From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04FAD158219; Fri, 28 Jun 2024 17:46:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719596808; cv=none; b=gzs9ZsTzOp70XoaiAOL0r780hYwKM101qyR9zoIuNLlhYEJdS+sI7dcr1xaPZT/6+Ro50nLwEvN8BviCMN691HouRSNcKOiar5rlMazz0waQLPlP8HyoABFGGqjoJFUQsE7cqhQS0xpwwpd515d7WOuA61nJVRP3EIXEeQrWCfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719596808; c=relaxed/simple; bh=nE1laE1r0oTP32KAdyXF+H8t0tKQ3Zjrg8yW/mvZQ0o=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pCU7C1tGxT483uTd7XLDLFWkeDmcoQwUIqGceLmxXM+9M3qluRlLWTCvyxmon4em7LH5hiB84aEaG+hippPhjWzDLB+TC6QqW4fCaSxpIlTILQNKnV1dJ1zwoOVX6U7UFAIIqMplpibVcUhENo9plAEqQhPlWL50+HNYZ6Aqwis= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=e4dhdpEp; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="e4dhdpEp" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 45SHjjqM3118844 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Fri, 28 Jun 2024 10:45:49 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 45SHjjqM3118844 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024061501; t=1719596751; bh=HvQfDLFw796OnEOGySdnHV+nxv/wyItcNcp+7+/wPBE=; h=From:To:Cc:Subject:Date:From; b=e4dhdpEpCH3xDLVjfLCWrqPLBWHimRp4qgnPteTL1579QWaI6idfDXbnp2+Z60hQi 0WkmlLHtAy0u5kNj49QgvsDhlApUGlWqbkn8fFniNxrEpxesmpEX6vchSQMJBM5YEv aeOpNMKxdbExNGSsm3sMlOB6v+bnE2wF2oo/NecfzmmKZWTd1AO/TqIyqzplPkyWqq a4/xKAbnG2kYvdm2baCKkSHnTaZ62eN33BFg1mNgb0AE4RA76jgXZ7BVHW/PvkK0Ls 4haHrYUlVulJZxtu0FHzFQHszNZ89rcl7qxR9aiS2M30CrMzEexd9q65gJ4aXogbbA ZfXW6pABVjI3g== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, will@kernel.org, peterz@infradead.org, akpm@linux-foundation.org, acme@kernel.org, namhyung@kernel.org, brgerst@gmail.com, andrew.cooper3@citrix.com, nik.borisov@suse.com Subject: [PATCH v4 0/4] x86/cpufeatures: Automatically generate required and disabled feature masks Date: Fri, 28 Jun 2024 10:45:40 -0700 Message-ID: <20240628174544.3118826-1-xin@zytor.com> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The x86 build process first generates required and disabled feature masks based on current build config, and then uses these generated masks to compile the source code. When a CPU feature is not enabled in a build config, e.g., when CONFIG_X86_FRED=n, its feature disable flag, i.e., DISABLE_FRED, needs to be properly defined and added to a specific disabled CPU features mask in , as the following patch does: https://lore.kernel.org/all/20231205105030.8698-8-xin3.li@intel.com/. As a result, the FRED feature bit is surely cleared in the generated kernel binary when CONFIG_X86_FRED=n. Recently there is another case to repeat the same exercise for the AMD SEV-SNP CPU feature: https://lore.kernel.org/all/20240126041126.1927228-2-michael.roth@amd.com/. https://lore.kernel.org/all/20240126041126.1927228-23-michael.roth@amd.com/. It was one thing when there were four of CPU feature masks, but with over 20 it is going to cause mistakes, e.g., https://lore.kernel.org/lkml/aaed79d5-d683-d1bc-7ba1-b33c8d6db618@suse.com/. We want to eliminate the stupidly repeated exercise to manually assign features to CPU feature words through introducing an AWK script to automatically generate a header with required and disabled CPU feature masks based on current build config, and this patch set does that. Link to v3: https://lore.kernel.org/lkml/20240622171435.3725548-1-xin@zytor.com/ Changes since v3: * Add a few high-level comments to the AWK script (Nikolay Borisov). * Use '1U' instead of '1' in feature mask shifting (Andrew Cooper). * Checking NCAPINTS isn't necessary anymore. It was needed when these macros had to be manually updated, but now if cpufeatures.h changes this header will be regenerated (Brian Gerst). * Enforce CPU feature mask values to be unsigned. Changes since v2: * Remove AWK code that generates extra debugging comments (Brian Gerst). * Move SSE_MASK to verify_cpu.S, the only place it is used (Brian Gerst). * Add a patch to generate macros {REQUIRED|DISABLED}_MASK_BIT_SET in the new AWK script (Brian Gerst). Changes since v1: * Keep the X86_{REQUIRED,DISABLED}_FEATURE_ prefixes solely in arch/x86/Kconfig.cpufeatures (Borislav Petkov). * Explain how config option names X86_{REQUIRED,DISABLED}_FEATURE_ are formed (Borislav Petkov). * Remove code generating unused macros {REQUIRED,DISABLED}_FEATURE(x) to tell if a CPU feature, e.g., X86_FEATURE_FRED, is a required or disabled feature for this particular compile-time configuration. H. Peter Anvin (Intel) (2): x86/cpufeatures: Add {required,disabled} feature configs x86/cpufeatures: Generate a feature mask header based on build config Xin Li (Intel) (2): x86/cpufeatures: Remove {disabled,required}-features.h x86/cpufeatures: Use AWK to generate {REQUIRED|DISABLED}_MASK_BIT_SET arch/x86/Kconfig | 4 +- arch/x86/Kconfig.cpu | 12 +- arch/x86/Kconfig.cpufeatures | 197 ++++++++++++++++++ arch/x86/Makefile | 17 +- arch/x86/boot/cpucheck.c | 3 +- arch/x86/boot/cpuflags.c | 1 - arch/x86/boot/mkcpustr.c | 3 +- arch/x86/include/asm/Kbuild | 1 + arch/x86/include/asm/asm-prototypes.h | 2 +- arch/x86/include/asm/atomic64_32.h | 2 +- arch/x86/include/asm/bitops.h | 4 +- arch/x86/include/asm/cmpxchg_32.h | 2 +- arch/x86/include/asm/cpufeature.h | 70 +------ arch/x86/include/asm/cpufeatures.h | 8 - arch/x86/include/asm/disabled-features.h | 161 -------------- arch/x86/include/asm/required-features.h | 105 ---------- arch/x86/kernel/verify_cpu.S | 4 + arch/x86/lib/Makefile | 2 +- arch/x86/lib/cmpxchg8b_emu.S | 2 +- arch/x86/tools/featuremasks.awk | 92 ++++++++ lib/atomic64_test.c | 2 +- tools/arch/x86/include/asm/cpufeatures.h | 8 - .../arch/x86/include/asm/disabled-features.h | 161 -------------- .../arch/x86/include/asm/required-features.h | 105 ---------- tools/perf/check-headers.sh | 2 - 25 files changed, 325 insertions(+), 645 deletions(-) create mode 100644 arch/x86/Kconfig.cpufeatures delete mode 100644 arch/x86/include/asm/disabled-features.h delete mode 100644 arch/x86/include/asm/required-features.h create mode 100755 arch/x86/tools/featuremasks.awk delete mode 100644 tools/arch/x86/include/asm/disabled-features.h delete mode 100644 tools/arch/x86/include/asm/required-features.h base-commit: f6a465a2d29701aa1a5189cae63a6870b65cef48 -- 2.45.2