diff mbox series

[v11,6/9] iommu/arm-smmu-v3: Add ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY

Message ID 716ac3e9d2564bbc47390160286a9ce1a1d85704.1722993435.git.nicolinc@nvidia.com
State Handled Elsewhere
Headers show
Series Add Tegra241 (Grace) CMDQV Support (part 1/2) | expand

Commit Message

Nicolin Chen Aug. 7, 2024, 2:11 a.m. UTC 
The CMDQV extension in NVIDIA Tegra241 SoC only supports CS_NONE in the
CS field of CMD_SYNC. Add a new SMMU option to accommodate that.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 17 ++++++++++++++++-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  9 +++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

Comments

Jason Gunthorpe Aug. 14, 2024, 5:31 p.m. UTC | #1 
On Tue, Aug 06, 2024 at 07:11:51PM -0700, Nicolin Chen wrote:
> The CMDQV extension in NVIDIA Tegra241 SoC only supports CS_NONE in the
> CS field of CMD_SYNC. Add a new SMMU option to accommodate that.
> 
> Suggested-by: Will Deacon <will@kernel.org>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 17 ++++++++++++++++-
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  9 +++++----
>  2 files changed, 21 insertions(+), 5 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason
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 df1149095860..e764236a9216 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -341,6 +341,15 @@  static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
 	return &smmu->cmdq;
 }
 
+static bool arm_smmu_cmdq_needs_busy_polling(struct arm_smmu_device *smmu,
+					     struct arm_smmu_cmdq *cmdq)
+{
+	if (cmdq == &smmu->cmdq)
+		return false;
+
+	return smmu->options & ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY;
+}
+
 static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 					 struct arm_smmu_cmdq *cmdq, u32 prod)
 {
@@ -351,6 +360,11 @@  static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
 		 FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH) |
 		 FIELD_PREP(CMDQ_SYNC_0_MSIATTR, ARM_SMMU_MEMATTR_OIWB);
 
+	if (arm_smmu_cmdq_needs_busy_polling(smmu, cmdq)) {
+		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_NONE);
+		return;
+	}
+
 	if (!(smmu->options & ARM_SMMU_OPT_MSIPOLL)) {
 		cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV);
 		return;
@@ -697,7 +711,8 @@  static int arm_smmu_cmdq_poll_until_sync(struct arm_smmu_device *smmu,
 					 struct arm_smmu_cmdq *cmdq,
 					 struct arm_smmu_ll_queue *llq)
 {
-	if (smmu->options & ARM_SMMU_OPT_MSIPOLL)
+	if (smmu->options & ARM_SMMU_OPT_MSIPOLL &&
+	    !arm_smmu_cmdq_needs_busy_polling(smmu, cmdq))
 		return __arm_smmu_cmdq_poll_until_msi(smmu, cmdq, llq);
 
 	return __arm_smmu_cmdq_poll_until_consumed(smmu, cmdq, llq);
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 6c5dc2f10a33..71818f586036 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -658,10 +658,11 @@  struct arm_smmu_device {
 #define ARM_SMMU_FEAT_HD		(1 << 22)
 	u32				features;
 
-#define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
-#define ARM_SMMU_OPT_PAGE0_REGS_ONLY	(1 << 1)
-#define ARM_SMMU_OPT_MSIPOLL		(1 << 2)
-#define ARM_SMMU_OPT_CMDQ_FORCE_SYNC	(1 << 3)
+#define ARM_SMMU_OPT_SKIP_PREFETCH			(1 << 0)
+#define ARM_SMMU_OPT_PAGE0_REGS_ONLY			(1 << 1)
+#define ARM_SMMU_OPT_MSIPOLL				(1 << 2)
+#define ARM_SMMU_OPT_CMDQ_FORCE_SYNC			(1 << 3)
+#define ARM_SMMU_OPT_SECONDARY_CMDQ_CS_NONE_ONLY	(1 << 4)
 	u32				options;
 
 	struct arm_smmu_cmdq		cmdq;