diff mbox series

[v4,4/8] iommu/arm-smmu-v3: move stall_enabled to the cd table

Message ID 20230803003234.v4.4.I5aa89c849228794a64146cfe86df21fb71629384@changeid (mailing list archive)
State New, archived
Headers show
Series Refactor the SMMU's CD table ownership | expand

Commit Message

Michael Shavit Aug. 2, 2023, 4:32 p.m. UTC
This controls whether CD entries will have the stall bit set when
writing entries into the table.

Signed-off-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---

(no changes since v2)

Changes in v2:
- Use a bitfield instead of a bool for stall_enabled

 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 8 ++++----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 3 ++-
 2 files changed, 6 insertions(+), 5 deletions(-)

Comments

Nicolin Chen Aug. 4, 2023, 11:32 p.m. UTC | #1
On Thu, Aug 03, 2023 at 12:32:32AM +0800, Michael Shavit wrote:
 
> This controls whether CD entries will have the stall bit set when
> writing entries into the table.

It'd be nicer to spare a few more lines here -- something like
this yet feel free to rephrase:

The stall bit of a CD entry should follow the master->stall_enabled and
has an inverse relationship with the STE.S1STALLD bit.

Also, a domain should be able to share between two masters, even if they
have different stall_enabled configurations, in which case, two masters
should have two sets of CD tables, i.e. having two different CD entries
for the same domain holding a CD.

So, move the "stall_enabled" out of domain to cd_table. It then controls
whether CD entries will have the stall bit set when writing entries into
the table.

> Signed-off-by: Michael Shavit <mshavit@google.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

With that,
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>

And btw, you should probably put your Signed-off-by at the end
the commit log, i.e. behind "Reviewed-by", meaning you created/
updated the commit, and then signed it off.

Nicolin
Michael Shavit Aug. 7, 2023, 12:21 p.m. UTC | #2
On Sat, Aug 5, 2023 at 7:32 AM Nicolin Chen <nicolinc@nvidia.com> wrote:
> It'd be nicer to spare a few more lines here -- something like
> this yet feel free to rephrase:

Yeah you're right, this commit message was pretty sparse. Will update.

> And btw, you should probably put your Signed-off-by at the end
> the commit log, i.e. behind "Reviewed-by", meaning you created/
> updated the commit, and then signed it off.
>
> Nicolin

Ah, thanks for the tip, will do as well :) .
diff mbox series

Patch

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 fe4b19c3b8de..c01023404c26 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1114,7 +1114,7 @@  int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid,
 			FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid) |
 			CTXDESC_CD_0_V;
 
-		if (smmu_domain->stall_enabled)
+		if (smmu_domain->cd_table.stall_enabled)
 			val |= CTXDESC_CD_0_S;
 	}
 
@@ -1141,6 +1141,7 @@  static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain,
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_ctx_desc_cfg *cdcfg = &smmu_domain->cd_table;
 
+	cdcfg->stall_enabled = master->stall_enabled;
 	cdcfg->max_cds_bits = master->ssid_bits;
 	max_contexts = 1 << cdcfg->max_cds_bits;
 
@@ -2121,8 +2122,6 @@  static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
 	if (ret)
 		goto out_unlock;
 
-	smmu_domain->stall_enabled = master->stall_enabled;
-
 	ret = arm_smmu_alloc_cd_tables(smmu_domain, master);
 	if (ret)
 		goto out_free_asid;
@@ -2461,7 +2460,8 @@  static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		ret = -EINVAL;
 		goto out_unlock;
 	} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 &&
-		   smmu_domain->stall_enabled != master->stall_enabled) {
+		   smmu_domain->cd_table.stall_enabled !=
+			   master->stall_enabled) {
 		ret = -EINVAL;
 		goto out_unlock;
 	}
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 35a93e885887..05b1f0ee6080 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -597,6 +597,8 @@  struct arm_smmu_ctx_desc_cfg {
 	unsigned int			num_l1_ents;
 	/* log2 of the maximum number of CDs supported by this table */
 	u8				max_cds_bits;
+	/* Whether CD entries in this table have the stall bit set. */
+	u8				stall_enabled:1;
 };
 
 struct arm_smmu_s2_cfg {
@@ -714,7 +716,6 @@  struct arm_smmu_domain {
 	struct mutex			init_mutex; /* Protects smmu pointer */
 
 	struct io_pgtable_ops		*pgtbl_ops;
-	bool				stall_enabled;
 	atomic_t			nr_ats_masters;
 
 	enum arm_smmu_domain_stage	stage;