Messages in this thread | | | Subject | Re: [PATCH v16 1/5] iommu/arm-smmu: Add pm_runtime/sleep ops | From | Robin Murphy <> | Date | Wed, 26 Sep 2018 16:27:39 +0100 |
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On 30/08/18 15:45, Vivek Gautam wrote: > From: Sricharan R <sricharan@codeaurora.org> > > The smmu needs to be functional only when the respective > master's using it are active. The device_link feature > helps to track such functional dependencies, so that the > iommu gets powered when the master device enables itself > using pm_runtime. So by adapting the smmu driver for > runtime pm, above said dependency can be addressed. > > This patch adds the pm runtime/sleep callbacks to the > driver and also the functions to parse the smmu clocks > from DT and enable them in resume/suspend. > > Also, while we enable the runtime pm add a pm sleep suspend > callback that pushes devices to low power state by turning > the clocks off in a system sleep. > Also add corresponding clock enable path in resume callback. > > Signed-off-by: Sricharan R <sricharan@codeaurora.org> > Signed-off-by: Archit Taneja <architt@codeaurora.org> > [vivek: rework for clock and pm ops] > Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> > Reviewed-by: Tomasz Figa <tfiga@chromium.org> > Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> > --- > drivers/iommu/arm-smmu.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 74 insertions(+), 3 deletions(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index fd1b80ef9490..d900e007c3c9 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -48,6 +48,7 @@ > #include <linux/of_iommu.h> > #include <linux/pci.h> > #include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > #include <linux/slab.h> > #include <linux/spinlock.h> > > @@ -205,6 +206,8 @@ struct arm_smmu_device { > u32 num_global_irqs; > u32 num_context_irqs; > unsigned int *irqs; > + struct clk_bulk_data *clks; > + int num_clks; > > u32 cavium_id_base; /* Specific to Cavium */ > > @@ -1896,10 +1899,12 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) > struct arm_smmu_match_data { > enum arm_smmu_arch_version version; > enum arm_smmu_implementation model; > + const char * const *clks; > + int num_clks; > }; > > #define ARM_SMMU_MATCH_DATA(name, ver, imp) \ > -static struct arm_smmu_match_data name = { .version = ver, .model = imp } > +static const struct arm_smmu_match_data name = { .version = ver, .model = imp } > > ARM_SMMU_MATCH_DATA(smmu_generic_v1, ARM_SMMU_V1, GENERIC_SMMU); > ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU); > @@ -1918,6 +1923,23 @@ static const struct of_device_id arm_smmu_of_match[] = { > }; > MODULE_DEVICE_TABLE(of, arm_smmu_of_match); > > +static void arm_smmu_fill_clk_data(struct arm_smmu_device *smmu, > + const char * const *clks) > +{ > + int i; > + > + if (smmu->num_clks < 1) > + return; > + > + smmu->clks = devm_kcalloc(smmu->dev, smmu->num_clks, > + sizeof(*smmu->clks), GFP_KERNEL); > + if (!smmu->clks) > + return; > + > + for (i = 0; i < smmu->num_clks; i++) > + smmu->clks[i].id = clks[i]; > +} > + > #ifdef CONFIG_ACPI > static int acpi_smmu_get_data(u32 model, struct arm_smmu_device *smmu) > { > @@ -2000,6 +2022,9 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev, > data = of_device_get_match_data(dev); > smmu->version = data->version; > smmu->model = data->model; > + smmu->num_clks = data->num_clks; > + > + arm_smmu_fill_clk_data(smmu, data->clks); > > parse_driver_options(smmu); > > @@ -2098,6 +2123,14 @@ static int arm_smmu_device_probe(struct platform_device *pdev) > smmu->irqs[i] = irq; > } > > + err = devm_clk_bulk_get(smmu->dev, smmu->num_clks, smmu->clks); > + if (err) > + return err; > + > + err = clk_bulk_prepare_enable(smmu->num_clks, smmu->clks); > + if (err) > + return err; > +
Hmm, if we error out beyond here it looks like we should strictly balance that prepare/enable before devres does the clk_bulk_put(), however the probe error path is starting to look like it needs a bit of love in general, so I might just spin a cleanup patch on top (and even then only for the sake of not being a bad example; SMMU probe failure is never a realistic situation for the system to actually recover from).
Otherwise,
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> err = arm_smmu_device_cfg_probe(smmu); > if (err) > return err; > @@ -2184,6 +2217,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev) > > /* Turn the thing off */ > writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0); > + > + clk_bulk_disable_unprepare(smmu->num_clks, smmu->clks); > + > return 0; > } > > @@ -2192,15 +2228,50 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev) > arm_smmu_device_remove(pdev); > } > > -static int __maybe_unused arm_smmu_pm_resume(struct device *dev) > +static int __maybe_unused arm_smmu_runtime_resume(struct device *dev) > { > struct arm_smmu_device *smmu = dev_get_drvdata(dev); > + int ret; > + > + ret = clk_bulk_enable(smmu->num_clks, smmu->clks); > + if (ret) > + return ret; > > arm_smmu_device_reset(smmu); > + > return 0; > } > > -static SIMPLE_DEV_PM_OPS(arm_smmu_pm_ops, NULL, arm_smmu_pm_resume); > +static int __maybe_unused arm_smmu_runtime_suspend(struct device *dev) > +{ > + struct arm_smmu_device *smmu = dev_get_drvdata(dev); > + > + clk_bulk_disable(smmu->num_clks, smmu->clks); > + > + return 0; > +} > + > +static int __maybe_unused arm_smmu_pm_resume(struct device *dev) > +{ > + if (pm_runtime_suspended(dev)) > + return 0; > + > + return arm_smmu_runtime_resume(dev); > +} > + > +static int __maybe_unused arm_smmu_pm_suspend(struct device *dev) > +{ > + if (pm_runtime_suspended(dev)) > + return 0; > + > + return arm_smmu_runtime_suspend(dev); > +} > + > +static const struct dev_pm_ops arm_smmu_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(arm_smmu_pm_suspend, arm_smmu_pm_resume) > + SET_RUNTIME_PM_OPS(arm_smmu_runtime_suspend, > + arm_smmu_runtime_resume, NULL) > +}; > > static struct platform_driver arm_smmu_driver = { > .driver = { >
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