[PATCH] memory: Add NVIDIA SMMU suspend/resume support

From: Mark Zhang
Date: Mon Dec 08 2014 - 01:22:16 EST

This patch adds suspend/resume support for NVIDIA SMMU.
This patch is created on top of Thierry Reding's patch set:

"[PATCH v7 00/12] NVIDIA Tegra memory controller and IOMMU support"

Signed-off-by: Mark Zhang <markz@xxxxxxxxxx>
---
drivers/iommu/tegra-smmu.c | 79 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/memory/tegra/mc.c | 21 ++++++++++++
drivers/memory/tegra/mc.h | 4 +++
3 files changed, 103 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 0909e0bae9ec..ab38805055a4 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -17,6 +17,8 @@
#include <soc/tegra/ahb.h>
#include <soc/tegra/mc.h>

+struct tegra_smmu_as;
+
struct tegra_smmu {
void __iomem *regs;
struct device *dev;
@@ -25,9 +27,10 @@ struct tegra_smmu {
const struct tegra_smmu_soc *soc;

unsigned long *asids;
+ struct tegra_smmu_as **as;
struct mutex lock;

- struct list_head list;
+ struct list_head swgroup_asid_list;
};

struct tegra_smmu_as {
@@ -40,6 +43,12 @@ struct tegra_smmu_as {
u32 attr;
};

+struct tegra_smmu_swgroup_asid {
+ struct list_head list;
+ unsigned swgroup_id;
+ unsigned asid;
+};
+
static inline void smmu_writel(struct tegra_smmu *smmu, u32 value,
unsigned long offset)
{
@@ -376,6 +385,7 @@ static int tegra_smmu_as_prepare(struct tegra_smmu *smmu,
as->smmu = smmu;
as->use_count++;

+ smmu->as[as->id] = as;
return 0;
}

@@ -386,6 +396,7 @@ static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
return;

tegra_smmu_free_asid(smmu, as->id);
+ smmu->as[as->id] = NULL;
as->smmu = NULL;
}

@@ -398,6 +409,7 @@ static int tegra_smmu_attach_dev(struct iommu_domain *domain,
struct of_phandle_args args;
unsigned int index = 0;
int err = 0;
+ struct tegra_smmu_swgroup_asid *sa = NULL;

while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
&args)) {
@@ -411,6 +423,14 @@ static int tegra_smmu_attach_dev(struct iommu_domain *domain,
return err;

tegra_smmu_enable(smmu, swgroup, as->id);
+
+ sa = kzalloc(sizeof(struct tegra_smmu_swgroup_asid),
+ GFP_KERNEL);
+ INIT_LIST_HEAD(&sa->list);
+ sa->swgroup_id = swgroup;
+ sa->asid = as->id;
+ list_add_tail(&sa->list, &smmu->swgroup_asid_list);
+
index++;
}

@@ -427,6 +447,7 @@ static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *de
struct tegra_smmu *smmu = as->smmu;
struct of_phandle_args args;
unsigned int index = 0;
+ struct tegra_smmu_swgroup_asid *sa = NULL;

while (of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
&args)) {
@@ -435,6 +456,13 @@ static void tegra_smmu_detach_dev(struct iommu_domain *domain, struct device *de
if (args.np != smmu->dev->of_node)
continue;

+ list_for_each_entry(sa, &smmu->swgroup_asid_list, list) {
+ if (sa->asid == as->id && sa->swgroup_id == swgroup)
+ break;
+ }
+ list_del(&sa->list);
+ kfree(sa);
+
tegra_smmu_disable(smmu, swgroup, as->id);
tegra_smmu_as_unprepare(smmu, as);
index++;
@@ -651,6 +679,48 @@ static void tegra_smmu_ahb_enable(void)
}
}

+void tegra_smmu_resume(struct tegra_smmu *smmu)
+{
+ struct tegra_smmu_as *as = NULL;
+ unsigned int bit;
+ u32 value;
+ struct tegra_smmu_swgroup_asid *sa = NULL;
+
+ for_each_set_bit(bit, smmu->asids, smmu->soc->num_asids) {
+ as = smmu->as[bit];
+ smmu->soc->ops->flush_dcache(as->pd, 0, SMMU_SIZE_PD);
+
+ smmu_writel(smmu, as->id & 0x7f, SMMU_PTB_ASID);
+ value = SMMU_PTB_DATA_VALUE(as->pd, as->attr);
+ smmu_writel(smmu, value, SMMU_PTB_DATA);
+ }
+
+ list_for_each_entry(sa, &smmu->swgroup_asid_list, list)
+ tegra_smmu_enable(smmu, sa->swgroup_id, sa->asid);
+
+ value = SMMU_PTC_CONFIG_ENABLE | SMMU_PTC_CONFIG_INDEX_MAP(0x3f);
+
+ if (smmu->soc->supports_request_limit)
+ value |= SMMU_PTC_CONFIG_REQ_LIMIT(8);
+
+ smmu_writel(smmu, value, SMMU_PTC_CONFIG);
+
+ value = SMMU_TLB_CONFIG_HIT_UNDER_MISS |
+ SMMU_TLB_CONFIG_ACTIVE_LINES(0x20);
+
+ if (smmu->soc->supports_round_robin_arbitration)
+ value |= SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION;
+
+ smmu_writel(smmu, value, SMMU_TLB_CONFIG);
+
+ smmu_flush_ptc(smmu, NULL, 0);
+ smmu_flush_tlb(smmu);
+ smmu_writel(smmu, SMMU_CONFIG_ENABLE, SMMU_CONFIG);
+ smmu_flush(smmu);
+
+ tegra_smmu_ahb_enable();
+}
+
struct tegra_smmu *tegra_smmu_probe(struct device *dev,
const struct tegra_smmu_soc *soc,
struct tegra_mc *mc)
@@ -684,7 +754,14 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
if (!smmu->asids)
return ERR_PTR(-ENOMEM);

+ smmu->as = devm_kzalloc(dev,
+ sizeof(struct tegra_smmu_as *) * soc->num_asids,
+ GFP_KERNEL);
+ if (!smmu->as)
+ return ERR_PTR(-ENOMEM);
+
mutex_init(&smmu->lock);
+ INIT_LIST_HEAD(&smmu->swgroup_asid_list);

smmu->regs = mc->regs;
smmu->soc = soc;
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 9b7c1645fd59..aa0c59ccd33a 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -283,6 +283,23 @@ static int tegra_mc_probe(struct platform_device *pdev)
return 0;
}

+#ifdef CONFIG_PM
+static int tegra_mc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ return 0;
+}
+
+static int tegra_mc_resume(struct platform_device *pdev)
+{
+ struct tegra_mc *mc = platform_get_drvdata(pdev);
+
+ if (IS_ENABLED(CONFIG_TEGRA_IOMMU_SMMU))
+ tegra_smmu_resume(mc->smmu);
+
+ return 0;
+}
+#endif
+
static struct platform_driver tegra_mc_driver = {
.driver = {
.name = "tegra-mc",
@@ -291,6 +308,10 @@ static struct platform_driver tegra_mc_driver = {
},
.prevent_deferred_probe = true,
.probe = tegra_mc_probe,
+#ifdef CONFIG_PM
+ .suspend = tegra_mc_suspend,
+ .resume = tegra_mc_resume,
+#endif
};

static int tegra_mc_init(void)
diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
index f714c309b960..cbf538b3f995 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -29,6 +29,7 @@ static inline void mc_writel(struct tegra_mc *mc, u32 value,
struct tegra_smmu *tegra_smmu_probe(struct device *dev,
const struct tegra_smmu_soc *soc,
struct tegra_mc *mc);
+void tegra_smmu_resume(struct tegra_smmu *smmu);
#else
static inline struct tegra_smmu *
tegra_smmu_probe(struct device *dev, const struct tegra_smmu_soc *soc,
@@ -36,6 +37,9 @@ tegra_smmu_probe(struct device *dev, const struct tegra_smmu_soc *soc,
{
return NULL;
}
+void tegra_smmu_resume(struct tegra_smmu *smmu)
+{
+}
#endif

#ifdef CONFIG_ARCH_TEGRA_3x_SOC
--
1.8.1.5

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