@@ -2596,6 +2596,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
struct arm_smmu_device *smmu;
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
struct arm_smmu_master *master;
+ struct arm_smmu_cd *cdptr;
if (!fwspec)
return -ENOENT;
@@ -2624,6 +2625,12 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
if (ret)
return ret;
+ if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
+ cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
+ if (!cdptr)
+ return -ENOMEM;
+ }
+
/*
* Prevent arm_smmu_share_asid() from trying to change the ASID
* of either the old or new domain while we are working on it.
@@ -2643,13 +2650,6 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
switch (smmu_domain->stage) {
case ARM_SMMU_DOMAIN_S1: {
struct arm_smmu_cd target_cd;
- struct arm_smmu_cd *cdptr;
-
- cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
- if (!cdptr) {
- ret = -ENOMEM;
- goto out_list_del;
- }
arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
@@ -2666,16 +2666,8 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
}
arm_smmu_enable_ats(master, smmu_domain);
- goto out_unlock;
-
-out_list_del:
- spin_lock_irqsave(&smmu_domain->devices_lock, flags);
- list_del(&master->domain_head);
- spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
-
-out_unlock:
mutex_unlock(&arm_smmu_asid_lock);
- return ret;
+ return 0;
}
static int arm_smmu_attach_dev_ste(struct device *dev,
Avoid arm_smmu_attach_dev() having to undo the changes to the smmu_domain->devices list, acquire the cdptr earlier so we don't need to handle that error. Now there is a clear break in arm_smmu_attach_dev() where all the prep-work has been done non-disruptively and we commit to making the HW change, which cannot fail. This completes transforming arm_smmu_attach_dev() so that it does not disturb the HW if it fails. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 24 +++++++-------------- 1 file changed, 8 insertions(+), 16 deletions(-)