On Thu, Jul 19, 2018 at 3:45 PM, Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx> wrote: > This series provides the support for turning on the arm-smmu's > clocks/power domains using runtime pm. This is done using > device links between smmu and client devices. The device link > framework keeps the two devices in correct order for power-cycling > across runtime PM or across system-wide PM. > > With addition of a new device link flag DL_FLAG_AUTOREMOVE_SUPPLIER [8] > (available in linux-next of Rafael's linux-pm tree [9]), the device links > created between arm-smmu and its clients will be automatically purged > when arm-smmu driver unbinds from its device. > > As not all implementations support clock/power gating, we are checking > for a valid 'smmu->dev's pm_domain' to conditionally enable the runtime > power management for such smmu implementations that can support it. > Otherwise, the clocks are turned to be always on in .probe until .remove. > With conditional runtime pm now, we avoid touching dev->power.lock > in fastpaths for smmu implementations that don't need to do anything > useful with pm_runtime. > This lets us to use the much-argued pm_runtime_get_sync/put_sync() > calls in map/unmap callbacks so that the clients do not have to > worry about handling any of the arm-smmu's power. > > This series also adds support for Qcom's arm-smmu-v2 variant that > has different clocks and power requirements. > > Previous version of this patch series is @ [2]. > > Tested this series on msm8996, and sdm845 after pulling in Rafael's linux-pm > linux-next[9] and Joerg's iommu next[10] branches. Hi Rafael, If the changes look good to you now, can you please consider giving your Ack. Thanks. Hi Robin, Will, If the series looks good to you, and if there's a chance, can you please consider picking this series for 4.19. Thanks. Best regards Vivek > > [v13] > Addressing Rafael's comments: > * Added .suspend pm callback to disable the clocks in system wide suspend. > * Added corresponding clock enable in .resume pm callback. > * Explicitly enabling/disabling the clocks now when runtime PM is disabled. > * device_link_add() doesn't depend on pm_runtime_enabled() as we can > use device links across system suspend/resume too. > > Addressing Robin's comments: > * Making device_link_add failures as non-fatal. > > * Removed IOMMU_OF_DECLARE() declaration as we don't need this after Rob's > patch that removed all of these declarations. > > [v12] > * Use new device link's flag introduced in [8] - > DL_FLAG_AUTOREMOVE_SUPPLIER. With this devices links are automatically > purged when arm-smmu driver unbinds. > * Using pm_runtime_force_suspend() instead of pm_runtime_disable() to > avoid following warning from arm_smmu_device_remove() > > [295711.537507] ------------[ cut here ]------------ > [295711.544226] Unpreparing enabled smmu_mdp_ahb_clk > [295711.549099] WARNING: CPU: 0 PID: 1 at ../drivers/clk/clk.c:697 > clk_core_unprepare+0xd8/0xe0 > ... > [295711.674073] Call trace: > [295711.679454] clk_core_unprepare+0xd8/0xe0 > [295711.682059] clk_unprepare+0x28/0x40 > [295711.685964] clk_bulk_unprepare+0x28/0x40 > [295711.689701] arm_smmu_device_remove+0x88/0xd8 > [295711.693692] arm_smmu_device_shutdown+0xc/0x18 > [295711.698120] platform_drv_shutdown+0x20/0x30 > > [v11] > * Some more cleanups for device link. We don't need an explicit > delete for device link from the driver, but just set the flag > DL_FLAG_AUTOREMOVE. > device_link_add() API description says - > "If the DL_FLAG_AUTOREMOVE is set, the link will be removed > automatically when the consumer device driver unbinds." > * Addressed the comments for 'smmu' in arm_smmu_map/unmap(). > * Dropped the patch [7] that introduced device_link_del_dev() API. > > [v10] > * Introduce device_link_del_dev() API to delete the link between > given consumer and supplier devices. The users of device link > do not need to store link pointer to delete the link later. > They can straightaway use this API by passing consumer and > supplier devices. > * Made corresponding changes to arm-smmu driver patch handling the > device links. > * Dropped the patch [6] that was adding device_link_find() API to > device core layer. device_link_del_dev() serves the purpose to > directly delete the link between two given devices. > > [v9] > * Removed 'rpm_supported' flag, instead checking on pm_domain > to enable runtime pm. > * Creating device link only when the runtime pm is enabled, as we > don't need a device link besides managing the power dependency > between supplier and consumer devices. > * Introducing a patch to add device_link_find() API that finds > and existing link between supplier and consumer devices. > Also, made necessary change to device_link_add() to use this API. > * arm_smmu_remove_device() now uses this device_link_find() to find > the device link between smmu device and the master device, and then > delete this link. > * Dropped the destroy_domain_context() fix [5] as it was rather, > introducing catastrophically bad problem by destroying > 'good dev's domain context. > * Added 'Reviwed-by' tag for Tomasz's review. > > [v8] > * Major change - > - Added a flag 'rpm_supported' which each platform that supports > runtime pm, can enable, and we enable runtime_pm over arm-smmu > only when this flag is set. > - Adding the conditional pm_runtime_get/put() calls to .map, .unmap > and .attach_dev ops. > - Dropped the patch [3] that exported pm_runtim_get/put_suupliers(), > and also dropped the user driver patch [4] for these APIs. > > * Clock code further cleanup > - doing only clk_bulk_enable() and clk_bulk_disable() in runtime pm > callbacks. We shouldn't be taking a slow path (clk_prepare/unprepare()) > from these runtime pm callbacks. Thereby, moved clk_bulk_prepare() to > arm_smmu_device_probe(), and clk_bulk_unprepare() to > arm_smmu_device_remove(). > - clk data filling to a common method arm_smmu_fill_clk_data() that > fills the clock ids and number of clocks. > > * Addressed other nits and comments > - device_link_add() error path fixed. > - Fix for checking negative error value from pm_runtime_get_sync(). > - Documentation redo. > > * Added another patch fixing the error path in arm_smmu_attach_dev() > to destroy allocated domain context. > > [v7] > * Addressed review comments given by Robin Murphy - > - Added device_link_del() in .remove_device path. > - Error path cleanup in arm_smmu_add_device(). > - Added pm_runtime_get/put_sync() in .remove path, and replaced > pm_runtime_force_suspend() with pm_runtime_disable(). > - clk_names cleanup in arm_smmu_init_clks() > * Added 'Reviewed-by' given by Rob H. > > ** Change logs for previous versions is available in last series [4]. > > > [1] https://patchwork.kernel.org/patch/10204925/ > [2] https://lkml.org/lkml/2018/7/8/124 > [3] https://patchwork.kernel.org/patch/10204945/ > [4] https://patchwork.kernel.org/patch/10204925/ > [5] https://patchwork.kernel.org/patch/10254105/ > [6] https://patchwork.kernel.org/patch/10277975/ > [7] https://patchwork.kernel.org/patch/10281613/ > [8] https://patchwork.kernel.org/patch/10491481/ > [9] https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=linux-next > [10] https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git/log/?h=next > > Sricharan R (3): > iommu/arm-smmu: Add pm_runtime/sleep ops > iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device > iommu/arm-smmu: Add the device_link between masters and smmu > > Vivek Gautam (1): > iommu/arm-smmu: Add support for qcom,smmu-v2 variant > > .../devicetree/bindings/iommu/arm,smmu.txt | 42 +++++ > drivers/iommu/arm-smmu.c | 192 +++++++++++++++++++-- > 2 files changed, 224 insertions(+), 10 deletions(-) > > -- > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member > of Code Aurora Forum, hosted by The Linux Foundation > > _______________________________________________ > iommu mailing list > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > https://lists.linuxfoundation.org/mailman/listinfo/iommu -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
