diff mbox

[v7,2/6] iommu/arm-smmu: Add pm_runtime/sleep ops

Message ID 1517999482-17317-3-git-send-email-vivek.gautam@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Vivek Gautam Feb. 7, 2018, 10:31 a.m. UTC
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 | 56 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 54 insertions(+), 2 deletions(-)

Comments

Tomasz Figa Feb. 13, 2018, 8:03 a.m. UTC | #1
Hi Vivek,

Thanks for the patch. Please see some comments inline.

On Wed, Feb 7, 2018 at 7:31 PM, Vivek Gautam
<vivek.gautam@codeaurora.org> 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 | 56 ++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 54 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 69e7c60792a8..9e2f917e16c2 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            *clocks;
> +       int                             num_clks;

nit: Perhaps "num_clocks" to be consistent with "clocks"?

>
>         u32                             cavium_id_base; /* Specific to Cavium */
>
> @@ -1897,10 +1900,12 @@ 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;

nit: Perhaps s/clks/clocks/ here or s/clocks/clks/ in struct arm_smmu_device?

>  };
>
>  #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 +2006,7 @@ 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;
>
>         parse_driver_options(smmu);
>
> @@ -2039,6 +2045,28 @@ static void arm_smmu_bus_init(void)
>  #endif
>  }
>
> +static int arm_smmu_init_clks(struct arm_smmu_device *smmu)
> +{
> +       int i;
> +       int num = smmu->num_clks;
> +       const struct arm_smmu_match_data *data;
> +
> +       if (num < 1)
> +               return 0;
> +
> +       smmu->clocks = devm_kcalloc(smmu->dev, num,
> +                                   sizeof(*smmu->clocks), GFP_KERNEL);
> +       if (!smmu->clocks)
> +               return -ENOMEM;
> +
> +       data = of_device_get_match_data(smmu->dev);
> +
> +       for (i = 0; i < num; i++)
> +               smmu->clocks[i].id = data->clks[i];

I'd argue that arm_smmu_device_dt_probe() is a better place for all
the code above, since this function is called regardless of whether
the device is probed from DT or not. Going further,
arm_smmu_device_acpi_probe() could fill smmu->num_clks and ->clocks
using ACPI-like way (as opposed to OF match data) if necessary.

Best regards,
Tomasz
Vivek Gautam Feb. 13, 2018, 10:25 a.m. UTC | #2
Hi Tomasz,


Please find my response inline below.

On Tue, Feb 13, 2018 at 1:33 PM, Tomasz Figa <tfiga@chromium.org> wrote:
> Hi Vivek,
>
> Thanks for the patch. Please see some comments inline.
>
> On Wed, Feb 7, 2018 at 7:31 PM, Vivek Gautam
> <vivek.gautam@codeaurora.org> 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 | 56 ++++++++++++++++++++++++++++++++++++++++++++++--
>>  1 file changed, 54 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
>> index 69e7c60792a8..9e2f917e16c2 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            *clocks;
>> +       int                             num_clks;
>
> nit: Perhaps "num_clocks" to be consistent with "clocks"?
>
>>
>>         u32                             cavium_id_base; /* Specific to Cavium */
>>
>> @@ -1897,10 +1900,12 @@ 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;
>
> nit: Perhaps s/clks/clocks/ here or s/clocks/clks/ in struct arm_smmu_device?

Sure. Will change to s/clocks/clks/ in struct arm_smmu_device.

>
>>  };
>>
>>  #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 +2006,7 @@ 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;
>>
>>         parse_driver_options(smmu);
>>
>> @@ -2039,6 +2045,28 @@ static void arm_smmu_bus_init(void)
>>  #endif
>>  }
>>
>> +static int arm_smmu_init_clks(struct arm_smmu_device *smmu)
>> +{
>> +       int i;
>> +       int num = smmu->num_clks;
>> +       const struct arm_smmu_match_data *data;
>> +
>> +       if (num < 1)
>> +               return 0;
>> +
>> +       smmu->clocks = devm_kcalloc(smmu->dev, num,
>> +                                   sizeof(*smmu->clocks), GFP_KERNEL);
>> +       if (!smmu->clocks)
>> +               return -ENOMEM;
>> +
>> +       data = of_device_get_match_data(smmu->dev);
>> +
>> +       for (i = 0; i < num; i++)
>> +               smmu->clocks[i].id = data->clks[i];
>
> I'd argue that arm_smmu_device_dt_probe() is a better place for all
> the code above, since this function is called regardless of whether
> the device is probed from DT or not. Going further,
> arm_smmu_device_acpi_probe() could fill smmu->num_clks and ->clocks
> using ACPI-like way (as opposed to OF match data) if necessary.

Right, it's valid to fill the data in arm_smmu_device_dt_probe().
Perhaps we can just keep the devm_clk_bulk_get() in arm_smmu_device_probe()
at the point where we are currently doing arm_smmu_init_clks().

Thanks & regards
Vivek

>
> Best regards,
> Tomasz
> --
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Tomasz Figa Feb. 14, 2018, 3:45 a.m. UTC | #3
On Tue, Feb 13, 2018 at 7:25 PM, Vivek Gautam
<vivek.gautam@codeaurora.org> wrote:
>>> +static int arm_smmu_init_clks(struct arm_smmu_device *smmu)
>>> +{
>>> +       int i;
>>> +       int num = smmu->num_clks;
>>> +       const struct arm_smmu_match_data *data;
>>> +
>>> +       if (num < 1)
>>> +               return 0;
>>> +
>>> +       smmu->clocks = devm_kcalloc(smmu->dev, num,
>>> +                                   sizeof(*smmu->clocks), GFP_KERNEL);
>>> +       if (!smmu->clocks)
>>> +               return -ENOMEM;
>>> +
>>> +       data = of_device_get_match_data(smmu->dev);
>>> +
>>> +       for (i = 0; i < num; i++)
>>> +               smmu->clocks[i].id = data->clks[i];
>>
>> I'd argue that arm_smmu_device_dt_probe() is a better place for all
>> the code above, since this function is called regardless of whether
>> the device is probed from DT or not. Going further,
>> arm_smmu_device_acpi_probe() could fill smmu->num_clks and ->clocks
>> using ACPI-like way (as opposed to OF match data) if necessary.
>
> Right, it's valid to fill the data in arm_smmu_device_dt_probe().
> Perhaps we can just keep the devm_clk_bulk_get() in arm_smmu_device_probe()
> at the point where we are currently doing arm_smmu_init_clks().

Sounds good to me. Thanks.

Best regards,
Tomasz
diff mbox

Patch

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 69e7c60792a8..9e2f917e16c2 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		*clocks;
+	int				num_clks;
 
 	u32				cavium_id_base; /* Specific to Cavium */
 
@@ -1897,10 +1900,12 @@  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 +2006,7 @@  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;
 
 	parse_driver_options(smmu);
 
@@ -2039,6 +2045,28 @@  static void arm_smmu_bus_init(void)
 #endif
 }
 
+static int arm_smmu_init_clks(struct arm_smmu_device *smmu)
+{
+	int i;
+	int num = smmu->num_clks;
+	const struct arm_smmu_match_data *data;
+
+	if (num < 1)
+		return 0;
+
+	smmu->clocks = devm_kcalloc(smmu->dev, num,
+				    sizeof(*smmu->clocks), GFP_KERNEL);
+	if (!smmu->clocks)
+		return -ENOMEM;
+
+	data = of_device_get_match_data(smmu->dev);
+
+	for (i = 0; i < num; i++)
+		smmu->clocks[i].id = data->clks[i];
+
+	return devm_clk_bulk_get(smmu->dev, num, smmu->clocks);
+}
+
 static int arm_smmu_device_probe(struct platform_device *pdev)
 {
 	struct resource *res;
@@ -2099,6 +2127,10 @@  static int arm_smmu_device_probe(struct platform_device *pdev)
 		smmu->irqs[i] = irq;
 	}
 
+	err = arm_smmu_init_clks(smmu);
+	if (err)
+		return err;
+
 	err = arm_smmu_device_cfg_probe(smmu);
 	if (err)
 		return err;
@@ -2197,7 +2229,27 @@  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	= {