Extract all common procedure, between the iommufd_access_attach() API and the new iommufd_access_replace() API, to an iommufd_access_change_pt() helper.
Add iommufd_access_replace() function for VFIO emulated pathway to use.
Suggested-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Kevin Tian kevin.tian@intel.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- drivers/iommu/iommufd/device.c | 53 ++++++++++++++++++++++++++-------- include/linux/iommufd.h | 1 + 2 files changed, 42 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 989bd485f92f..051bd8e99858 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -769,38 +769,67 @@ void iommufd_access_detach(struct iommufd_access *access) } EXPORT_SYMBOL_NS_GPL(iommufd_access_detach, IOMMUFD);
-int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id) +static int iommufd_access_change_pt(struct iommufd_access *access, u32 ioas_id) { struct iommufd_ioas *new_ioas; - int rc = 0; + int rc;
- mutex_lock(&access->ioas_lock); - if (access->ioas) { - mutex_unlock(&access->ioas_lock); - return -EINVAL; - } + lockdep_assert_held(&access->ioas_lock);
new_ioas = iommufd_get_ioas(access->ictx, ioas_id); - if (IS_ERR(new_ioas)) { - mutex_unlock(&access->ioas_lock); + if (IS_ERR(new_ioas)) return PTR_ERR(new_ioas); - }
rc = iopt_add_access(&new_ioas->iopt, access); if (rc) { - mutex_unlock(&access->ioas_lock); iommufd_put_object(&new_ioas->obj); return rc; } iommufd_ref_to_users(&new_ioas->obj);
+ if (access->ioas) + __iommufd_access_detach(access); access->ioas = new_ioas; access->ioas_unpin = new_ioas; - mutex_unlock(&access->ioas_lock); return 0; } + +int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id) +{ + int rc; + + mutex_lock(&access->ioas_lock); + if (access->ioas) { + mutex_unlock(&access->ioas_lock); + return -EINVAL; + } + + rc = iommufd_access_change_pt(access, ioas_id); + mutex_unlock(&access->ioas_lock); + return rc; +} EXPORT_SYMBOL_NS_GPL(iommufd_access_attach, IOMMUFD);
+int iommufd_access_replace(struct iommufd_access *access, u32 ioas_id) +{ + int rc; + + mutex_lock(&access->ioas_lock); + if (!access->ioas) { + mutex_unlock(&access->ioas_lock); + return -ENOENT; + } + if (access->ioas->obj.id == ioas_id) { + mutex_unlock(&access->ioas_lock); + return 0; + } + + rc = iommufd_access_change_pt(access, ioas_id); + mutex_unlock(&access->ioas_lock); + return rc; +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_replace, IOMMUFD); + /** * iommufd_access_notify_unmap - Notify users of an iopt to stop using it * @iopt: iopt to work on diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index d25fbd3a80b1..ea3e704dde8d 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -48,6 +48,7 @@ iommufd_access_create(struct iommufd_ctx *ictx, const struct iommufd_access_ops *ops, void *data, u32 *id); void iommufd_access_destroy(struct iommufd_access *access); int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id); +int iommufd_access_replace(struct iommufd_access *access, u32 ioas_id); void iommufd_access_detach(struct iommufd_access *access);
struct iommufd_ctx *iommufd_access_to_ictx(struct iommufd_access *access);