On Wednesday 19 June 2013, David Daney wrote: > On 06/19/2013 03:01 AM, Arnd Bergmann wrote: > > It's also wrong to use the > > __raw_* variant, which is not guaranteed to be atomic and is not > > endian-safe. > > We do runtime probing and only use this function on platforms where it > is appropriate, so atomicity is not an issue. As for endianess, I used > the __raw_ variant precisely because it is correct for both big and > little endian kernels. You don't know what the compiler turns a __raw_writeq into, it could always to eight byte wise stores, that's why typically writeq is an inline assembly while __raw_writeq is just a pointer dereference. __raw_* never do endian swaps, so it will be wrong on either big-endian CPUs or on little-endian CPUs, depending on what the MMIO register needs. Arnd
