From: Jason Gunthorpe jgg@nvidia.com
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.
Tested-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 24 +++++++-------------- 1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 9ee8f6f420c1..723d41ae8105 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2896,6 +2896,7 @@ 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; @@ -2924,6 +2925,12 @@ 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. @@ -2943,13 +2950,6 @@ 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, @@ -2966,16 +2966,8 @@ 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_init(&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,