Messages in this thread | | | Subject | Re: [PATCH v6 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops | From | Robin Murphy <> | Date | Wed, 31 Jan 2018 12:23:43 +0000 |
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On 19/01/18 11:43, 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. > > Signed-off-by: Sricharan R <sricharan@codeaurora.org> > Signed-off-by: Archit Taneja <architt@codeaurora.org> > [vivek: Clock rework to request bulk of clocks] > Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> > --- > drivers/iommu/arm-smmu.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 53 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 78d4c6b8f1ba..21acffe91a1c 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 +206,9 @@ struct arm_smmu_device { > u32 num_global_irqs; > u32 num_context_irqs; > unsigned int *irqs; > + struct clk_bulk_data *clocks; > + int num_clks; > + const char * const *clk_names;
This seems unnecessary, as we use it a grand total of of once, during initialisation when we have the source data directly to hand. Just pass data->clks into arm_smmu_init_clks() as an additional argument.
Otherwise, I think this looks reasonable; it's about as unobtrusive as it's going to get.
Robin.
> u32 cavium_id_base; /* Specific to Cavium */ > > @@ -1685,6 +1689,25 @@ static int arm_smmu_id_size_to_bits(int size) > } > } > > +static int arm_smmu_init_clocks(struct arm_smmu_device *smmu) > +{ > + int i; > + int num = smmu->num_clks; > + > + if (num < 1) > + return 0; > + > + smmu->clocks = devm_kcalloc(smmu->dev, num, > + sizeof(*smmu->clocks), GFP_KERNEL); > + if (!smmu->clocks) > + return -ENOMEM; > + > + for (i = 0; i < num; i++) > + smmu->clocks[i].id = smmu->clk_names[i]; > + > + return devm_clk_bulk_get(smmu->dev, num, smmu->clocks); > +} > + > static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) > { > unsigned long size; > @@ -1897,10 +1920,12 @@ 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); > @@ -2001,6 +2026,8 @@ 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->clk_names = data->clks; > + smmu->num_clks = data->num_clks; > > parse_driver_options(smmu); > > @@ -2099,6 +2126,10 @@ static int arm_smmu_device_probe(struct platform_device *pdev) > smmu->irqs[i] = irq; > } > > + err = arm_smmu_init_clocks(smmu); > + if (err) > + return err; > + > err = arm_smmu_device_cfg_probe(smmu); > if (err) > return err; > @@ -2197,7 +2228,27 @@ static int __maybe_unused arm_smmu_pm_resume(struct device *dev) > return 0; > } > > -static SIMPLE_DEV_PM_OPS(arm_smmu_pm_ops, NULL, arm_smmu_pm_resume); > +static int __maybe_unused arm_smmu_runtime_resume(struct device *dev) > +{ > + struct arm_smmu_device *smmu = dev_get_drvdata(dev); > + > + return clk_bulk_prepare_enable(smmu->num_clks, smmu->clocks); > +} > + > +static int __maybe_unused arm_smmu_runtime_suspend(struct device *dev) > +{ > + struct arm_smmu_device *smmu = dev_get_drvdata(dev); > + > + clk_bulk_disable_unprepare(smmu->num_clks, smmu->clocks); > + > + return 0; > +} > + > +static const struct dev_pm_ops arm_smmu_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(NULL, 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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