Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Mon, 9 Jul 2018 11:23:19 +0200 | Subject | Re: [RESEND PATCH v2] devres: Really align data field to unsigned long long |
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On Mon, Jul 9, 2018 at 11:15 AM David Laight <David.Laight@aculab.com> wrote: > From: Alexey Brodkin > > Sent: 09 July 2018 05:45 > > Depending on ABI "long long" type of a particular 32-bit CPU > > might be aligned by either word (32-bits) or double word (64-bits). > > Make sure "data" is really 64-bit aligned for any 32-bit CPU. > > > > At least for 32-bit ARC cores ABI requires "long long" types > > to be aligned by normal 32-bit word. This makes "data" field aligned to > > 12 bytes. Which is still OK as long as we use 32-bit data only. > > > > But once we want to use native atomic64_t type (i.e. when we use special > > instructions LLOCKD/SCONDD for accessing 64-bit data) we easily hit > > misaligned access exception. > > Shouldn't there be a typedef for the actual type. > Perhaps it is even atomic64_t ? > And have the __aligned(8) applied to that typedef ??
That indeed sounds like the best thing to do, as it will fix this issue in other places, too.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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