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Every driver therefore implements its own loop over the > array, and a driver wanting to process that array in fixed-size chunks > (e.g. to issue commands out of a fixed-size on-stack buffer) has to carry > the loop and its sub-array bookkeeping all on its own. > > Move the iteration into the iommufd core instead. Invoke the op with a > sub-array that starts at the first not-yet-handled entry, let it handle a > prefix of that sub-array and report the count via array->entry_num, then > advance the base pointer and re-invoke the op until the entire array has > been consumed or until the op returns an error along the way. > > A driver that handles the entire window in one single call, as all of the > current drivers happen to do, finishes the loop in just one pass, so this > does not change any of the existing behavior. It instead lets each of the > drivers convert to bounded chunk processing on its own, done by each of the > subsequent changes. > > Suggested-by: Jason Gunthorpe > Reviewed-by: Kevin Tian > Reviewed-by: Lu Baolu > Reviewed-by: Pranjal Shrivastava > Assisted-by: Claude:claude-opus-4-8 > Signed-off-by: Nicolin Chen > --- > include/linux/iommu.h | 6 ++++-- > include/linux/iommufd.h | 2 ++ > drivers/iommu/iommufd/hw_pagetable.c | 25 +++++++++++++++---------- > 3 files changed, 21 insertions(+), 12 deletions(-) Reviewed-by: Jason Gunthorpe Jason