From: Damien Lespiau <damien.lespiau@intel.com>
To: Dave Gordon <david.s.gordon@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915/bdw: Fix the write setting up the WIZ hashing mode
Date: Mon, 8 Dec 2014 14:36:18 +0000 [thread overview]
Message-ID: <20141208143618.GA6041@strange.ger.corp.intel.com> (raw)
In-Reply-To: <5485B309.50103@intel.com>
On Mon, Dec 08, 2014 at 02:17:45PM +0000, Dave Gordon wrote:
> On 08/12/14 13:59, Damien Lespiau wrote:
> > On Mon, Dec 08, 2014 at 02:33:57PM +0200, Jani Nikula wrote:
> >>> #define _MASKED_BIT_ENABLE(a) (((a) << 16) | (a))
> >>> #define _MASKED_BIT_DISABLE(a) ((a) << 16)
> >>> +#define _MASKED_FIELD(value, mask) (((mask) << 16) | (value))
> >>
> >> Obligatory bikeshed, wouldn't you say _MASKED_BIT_{ENABLE,DISABLE} are
> >> special cases of _MASKED_FIELD...? ;)
> >
> > That's because we're not just enabling or disabling bits here but
> > setting a multi-bits value.
> >
> > _MASKED_FIELD(2 << 4, 0x3 << 4);
> >
>
> So you could
>
> #define __MASKED_BIT_DISABLE(a) (__MASKED_FIELD(0, (a)))
> #define __MASKED_BIT_ENABLE(a) (__MASKED_FIELD((a), (a)))
>
> which I think is what Jani was referring to ...
>
> Bikeshed++: do we care about the double evaluation of (a) in these macros?
Oh of course, misread that. We could also avoid the double evaluation
indeed and chris suggests (on IRC) BUILD_BUG_ON(bit & ~mask); (super
good!)
--
Damien
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2014-12-08 14:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-06 20:14 [PATCH] drm/i915/bdw: Fix the write setting up the WIZ hashing mode Damien Lespiau
2014-12-07 4:48 ` shuang.he
2014-12-08 12:33 ` Jani Nikula
2014-12-08 13:59 ` Damien Lespiau
2014-12-08 14:17 ` Dave Gordon
2014-12-08 14:36 ` Damien Lespiau [this message]
2014-12-08 14:21 ` Daniel Vetter
2014-12-08 14:23 ` Daniel Vetter
2014-12-08 14:46 ` Damien Lespiau
2014-12-08 16:22 ` [PATCH v2] " Damien Lespiau
2014-12-08 16:27 ` Daniel Vetter
2014-12-08 16:50 ` Dave Gordon
2014-12-08 16:54 ` Damien Lespiau
2014-12-08 16:56 ` Dave Gordon
2014-12-08 17:33 ` [PATCH v3] " Damien Lespiau
2014-12-09 22:14 ` shuang.he
2014-12-10 9:42 ` Jani Nikula
2014-12-10 12:03 ` Damien Lespiau
2014-12-10 13:55 ` Daniel Vetter
2014-12-09 19:14 ` [PATCH v2] " shuang.he
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20141208143618.GA6041@strange.ger.corp.intel.com \
--to=damien.lespiau@intel.com \
--cc=david.s.gordon@intel.com \
--cc=intel-gfx@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox