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Commit fe941054 authored by Linux Build Service Account's avatar Linux Build Service Account Committed by Gerrit - the friendly Code Review server
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Merge "iommu/arm-smmu: add option to enable halt/resume of SMMU"

parents 987c601c a32e434e

Documentation/devicetree/bindings/iommu/arm,smmu.txt

+8 −0
Original line number Diff line number Diff line
@@ -110,6 +110,14 @@ conditions. 
		  useful if the upstream hardware is capable of switching

		  between multiple domains within a single context bank.



- qcom,enable-smmu-halt : Before SMMU is powered down, SMMU needs to be in

		  idle state prior to power collapse. When 'halt' is received by

		  SMMU, it ensures that no new requests enters and all

		  outstanding requests are completed and generates an

		  acknowledgment for halt request. So add an option to register

		  a call back notifier on regulators in whcih SMMU can be halted

		  or resumed when regulator is powered down/up.



- clocks        : List of clocks to be used during SMMU register access. See

                  Documentation/devicetree/bindings/clock/clock-bindings.txt

                  for information about the format. For each clock specified

drivers/iommu/arm-smmu.c

+51 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/notifier.h>



#include <linux/amba/bus.h>

#include <soc/qcom/msm_tz_smmu.h>
@@ -359,6 +360,7 @@ struct arm_smmu_device { 
#define ARM_SMMU_OPT_NO_M		(1 << 8)

#define ARM_SMMU_OPT_NO_SMR_CHECK	(1 << 9)

#define ARM_SMMU_OPT_DYNAMIC		(1 << 10)

#define ARM_SMMU_OPT_HALT		(1 << 11)

	u32				options;

	enum arm_smmu_arch_version	version;
@@ -385,6 +387,7 @@ struct arm_smmu_device { 
	struct clk			**clocks;



	struct regulator		*gdsc;

	struct notifier_block		regulator_nb;



	/* Protects against domains attaching to the same SMMU concurrently */

	struct mutex			attach_lock;
@@ -474,6 +477,7 @@ static struct arm_smmu_option_prop arm_smmu_options[] = { 
	{ ARM_SMMU_OPT_NO_M, "qcom,no-mmu-enable" },

	{ ARM_SMMU_OPT_NO_SMR_CHECK, "qcom,no-smr-check" },

	{ ARM_SMMU_OPT_DYNAMIC, "qcom,dynamic" },

	{ ARM_SMMU_OPT_HALT, "qcom,enable-smmu-halt"},

	{ 0, NULL},

};
@@ -2921,6 +2925,49 @@ static int arm_smmu_id_size_to_bits(int size) 
	}

}



static int regulator_notifier(struct notifier_block *nb,

		unsigned long event, void *data)

{

	int ret = 0;

	struct arm_smmu_device *smmu = container_of(nb,

					struct arm_smmu_device, regulator_nb);



	ret = arm_smmu_prepare_clocks(smmu);

	if (ret)

		goto out;



	ret = arm_smmu_enable_clocks_atomic(smmu);

	if (ret)

		goto unprepare_clock;



	if (event == REGULATOR_EVENT_DISABLE)

		arm_smmu_halt(smmu);

	else if (event == REGULATOR_EVENT_ENABLE)

		arm_smmu_resume(smmu);



	arm_smmu_disable_clocks_atomic(smmu);

unprepare_clock:

	arm_smmu_unprepare_clocks(smmu);

out:

	return ret;

}



static int register_regulator_notifier(struct arm_smmu_device *smmu)

{

	struct device *dev = smmu->dev;

	int ret = 0;



	if (smmu->options & ARM_SMMU_OPT_HALT) {

		smmu->regulator_nb.notifier_call = regulator_notifier;

		ret = regulator_register_notifier(smmu->gdsc,

						&smmu->regulator_nb);



		if (ret)

			dev_err(dev, "Regulator notifier request failed\n");

	}

	return ret;

}



static int arm_smmu_init_regulators(struct arm_smmu_device *smmu)

{

	struct device *dev = smmu->dev;
@@ -3349,6 +3396,10 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) 


	idr_init(&smmu->asid_idr);



	err = register_regulator_notifier(smmu);

	if (err)

		goto out_free_irqs;



	INIT_LIST_HEAD(&smmu->list);

	spin_lock(&arm_smmu_devices_lock);

	list_add(&smmu->list, &arm_smmu_devices);