[PATCH v3 0/2] Let iommupt manage changes in page size internally

[Jason Gunthorpe <jgg@nvidia.com>]

Currently the core code has some helpers that use iommu_pgsize() to
fragment operations into single page-size chunks and then the driver has a
simplified single-page size implementation. This was helpful in
simplifying the driver code.

However, iommupt has a single shared implementation for all formats so we
can accept a little more complexity. Have the core code directly call
iommupt with the requested range to map/unmap and rely on it to change the
page size across the range as required.

The iommupt implementation of unmap is already fine to work like this, and
the map implementation can reset its walking paramters in-place with a
little more code.

The net result is about a 5% performance bump in the simple iommupt
map/unmap benchmarks of mapped alignment, and probably more for
unaligned/oddly sized ranges that are changing page sizes.

Introduce a iommupt_from_domain() function as a general way to convert
an iommu_domain to a struct pt_iommu if it is a iommupt based domain. I
expect to keep using this as more optimizations are introduced.

v3:
 - Rebase to v7.0-rc1
v2: https://patch.msgid.link/r/0-v2-973a6bdc820f+693-iommpt_map_direct_jgg@nvidia.com
 - Rebase to latest iommu tree
 - Adjust to the IOMMU_DEBUG_PAGEALLOC work
 - Fix missed trace calls for both map and unmap
 - Add a comment explaining the level changes
v1: https://patch.msgid.link/r/0-v1-d7be57da596d+3f8c0-iommpt_map_direct_jgg@nvidia.com

Jason Gunthorpe (2):
  iommupt: Directly call iommupt's unmap_range()
  iommupt: Avoid rewalking during map

 drivers/iommu/generic_pt/iommu_pt.h         | 162 +++++++++++---------
 drivers/iommu/generic_pt/kunit_generic_pt.h |  12 ++
 drivers/iommu/generic_pt/pt_iter.h          |  22 +++
 drivers/iommu/iommu.c                       |  66 ++++++--
 include/linux/generic_pt/iommu.h            |  69 +++++++--
 include/linux/iommu.h                       |   1 +
 6 files changed, 231 insertions(+), 101 deletions(-)


base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
-- 
2.43.0