On 2022-01-11 4:02 p.m., Jason Gunthorpe wrote: > On Tue, Jan 11, 2022 at 03:57:07PM -0700, Logan Gunthorpe wrote: >> >> >> On 2022-01-11 3:53 p.m., Jason Gunthorpe wrote: >>> I just want to share the whole API that will have to exist to >>> reasonably support this flexible array of intervals data structure.. >> >> Is that really worth it? I feel like type safety justifies replicating a >> bit of iteration and allocation infrastructure. Then there's no silly >> mistakes of thinking one array is one thing when it is not. > > If it is a 'a bit' then sure, but I suspect doing a good job here will > be a lot of code here. > > Look at how big scatterlist is, for instance. Yeah, but scatterlist has a ton of cruft; numerous ways to allocate, multiple iterators, developers using it in different ways, etc, etc. It's a big mess. bvec.h is much smaller (though includes stuff that wouldn't necessarily be appropriate here). Also some things apply to one but not the other. eg: a memcpy to/from function might make sense for a phy_range but makes no sense for a dma_range. > Maybe we could have a generic 64 bit interval arry and then two type > wrappers that do dma and physaddr casting? IDK. > > Not sure type safety of DMA vs CPU address is critical? I would argue it is. A DMA address is not a CPU address and should not be treated the same. Logan
