On Wed, 2008-10-08 at 09:13 +0200, Geert Uytterhoeven wrote: > On Tue, 7 Oct 2008, Harvey Harrison wrote: > > [related question regarding the SCSI-private endian helper needs at the end] > > > > Currently on the read side, we have (le16 as an example endianness) > > > > le16_to_cpup(__le16 *) > > get_unaligned_le16(void *) > > > > And on the write side: > > > > *(__le16)ptr = cpu_to_le16(u16) > > put_unaligned_le16(u16, void *); > > > > On the read side, Al said he would have preferred the unaligned version > > take the same types as the aligned, rather than void *. AKPM didn't think > > As I said before, me too (take the same types as the aligned). I like to > rely on sparse for: > > struct { > ... > __le32 x; > ... > } s __attribute__ ((packed)); > > get_unaligned_le16(&s.x); Agreed. > > > the use of get_ was that great as get/put generally implies some kind of reference > > taking in the kernel. > > OK. > > > As the le16_to_cpup has been around for so long and is more recognizable, let's > > make it the same for the unaligned case and typesafe: > > > > le16_to_cpup(__le16 *) > > unaligned_le16_to_cpup(__le16 *) > > I always hated that naming... True, but there are already lots of places that use them...and I didn't want to introduce an identical name for something that already exists, so I worked using the existing name. I think load_le16/load_unaligned_le16 is the best so far, but I can see people being unhappy with the duplication of le16_to_cpup. But it is trivial to move existing users over if that's the way the decision goes. > > > On the write side, the above get/put and type issues are still there, in addition AKPM felt > > that the ordering of the put_unaligned parameters was opposite what was intuitive and that > > the pointer should come first. > > > > In this case, as there is currently no aligned helper (other than in some drivers defining macros) > > define the api thusly: > > > > Aligned: > > write_le16(__le16 *ptr, u16 val) > > > > Unaligned: > > unaligned_write_le16(__le16 *ptr, u16 val) > > Does it write to MMIO I/O space? No? Then please don't use write (like > in writeb()). > > What about load_{unaligned_,}le16() and store_{unaligned_,}le16()? OK, will stay away from write as well. I think store looks good, with load_ there is still a question of duplicating existing functionality. Thanks for the feedback. Harvey -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html