| Message ID | 20230731184817.v2.5.Idedc0f496231e2faab3df057219c5e2d937bbfe4@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Refactor the SMMU's CD table ownership | expand |
On Mon, Jul 31, 2023 at 06:48:15PM +0800, Michael Shavit wrote: > This commit explicitly keeps track of whether a CD table is installed in > an STE so that arm_smmu_sync_cd can skip the sync when unnecessary. This > was previously achieved through the domain->devices list, but we are > moving to a model where arm_smmu_sync_cd directly operates on a master > and the master's CD table instead of a domain. > > Signed-off-by: Michael Shavit <mshavit@google.com> > --- > > Changes in v2: > - Store field as a bit instead of a bool. Fix comment about STE being > live before the sync in write_ctx_desc(). Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Jason
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 654acf6002bf3..4f7fe19d88fda 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -987,6 +987,9 @@ static void arm_smmu_sync_cd(struct arm_smmu_domain *smmu_domain, }, }; + if (!smmu_domain->cd_table.installed) + return; + cmds.num = 0; spin_lock_irqsave(&smmu_domain->devices_lock, flags); @@ -1098,7 +1101,7 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid, cdptr[3] = cpu_to_le64(cd->mair); /* - * STE is live, and the SMMU might read dwords of this CD in any + * STE may be live, and the SMMU might read dwords of this CD in any * order. Ensure that it observes valid values before reading * V=1. */ @@ -1368,6 +1371,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid, cd_table->l1_desc ? STRTAB_STE_0_S1FMT_64K_L2 : STRTAB_STE_0_S1FMT_LINEAR); + cd_table->installed = true; } if (s2_cfg) { 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 05b1f0ee60808..3a56987a5fd0b 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -599,6 +599,8 @@ struct arm_smmu_ctx_desc_cfg { u8 max_cds_bits; /* Whether CD entries in this table have the stall bit set. */ u8 stall_enabled:1; + /* Whether this CD table is installed in any STE */ + u8 installed:1; }; struct arm_smmu_s2_cfg {
This commit explicitly keeps track of whether a CD table is installed in an STE so that arm_smmu_sync_cd can skip the sync when unnecessary. This was previously achieved through the domain->devices list, but we are moving to a model where arm_smmu_sync_cd directly operates on a master and the master's CD table instead of a domain. Signed-off-by: Michael Shavit <mshavit@google.com> --- Changes in v2: - Store field as a bit instead of a bool. Fix comment about STE being live before the sync in write_ctx_desc(). drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 6 +++++- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 ++ 2 files changed, 7 insertions(+), 1 deletion(-)