iommu/tegra-smmu: Parameterize number of TLB lines

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>

3 files changed, 3 insertions, 0 deletions

diff --git a/drivers/memory/tegra/tegra114.c b/drivers/memory/tegra/tegra114.c
index 7122f39..8053f70 100644
--- a/drivers/memory/tegra/tegra114.c
+++ b/drivers/memory/tegra/tegra114.c
@@ -919,6 +919,7 @@ 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,
 };
 
diff --git a/drivers/memory/tegra/tegra124.c b/drivers/memory/tegra/tegra124.c
index ebda632..7d734bef 100644
--- a/drivers/memory/tegra/tegra124.c
+++ b/drivers/memory/tegra/tegra124.c
@@ -1029,6 +1029,7 @@ static const struct tegra_smmu_soc tegra132_smmu_soc = {
 	.num_swgroups = ARRAY_SIZE(tegra124_swgroups),
 	.supports_round_robin_arbitration = true,
 	.supports_request_limit = true,
+	.num_tlb_lines = 32,
 	.num_asids = 128,
 };
 
diff --git a/drivers/memory/tegra/tegra30.c b/drivers/memory/tegra/tegra30.c
index 3cb30b6..7e0694d 100644
--- a/drivers/memory/tegra/tegra30.c
+++ b/drivers/memory/tegra/tegra30.c
@@ -941,6 +941,7 @@ 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,
 };