From: Thierry Reding Date: Thu, 6 Aug 2015 12:20:31 +0000 (+0200) Subject: iommu/tegra-smmu: Parameterize number of TLB lines X-Git-Tag: v4.2.2~22 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=218014334367fca6910477b2430dfa6680eebdf7;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index c1f2e521dc52c..2cd439203d0f9 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c @@ -27,6 +27,7 @@ struct tegra_smmu { const struct tegra_smmu_soc *soc; unsigned long pfn_mask; + unsigned long tlb_mask; unsigned long *asids; struct mutex lock; @@ -68,7 +69,8 @@ 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) @@ -816,6 +818,9 @@ 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); @@ -825,7 +830,7 @@ 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 9f579589e8000..9bf11ea90549e 100644 --- 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 966e1557e6f41..70ed80d234317 100644 --- a/drivers/memory/tegra/tegra124.c +++ b/drivers/memory/tegra/tegra124.c @@ -1023,6 +1023,7 @@ 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 1abcd8f6f3ba6..b2a34fefabefe 100644 --- 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 1ab2813273cd1..bf2058690cebb 100644 --- a/include/soc/tegra/mc.h +++ b/include/soc/tegra/mc.h @@ -66,6 +66,7 @@ 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;