From patchwork Thu Feb 8 07:45:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas De Marchi X-Patchwork-Id: 13549396 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 3AA54C4828F for ; Thu, 8 Feb 2024 07:45:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D74F310E33F; Thu, 8 Feb 2024 07:45:18 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="HJCNTELL"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) by gabe.freedesktop.org (Postfix) with ESMTPS id D3B7410E280; Thu, 8 Feb 2024 07:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707378317; x=1738914317; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=l4UY2L4RJrFs6qSEBykdb5P7iOGl7l18XZf5QdzVkjg=; b=HJCNTELLX9ttNzPrgsaVkn+qvxeYpPLAcuPS7fj7uVjx2jyfy8BJwwT8 sLn3zibxpWg9Zd5aIUhrVnms4zjWxJXGAPQ1+EZJhwz38Jwghg/q1P07g kfImAnLqY+KqkXlebyDJepNHxHcjSvedmZqWASkD4hna7sQC7sut2JQnV euU4S4q50vhYzCjZbeb2CShnBQ7aSpTyt3INVaEJkMLMcJAw5Y+UXPBwI Et1ZOnaOAaAqu55D1SxImBiPLV333Y9kTH4Q7vURrZXdw6tHCDEywbff4 ellTTLivnVbawR9AZvxVInj9dbxuzjP/HZWwaox+dSv/3FFdNt/c8MqJ3 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10977"; a="12242637" X-IronPort-AV: E=Sophos;i="6.05,252,1701158400"; d="scan'208";a="12242637" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2024 23:45:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,252,1701158400"; d="scan'208";a="6195648" Received: from lucas-s2600cw.jf.intel.com ([10.165.21.196]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Feb 2024 23:45:16 -0800 From: Lucas De Marchi To: Yury Norov Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Andy Shevchenko , Jani Nikula , intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Lucas De Marchi , Jani Nikula Subject: [PATCH v3 1/3] bits: introduce fixed-type genmasks Date: Wed, 7 Feb 2024 23:45:19 -0800 Message-ID: <20240208074521.577076-2-lucas.demarchi@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240208074521.577076-1-lucas.demarchi@intel.com> References: <20240208074521.577076-1-lucas.demarchi@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Yury Norov Generalize __GENMASK() to support different types, and implement fixed-types versions of GENMASK() based on it. The fixed-type version allows more strict checks to the min/max values accepted, which is useful for defining registers like implemented by i915 and xe drivers with their REG_GENMASK*() macros. The strict checks rely on shift-count-overflow compiler check to fail the build if a number outside of the range allowed is passed. Example: #define FOO_MASK GENMASK_U32(33, 4) will generate a warning like: ../include/linux/bits.h:41:31: error: left shift count >= width of type [-Werror=shift-count-overflow] 41 | (((t)~0ULL - ((t)(1) << (l)) + 1) & \ | ^~ Signed-off-by: Yury Norov Signed-off-by: Lucas De Marchi Acked-by: Jani Nikula Reviewed-by: Andi Shyti Signed-off-by: Yury Norov Acked-by: Jani Nikula Reviewed-by: Andi Shyti Signed-off-by: Lucas De Marchi --- include/linux/bitops.h | 1 - include/linux/bits.h | 32 ++++++++++++++++++++++---------- 2 files changed, 22 insertions(+), 11 deletions(-) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 2ba557e067fe..1db50c69cfdb 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -15,7 +15,6 @@ # define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n))) #endif -#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) #define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long)) #define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64)) #define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32)) diff --git a/include/linux/bits.h b/include/linux/bits.h index 7c0cf5031abe..bd56f32de44e 100644 --- a/include/linux/bits.h +++ b/include/linux/bits.h @@ -6,6 +6,8 @@ #include #include +#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) + #define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG)) #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) #define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG)) @@ -30,16 +32,26 @@ #define GENMASK_INPUT_CHECK(h, l) 0 #endif -#define __GENMASK(h, l) \ - (((~UL(0)) - (UL(1) << (l)) + 1) & \ - (~UL(0) >> (BITS_PER_LONG - 1 - (h)))) -#define GENMASK(h, l) \ - (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l)) +/* + * Generate a mask for the specified type @t. Additional checks are made to + * guarantee the value returned fits in that type, relying on + * shift-count-overflow compiler check to detect incompatible arguments. + * For example, all these create build errors or warnings: + * + * - GENMASK(15, 20): wrong argument order + * - GENMASK(72, 15): doesn't fit unsigned long + * - GENMASK_U32(33, 15): doesn't fit in a u32 + */ +#define __GENMASK(t, h, l) \ + (GENMASK_INPUT_CHECK(h, l) + \ + (((t)~0ULL - ((t)(1) << (l)) + 1) & \ + ((t)~0ULL >> (BITS_PER_TYPE(t) - 1 - (h))))) -#define __GENMASK_ULL(h, l) \ - (((~ULL(0)) - (ULL(1) << (l)) + 1) & \ - (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h)))) -#define GENMASK_ULL(h, l) \ - (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) +#define GENMASK(h, l) __GENMASK(unsigned long, h, l) +#define GENMASK_ULL(h, l) __GENMASK(unsigned long long, h, l) +#define GENMASK_U8(h, l) __GENMASK(u8, h, l) +#define GENMASK_U16(h, l) __GENMASK(u16, h, l) +#define GENMASK_U32(h, l) __GENMASK(u32, h, l) +#define GENMASK_U64(h, l) __GENMASK(u64, h, l) #endif /* __LINUX_BITS_H */