Commit 13abe4fa authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Will Deacon
Browse files

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: default avatarNicolin Chen <nicolinc@nvidia.com>
Tested-by: default avatarShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: default avatarMichael Shavit <mshavit@google.com>
Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarMostafa Saleh <smostafa@google.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/6-v9-5040dc602008+177d7-smmuv3_newapi_p2_jgg@nvidia.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent b2f4c0fc

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

+8 −16
Original line number Diff line number Diff line
@@ -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,