Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752136AbcLENgR (ORCPT ); Mon, 5 Dec 2016 08:36:17 -0500 Received: from smtpoutz27.laposte.net ([194.117.213.102]:41301 "EHLO smtp.laposte.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751998AbcLENgL (ORCPT ); Mon, 5 Dec 2016 08:36:11 -0500 To: zijun_hu , Sasha Levin , Andrew Morton , linux-kernel@vger.kernel.org, Linus Torvalds Cc: Mason , Maxime Coquelin , Harvey Harrison , Borislav Petkov From: Sebastian Frias Subject: [PATCH] bitops: add equivalent of BIT(x) for bitfields Message-ID: <196dd443-e3c7-2c37-1dd1-bc1d249ea2fb@laposte.net> Date: Mon, 5 Dec 2016 14:36:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-VR-SrcIP: 92.154.11.170 X-VR-FullState: 0 X-VR-Score: -100 X-VR-Cause-1: gggruggvucftvghtrhhoucdtuddrfeelfedrgeekgddujecutefuodetggdotefrodftvfcurfhrohhf X-VR-Cause-2: ihhlvgemucfntefrqffuvffgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhs X-VR-Cause-3: ucdlqddutddtmdenucfjughrpefvhffukffffgggtgfgsehtjeertddtfeejnecuhfhrohhmpefuvggs X-VR-Cause-4: rghsthhirghnucfhrhhirghsuceoshhfkeegsehlrghpohhsthgvrdhnvghtqeenucfkphepledvrddu X-VR-Cause-5: heegrdduuddrudejtdenucfrrghrrghmpehmohguvgepshhmthhpohhuthdphhgvlhhopegludejvddr X-VR-Cause-6: vdejrddtrddvudegngdpihhnvghtpeelvddrudehgedruddurddujedtpdhmrghilhhfrhhomhepshhf X-VR-Cause-7: keegsehlrghpohhsthgvrdhnvghtpdhrtghpthhtohepiihijhhunhgphhhusehhthgtrdgtohhm X-VR-AvState: No X-VR-State: 0 X-VR-State: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1377 Lines: 46 Introduce SETBITFIELD(msb, lsb, value) macro to ease dealing with continuous bitfields, just as BIT(x) does for single bits. SETBITFIELD_ULL(msb, lsb, value) macro is also added. Signed-off-by: Sebastian Frias --- Code protected with "#ifdef __KERNEL__" just as the BIT(x) macros. I would have preferred another name, like BITS(x) but it is already used. Suggestions for other names welcome. --- include/linux/bitops.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index a83c822..4659237 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -24,6 +24,20 @@ #define GENMASK_ULL(h, l) \ (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) +#ifdef __KERNEL__ +/* + * Equivalent of BIT(x) but for contiguous bitfields + * SETBITFIELD(1, 0,0xff) = 0x00000003 + * SETBITFIELD(3, 0,0xff) = 0x0000000f + * SETBITFIELD(15,8,0xff) = 0x0000ff00 + * SETBITFIELD(6, 6, 1) = 0x00000040 == BIT(6) + */ +#define SETBITFIELD(msb, lsb, val) \ + (((val) << (lsb)) & (GENMASK((msb), (lsb)))) +#define SETBITFIELD_ULL(msb, lsb, val) \ + (((val) << (lsb)) & (GENMASK_ULL((msb), (lsb)))) +#endif + extern unsigned int __sw_hweight8(unsigned int w); extern unsigned int __sw_hweight16(unsigned int w); extern unsigned int __sw_hweight32(unsigned int w); -- 1.8.3.1