lwn.git/drivers/iommu/tegra-gart.c, branch docs-5.2a

iommu/tegra: gart: Perform code refactoring

2019-01-16T12:54:16+00:00

Removed redundant safety-checks in the code and some debug code that isn't actually very useful for debugging, like enormous pagetable dump on each fault. The majority of the changes are code reshuffling, variables/whitespaces clean up and removal of debug messages that duplicate messages of the IOMMU-core. Now the GART translation is kept disabled while GART is suspended. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Simplify clients-tracking code

2019-01-16T12:54:14+00:00

GART is a simple IOMMU provider that has single address space. There is no need to setup global clients list and manage it for tracking of the active domain, hence lot's of code could be safely removed and replaced with a simpler alternative. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Don't detach devices from inactive domains

2019-01-16T12:54:14+00:00

There could be unlimited number of allocated domains, but only one domain can be active at a time. Hence devices must be detached only from the active domain. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Prepend error/debug messages with "gart:"

2019-01-16T12:54:14+00:00

GART became a part of Memory Controller, hence now the drivers device is Memory Controller and not GART. As a result all printed messages are prepended with the "tegra-mc 7000f000.memory-controller:", so let's prepend GART's messages with "gart:" in order to differentiate them from the MC. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Don't use managed resources

2019-01-16T12:54:14+00:00

GART is a part of the Memory Controller driver that is always built-in, hence there is no benefit from the use of managed resources. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Allow only one active domain at a time

2019-01-16T12:54:14+00:00

GART has a single address space that is shared by all devices, hence only one domain could be active at a time. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Fix NULL pointer dereference

2019-01-16T12:54:14+00:00

Fix NULL pointer dereference on IOMMU domain destruction that happens because clients list is being iterated unsafely and its elements are getting deleted during the iteration. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Fix spinlock recursion

2019-01-16T12:54:14+00:00

Fix spinlock recursion bug that happens on IOMMU domain destruction if any of the allocated domains have devices attached to them. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel

iommu/tegra: gart: Integrate with Memory Controller driver

2019-01-16T12:54:12+00:00

The device-tree binding has been changed. There is no separate GART device anymore, it is squashed into the Memory Controller. Integrate GART module with the MC in a way it is done for the SMMU on Tegra30+. Signed-off-by: Dmitry Osipenko Signed-off-by: Joerg Roedel

iommu/tegra: gart: Optimize mapping / unmapping performance

2019-01-16T12:54:09+00:00

Currently GART writes one page entry at a time. More optimal would be to aggregate the writes and flush BUS buffer in the end, this gives map/unmap 10-40% performance boost (depending on size of mapping) in comparison to flushing after each page entry update. Signed-off-by: Dmitry Osipenko Acked-by: Thierry Reding Signed-off-by: Joerg Roedel