[0/3] iommu/arm-smmu-v3: Reduce latency in __arm_smmu_tlb_inv_range()

Message

Nicolin Chen Aug. 22, 2023, 8:45 a.m. UTC

This series is reformatted from the tlb_invalidate_threshold patch:
https://lore.kernel.org/linux-iommu/ZN5oojF6vKOKB%2FeI@Asurada-Nvidia/
The discussion in the thread above moved towards the direction of adding
an arbitrary max_tlbi_ops (similar to MAX_TLBI_OPS in tlbflush.h file).

The changes here aim to reduce the latency in __arm_smmu_tlb_inv_range()
due to the large number of TLBI commands on an SMMU without the support
of range TLBI commands. The solution is to add a threshold at the number
of TLBI commands that one __arm_smmu_tlb_inv_range() callback can issue,
and to replace those TLBI commands with one single per-asid or per-vmid
TLBI command.

Nicolin Chen (3):
  iommu/io-pgtable-arm: Add nents_per_pgtable in struct io_pgtable_cfg
  iommu/arm-smmu-v3: Add an arm_smmu_tlb_inv_domain helper
  iommu/arm-smmu-v3: Add a max_tlbi_ops for __arm_smmu_tlb_inv_range()

 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 34 +++++++++++++++------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  1 +
 drivers/iommu/io-pgtable-arm.c              |  3 ++
 include/linux/io-pgtable.h                  |  2 ++
 4 files changed, 30 insertions(+), 10 deletions(-)