2nd version of https://patchwork.freedesktop.org/series/99378/ As first patch I'm including the dma-buf-map rename to iosys-map for completeness and to allow the other patches to be reviewed. However the first patch was also sent by itself. I think all the feedback from v1 was incorporated in this version. All the new helpers in iosys-map were squashed in a single patch as requested. Original cover letter: While porting i915 to arm64 we noticed some issues accessing lmem. Some writes were getting corrupted and the final state of the buffer didn't have exactly what we wrote. This became evident when enabling GuC submission: depending on the number of engines the ADS struct was being corrupted and GuC would reject it, refusin to initialize.