On 2025/2/26 3:39, Jason Gunthorpe wrote:
Generally drivers have a specific idea what their HW structure size should be. In a lot of cases this is related to PAGE_SIZE, but not always. ARM64, for example, allows a 4K IO page table size on a 64K CPU page table system. Currently we don't have any good support for sub page allocations, but make the API accommodate this by accepting a sub page size from the caller and rounding up internally. This is done by moving away from order as the size input and using size: size == 1 << (order + PAGE_SHIFT) Following patches convert drivers away from using order and try to specify allocation sizes independent of PAGE_SIZE. Signed-off-by: Jason Gunthorpe<jgg@xxxxxxxxxx>
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
