From nobody Sun Dec 14 19:24:41 2025 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 7DF7F1A5BB7; Wed, 5 Mar 2025 18:48:33 +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=1741200515; cv=none; b=QPMnUXsa40KaFojrcdtA+ai8Xo4q15FlFdIhOaod7Le/xNul7dD5L1HU6zlJpt3xoKvz9O9imFJBf3I8uViibMHQ2UGZ/+CD7oAnW+PJ5a2U0Y4OTHD01jQ9wTWIPUHn+s1LKbQei7ZTYjSDZ5CuXU3/AHIzPYwYhZFZmzxMouY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741200515; c=relaxed/simple; bh=+1JKmB976MUNfqZQK0KEJMuqqyYampOrouBQrnOjaiE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N53WEKjBNyMDcHSCzwkm7GrhSKueZ7EuqIWBIKypJC+FWLHPCSLE3vHoC6AHoyMrPSkaQLqTel0/Bb+hSLZx+9zPfJEFmdRf+YvGYn64t/zel2UMErekKobeU8ZkgkhFUSpFEiOyTBAa8eZdvP3Y6LfDbzH3U0IVGidX08iskxw= 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=diRpWtyI; 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="diRpWtyI" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 525IlQXv3341787 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 5 Mar 2025 10:47:33 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 525IlQXv3341787 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025021701; t=1741200454; bh=T6Z4/Zqhd/fUPquA8qgPYFfqaTqcxPWT94ygIKdpArY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=diRpWtyIhHg/vEy1mUkajSRaqCM7OWPNGfSj51juntPIcPm+9QlMxQstkIOLeTMWQ RbYH7aEaOWEHHQtNjisAt9FGi7TUjeeM7kQ7PgGitr6UC2i+O7M0spuCPNJwUnBqDD m3zdEqWYz/nd0TlD+YWfUK/28X2JvjHYqJtSE4YAzh74qotML3Ma7DTlIxC27spO2+ Slzy2hYri/n8MI1oUOnzQVPw7wq4fNBUKK6GTfy15R/q7oMsGf5aaGse0mtvluZP2F /Cxtar4D2tIfbnFmdo66znhLsubq+S5zG1iv3bx+yB0CC/vmE61xkwuFwoIhF7WBek JjWqqJhlxtFWg== 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, yury.norov@gmail.com, akpm@linux-foundation.org, acme@kernel.org, namhyung@kernel.org, brgerst@gmail.com, andrew.cooper3@citrix.com, nik.borisov@suse.com, sraithal@amd.com, philip.li@intel.com Subject: [PATCH v7 2/4] x86/cpufeatures: Generate a feature mask header based on build config Date: Wed, 5 Mar 2025 10:47:22 -0800 Message-ID: <20250305184725.3341760-3-xin@zytor.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250305184725.3341760-1-xin@zytor.com> References: <20250305184725.3341760-1-xin@zytor.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Introduce an AWK script to auto-generate a header with required and disabled feature masks based on and current build config. Thus for any CPU feature with a build config, e.g., X86_FRED, simply add config X86_DISABLED_FEATURE_FRED def_bool y depends on !X86_FRED to arch/x86/Kconfig.cpufeatures, instead of adding a conditional CPU feature disable flag, e.g., DISABLE_FRED. Lastly the generated required and disabled feature masks will be added to their corresponding feature masks for this particular compile-time configuration. [ Xin: build integration improvements ] Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li (Intel) Reviewed-by: Nikolay Borisov Reviewed-by: Ingo Molnar --- Changes in v7: * Fix build error with "make distclean; make headers" (Aithal, Srikanth). * Collect reviewed-bys. Change in v6: * Make the AWK script work for mawk and BusyBox awk (Borislav Petkov). Change in v5: * More polishes (Nikolay Borisov). Changes in v4: * Add a few high-level comments to the AWK script (Nikolay Borisov). * Enforce CPU feature mask values to be unsigned. Changes in v3: * 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). Change in v2: * 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. --- arch/x86/Makefile | 15 ++++++ 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/cpufeature.h | 1 + arch/x86/include/asm/cpufeatures.h | 8 --- arch/x86/kernel/verify_cpu.S | 4 ++ arch/x86/tools/featuremasks.awk | 81 ++++++++++++++++++++++++++++++ 9 files changed, 105 insertions(+), 12 deletions(-) create mode 100755 arch/x86/tools/featuremasks.awk diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 6784129328f6..f0e8a23d2678 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -268,6 +268,21 @@ archscripts: scripts_basic archheaders: $(Q)$(MAKE) $(build)=3Darch/x86/entry/syscalls all =20 +### +# Feature masks header generation + +featuremasks_hdr :=3D arch/x86/include/generated/asm/featuremasks.h +featuremasks_awk :=3D $(srctree)/arch/x86/tools/featuremasks.awk +cpufeatures_hdr :=3D $(srctree)/arch/x86/include/asm/cpufeatures.h +targets +=3D $(featuremasks_hdr) +quiet_cmd_gen_featuremasks =3D GEN $@ + cmd_gen_featuremasks =3D $(AWK) -f $(featuremasks_awk) $(cpufeatures= _hdr) $(KCONFIG_CONFIG) > $@ + +$(featuremasks_hdr): $(featuremasks_awk) $(cpufeatures_hdr) $(KCONFIG_CONF= IG) FORCE + $(shell mkdir -p $(dir $@)) + $(call if_changed,gen_featuremasks) +archprepare: $(featuremasks_hdr) + ### # Kernel objects =20 diff --git a/arch/x86/boot/cpucheck.c b/arch/x86/boot/cpucheck.c index 0aae4d4ed615..8d03a741d1b2 100644 --- a/arch/x86/boot/cpucheck.c +++ b/arch/x86/boot/cpucheck.c @@ -22,10 +22,11 @@ # include "boot.h" #endif #include +#include #include #include -#include #include + #include "string.h" #include "msr.h" =20 diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c index d75237ba7ce9..0cabdacb2a2f 100644 --- a/arch/x86/boot/cpuflags.c +++ b/arch/x86/boot/cpuflags.c @@ -3,7 +3,6 @@ #include "bitops.h" =20 #include -#include #include #include "cpuflags.h" =20 diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c index da0ccc5de538..b90110109675 100644 --- a/arch/x86/boot/mkcpustr.c +++ b/arch/x86/boot/mkcpustr.c @@ -12,8 +12,6 @@ =20 #include =20 -#include "../include/asm/required-features.h" -#include "../include/asm/disabled-features.h" #include "../include/asm/cpufeatures.h" #include "../include/asm/vmxfeatures.h" #include "../kernel/cpu/capflags.c" @@ -23,6 +21,7 @@ int main(void) int i, j; const char *str; =20 + printf("#include \n\n"); printf("static const char x86_cap_strs[] =3D\n"); =20 for (i =3D 0; i < NCAPINTS; i++) { diff --git a/arch/x86/include/asm/Kbuild b/arch/x86/include/asm/Kbuild index 58f4ddecc5fa..51022d21003e 100644 --- a/arch/x86/include/asm/Kbuild +++ b/arch/x86/include/asm/Kbuild @@ -8,6 +8,7 @@ generated-y +=3D syscalls_x32.h generated-y +=3D unistd_32_ia32.h generated-y +=3D unistd_64_x32.h generated-y +=3D xen-hypercalls.h +generated-y +=3D featuremasks.h =20 generic-y +=3D early_ioremap.h generic-y +=3D fprobe.h diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufe= ature.h index e955da397e0e..d521759fe40d 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -9,6 +9,7 @@ #include #include #include +#include =20 enum cpuid_leafs { diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpuf= eatures.h index 0bc420319ee2..966685fe6d52 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -2,14 +2,6 @@ #ifndef _ASM_X86_CPUFEATURES_H #define _ASM_X86_CPUFEATURES_H =20 -#ifndef _ASM_X86_REQUIRED_FEATURES_H -#include -#endif - -#ifndef _ASM_X86_DISABLED_FEATURES_H -#include -#endif - /* * Defines x86 CPU feature bits */ diff --git a/arch/x86/kernel/verify_cpu.S b/arch/x86/kernel/verify_cpu.S index 1258a5872d12..a23a65d5d177 100644 --- a/arch/x86/kernel/verify_cpu.S +++ b/arch/x86/kernel/verify_cpu.S @@ -29,8 +29,12 @@ */ =20 #include +#include #include =20 +#define SSE_MASK \ + (REQUIRED_MASK0 & ((1<<(X86_FEATURE_XMM & 31)) | (1<<(X86_FEATURE_XMM2 & = 31)))) + SYM_FUNC_START_LOCAL(verify_cpu) pushf # Save caller passed flags push $0 # Kill any dangerous flags diff --git a/arch/x86/tools/featuremasks.awk b/arch/x86/tools/featuremasks.= awk new file mode 100755 index 000000000000..fd3e72147157 --- /dev/null +++ b/arch/x86/tools/featuremasks.awk @@ -0,0 +1,81 @@ +#!/usr/bin/awk +# +# Convert cpufeatures.h to a list of compile-time masks +# Note: this blithly assumes that each word has at least one +# feature defined in it; if not, something else is wrong! +# + +BEGIN { + printf "#ifndef _ASM_X86_FEATUREMASKS_H\n"; + printf "#define _ASM_X86_FEATUREMASKS_H\n\n"; + + file =3D 0 +} + +FNR =3D=3D 1 { + ++file; + + # arch/x86/include/asm/cpufeatures.h + if (file =3D=3D 1) + FS =3D "[ \t()*+]+"; + + # .config + if (file =3D=3D 2) + FS =3D "=3D"; +} + +# Create a dictionary of sorts, containing all defined feature bits +file =3D=3D 1 && $1 ~ /^#define$/ && $2 ~ /^X86_FEATURE_/ { + nfeat =3D $3 * $4 + $5; + feat =3D $2; + sub(/^X86_FEATURE_/, "", feat); + feats[nfeat] =3D feat; +} +file =3D=3D 1 && $1 ~ /^#define$/ && $2 =3D=3D "NCAPINTS" { + ncapints =3D int($3); +} + +# Create a dictionary featstat[REQUIRED|DISABLED, FEATURE_NAME] =3D on | o= ff +file =3D=3D 2 && $1 ~ /^CONFIG_X86_(REQUIRED|DISABLED)_FEATURE_/ { + on =3D ($2 =3D=3D "y"); + if (split($1, fs, "CONFIG_X86_|_FEATURE_") =3D=3D 3) + featstat[fs[2], fs[3]] =3D on; +} + +END { + sets[1] =3D "REQUIRED"; + sets[2] =3D "DISABLED"; + + for (ns in sets) { + s =3D sets[ns]; + + printf "/*\n"; + printf " * %s features:\n", s; + printf " *\n"; + fstr =3D ""; + for (i =3D 0; i < ncapints; i++) { + mask =3D 0; + for (j =3D 0; j < 32; j++) { + feat =3D feats[i*32 + j]; + if (featstat[s, feat]) { + nfstr =3D fstr " " feat; + if (length(nfstr) > 72) { + printf " * %s\n", fstr; + nfstr =3D " " feat; + } + fstr =3D nfstr; + mask +=3D (2 ^ j); + } + } + masks[i] =3D mask; + } + printf " * %s\n */\n", fstr; + + for (i =3D 0; i < ncapints; i++) + printf "#define %s_MASK%d\t0x%08xU\n", s, i, masks[i]; + + printf "#define %s_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS !=3D %d)\n\n", = s, ncapints; + } + + printf "#endif /* _ASM_X86_FEATUREMASKS_H */\n"; +} --=20 2.48.1