[PATCH v1 0/9] Tegra GART driver clean up and optimization

From: Dmitry Osipenko
Date: Tue May 08 2018 - 14:17:38 EST


This series addresses multiple shortcomings of the GART driver:

1. Thierry noticed that Memory Controller driver uses registers that belong
to GART in [0] and for now MC driver only reports the fact of GART's page
fault. The first two patches of the series are addressing this shortcoming.

[0] https://www.spinics.net/lists/linux-tegra/msg33072.html

2. Currently GART is kept disabled by the commit c7e3ca515e784 ("iommu/tegra:
gart: Do not register with bus"). If GART is re-enabled than all devices
in the system are getting assigned to the GART as it is a global systems
IOMMU provider. This is wrong simply because GART doesn't handle all those
devices. This series makes GART to accept only devices that are explicitly
assigned to GART in device tree using 'iommu' phandle.

3. This series makes a generic clean up of the driver by removing dead code,
allowing to have one IOMMU domain at max, etc.

4. This series introduces and utilizes iotlb_sync_map() callback that was
previously suggested by Joerg Roedel in [1].

[1] https://www.spinics.net/lists/linux-tegra/msg32914.html

Dmitry Osipenko (9):
memory: tegra: Provide facility for integration with the GART driver
iommu/tegra: gart: Provide access to Memory Controller driver
iommu/tegra: gart: Remove code related to module unloading
iommu/tegra: gart: Remove pr_fmt and clean up includes
iommu/tegra: gart: Clean up driver probe failure unwinding
iommu/tegra: gart: Ignore devices without IOMMU phandle in DT
iommu/tegra: gart: Provide single domain and group for all devices
iommu: Introduce iotlb_sync_map callback
iommu/tegra: gart: Optimize mapping / unmapping performance

drivers/iommu/iommu.c | 8 +-
drivers/iommu/tegra-gart.c | 216 +++++++++++++++++--------------------
drivers/memory/tegra/mc.c | 26 ++++-
include/linux/iommu.h | 1 +
include/soc/tegra/mc.h | 13 +++
5 files changed, 143 insertions(+), 121 deletions(-)