Re: [PATCH v5 9/9] iommu/arm-smmu-v3: Support the DS expansion of RIL's SCALE
From: Mostafa Saleh <smostafa@google.com>
Date: 2026-09-07 14:44:38
Also in:
linux-arm-kernel, linux-iommu, linux-patches, stable
On Tue, Sep 01, 2026 at 02:49:58PM -0300, Jason Gunthorpe wrote:
If DS is supported then SCALE can go up to 39. Compute a scale max that is compatible for the entire invs list.
I see in some places scale is still assumed to 32 as in: - arm_smmu_ril_init_end - arm_smmu_tlbi_calc_range Would those need to be updated also? Thanks, Mostafa
quoted hunk ↗ jump to hunk
Reviewed-by: Nicolin Chen <redacted> Tested-by: Nicolin Chen <redacted> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 ++++++++++++--- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 ++ 2 files changed, 14 insertions(+), 3 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 b99229a5bbacca..2a159be751891e 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c@@ -1060,9 +1060,16 @@ static void arm_smmu_invs_update_caps(struct arm_smmu_invs *invs, invs->has_ats = true; if (inv->smmu->features & ARM_SMMU_FEAT_RANGE_INV) { + unsigned int scale_max; + invs->has_range_inv = true; if (inv->smmu->options & ARM_SMMU_OPT_FULL_CONT_RIL) invs->has_full_cont_ril = true; + + scale_max = (inv->smmu->features & ARM_SMMU_FEAT_DS) ? 39 : 31; + if (!invs->range_inv_scale_max || + scale_max < invs->range_inv_scale_max) + invs->range_inv_scale_max = scale_max; } }@@ -2625,7 +2632,8 @@ static unsigned int arm_smmu_compute_ttl(u8 leaf_bitmap, u8 table_bitmap, * covered by one command. */ static void arm_smmu_tlbi_calc_range(struct arm_smmu_tlbi *tlbi, - bool single_ril) + bool single_ril, + unsigned int scale_max) { u8 tgsz_lg2 = tlbi->tgsz_lg2; unsigned int ttl = arm_smmu_compute_ttl(@@ -2647,7 +2655,7 @@ static void arm_smmu_tlbi_calc_range(struct arm_smmu_tlbi *tlbi, * address beyond alignment to tg (so long as TTL=0). */ first.scale = fls64((num_tg - 1) / 32); - if (first.scale > 31) { + if (first.scale > scale_max) { /* Range too large for a single command do full invalidation */ tlbi->range.use_full_inv = true; return;@@ -2917,7 +2925,8 @@ void arm_smmu_domain_tlbi(struct arm_smmu_tlbi *tlbi, arm_smmu_tlbi_calc_range( tlbi, smmu_domain->stage == ARM_SMMU_DOMAIN_SVA && - invs->has_full_cont_ril); + invs->has_full_cont_ril, + invs->range_inv_scale_max); } }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 6582203eb7425f..8b251a188810c9 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h@@ -760,6 +760,7 @@ static inline bool arm_smmu_inv_is_ats(const struct arm_smmu_inv *inv) * @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 * @has_full_cont_ril: flag if any entry's SMMU requires the CONT RIL workaround + * @range_inv_scale_max: max SCALE usable by all range-capable SMMUs * @rcu: rcu head for kfree_rcu() * @inv: flexible invalidation array *@@ -791,6 +792,7 @@ struct arm_smmu_invs { bool has_ats; bool has_range_inv; bool has_full_cont_ril; + u8 range_inv_scale_max; struct rcu_head rcu; struct arm_smmu_inv inv[] __counted_by(max_invs); };-- 2.43.0