From patchwork Tue Mar 25 15:59:55 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Vincent Mailhol X-Patchwork-Id: 14029185 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 88BB0C3600E for ; Tue, 25 Mar 2025 16:01:09 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6E10510E5A6; Tue, 25 Mar 2025 16:00:58 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="ZLFFnVFu"; dkim-atps=neutral Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6CCDA10E59F; Tue, 25 Mar 2025 16:00:50 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id EEF60A4AB36; Tue, 25 Mar 2025 15:55:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id A3F66C4CEE4; Tue, 25 Mar 2025 16:00:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742918448; bh=Qyqawt3yEY8kEjetVfNw5tS/eDbvtY8p88+b2hatK2U=; h=From:Subject:Date:To:Cc:Reply-To:From; b=ZLFFnVFuaqhxd5I0DmFhj7b427aVOF0/wmgCHjV4XLV4NL4Jp+m390mh2sFz/F9HE YldIk4doKEVLu1Rgnc0mS7GVz2OSUBUSQDjbkPiCiyH/MYdy2fpiPhQxf8CzwqD+3d b8juY4IM25Evt79eVpuYL8sXT5Zpg1PbWdZt2wfCKPzM+G1/S5v6YDC6ZbknddAnT7 MLjqgQstl+99wl3+hhw6+kTk4tp9pja5mZ0GBdfQrAt8+qYQDGaGpCgqgCVFhQqt2A 3ceRUbBzko5ayMyUySWzsxJL+UFdtctVHErwuvCM0gqGEUjQ4kYl7clal28wNVg3E6 4zFvw1McrgryA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 959EAC3600B; Tue, 25 Mar 2025 16:00:48 +0000 (UTC) Subject: [PATCH v8 0/6] bits: Fixed-type GENMASK_U*() and BIT_U*() Date: Wed, 26 Mar 2025 00:59:55 +0900 Message-Id: <20250326-fixed-type-genmasks-v8-0-24afed16ca00@wanadoo.fr> MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAPvS4mcC/23RTW7DIBQE4KtYrIuL+TE4q9yj6gLDI0aNTQrEb RTl7sW1KrmKlyPxPo2GO0oQPSR0qO4owuyTD1MJ6qVCZtDTCbC3JSNKqCCUKuz8N1icbxfAJ5h GnT4SVrbRQgjHOChULi8RlmeL+vZesothxHmIoP8sTihRRHJBm1pISWSLG3y+Gp1qC6OOZvBHP 2U41yaMCzn4lEO8/fac+QKvlRgRu5VmjglulGTWWNdKyo5fetI2hNpFtHSaxRZp9xFRkJ5zBp0 1vW6fkXaL7I8ztwVxomONAMkM7Z4QuUEo3UdkQaxmijjXGNH/Rx7r5hE+r+UD8zo86nUCXOYbf T5UIfqTn16LlmG5ePwA1/rO9foBAAA= X-Change-ID: 20250228-fixed-type-genmasks-8d1a555f34e8 To: Yury Norov , Lucas De Marchi , Rasmus Villemoes , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Andrew Morton Cc: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Andi Shyti , David Laight , Andy Shevchenko , Catalin Marinas , Anshuman Khandual , linux-arm-kernel@lists.infradead.org, Vincent Mailhol , Jani Nikula X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=5325; i=mailhol.vincent@wanadoo.fr; h=from:subject:message-id; bh=Qyqawt3yEY8kEjetVfNw5tS/eDbvtY8p88+b2hatK2U=; b=owGbwMvMwCV2McXO4Xp97WbG02pJDOmPLkt1sV17eDToX5FbpYcyg85HyzccM3pONpx1W9JQn elso9XTUcrCIMbFICumyLKsnJNboaPQO+zQX0uYOaxMIEMYuDgFYCLKLYwMX0JYr1z34WlecTP4 t4yZSky58f6kmTz1h7WnG3uXRyspMTJcX9rwf5aEnMCJmEcucVVe83xmzl2oM1VWyuYhy7xXrP8 5AQ== X-Developer-Key: i=mailhol.vincent@wanadoo.fr; a=openpgp; fpr=ED8F700574E67F20E574E8E2AB5FEB886DBB99C2 X-Endpoint-Received: by B4 Relay for mailhol.vincent@wanadoo.fr/default with auth_id=291 X-Original-From: Vincent Mailhol 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: , Reply-To: mailhol.vincent@wanadoo.fr Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Vincent Mailhol Introduce some fixed width variant of the GENMASK() and the BIT() macros in bits.h. For example: GENMASK_U16(16, 0) will raise a build bug. This series is a continuation of: https://lore.kernel.org/intel-xe/20240208074521.577076-1-lucas.demarchi@intel.com from Lucas De Marchi. Above series is one year old. I really think that this was a good idea and I do not want this series to die. So I am volunteering to revive it. Meanwhile, many changes occurred in bits.h. The most significant change is that __GENMASK() was moved to the uapi headers. For this reason, a new GENMASK_TYPE() is introduced instead and the uapi __GENMASK() is left untouched. Finally, I do not think it makes sense to expose the fixed width variants to the asm. The fixed width integers type are a C concept. So the GENMASK_U*() are only visible to the non-asm code. For asm, the long and long long variants seem sufficient. This series does not modify the actual GENMASK(), GENMASK_ULL() and GENMASK_U128(). A consolidation of the existing genmasks will be proposed later on in a separate series. As requested, here are the bloat-o-meter stats: $ ./scripts/bloat-o-meter vmlinux_before.o vmlinux_after.o add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0) Function old new delta Total: Before=22781662, After=22781662, chg +0.00% (done with GCC 12.4.1 on an x86_64_defconfig) --- 2.43.0 --- Changes from v7: - Meanwhile, in commit db6fe4d61ece ("lib: Move KUnit tests into tests/ subdirectory"), lib/test_bits.c was moved to lib/tests/test_bits.c. Rebase onto Linus's master branch so that this change is reflected. - Remove the note in the cover letter on the return type, instead add an explanation in patch "bits: introduce fixed-type GENMASK_U*()". - s/shift-count-overflow/-Wshift-count-overflow/g - Link to v7: https://lore.kernel.org/r/20250322-fixed-type-genmasks-v7-0-da380ff1c5b9@wanadoo.fr Changes from v6: - Split the series in two: this series leave any existing GENMASK*() unmodified. The consolidation will be done in a separate series. - Collect some Reviewed-by tag. - Address miscellaneous nitpick on the code comments and the line wrapping (details in each patch). - Link to v6: https://lore.kernel.org/r/20250308-fixed-type-genmasks-v6-0-f59315e73c29@wanadoo.fr Changes from v5: - Update the cover letter message. I was still refering to GENMASK_t() instead of GENMASK_TYPE(). - Add a comment in the cover letter to explain that a common GENMASK_TYPE() for C and asm wouldn't allow to generate the u128 variant. - Restore the comment saying that BUILD_BUG_ON() is not available in asm code. - Add a FIXME message to highlight the absence of the asm GENMASK*() unit tests. - Use git's histogram diff algorithm - Link to v5: https://lore.kernel.org/r/20250306-fixed-type-genmasks-v5-0-b443e9dcba63@wanadoo.fr Changes from v4: - Rebase on https://github.com/norov/linux/tree/bitmap-for-next - Rename GENMASK_t() to GENMASK_TYPE() - First patch of v4 (the typo fix 'init128' -> 'int128') is removed because it was resent separately in: https://lore.kernel.org/all/20250305-fix_init128_typo-v1-1-cbe5b8e54e7d@wanadoo.fr - Replace the (t)~ULL(0) by type_max(t). This way, GENMASK_TYPE() can now be used to generate GENMASK_U128(). - Get rid of the unsigned int cast for the U8 and U16 variants. - Add the BIT_TYPE() helper macro. - Link to v4: https://lore.kernel.org/r/20250305-fixed-type-genmasks-v4-0-1873dcdf6723@wanadoo.fr Changes from v3: - Rebase on v6.14-rc5 - Fix a typo in GENMASK_U128() comment. - Split the asm and non-asm definition of - Replace ~0ULL by ~ULL(0) - Since v3, __GENMASK() was moved to the uapi and people started using directly. Introduce GENMASK_t() instead. - Link to v3: https://lore.kernel.org/intel-xe/20240208074521.577076-1-lucas.demarchi@intel.com Changes from v2: - Document both in commit message and code about the strict type checking and give examples how it´d break with invalid params. - Link to v2: https://lore.kernel.org/intel-xe/20240124050205.3646390-1-lucas.demarchi@intel.com Link to v1: https://lore.kernel.org/intel-xe/20230509051403.2748545-1-lucas.demarchi@intel.com --- Lucas De Marchi (3): bits: introduce fixed-type BIT_U*() drm/i915: Convert REG_GENMASK*() to fixed-width GENMASK_U*() test_bits: add tests for GENMASK_U*() Vincent Mailhol (3): bits: add comments and newlines to #if, #else and #endif directives bits: introduce fixed-type GENMASK_U*() test_bits: add tests for BIT_U*() drivers/gpu/drm/i915/i915_reg_defs.h | 108 ++++------------------------------- include/linux/bitops.h | 1 - include/linux/bits.h | 57 +++++++++++++++++- lib/tests/test_bits.c | 30 ++++++++++ 4 files changed, 96 insertions(+), 100 deletions(-) --- base-commit: 2df0c02dab829dd89360d98a8a1abaa026ef5798 change-id: 20250228-fixed-type-genmasks-8d1a555f34e8 Best regards,