From patchwork Thu Mar 12 16:44:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Elder X-Patchwork-Id: 11434883 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B7F10161F for ; Thu, 12 Mar 2020 16:44:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 974F92072F for ; Thu, 12 Mar 2020 16:44:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="MrqD06Qh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726513AbgCLQot (ORCPT ); Thu, 12 Mar 2020 12:44:49 -0400 Received: from mail-qk1-f195.google.com ([209.85.222.195]:33243 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726299AbgCLQoh (ORCPT ); Thu, 12 Mar 2020 12:44:37 -0400 Received: by mail-qk1-f195.google.com with SMTP id p62so7338024qkb.0 for ; Thu, 12 Mar 2020 09:44:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Ec7R0bi2nVM+F7rZN313cf7V1mbBY7UX4j8RKAtVudI=; b=MrqD06QhTj4HWofBJT7nxxIOwPRtSzDwxbA1IXIAZd+3Ka1QMh5FZbIGfKIWSR8h8X RuhrJagdGXsh+9vfSSTWITbjq4YzFxdkSVMCM6j7VKrnWPUc30Gb+4D77DX+SnDJ7Bqz Ig1o2b+WMvY/9fPKVhn5DyUTVxV96sih4P5gASQWiwy8cGlg0c0O38W6JEBKQASbDJyo P1VInXw4lJxd6FqY/dsvw4FNJUD2ziFu+Kxv2oGesiYBEA5SqBIn2nWZZ+LI9aJVQuFk o+HMBW4yav8ghIPKwdGWwcqKKVGPBmOVeUsmujGojgqCtuqZIbtyY2s4YMtl3YfypgpD J6tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Ec7R0bi2nVM+F7rZN313cf7V1mbBY7UX4j8RKAtVudI=; b=l+q85aK0DxF6Y34kpxe2HSq5BURaH3DzMZbxfvPhNmS/mRuobfdXaA2D0UbQCi0Hpg eisPZympzBiHJb61symSVjRZDbRd4sjDqXeAwZSvS/ncxnYGZeA4M/mro70kdQtd3Mo3 1NnBiHxhlyCycR2sMo6oFLZP/hwvXkrae3KmGLr9DMI34w9TP/6g8BfyRhVs6ICku5xO P70vIag1fwt8QGM3qTr+NiB7TpHRU6GdZp91obhC+CIpJX9eYheOLhqHhxC468lyxm0V TC0iua7G0WusBYgP8MEpCMHV/m78AHgO2YRu4TwUl/Xb8RsLd5XFlE3c5yQcFuGwRiUn 3BhQ== X-Gm-Message-State: ANhLgQ3+clKsKaoMKNsAecdyrLky9Z3mFXrr+HrmKER6cjcE4mAY0c+5 BllYhW5prWm7ughN0TVVQtCDqA== X-Google-Smtp-Source: ADFU+vtioYETrA227Ha7YqY55Gh12iS6/cs2tK2mVB2+BbYDGinlbtWcnlzwX3ec9WHmb3gPZUx3ug== X-Received: by 2002:a37:987:: with SMTP id 129mr8799401qkj.83.1584031475735; Thu, 12 Mar 2020 09:44:35 -0700 (PDT) Received: from localhost.localdomain (c-73-185-129-58.hsd1.mn.comcast.net. [73.185.129.58]) by smtp.gmail.com with ESMTPSA id j4sm7244743qtn.78.2020.03.12.09.44.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Mar 2020 09:44:35 -0700 (PDT) From: Alex Elder To: David Miller , Bjorn Andersson , Andy Gross Cc: Rob Herring , Mark Rutland , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org (open list), Jakub Kicinski Subject: [PATCH 1/2] bitfield.h: add FIELD_MAX() and field_max() Date: Thu, 12 Mar 2020 11:44:27 -0500 Message-Id: <20200312164428.18132-2-elder@linaro.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200312164428.18132-1-elder@linaro.org> References: <20200312164428.18132-1-elder@linaro.org> MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Define FIELD_MAX(), which supplies the maximum value that can be represented by a field value. Define field_max() as well, to go along with the lower-case forms of the field mask functions. Signed-off-by: Alex Elder Acked-by: Jakub Kicinski --- include/linux/bitfield.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index 4bbb5f1c8b5b..48ea093ff04c 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -55,6 +55,19 @@ (1ULL << __bf_shf(_mask))); \ }) +/** + * FIELD_MAX() - produce the maximum value representable by a field + * @_mask: shifted mask defining the field's length and position + * + * FIELD_MAX() returns the maximum value that can be held in the field + * specified by @_mask. + */ +#define FIELD_MAX(_mask) \ + ({ \ + __BF_FIELD_CHECK(_mask, 0ULL, 0ULL, "FIELD_MAX: "); \ + (typeof(_mask))((_mask) >> __bf_shf(_mask)); \ + }) + /** * FIELD_FIT() - check if value fits in the field * @_mask: shifted mask defining the field's length and position @@ -110,6 +123,7 @@ static __always_inline u64 field_mask(u64 field) { return field / field_multiplier(field); } +#define field_max(field) ((typeof(field))field_mask(field)) #define ____MAKE_OP(type,base,to,from) \ static __always_inline __##type type##_encode_bits(base v, base field) \ { \