iommu/tegra-smmu: Parameterize number of TLB lines

commit 11cec15bf3fb498206ef63b1fa26c27689e02d0e upstream.

The number of TLB lines was increased from 16 on Tegra30 to 32 on
Tegra114 and later. Parameterize the value so that the initial default
can be set accordingly.

On Tegra30, initializing the value to 32 would effectively disable the
TLB and hence cause massive latencies for memory accesses translated
through the SMMU. This is especially noticeable for isochronuous clients
such as display, whose FIFOs would continuously underrun.

Fixes: 891846516317 ("memory: Add NVIDIA Tegra memory controller support")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index c845d99ecf6b8c50757998f08c86224c70064acb..e0ff5f4d7fed56a590952648ffcb50fa7568d9a9 100644 (file)
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -26,6 +26,7 @@ struct tegra_smmu {
        const struct tegra_smmu_soc *soc;
 
        unsigned long pfn_mask;
+       unsigned long tlb_mask;
 
        unsigned long *asids;
        struct mutex lock;
@@ -65,7 +66,8 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
 #define SMMU_TLB_CONFIG 0x14
 #define  SMMU_TLB_CONFIG_HIT_UNDER_MISS (1 << 29)
 #define  SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION (1 << 28)
-#define  SMMU_TLB_CONFIG_ACTIVE_LINES(x) ((x) & 0x3f)
+#define  SMMU_TLB_CONFIG_ACTIVE_LINES(smmu) \
+       ((smmu)->soc->num_tlb_lines & (smmu)->tlb_mask)
 
 #define SMMU_PTC_CONFIG 0x18
 #define  SMMU_PTC_CONFIG_ENABLE (1 << 29)
@@ -716,6 +718,9 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
        smmu->pfn_mask = BIT_MASK(mc->soc->num_address_bits - PAGE_SHIFT) - 1;
        dev_dbg(dev, "address bits: %u, PFN mask: %#lx\n",
                mc->soc->num_address_bits, smmu->pfn_mask);
+       smmu->tlb_mask = (smmu->soc->num_tlb_lines << 1) - 1;
+       dev_dbg(dev, "TLB lines: %u, mask: %#lx\n", smmu->soc->num_tlb_lines,
+               smmu->tlb_mask);
 
        value = SMMU_PTC_CONFIG_ENABLE | SMMU_PTC_CONFIG_INDEX_MAP(0x3f);
 
@@ -725,7 +730,7 @@ struct tegra_smmu *tegra_smmu_probe(struct device *dev,
        smmu_writel(smmu, value, SMMU_PTC_CONFIG);
 
        value = SMMU_TLB_CONFIG_HIT_UNDER_MISS |
-               SMMU_TLB_CONFIG_ACTIVE_LINES(0x20);
+               SMMU_TLB_CONFIG_ACTIVE_LINES(smmu);
 
        if (soc->supports_round_robin_arbitration)
                value |= SMMU_TLB_CONFIG_ROUND_ROBIN_ARBITRATION;

diff --git a/drivers/memory/tegra/tegra114.c b/drivers/memory/tegra/tegra114.c
index 511e9a25c151cda23f11bc73d2121ed7884175fa..16c4d26f51e727a90489240e1c9e769d5d21568a 100644 (file)
--- a/drivers/memory/tegra/tegra114.c
+++ b/drivers/memory/tegra/tegra114.c
@@ -935,6 +935,7 @@ static const struct tegra_smmu_soc tegra114_smmu_soc = {
        .num_swgroups = ARRAY_SIZE(tegra114_swgroups),
        .supports_round_robin_arbitration = false,
        .supports_request_limit = false,
+       .num_tlb_lines = 32,
        .num_asids = 4,
        .ops = &tegra114_smmu_ops,
 };

diff --git a/drivers/memory/tegra/tegra124.c b/drivers/memory/tegra/tegra124.c
index 278d40b854c15a6ae72629e9a5a83cd2539674d5..b153d0b732cf6a983a28df04ba8715da48b058a3 100644 (file)
--- a/drivers/memory/tegra/tegra124.c
+++ b/drivers/memory/tegra/tegra124.c
@@ -981,6 +981,7 @@ static const struct tegra_smmu_soc tegra124_smmu_soc = {
        .num_swgroups = ARRAY_SIZE(tegra124_swgroups),
        .supports_round_robin_arbitration = true,
        .supports_request_limit = true,
+       .num_tlb_lines = 32,
        .num_asids = 128,
        .ops = &tegra124_smmu_ops,
 };

diff --git a/drivers/memory/tegra/tegra30.c b/drivers/memory/tegra/tegra30.c
index 71fe9376fe53379180c4256b47ec15f576ab2f67..f422b18f45f3020724653cd205e0524ff7e1d781 100644 (file)
--- a/drivers/memory/tegra/tegra30.c
+++ b/drivers/memory/tegra/tegra30.c
@@ -957,6 +957,7 @@ static const struct tegra_smmu_soc tegra30_smmu_soc = {
        .num_swgroups = ARRAY_SIZE(tegra30_swgroups),
        .supports_round_robin_arbitration = false,
        .supports_request_limit = false,
+       .num_tlb_lines = 16,
        .num_asids = 4,
        .ops = &tegra30_smmu_ops,
 };

diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
index 63deb8d9f82af579cbcf3dfe7d96f47cfd04d7e8..d298857cd8459bd8641db6b7792253ab9da76448 100644 (file)
--- a/include/soc/tegra/mc.h
+++ b/include/soc/tegra/mc.h
@@ -59,6 +59,7 @@ struct tegra_smmu_soc {
        bool supports_round_robin_arbitration;
        bool supports_request_limit;
 
+       unsigned int num_tlb_lines;
        unsigned int num_asids;
 
        const struct tegra_smmu_ops *ops;