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charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240708_043123_198851_5D6FF9F0 X-CRM114-Status: GOOD ( 38.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jul 05, 2024 at 05:32:24PM -0700, Nicolin Chen wrote: > On Fri, Jul 05, 2024 at 11:10:47AM -0700, Nicolin Chen wrote: > > On Fri, Jul 05, 2024 at 04:27:21PM +0100, Will Deacon wrote: > > > On Tue, Jul 02, 2024 at 01:10:19PM -0700, Nicolin Chen wrote: > > > > On Tue, Jul 02, 2024 at 12:47:14PM -0700, Nicolin Chen wrote: > > > > > @@ -345,6 +345,11 @@ 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 (cmdq->type == TEGRA241_VCMDQ) { > > > > > + 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; > > > > > @@ -690,7 +695,8 @@ 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 && > > > > > + cmdq->type != TEGRA241_VCMDQ) { > > > > > return __arm_smmu_cmdq_poll_until_msi(smmu, cmdq, llq); > > > > > > > > > > -------------------------------------------------------------- > > > > > > > > > > Would you prefer this one? I feel CMDQ_QUIRK_SYNC_CS_NONE_ONLY > > > > > is more general looking though.. > > > > > > > > And we would need some additional lines of comments for the two > > > > pieces above, explaining why TEGRA241_VCMDQ type needs the first > > > > one while bypasses the second one. Again, it feels even worse :( > > > > > > I hacked the code around a bit this afternoon. Please can you see if: > > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-nicolin/grace-vcmdq-wip > > > > > > does roughly what you need? > > > > I appreciate the patch. Yet, we cannot use IORT's model field. > > This would need to go through IORT documentation, for A. And B, > > we had a very long discussion with ARM (Robin was there) years > > ago, and concluded that this CMDQV would not be a model in IORT > > but a DSDT node as an extension. So, this is firm... > > > > With that, we cannot avoid an unconditional hard-coding tegra > > function call even if we switch to an impl design: > > > > +static int acpi_smmu_impl_init(u32 model, struct arm_smmu_device *smmu) > > +{ > > + /* > > + * unconditional go through ACPI table to detect if there is a tegra241 > > + * implementation that extends SMMU with a CMDQV. The probe() will fill > > + * the smmu->impl pointer upon success. Otherwise, fall back to regular > > + * SMMU CMDQ. > > + */ > > + tegra241_impl_acpi_probe(smmu); > > + return 0; > > +} > > > > As for arm_smmu_cmdq_needs_busy_polling, it doesn't really look > > very optimal to me. But if you insist on having an smmu option, > > we still have to take in the PATCH-3 in this series, enforcing > > an arm_smmu_cmdq_build_sync_cmd() call in the IRQ handler too. > > So, it would eventually look like [attachment]. > > Please ignore the attachment. Since we are adding arm_smmu_impl, > I figure that we could add an arm_smmu_cmdq_impl too. There's an > another small feature that I didn't implement in this v9, while > being able to benefit from a cmdq impl now. > > The impl can also hold a boolean busy_polling, so we won't need > a global smmu option. So /that/ might be overkill. Architectural queues can use polling, so I don't mind having that option in the driver and it should keep the number of impl hooks to a minimum. > I will send a new version asap, though I am not sure if we can > still make it to this cycle that we hoped for :-/ I'm in fixes-only mode at this point, especially since we've not had a linux-next for a while. Will