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Message-ID: <1bbaff1b-a3db-e9c4-5b32-2792ed6c4952@codeaurora.org>
Date: Thu, 1 Feb 2018 11:43:57 +0530
From: Vivek Gautam <vivek.gautam@...eaurora.org>
To: Robin Murphy <robin.murphy@....com>, alex.williamson@...hat.com,
robh+dt@...nel.org, mark.rutland@....com, rjw@...ysocki.net,
will.deacon@....com, iommu@...ts.linux-foundation.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-pm@...r.kernel.org, dri-devel@...ts.freedesktop.org,
freedreno@...ts.freedesktop.org, sboyd@...eaurora.org
Cc: gregkh@...uxfoundation.org, sricharan@...eaurora.org,
m.szyprowski@...sung.com, architt@...eaurora.org,
linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v6 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops
On 1/31/2018 5:53 PM, Robin Murphy wrote:
> On 19/01/18 11:43, Vivek Gautam wrote:
>> From: Sricharan R <sricharan@...eaurora.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@...eaurora.org>
>> Signed-off-by: Archit Taneja <architt@...eaurora.org>
>> [vivek: Clock rework to request bulk of clocks]
>> Signed-off-by: Vivek Gautam <vivek.gautam@...eaurora.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.
Sure, will do that.
>
> Otherwise, I think this looks reasonable; it's about as unobtrusive as
> it's going to get.
Thanks for reviewing.
regards
Vivek
>
> 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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