Re: [PATCH] NVMe: Fix compilation on architecturs without readq/writeq

From: Hitoshi Mitake
Date: Sun Feb 05 2012 - 02:01:44 EST

On Sun, Feb 5, 2012 at 15:53, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> On Sat, Feb 4, 2012 at 16:39, Hitoshi Mitake <h.mitake@xxxxxxxxx> wrote:
>>> I worked myself on a driver (which sadly never shipped) which had an WC
>>> window and a UC window... the final write in a series had a completion bit
>>> in it and would go to the UC window after setting up a whole chunk of
>>> operations in the WC window (writing UC memory flushes WC memory ahead of
>>> it.)
>>> Thus, the two-part breakdown of writeq() to the UC window had to write the
>>> low half to the WC window instead.  This is clearly not generic.
>> Because of my ignorant, I don't know the words "UC window" and "WC window"
>> in this context. Could you teach me?
> UN = uncached, WC = writecombining.

Thanks a lot for your teaching!

> Gr{oetje,eeting}s,
>                         Geert
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
> 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

Hitoshi Mitake
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