]> git.hungrycats.org Git - linux/commit
iommu/tegra-smmu: Parameterize number of TLB lines
authorThierry Reding <treding@nvidia.com>
Thu, 6 Aug 2015 12:20:31 +0000 (14:20 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 29 Sep 2015 17:33:33 +0000 (19:33 +0200)
commit218014334367fca6910477b2430dfa6680eebdf7
treee0248f04afd81e028676133e5d3cfae2ac0fb3ca
parentdd50b7122e71b900eba156031b88a5c6513f22bb
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>
drivers/iommu/tegra-smmu.c
drivers/memory/tegra/tegra114.c
drivers/memory/tegra/tegra124.c
drivers/memory/tegra/tegra30.c
include/soc/tegra/mc.h