,14 @@ static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu, } \ ret; \ }) + +/* Helper for IOMMU driver to destroy structures created by allocators above */ +#define iommufd_struct_destroy(drv_struct, member) \ + ({ \ + static_assert(__same_type(struct iommufd_object, \ + drv_struct->member.obj)); \ + static_assert(offsetof(typeof(*drv_struct), member.obj) == 0); \ + iommufd_object_abort(drv_struct->member.ictx, \ + &drv_struct->member.obj); \ + }) #endif
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
index 922cd1fe7ec2..7980a09761c2 100644
--- a/drivers/iommu/iommufd/driver.c
+++ b/drivers/iommu/iommufd/driver.c@@ -36,6 +36,20 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, } EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, "IOMMUFD"); +/* Undo _iommufd_object_alloc() if iommufd_object_finalize() was not called */ +void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj) +{ + XA_STATE(xas, &ictx->objects, obj->id); + void *old; + + xa_lock(&ictx->objects); + old = xas_store(&xas, NULL); + xa_unlock(&ictx->objects); + WARN_ON(old != XA_ZERO_ENTRY); + kfree(obj); +} +EXPORT_SYMBOL_NS_GPL(iommufd_object_abort, "IOMMUFD"); + /* Caller should xa_lock(&viommu->vdevs) to protect the return value */ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id)
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 3df468f64e7d..2b9ee9b4a424 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c@@ -51,19 +51,6 @@ void iommufd_object_finalize(struct iommufd_ctx *ictx, WARN_ON(old != XA_ZERO_ENTRY); } -/* Undo _iommufd_object_alloc() if iommufd_object_finalize() was not called */ -void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj) -{ - XA_STATE(xas, &ictx->objects, obj->id); - void *old; - - xa_lock(&ictx->objects); - old = xas_store(&xas, NULL); - xa_unlock(&ictx->objects); - WARN_ON(old != XA_ZERO_ENTRY); - kfree(obj); -} - /* * Abort an object that has been fully initialized and needs destroy, but has * not been finalized.
--
2.43.0