Commit 84132633 authored by H. Peter Anvin (Intel)'s avatar H. Peter Anvin (Intel) Committed by Ingo Molnar
Browse files

x86/cpufeatures: Generate the <asm/cpufeaturemasks.h> header based on build config 



Introduce an AWK script to auto-generate the <asm/cpufeaturemasks.h> header
with required and disabled feature masks based on <asm/cpufeatures.h>
and the 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 ]
  [ mingo: Improved changelog and comments ]

Signed-off-by: default avatarH. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: default avatarXin Li (Intel) <xin@zytor.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarNikolay Borisov <nik.borisov@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250305184725.3341760-3-xin@zytor.com
parent 3d37d939

arch/x86/Makefile

+15 −0
Original line number Diff line number Diff line
@@ -268,6 +268,21 @@ archscripts: scripts_basic 
archheaders:

	$(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all



###

# <asm/cpufeaturemasks.h> header generation



cpufeaturemasks.hdr := arch/x86/include/generated/asm/cpufeaturemasks.h

cpufeaturemasks.awk := $(srctree)/arch/x86/tools/cpufeaturemasks.awk

cpufeatures_hdr := $(srctree)/arch/x86/include/asm/cpufeatures.h

targets += $(cpufeaturemasks.hdr)

quiet_cmd_gen_featuremasks = GEN     $@

      cmd_gen_featuremasks = $(AWK) -f $(cpufeaturemasks.awk) $(cpufeatures_hdr) $(KCONFIG_CONFIG) > $@



$(cpufeaturemasks.hdr): $(cpufeaturemasks.awk) $(cpufeatures_hdr) $(KCONFIG_CONFIG) FORCE

	$(shell mkdir -p $(dir $@))

	$(call if_changed,gen_featuremasks)

archprepare: $(cpufeaturemasks.hdr)



###

# Kernel objects

arch/x86/boot/cpucheck.c

+2 −1
Original line number Diff line number Diff line
@@ -22,10 +22,11 @@ 
# include "boot.h"

#endif

#include <linux/types.h>

#include <asm/cpufeaturemasks.h>

#include <asm/intel-family.h>

#include <asm/processor-flags.h>

#include <asm/required-features.h>

#include <asm/msr-index.h>



#include "string.h"

#include "msr.h"

arch/x86/boot/cpuflags.c

+0 −1
Original line number Diff line number Diff line
@@ -3,7 +3,6 @@ 
#include "bitops.h"



#include <asm/processor-flags.h>

#include <asm/required-features.h>

#include <asm/msr-index.h>

#include "cpuflags.h"

arch/x86/boot/mkcpustr.c

+1 −2
Original line number Diff line number Diff line
@@ -12,8 +12,6 @@ 


#include <stdio.h>



#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;



	printf("#include <asm/cpufeaturemasks.h>\n\n");

	printf("static const char x86_cap_strs[] =\n");



	for (i = 0; i < NCAPINTS; i++) {

arch/x86/include/asm/Kbuild

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ generated-y += syscalls_x32.h 
generated-y += unistd_32_ia32.h

generated-y += unistd_64_x32.h

generated-y += xen-hypercalls.h

generated-y += cpufeaturemasks.h



generic-y += early_ioremap.h

generic-y += fprobe.h