linux-kernel - [PATCH 0/4] log2: make is_power_of

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Message-Id: <20230330104243.2120761-1-jani.nikula@intel.com>
Date:   Thu, 30 Mar 2023 13:42:39 +0300
From:   Jani Nikula <jani.nikula@...el.com>
To:     linux-kernel@...r.kernel.org
Cc:     intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        jani.nikula@...el.com, Andrew Morton <akpm@...ux-foundation.org>,
        Christian König <christian.koenig@....com>,
        David Gow <davidgow@...gle.com>
Subject: [PATCH 0/4] log2: make is_power_of_2() more generic

is_power_of_2() only works for types <= sizeof(unsigned long) and it's
also not a constant expression. There are a number of places in kernel
where is_power_of_2() is called on u64, which fails on 32-bit
builds. Try to remedy that. While at it, make it a constant expression
when possible.

I admit I've only lightly tested this, and I haven't tried it with
allmodconfig.


Jani Nikula (4):
  log2: add helper __IS_POWER_OF_2()
  log2: have is_power_of_2() support bigger types than unsigned long
  log2: allow use of is_power_of_2() in constant expressions
  drm/i915/reg: use is_power_of_2() from log2.h

 drivers/gpu/drm/i915/i915_reg_defs.h |  7 +------
 include/linux/log2.h                 | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 11 deletions(-)

-- 
2.39.2