Commit f0ea207e authored by Nicolin Chen's avatar Nicolin Chen Committed by Jason Gunthorpe
Browse files

iommu/arm-smmu-v3: Introduce struct arm_smmu_vmaster 

Use it to store all vSMMU-related data. The vsid (Virtual Stream ID) will
be the first use case. Since the vsid reader will be the eventq handler
that already holds a streams_mutex, reuse that to fence the vmaster too.

Also add a pair of arm_smmu_attach_prepare/commit_vmaster helpers to set
or unset the master->vmaster pointer. Put the helpers inside the existing
arm_smmu_attach_prepare/commit().

For identity/blocked ops that don't call arm_smmu_attach_prepare/commit(),
add a simpler arm_smmu_master_clear_vmaster helper to unset the vmaster.

Link: https://patch.msgid.link/r/a7f282e1a531279e25f06c651e95d56f6b120886.1741719725.git.nicolinc@nvidia.com


Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarPranjal Shrivastava <praan@google.com>
Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 2ec0458e

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

+41 −0
Original line number Diff line number Diff line
@@ -85,6 +85,47 @@ static void arm_smmu_make_nested_domain_ste( 
	}

}



int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,

				    struct arm_smmu_nested_domain *nested_domain)

{

	struct arm_smmu_vmaster *vmaster;

	unsigned long vsid;

	int ret;



	iommu_group_mutex_assert(state->master->dev);



	ret = iommufd_viommu_get_vdev_id(&nested_domain->vsmmu->core,

					 state->master->dev, &vsid);

	if (ret)

		return ret;



	vmaster = kzalloc(sizeof(*vmaster), GFP_KERNEL);

	if (!vmaster)

		return -ENOMEM;

	vmaster->vsmmu = nested_domain->vsmmu;

	vmaster->vsid = vsid;

	state->vmaster = vmaster;



	return 0;

}



void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state)

{

	struct arm_smmu_master *master = state->master;



	mutex_lock(&master->smmu->streams_mutex);

	kfree(master->vmaster);

	master->vmaster = state->vmaster;

	mutex_unlock(&master->smmu->streams_mutex);

}



void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master)

{

	struct arm_smmu_attach_state state = { .master = master };



	arm_smmu_attach_commit_vmaster(&state);

}



static int arm_smmu_attach_dev_nested(struct iommu_domain *domain,

				      struct device *dev)

{

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

+17 −1
Original line number Diff line number Diff line
@@ -2803,6 +2803,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, 
	struct arm_smmu_domain *smmu_domain =

		to_smmu_domain_devices(new_domain);

	unsigned long flags;

	int ret;



	/*

	 * arm_smmu_share_asid() must not see two domains pointing to the same
@@ -2832,9 +2833,18 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, 
	}



	if (smmu_domain) {

		if (new_domain->type == IOMMU_DOMAIN_NESTED) {

			ret = arm_smmu_attach_prepare_vmaster(

				state, to_smmu_nested_domain(new_domain));

			if (ret)

				return ret;

		}



		master_domain = kzalloc(sizeof(*master_domain), GFP_KERNEL);

		if (!master_domain)

		if (!master_domain) {

			kfree(state->vmaster);

			return -ENOMEM;

		}

		master_domain->master = master;

		master_domain->ssid = state->ssid;

		if (new_domain->type == IOMMU_DOMAIN_NESTED)
@@ -2861,6 +2871,7 @@ int arm_smmu_attach_prepare(struct arm_smmu_attach_state *state, 
			spin_unlock_irqrestore(&smmu_domain->devices_lock,

					       flags);

			kfree(master_domain);

			kfree(state->vmaster);

			return -EINVAL;

		}
@@ -2893,6 +2904,8 @@ void arm_smmu_attach_commit(struct arm_smmu_attach_state *state) 


	lockdep_assert_held(&arm_smmu_asid_lock);



	arm_smmu_attach_commit_vmaster(state);



	if (state->ats_enabled && !master->ats_enabled) {

		arm_smmu_enable_ats(master);

	} else if (state->ats_enabled && master->ats_enabled) {
@@ -3162,6 +3175,7 @@ static int arm_smmu_attach_dev_identity(struct iommu_domain *domain, 
	struct arm_smmu_ste ste;

	struct arm_smmu_master *master = dev_iommu_priv_get(dev);



	arm_smmu_master_clear_vmaster(master);

	arm_smmu_make_bypass_ste(master->smmu, &ste);

	arm_smmu_attach_dev_ste(domain, dev, &ste, STRTAB_STE_1_S1DSS_BYPASS);

	return 0;
@@ -3180,7 +3194,9 @@ static int arm_smmu_attach_dev_blocked(struct iommu_domain *domain, 
					struct device *dev)

{

	struct arm_smmu_ste ste;

	struct arm_smmu_master *master = dev_iommu_priv_get(dev);



	arm_smmu_master_clear_vmaster(master);

	arm_smmu_make_abort_ste(&ste);

	arm_smmu_attach_dev_ste(domain, dev, &ste,

				STRTAB_STE_1_S1DSS_TERMINATE);

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

+28 −0
Original line number Diff line number Diff line
@@ -799,6 +799,11 @@ struct arm_smmu_stream { 
	struct rb_node			node;

};



struct arm_smmu_vmaster {

	struct arm_vsmmu		*vsmmu;

	unsigned long			vsid;

};



struct arm_smmu_event {

	u8				stall : 1,

					ssv : 1,
@@ -824,6 +829,7 @@ struct arm_smmu_master { 
	struct arm_smmu_device		*smmu;

	struct device			*dev;

	struct arm_smmu_stream		*streams;

	struct arm_smmu_vmaster		*vmaster; /* use smmu->streams_mutex */

	/* Locked by the iommu core using the group mutex */

	struct arm_smmu_ctx_desc_cfg	cd_table;

	unsigned int			num_streams;
@@ -972,6 +978,7 @@ struct arm_smmu_attach_state { 
	bool disable_ats;

	ioasid_t ssid;

	/* Resulting state */

	struct arm_smmu_vmaster *vmaster;

	bool ats_enabled;

};
@@ -1055,9 +1062,30 @@ struct iommufd_viommu *arm_vsmmu_alloc(struct device *dev, 
				       struct iommu_domain *parent,

				       struct iommufd_ctx *ictx,

				       unsigned int viommu_type);

int arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,

				    struct arm_smmu_nested_domain *nested_domain);

void arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state);

void arm_smmu_master_clear_vmaster(struct arm_smmu_master *master);

#else

#define arm_smmu_hw_info NULL

#define arm_vsmmu_alloc NULL



static inline int

arm_smmu_attach_prepare_vmaster(struct arm_smmu_attach_state *state,

				struct arm_smmu_nested_domain *nested_domain)

{

	return 0;

}



static inline void

arm_smmu_attach_commit_vmaster(struct arm_smmu_attach_state *state)

{

}



static inline void

arm_smmu_master_clear_vmaster(struct arm_smmu_master *master)

{

}

#endif /* CONFIG_ARM_SMMU_V3_IOMMUFD */



#endif /* _ARM_SMMU_V3_H */