On 3/6/2020 3:52 AM, Doug Anderson wrote: > Hi, > > On Thu, Mar 5, 2020 at 9:07 AM Maulik Shah <mkshah@xxxxxxxxxxxxxx> wrote: >> Changes in v12: >> - Kconfig change to remove COMPILE_TEST was dropped in v11, reinclude it. >> >> Changes in v11: >> - Address Doug's comments on change 2 and 3 >> - Include change to invalidate TCSes before flush from [4] >> >> Changes in v10: >> - Address Evan's comments to update commit message on change 2 >> - Add Evan's Reviewed by on change 2 >> - Remove comment from rpmh_flush() related to last CPU invoking it >> - Rebase all changes on top of next-20200302 >> >> Changes in v9: >> - Keep rpmh_flush() to invoke from within cache_lock >> - Remove comments related to only last cpu invoking rpmh_flush() >> >> Changes in v8: >> - Address Stephen's comments on changes 2 and 3 >> - Add Reviewed by from Stephen on change 1 >> >> Changes in v7: >> - Address Srinivas's comments to update commit text >> - Add Reviewed by from Srinivas >> >> Changes in v6: >> - Drop 1 & 2 changes from v5 as they already landed in maintainer tree >> - Drop 3 & 4 changes from v5 as no user at present for power domain in rsc >> - Rename subject to appropriate since power domain changes are dropped >> - Rebase other changes on top of next-20200221 >> >> Changes in v5: >> - Add Rob's Acked by on dt-bindings change >> - Drop firmware psci change >> - Update cpuidle stats in dtsi to follow PC mode >> - Include change to update dirty flag when data is updated from [4] >> - Add change to invoke rpmh_flush when caches are dirty >> >> Changes in v4: >> - Add change to allow hierarchical topology in PC mode >> - Drop hierarchical domain idle states converter from v3 >> - Address Merge sc7180 dtsi change to add low power modes >> >> Changes in v3: >> - Address Rob's comment on dt property value >> - Address Stephen's comments on rpmh-rsc driver change >> - Include sc7180 cpuidle low power mode changes from [1] >> - Include hierarchical domain idle states converter change from [2] >> >> Changes in v2: >> - Add Stephen's Reviewed-By to the first three patches >> - Addressed Stephen's comments on fourth patch >> - Include changes to connect rpmh domain to cpuidle and genpds >> >> Resource State Coordinator (RSC) is responsible for powering off/lowering >> the requirements from CPU subsystem for the associated hardware like buses, >> clocks, and regulators when all CPUs and cluster is powered down. >> >> RSC power domain uses last-man activities provided by genpd framework based >> on Ulf Hansoon's patch series[3], when the cluster of CPUs enter deepest >> idle states. As a part of domain poweroff, RSC can lower resource state >> requirements by flushing the cached sleep and wake state votes for various >> resources. >> >> [1] https://patchwork.kernel.org/patch/11218965 >> [2] https://patchwork.kernel.org/patch/10941671 >> [3] https://patchwork.kernel.org/project/linux-arm-msm/list/?series=222355 >> [4] https://patchwork.kernel.org/project/linux-arm-msm/list/?series=236503 >> >> Maulik Shah (3): >> arm64: dts: qcom: sc7180: Add cpuidle low power states >> soc: qcom: rpmh: Update dirty flag only when data changes >> soc: qcom: rpmh: Invoke rpmh_flush for dirty caches >> >> arch/arm64/boot/dts/qcom/sc7180.dtsi | 78 ++++++++++++++++++++++++++++++++++++ >> drivers/soc/qcom/rpmh.c | 27 ++++++++++--- >> 2 files changed, 100 insertions(+), 5 deletions(-) > One overall optimization idea? > > Should we add two API calls: > > rpmh_start_operations() > rpmh_end_operations() > > These optional API calls would be an optimization a client could use. > When rpmh_start_operations() is called then RPMH code will inhibit > flushing (but will still update the "dirty" flag). When > rpmh_end_operations() is called then the RPMH will flush if the dirty > flag is set. > > This is a pretty simple concept but should have a huge impact in the > number of times we program hardware in non-OSI mode. Specifically, if > we don't do that and we look at what happens in the interconnect code: > > 1. We "invalidate" the batch. We have to flush the non-batch commands > back into the hardware. > > 2. We program the "wake only" commands. We have to flush the batch > wake-only commands and also the non-batch commands back into the > hardware. > > 3. We program the "sleep only" commands. We have to flush yet again > with everything. > > > > -Doug Implemented in v13. Thanks, Maulik -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
