[tip: x86/cpu] x86/cpufeatures: Use AWK to generate {REQUIRED|DISABLED}_MASK_BIT_SET in <asm/cpufeaturemasks.h>

From: tip-bot2 for Xin Li (Intel)
Date: Mon Mar 10 2025 - 04:18:37 EST

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID: 55d9f0b05e1ca53c0884545445b7e29466679a33
Gitweb: https://git.kernel.org/tip/55d9f0b05e1ca53c0884545445b7e29466679a33
Author: Xin Li (Intel) <xin@xxxxxxxxx>
AuthorDate: Fri, 28 Feb 2025 00:23:38 -08:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Mon, 10 Mar 2025 09:04:03 +01:00

x86/cpufeatures: Use AWK to generate {REQUIRED|DISABLED}_MASK_BIT_SET in <asm/cpufeaturemasks.h>

Generate the {REQUIRED|DISABLED}_MASK_BIT_SET macros in the newly added AWK
script that generates <asm/cpufeaturemasks.h>.

Suggested-by: Brian Gerst <brgerst@xxxxxxxxx>
Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Brian Gerst <brgerst@xxxxxxxxx>
Reviewed-by: Nikolay Borisov <nik.borisov@xxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20250228082338.73859-6-xin@xxxxxxxxx
---
arch/x86/include/asm/cpufeature.h | 69 +-----------------------------
arch/x86/tools/cpufeaturemasks.awk | 9 +++-
2 files changed, 8 insertions(+), 70 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index d54db88..910601c 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -51,75 +51,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
#define test_cpu_cap(c, bit) \
arch_test_bit(bit, (unsigned long *)((c)->x86_capability))

-/*
- * There are 32 bits/features in each mask word. The high bits
- * (selected with (bit>>5) give us the word number and the low 5
- * bits give us the bit/feature number inside the word.
- * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
- * see if it is set in the mask word.
- */
-#define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \
- (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
-
-/*
- * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the
- * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all
- * header macros which use NCAPINTS need to be changed. The duplicated macro
- * use causes the compiler to issue errors for all headers so that all usage
- * sites can be corrected.
- */
-#define REQUIRED_MASK_BIT_SET(feature_bit) \
- ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 21, feature_bit) || \
- REQUIRED_MASK_CHECK || \
- BUILD_BUG_ON_ZERO(NCAPINTS != 22))
-
-#define DISABLED_MASK_BIT_SET(feature_bit) \
- ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \
- CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 21, feature_bit) || \
- DISABLED_MASK_CHECK || \
- BUILD_BUG_ON_ZERO(NCAPINTS != 22))
-
#define cpu_has(c, bit) \
(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
test_cpu_cap(c, bit))
diff --git a/arch/x86/tools/cpufeaturemasks.awk b/arch/x86/tools/cpufeaturemasks.awk
index 59757ca..173d5bf 100755
--- a/arch/x86/tools/cpufeaturemasks.awk
+++ b/arch/x86/tools/cpufeaturemasks.awk
@@ -74,7 +74,14 @@ END {
for (i = 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 != %d)\n\n", s, ncapints;
+ printf "\n#define %s_MASK_BIT_SET(x)\t\t\t\\\n", s;
+ printf "\t((\t\t\t\t\t";
+ for (i = 0; i < ncapints; i++) {
+ if (masks[i])
+ printf "\t\\\n\t\t((x) >> 5) == %2d ? %s_MASK%d :", i, s, i;
+ }
+ printf " 0\t\\\n";
+ printf "\t) & (1U << ((x) & 31)))\n\n";
}

printf "#endif /* _ASM_X86_CPUFEATUREMASKS_H */\n";