[PATCH v14 1/4] iommu/arm-smmu: Add pm_runtime/sleep ops

Vivek Gautam
2018-07-27T07:02:21Z

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>
---

Changes since v13:
- Moved arm_smmu_device_reset() from arm_smmu_pm_resume() to
arm_smmu_runtime_resume(). arm_smmu_pm_resume() calls just
runtime_resume() now.

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 c73cfce1ccc0..5f6a9e3c0079 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 */

@@ -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);
@@ -1919,6 +1924,23 @@ 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)
{
@@ -2001,6 +2023,9 @@ 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);

@@ -2099,6 +2124,14 @@ 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(smmu->num_clks, smmu->clks);
+ if (err)
+ return err;
+
err = arm_smmu_device_cfg_probe(smmu);
if (err)
return err;
@@ -2181,6 +2214,9 @@ 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_unprepare(smmu->num_clks, smmu->clks);
+
return 0;
}

@@ -2189,15 +2225,50 @@ 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 = {