On Tue, Apr 30, 2024 at 11:22:01AM -0300, Jason Gunthorpe wrote:
> On Mon, Apr 29, 2024 at 09:43:45PM -0700, Nicolin Chen wrote:
> > The CMDQV extension in NVIDIA Tegra241 SoC only supports CS_NONE in the
> > CS field of CMD_SYNC. Add a quirk flag to accommodate that.
> >
> > Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > ---
> > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++++++++--
> > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 4 ++++
> > 2 files changed, 12 insertions(+), 2 deletions(-)
>
> This seems fine, other than the misplaced hunk
>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
>
> But it might be tidier like the below. There is already a function
> that is called to build the sync that has the q, just build it
> directly there and avoid going through the ent?
Yea, and looks like we can have a patch tidying the existing sync
building function, and then another one adding CS_NONE.
> static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu,
> - struct arm_smmu_queue *q, u32 prod)
> + struct arm_smmu_queue *q, u32 prod,
> + bool msi)
> {
...
> + if (!msi || !(smmu->options & ARM_SMMU_OPT_MSIPOLL)) {
> + cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV);
> + return;
> + }
...
> @@ -402,9 +395,6 @@ void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
> u64 cmd[CMDQ_ENT_DWORDS];
> u32 cons = readl_relaxed(q->cons_reg);
> u32 idx = FIELD_GET(CMDQ_CONS_ERR, cons);
> - struct arm_smmu_cmdq_ent cmd_sync = {
> - .opcode = CMDQ_OP_CMD_SYNC,
> - };
>
> dev_err(smmu->dev, "CMDQ error (cons 0x%08x): %s\n", cons,
> idx < ARRAY_SIZE(cerror_str) ? cerror_str[idx] : "Unknown");
> @@ -437,11 +427,8 @@ void __arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu,
> for (i = 0; i < ARRAY_SIZE(cmd); ++i)
> dev_err(smmu->dev, "\t0x%016llx\n", (unsigned long long)cmd[i]);
>
> - if (q->quirks & CMDQ_QUIRK_SYNC_CS_NONE_ONLY)
> - cmd_sync.sync.cs_none = true;
> -
> /* Convert the erroneous command into a CMD_SYNC */
> - arm_smmu_cmdq_build_cmd(cmd, &cmd_sync);
> + arm_smmu_cmdq_build_sync_cmd(cmd, smmu, q, 0, false);
>
> queue_write(Q_ENT(q, cons), cmd, q->ent_dwords);
Here is the only caller for "msi=false". Maybe we could just do:
+ arm_smmu_cmdq_build_sync_cmd(cmd, smmu, q, cons);
So, no need of "bool msi"? It would slightly change the behavior
though, a SYNC for ARM_SMMU_OPT_MSIPOLL should be still a SYNC.
Thanks
Nicolin
