From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4F0FC433F5 for ; Tue, 22 Feb 2022 16:50:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=d8UQhwuwoAkbFZ57jztu2SSHAHpShjKkjidJXZ4cRn4=; b=013sS2KcIoBPNiUpk291GPDUYY 9vz5DPXuwIO3XpioS3cx1TzSFLNvS1mIQIfv1PwneOsL0eo5OaS6vI5wTXLi3d0BvTtC03L0XIDkD ZJe22IdstnjS2LC1y1KhhNS8NNDGLwWBNwQZsMuVU5VZLbspnep0JYBu3x+2f9FOb6QuZwQFBpHB0 rf9RDFRXu8qUJVEhgruE2otuWgFA+cBkCqG9gUpyMj7mWFrv6aD1p7h2Rq68gFYdSfRUQTbEsB9eU GaM0/V8MPipKzkdXSejtKoPvlJ4WESNzuQ936QpUnMdLnEyCV62dIXvYXnvHtuCxo8W572GZwevas WVl2Ec2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nMYNA-00AlNK-S0; Tue, 22 Feb 2022 16:50:45 +0000 Received: from relay5.hostedemail.com ([64.99.140.39]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nMYIc-00AjfJ-FU for linux-nvme@lists.infradead.org; Tue, 22 Feb 2022 16:46:04 +0000 Received: from omf18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 784C8A5A; Tue, 22 Feb 2022 16:45:56 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf18.hostedemail.com (Postfix) with ESMTPA id 396B643; Tue, 22 Feb 2022 16:45:34 +0000 (UTC) Message-ID: <66a0c8210cf9e7dfcc3fa2d247de1eebd5a8acb7.camel@perches.com> Subject: Re: [PATCHv3 04/10] linux/kernel: introduce lower_48_bits macro From: Joe Perches To: Keith Busch , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-crypto@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Cc: axboe@kernel.dk, hch@lst.de, martin.petersen@oracle.com, colyli@suse.de, Bart Van Assche Date: Tue, 22 Feb 2022 08:45:53 -0800 In-Reply-To: <20220222163144.1782447-5-kbusch@kernel.org> References: <20220222163144.1782447-1-kbusch@kernel.org> <20220222163144.1782447-5-kbusch@kernel.org> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.40.4-1ubuntu2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspamout08 X-Rspamd-Queue-Id: 396B643 X-Stat-Signature: yzf67mxeguumtukwkfw7sqsufuzga6du X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX1+NisYWVxViQyJRvI3jjilg5uVaEbHyZ28= X-HE-Tag: 1645548334-553202 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220222_084602_642914_36582920 X-CRM114-Status: UNSURE ( 8.19 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, 2022-02-22 at 08:31 -0800, Keith Busch wrote: > Recent data integrity field enhancements allow 48-bit reference tags. > Introduce a helper macro since this will be a repeated operation. [] > diff --git a/include/linux/kernel.h b/include/linux/kernel.h [] > @@ -63,6 +63,12 @@ > } \ > ) > > +/** > + * lower_48_bits - return bits 0-47 of a number > + * @n: the number we're accessing > + */ > +#define lower_48_bits(n) ((u64)((n) & 0xffffffffffffull)) why not make this a static inline function? And visually, it's difficult to quickly count a repeated character to 12. Perhaps: static inline u64 lower_48_bits(u64 val) { return val & GENMASK_ULL(47, 0); }