Re: [PATCH v2 4/8] iommu/arm-smmu-v3: Keep track in the arm_smmu_invs if RIL is used

[Mostafa Saleh <smostafa@google.com>]

On Mon, Jul 06, 2026 at 01:26:41PM -0300, Jason Gunthorpe wrote:
> Summarize if any of the inv entries will use RIL. The next patch will use
> this to avoid RIL pre-calculations unless RIL is being used by the
> invalidation.
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Mostafa Saleh <smostafa@google.com>

Thanks,
Mostafa

> ---
>  .../iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c  | 30 +++++++++----------
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 18 ++++++++---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  2 ++
>  3 files changed, 31 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c
> index add671363c828c..785dd21bd68b7a 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c
> @@ -655,37 +655,37 @@ static void arm_smmu_v3_invs_test_verify(struct kunit *test,
>  
>  static struct arm_smmu_invs invs1 = {
>  	.num_invs = 3,
> -	.inv = { { .type = INV_TYPE_S2_VMID, .id = 1, },
> -		 { .type = INV_TYPE_S2_VMID_S1_CLEAR, .id = 1, },
> -		 { .type = INV_TYPE_ATS, .id = 3, }, },
> +	.inv = { { .smmu = &smmu, .type = INV_TYPE_S2_VMID, .id = 1, },
> +		 { .smmu = &smmu, .type = INV_TYPE_S2_VMID_S1_CLEAR, .id = 1, },
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 3, }, },
>  };
>  
>  static struct arm_smmu_invs invs2 = {
>  	.num_invs = 3,
> -	.inv = { { .type = INV_TYPE_S2_VMID, .id = 1, }, /* duplicated */
> -		 { .type = INV_TYPE_ATS, .id = 4, },
> -		 { .type = INV_TYPE_ATS, .id = 5, }, },
> +	.inv = { { .smmu = &smmu, .type = INV_TYPE_S2_VMID, .id = 1, }, /* duplicated */
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 4, },
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 5, }, },
>  };
>  
>  static struct arm_smmu_invs invs3 = {
>  	.num_invs = 3,
> -	.inv = { { .type = INV_TYPE_S2_VMID, .id = 1, }, /* duplicated */
> -		 { .type = INV_TYPE_ATS, .id = 5, }, /* recover a trash */
> -		 { .type = INV_TYPE_ATS, .id = 6, }, },
> +	.inv = { { .smmu = &smmu, .type = INV_TYPE_S2_VMID, .id = 1, }, /* duplicated */
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 5, }, /* recover a trash */
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 6, }, },
>  };
>  
>  static struct arm_smmu_invs invs4 = {
>  	.num_invs = 3,
> -	.inv = { { .type = INV_TYPE_ATS, .id = 10, .ssid = 1 },
> -		 { .type = INV_TYPE_ATS, .id = 10, .ssid = 3 },
> -		 { .type = INV_TYPE_ATS, .id = 12, .ssid = 1 }, },
> +	.inv = { { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 10, .ssid = 1 },
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 10, .ssid = 3 },
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 12, .ssid = 1 }, },
>  };
>  
>  static struct arm_smmu_invs invs5 = {
>  	.num_invs = 3,
> -	.inv = { { .type = INV_TYPE_ATS, .id = 10, .ssid = 2 },
> -		 { .type = INV_TYPE_ATS, .id = 10, .ssid = 3 }, /* duplicate */
> -		 { .type = INV_TYPE_ATS, .id = 12, .ssid = 2 }, },
> +	.inv = { { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 10, .ssid = 2 },
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 10, .ssid = 3 }, /* duplicate */
> +		 { .smmu = &smmu, .type = INV_TYPE_ATS, .id = 12, .ssid = 2 }, },
>  };
>  
>  static void arm_smmu_v3_invs_test(struct kunit *test)
> 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 1ad642e09eb92d..02323fd7709f07 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -988,6 +988,18 @@ static inline int arm_smmu_invs_iter_next_cmp(struct arm_smmu_invs *invs_l,
>  	return arm_smmu_inv_cmp(cur_l, &invs_r->inv[next_r]);
>  }
>  
> +static void arm_smmu_invs_update_caps(struct arm_smmu_invs *invs,
> +				      const struct arm_smmu_inv *inv)
> +{
> +	if (arm_smmu_inv_is_ats(inv))
> +		invs->has_ats = true;
> +
> +	if (!(inv->smmu->features & ARM_SMMU_FEAT_RANGE_INV))
> +		return;
> +
> +	invs->has_range_inv = true;
> +}
> +
>  /**
>   * arm_smmu_invs_for_each_cmp - Iterate over two sorted arrays computing for
>   *                              arm_smmu_invs_merge() or arm_smmu_invs_unref()
> @@ -1058,8 +1070,7 @@ struct arm_smmu_invs *arm_smmu_invs_merge(struct arm_smmu_invs *invs,
>  		 */
>  		if (new != new_invs->inv)
>  			WARN_ON_ONCE(arm_smmu_inv_cmp(new - 1, new) == 1);
> -		if (arm_smmu_inv_is_ats(new))
> -			new_invs->has_ats = true;
> +		arm_smmu_invs_update_caps(new_invs, new);
>  		new++;
>  	}
>  
> @@ -1169,8 +1180,7 @@ struct arm_smmu_invs *arm_smmu_invs_purge(struct arm_smmu_invs *invs)
>  
>  	arm_smmu_invs_for_each_entry(invs, i, inv) {
>  		new_invs->inv[num_invs] = *inv;
> -		if (arm_smmu_inv_is_ats(inv))
> -			new_invs->has_ats = true;
> +		arm_smmu_invs_update_caps(new_invs, inv);
>  		num_invs++;
>  	}
>  
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index 2fc695817671fe..3ef55f8af63d90 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -755,6 +755,7 @@ static inline bool arm_smmu_inv_is_ats(const struct arm_smmu_inv *inv)
>   *               Must not be greater than @num_invs
>   * @rwlock: optional rwlock to fence ATS operations
>   * @has_ats: flag if the array contains an INV_TYPE_ATS or INV_TYPE_ATS_FULL
> + * @has_range_inv: flag if any entry's SMMU supports range invalidation
>   * @rcu: rcu head for kfree_rcu()
>   * @inv: flexible invalidation array
>   *
> @@ -784,6 +785,7 @@ struct arm_smmu_invs {
>  	size_t num_trashes;
>  	rwlock_t rwlock;
>  	bool has_ats;
> +	bool has_range_inv;
>  	struct rcu_head rcu;
>  	struct arm_smmu_inv inv[] __counted_by(max_invs);
>  };
> -- 
> 2.43.0
>