This series introduces the iova_to_phys_length interface across the IOMMU
subsystem. The new callback returns both the physical address and the PTE
mapping size in a single page table walk, enabling callers such as iommufd
and VFIO to traverse IOVA space efficiently by actual mapping granularity
instead of fixed PAGE_SIZE steps.
Motivation
==========
The current iova_to_phys interface only returns a physical address with no
indication of the mapping page size. This forces callers to iterate one
PAGE_SIZE at a time when collecting PFNs or unmapping IOVA ranges, which is
extremely inefficient for large mappings (e.g., 2MB or 1GB huge pages
require 512 or 262144 page-table walks respectively).
The new iova_to_phys_length interface solves this by providing the
contiguous mapping size alongside the physical address in a single walk.
Design
======
Core layer (patch 1):
- Adds iova_to_phys_length to iommu_domain_ops
- iommu_iova_to_phys_length() detects invalid states by checking
ops->iova_to_phys_length (not domain->type), returns PHYS_ADDR_MAX
on error
- iommu_iova_to_phys() is preserved as a thin wrapper calling
iova_to_phys_length internally, converting PHYS_ADDR_MAX back to 0
for historical API compatibility
io-pgtable backends (patches 2-4):
- ARM LPAE, ARM v7s, and DART each implement iova_to_phys_length
returning phys + page size, with PHYS_ADDR_MAX for error paths
- The old iova_to_phys is kept temporarily as a wrapper
generic_pt framework (patch 5):
- Implements iova_to_phys_length using pt_entry_oa_lg2sz() which
already accounts for contiguous PTE hints, returning the correct
mapping size in a single leaf-entry lookup
Per-driver migration (patches 6-22):
- Each IOMMU driver (arm-smmu-v3, arm-smmu, qcom, apple-dart,
ipmmu-vmsa, mtk, exynos, fsl_pamu, msm, omap, rockchip, s390,
sprd, sun50i, tegra-smmu, virtio) implements iova_to_phys_length
in its own atomic commit
- All error paths return PHYS_ADDR_MAX
Caller conversion (patches 23-25):
- iommufd/pages.c uses iova_to_phys_length to batch PFN collection
by actual mapping granularity
- VFIO type1 uses iova_to_phys_length for efficient unmap traversal
- drm/panfrost and drm/panthor switch to the new interface
Cleanup (patches 26-30):
- io-pgtable selftests switch to iova_to_phys_length
- Remove deprecated iova_to_phys wrappers from io-pgtable backends
- Remove iova_to_phys from iommu_domain_ops and io_pgtable_ops
Changes in v2:
- Use PHYS_ADDR_MAX (~(phys_addr_t)0) as error return instead of 0
throughout the entire call chain, per review feedback (Jason)
- Detect invalid domain states by checking ops->iova_to_phys_length
rather than domain->type == IOMMU_DOMAIN_BLOCKED (Jason)
- iommu_iova_to_phys() wrapper converts PHYS_ADDR_MAX -> 0 to
maintain historical semantic for existing callers
- generic_pt: use pt_entry_oa_lg2sz() which already handles
contiguous PTE hints natively (Jason)
- All drivers updated to return PHYS_ADDR_MAX for error/fault paths
instead of 0
Guanghui Feng (30):
iommu: introduce iova_to_phys_length in iommu_domain_ops
iommu/io-pgtable-arm: introduce iova_to_phys_length in io_pgtable_ops
iommu/io-pgtable-arm-v7s: introduce iova_to_phys_length in
io_pgtable_ops
iommu/io-pgtable-dart: introduce iova_to_phys_length in io_pgtable_ops
iommu/generic_pt: implement iova_to_phys_length
iommu/arm-smmu-v3: implement iova_to_phys_length
iommu/arm-smmu: implement iova_to_phys_length
iommu/qcom_iommu: implement iova_to_phys_length
iommu/apple-dart: implement iova_to_phys_length
iommu/ipmmu-vmsa: implement iova_to_phys_length
iommu/mtk_iommu: implement iova_to_phys_length
iommu/exynos: implement iova_to_phys_length
iommu/fsl_pamu: implement iova_to_phys_length
iommu/msm: implement iova_to_phys_length
iommu/mtk_v1: implement iova_to_phys_length
iommu/omap: implement iova_to_phys_length
iommu/rockchip: implement iova_to_phys_length
iommu/s390: implement iova_to_phys_length
iommu/sprd: implement iova_to_phys_length
iommu/sun50i: implement iova_to_phys_length
iommu/tegra-smmu: implement iova_to_phys_length
iommu/virtio: implement iova_to_phys_length
vfio/iommufd: use iova_to_phys_length for efficient unmap
drm/panfrost: switch to iova_to_phys_length
drm/panthor: switch to iova_to_phys_length
iommu/io-pgtable: selftests switch to iova_to_phys_length
iommu/io-pgtable-arm: remove deprecated iova_to_phys wrapper
iommu/io-pgtable-arm-v7s: remove deprecated iova_to_phys wrapper
iommu/io-pgtable-dart: remove deprecated iova_to_phys wrapper
iommu: remove iova_to_phys from domain_ops and io_pgtable_ops
drivers/gpu/drm/panfrost/panfrost_mmu.c | 2 +-
drivers/gpu/drm/panthor/panthor_mmu.c | 2 +-
drivers/iommu/apple-dart.c | 13 ++--
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 12 ++-
.../iommu/arm/arm-smmu/arm-smmu-qcom-debug.c | 2 +-
drivers/iommu/arm/arm-smmu/arm-smmu.c | 15 ++--
drivers/iommu/arm/arm-smmu/qcom_iommu.c | 13 ++--
drivers/iommu/exynos-iommu.c | 23 ++++--
drivers/iommu/fsl_pamu_domain.c | 28 ++++++-
drivers/iommu/generic_pt/iommu_pt.h | 57 ++++++++------
drivers/iommu/io-pgtable-arm-selftests.c | 12 +--
drivers/iommu/io-pgtable-arm-v7s.c | 27 ++++---
drivers/iommu/io-pgtable-arm.c | 16 ++--
drivers/iommu/io-pgtable-dart.c | 21 ++++--
drivers/iommu/iommu.c | 32 +++++++-
drivers/iommu/iommufd/pages.c | 75 ++++++++++++++++---
drivers/iommu/iommufd/selftest.c | 2 +-
drivers/iommu/ipmmu-vmsa.c | 12 ++-
drivers/iommu/msm_iommu.c | 29 +++++--
drivers/iommu/mtk_iommu.c | 14 +++-
drivers/iommu/mtk_iommu_v1.c | 16 +++-
drivers/iommu/omap-iommu.c | 34 ++++++---
drivers/iommu/rockchip-iommu.c | 13 +++-
drivers/iommu/s390-iommu.c | 21 ++++--
drivers/iommu/sprd-iommu.c | 20 +++--
drivers/iommu/sun50i-iommu.c | 17 +++--
drivers/iommu/tegra-smmu.c | 14 +++-
drivers/iommu/virtio-iommu.c | 15 +++-
drivers/vfio/vfio_iommu_type1.c | 26 +++++--
include/linux/generic_pt/iommu.h | 13 ++--
include/linux/io-pgtable.h | 10 ++-
include/linux/iommu.h | 12 ++-
32 files changed, 443 insertions(+), 175 deletions(-)
--
2.43.7
