[PATCH v2] memory: Add NVIDIA SMMU suspend/resume support

From: Mark Zhang
Date: Tue Dec 23 2014 - 20:10:58 EST


This patch adds suspend/resume support for NVIDIA SMMU.

Signed-off-by: Mark Zhang <markz@xxxxxxxxxx>
---
Hi Alex/Olof/Thierry/Hiroshi,

This patch is created on top of Thierry Reding's patch set:
"[PATCH v7 00/12] NVIDIA Tegra memory controller and IOMMU support"

Changes since v1:
- Remove the list which saves "tegra_smmu_swgroup_asid" instances
- Save all ASID registers when suspend then restore them when resume

drivers/iommu/tegra-smmu.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/memory/tegra/mc.c | 24 ++++++++++++++++
drivers/memory/tegra/mc.h | 8 ++++++
3 files changed, 103 insertions(+)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 0909e0bae9ec..e735840d35d8 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;
@@ -25,8 +27,11 @@ struct tegra_smmu {
const struct tegra_smmu_soc *soc;

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

+ u32 *asid_reg_save;
+
struct list_head list;
};

@@ -376,6 +381,7 @@ 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 +392,7 @@ 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;
}

@@ -651,6 +658,58 @@ static void tegra_smmu_ahb_enable(void)
}
}

+void tegra_smmu_suspend(struct tegra_smmu *smmu)
+{
+ int i;
+
+ for (i = 0; i < smmu->soc->num_swgroups; i++)
+ smmu->asid_reg_save[i] = smmu_readl(smmu,
+ smmu->soc->swgroups[i].reg);
+}
+
+void tegra_smmu_resume(struct tegra_smmu *smmu)
+{
+ struct tegra_smmu_as *as;
+ unsigned int bit;
+ u32 value;
+ int i;
+
+ 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);
+ }
+
+ for (i = 0; i < smmu->soc->num_swgroups; i++)
+ smmu_writel(smmu, smmu->asid_reg_save[i],
+ smmu->soc->swgroups[i].reg);
+
+ 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)
@@ -684,6 +743,18 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
if (!smmu->asids)
return ERR_PTR(-ENOMEM);

+ smmu->asid_reg_save = devm_kzalloc(dev,
+ sizeof(u32) * smmu->soc->num_swgroups,
+ GFP_KERNEL);
+ if (!smmu->asid_reg_save)
+ 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);

smmu->regs = mc->regs;
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 9b7c1645fd59..f48368fca423 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -283,6 +283,28 @@ static int tegra_mc_probe(struct platform_device *pdev)
return 0;
}

+#ifdef CONFIG_PM_SLEEP
+static int tegra_mc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct tegra_mc *mc = platform_get_drvdata(pdev);
+
+ if (IS_ENABLED(CONFIG_TEGRA_IOMMU_SMMU))
+ tegra_smmu_suspend(mc->smmu);
+
+ 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 +313,8 @@ static struct platform_driver tegra_mc_driver = {
},
.prevent_deferred_probe = true,
.probe = tegra_mc_probe,
+ .suspend = tegra_mc_suspend,
+ .resume = tegra_mc_resume,
};

static int tegra_mc_init(void)
diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
index f714c309b960..efc45ceed5ba 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -29,6 +29,8 @@ 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_suspend(struct tegra_smmu *smmu);
+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 +38,12 @@ tegra_smmu_probe(struct device *dev, const struct tegra_smmu_soc *soc,
{
return NULL;
}
+void tegra_smmu_suspend(struct tegra_smmu *smmu)
+{
+}
+void tegra_smmu_resume(struct tegra_smmu *smmu)
+{
+}
#endif

#ifdef CONFIG_ARCH_TEGRA_3x_SOC
--
1.8.1.5

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