From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Date: Tue, 10 Aug 2021 12:18:08 +0530
Subject: iommu/arm-smmu: Add clk_bulk_{prepare/unprepare} to system pm
 callbacks
Git-commit: afefe67e0893325d75eb7b816dd394eef2eac628
Patch-mainline: v5.15-rc1
References: bsc#1192202

Some clocks for SMMU can have parent as XO such as gpu_cc_hub_cx_int_clk
of GPU SMMU in QTI SC7280 SoC and in order to enter deep sleep states in
such cases, we would need to drop the XO clock vote in unprepare call and
this unprepare callback for XO is in RPMh (Resource Power Manager-Hardened)
clock driver which controls RPMh managed clock resources for new QTI SoCs.

Given we cannot have a sleeping calls such as clk_bulk_prepare() and
clk_bulk_unprepare() in arm-smmu runtime pm callbacks since the iommu
operations like map and unmap can be in atomic context and are in fast
path, add this prepare and unprepare call to drop the XO vote only for
system pm callbacks since it is not a fast path and we expect the system
to enter deep sleep states with system pm as opposed to runtime pm.

This is a similar sequence of clock requests (prepare,enable and
disable,unprepare) in arm-smmu probe and remove.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Co-developed-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Link: https://lore.kernel.org/r/20210810064808.32486-1-saiprakash.ranjan@codeaurora.org
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/arm/arm-smmu/arm-smmu.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -2280,18 +2280,38 @@ static int __maybe_unused arm_smmu_runti
 
 static int __maybe_unused arm_smmu_pm_resume(struct device *dev)
 {
+	int ret;
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+	ret = clk_bulk_prepare(smmu->num_clks, smmu->clks);
+	if (ret)
+		return ret;
+
 	if (pm_runtime_suspended(dev))
 		return 0;
 
-	return arm_smmu_runtime_resume(dev);
+	ret = arm_smmu_runtime_resume(dev);
+	if (ret)
+		clk_bulk_unprepare(smmu->num_clks, smmu->clks);
+
+	return ret;
 }
 
 static int __maybe_unused arm_smmu_pm_suspend(struct device *dev)
 {
+	int ret = 0;
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
 	if (pm_runtime_suspended(dev))
-		return 0;
+		goto clk_unprepare;
+
+	ret = arm_smmu_runtime_suspend(dev);
+	if (ret)
+		return ret;
 
-	return arm_smmu_runtime_suspend(dev);
+clk_unprepare:
+	clk_bulk_unprepare(smmu->num_clks, smmu->clks);
+	return ret;
 }
 
 static const struct dev_pm_ops arm_smmu_pm_ops = {