I think this is moving into the wrong direction. The right fix here is to get of all the dma_attrs boilerplate code and just replace it with a simple enum dma_flags. This would simplify both the callers and most importantly the wrappers for the flag-less versions a lot.
- [PATCH 0/4] dma-mapping: Constify dma_attrs Krzysztof Kozlowski
- [RFC 4/4] dma-mapping: Constify dma_attrs Krzysztof Kozlowski
- [PATCH 1/4] dma-mapping: Constify attrs pass... Krzysztof Kozlowski
- [PATCH 3/4] arm64: dma-mapping: Constify att... Krzysztof Kozlowski
- [PATCH 2/4] ARM: dma-mapping: Constify attrs... Krzysztof Kozlowski
- Re: [PATCH 2/4] ARM: dma-mapping: Consti... Russell King - ARM Linux
- Re: [PATCH 0/4] dma-mapping: Constify dma_at... Christoph Hellwig
- Re: [PATCH 0/4] dma-mapping: Constify dm... Krzysztof Kozlowski