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authorJason Gunthorpe <jgg@nvidia.com>2024-04-30 20:21:38 +0300
committerWill Deacon <will@kernel.org>2024-05-01 17:33:52 +0300
commit13abe4faac4348da0cf1c4eeb2b1b39fcfdb4b8f (patch)
tree969421f373e3c5fde3c7eaa0b9e3208c4c412be9
parentb2f4c0fcf094dacd2d1fb96a6fd6598919501589 (diff)
downloadlinux-13abe4faac4348da0cf1c4eeb2b1b39fcfdb4b8f.tar.xz
iommu/arm-smmu-v3: Allocate the CD table entry in advance
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> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Michael Shavit <mshavit@google.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reviewed-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/6-v9-5040dc602008+177d7-smmuv3_newapi_p2_jgg@nvidia.com Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r--drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c24
1 files 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 6d04b742a0e0..d7d532c571ad 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2635,6 +2635,7 @@ 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;
@@ -2663,6 +2664,12 @@ 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_alloc_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.
@@ -2682,13 +2689,6 @@ 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_alloc_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,
@@ -2705,16 +2705,8 @@ 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,