aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2023-06-27 12:25:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-06-27 12:25:42 -0700
commit4baa098a147d76a9ad1a6867fa14286db52085b6 (patch)
tree7e75c0343e407436d279aa9dad56e033f192cc19
parent4aacacee8617424e1dacead8d830e5b768eb3e53 (diff)
parent5516c89d58283413134f8d26960c6303d5d5bd89 (diff)
downloadlivepatching-4baa098a147d76a9ad1a6867fa14286db52085b6.tar.gz
Merge tag 'x86_misc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov: - Remove the local symbols prefix of the get/put_user() exception handling symbols so that tools do not get confused by the presence of code belonging to the wrong symbol/not belonging to any symbol - Improve csum_partial()'s performance - Some improvements to the kcpuid tool * tag 'x86_misc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/lib: Make get/put_user() exception handling a visible symbol x86/csum: Fix clang -Wuninitialized in csum_partial() x86/csum: Improve performance of `csum_partial` tools/x86/kcpuid: Add .gitignore tools/x86/kcpuid: Dump the correct CPUID function in error
-rw-r--r--arch/x86/lib/csum-partial_64.c101
-rw-r--r--arch/x86/lib/getuser.S32
-rw-r--r--arch/x86/lib/putuser.S24
-rw-r--r--lib/Kconfig.debug17
-rw-r--r--lib/Makefile1
-rw-r--r--lib/checksum_kunit.c334
-rw-r--r--tools/arch/x86/kcpuid/.gitignore1
-rw-r--r--tools/arch/x86/kcpuid/kcpuid.c7
8 files changed, 453 insertions, 64 deletions
diff --git a/arch/x86/lib/csum-partial_64.c b/arch/x86/lib/csum-partial_64.c
index 50734a23034c43..cea25ca8b8cf69 100644
--- a/arch/x86/lib/csum-partial_64.c
+++ b/arch/x86/lib/csum-partial_64.c
@@ -5,22 +5,34 @@
* This file contains network checksum routines that are better done
* in an architecture-specific manner due to speed.
*/
-
+
#include <linux/compiler.h>
#include <linux/export.h>
#include <asm/checksum.h>
#include <asm/word-at-a-time.h>
-static inline unsigned short from32to16(unsigned a)
+static inline unsigned short from32to16(unsigned a)
{
- unsigned short b = a >> 16;
+ unsigned short b = a >> 16;
asm("addw %w2,%w0\n\t"
- "adcw $0,%w0\n"
+ "adcw $0,%w0\n"
: "=r" (b)
: "0" (b), "r" (a));
return b;
}
+static inline __wsum csum_tail(u64 temp64, int odd)
+{
+ unsigned int result;
+
+ result = add32_with_carry(temp64 >> 32, temp64 & 0xffffffff);
+ if (unlikely(odd)) {
+ result = from32to16(result);
+ result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+ }
+ return (__force __wsum)result;
+}
+
/*
* Do a checksum on an arbitrary memory area.
* Returns a 32bit checksum.
@@ -35,7 +47,7 @@ static inline unsigned short from32to16(unsigned a)
__wsum csum_partial(const void *buff, int len, __wsum sum)
{
u64 temp64 = (__force u64)sum;
- unsigned odd, result;
+ unsigned odd;
odd = 1 & (unsigned long) buff;
if (unlikely(odd)) {
@@ -47,21 +59,52 @@ __wsum csum_partial(const void *buff, int len, __wsum sum)
buff++;
}
- while (unlikely(len >= 64)) {
+ /*
+ * len == 40 is the hot case due to IPv6 headers, but annotating it likely()
+ * has noticeable negative affect on codegen for all other cases with
+ * minimal performance benefit here.
+ */
+ if (len == 40) {
asm("addq 0*8(%[src]),%[res]\n\t"
"adcq 1*8(%[src]),%[res]\n\t"
"adcq 2*8(%[src]),%[res]\n\t"
"adcq 3*8(%[src]),%[res]\n\t"
"adcq 4*8(%[src]),%[res]\n\t"
- "adcq 5*8(%[src]),%[res]\n\t"
- "adcq 6*8(%[src]),%[res]\n\t"
- "adcq 7*8(%[src]),%[res]\n\t"
"adcq $0,%[res]"
- : [res] "+r" (temp64)
- : [src] "r" (buff)
- : "memory");
- buff += 64;
- len -= 64;
+ : [res] "+r"(temp64)
+ : [src] "r"(buff), "m"(*(const char(*)[40])buff));
+ return csum_tail(temp64, odd);
+ }
+ if (unlikely(len >= 64)) {
+ /*
+ * Extra accumulators for better ILP in the loop.
+ */
+ u64 tmp_accum, tmp_carries;
+
+ asm("xorl %k[tmp_accum],%k[tmp_accum]\n\t"
+ "xorl %k[tmp_carries],%k[tmp_carries]\n\t"
+ "subl $64, %[len]\n\t"
+ "1:\n\t"
+ "addq 0*8(%[src]),%[res]\n\t"
+ "adcq 1*8(%[src]),%[res]\n\t"
+ "adcq 2*8(%[src]),%[res]\n\t"
+ "adcq 3*8(%[src]),%[res]\n\t"
+ "adcl $0,%k[tmp_carries]\n\t"
+ "addq 4*8(%[src]),%[tmp_accum]\n\t"
+ "adcq 5*8(%[src]),%[tmp_accum]\n\t"
+ "adcq 6*8(%[src]),%[tmp_accum]\n\t"
+ "adcq 7*8(%[src]),%[tmp_accum]\n\t"
+ "adcl $0,%k[tmp_carries]\n\t"
+ "addq $64, %[src]\n\t"
+ "subl $64, %[len]\n\t"
+ "jge 1b\n\t"
+ "addq %[tmp_accum],%[res]\n\t"
+ "adcq %[tmp_carries],%[res]\n\t"
+ "adcq $0,%[res]"
+ : [tmp_accum] "=&r"(tmp_accum),
+ [tmp_carries] "=&r"(tmp_carries), [res] "+r"(temp64),
+ [len] "+r"(len), [src] "+r"(buff)
+ : "m"(*(const char *)buff));
}
if (len & 32) {
@@ -70,45 +113,37 @@ __wsum csum_partial(const void *buff, int len, __wsum sum)
"adcq 2*8(%[src]),%[res]\n\t"
"adcq 3*8(%[src]),%[res]\n\t"
"adcq $0,%[res]"
- : [res] "+r" (temp64)
- : [src] "r" (buff)
- : "memory");
+ : [res] "+r"(temp64)
+ : [src] "r"(buff), "m"(*(const char(*)[32])buff));
buff += 32;
}
if (len & 16) {
asm("addq 0*8(%[src]),%[res]\n\t"
"adcq 1*8(%[src]),%[res]\n\t"
"adcq $0,%[res]"
- : [res] "+r" (temp64)
- : [src] "r" (buff)
- : "memory");
+ : [res] "+r"(temp64)
+ : [src] "r"(buff), "m"(*(const char(*)[16])buff));
buff += 16;
}
if (len & 8) {
asm("addq 0*8(%[src]),%[res]\n\t"
"adcq $0,%[res]"
- : [res] "+r" (temp64)
- : [src] "r" (buff)
- : "memory");
+ : [res] "+r"(temp64)
+ : [src] "r"(buff), "m"(*(const char(*)[8])buff));
buff += 8;
}
if (len & 7) {
- unsigned int shift = (8 - (len & 7)) * 8;
+ unsigned int shift = (-len << 3) & 63;
unsigned long trail;
trail = (load_unaligned_zeropad(buff) << shift) >> shift;
asm("addq %[trail],%[res]\n\t"
"adcq $0,%[res]"
- : [res] "+r" (temp64)
- : [trail] "r" (trail));
+ : [res] "+r"(temp64)
+ : [trail] "r"(trail));
}
- result = add32_with_carry(temp64 >> 32, temp64 & 0xffffffff);
- if (unlikely(odd)) {
- result = from32to16(result);
- result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
- }
- return (__force __wsum)result;
+ return csum_tail(temp64, odd);
}
EXPORT_SYMBOL(csum_partial);
@@ -118,6 +153,6 @@ EXPORT_SYMBOL(csum_partial);
*/
__sum16 ip_compute_csum(const void *buff, int len)
{
- return csum_fold(csum_partial(buff,len,0));
+ return csum_fold(csum_partial(buff, len, 0));
}
EXPORT_SYMBOL(ip_compute_csum);
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index b64a2bd1a1efae..9c63713477bbb7 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -143,43 +143,43 @@ SYM_FUNC_END(__get_user_nocheck_8)
EXPORT_SYMBOL(__get_user_nocheck_8)
-SYM_CODE_START_LOCAL(.Lbad_get_user_clac)
+SYM_CODE_START_LOCAL(__get_user_handle_exception)
ASM_CLAC
.Lbad_get_user:
xor %edx,%edx
mov $(-EFAULT),%_ASM_AX
RET
-SYM_CODE_END(.Lbad_get_user_clac)
+SYM_CODE_END(__get_user_handle_exception)
#ifdef CONFIG_X86_32
-SYM_CODE_START_LOCAL(.Lbad_get_user_8_clac)
+SYM_CODE_START_LOCAL(__get_user_8_handle_exception)
ASM_CLAC
bad_get_user_8:
xor %edx,%edx
xor %ecx,%ecx
mov $(-EFAULT),%_ASM_AX
RET
-SYM_CODE_END(.Lbad_get_user_8_clac)
+SYM_CODE_END(__get_user_8_handle_exception)
#endif
/* get_user */
- _ASM_EXTABLE(1b, .Lbad_get_user_clac)
- _ASM_EXTABLE(2b, .Lbad_get_user_clac)
- _ASM_EXTABLE(3b, .Lbad_get_user_clac)
+ _ASM_EXTABLE(1b, __get_user_handle_exception)
+ _ASM_EXTABLE(2b, __get_user_handle_exception)
+ _ASM_EXTABLE(3b, __get_user_handle_exception)
#ifdef CONFIG_X86_64
- _ASM_EXTABLE(4b, .Lbad_get_user_clac)
+ _ASM_EXTABLE(4b, __get_user_handle_exception)
#else
- _ASM_EXTABLE(4b, .Lbad_get_user_8_clac)
- _ASM_EXTABLE(5b, .Lbad_get_user_8_clac)
+ _ASM_EXTABLE(4b, __get_user_8_handle_exception)
+ _ASM_EXTABLE(5b, __get_user_8_handle_exception)
#endif
/* __get_user */
- _ASM_EXTABLE(6b, .Lbad_get_user_clac)
- _ASM_EXTABLE(7b, .Lbad_get_user_clac)
- _ASM_EXTABLE(8b, .Lbad_get_user_clac)
+ _ASM_EXTABLE(6b, __get_user_handle_exception)
+ _ASM_EXTABLE(7b, __get_user_handle_exception)
+ _ASM_EXTABLE(8b, __get_user_handle_exception)
#ifdef CONFIG_X86_64
- _ASM_EXTABLE(9b, .Lbad_get_user_clac)
+ _ASM_EXTABLE(9b, __get_user_handle_exception)
#else
- _ASM_EXTABLE(9b, .Lbad_get_user_8_clac)
- _ASM_EXTABLE(10b, .Lbad_get_user_8_clac)
+ _ASM_EXTABLE(9b, __get_user_8_handle_exception)
+ _ASM_EXTABLE(10b, __get_user_8_handle_exception)
#endif
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index 3062d09a776d50..1451e0c4ae22af 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -131,22 +131,22 @@ SYM_FUNC_START(__put_user_nocheck_8)
SYM_FUNC_END(__put_user_nocheck_8)
EXPORT_SYMBOL(__put_user_nocheck_8)
-SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
+SYM_CODE_START_LOCAL(__put_user_handle_exception)
ASM_CLAC
.Lbad_put_user:
movl $-EFAULT,%ecx
RET
-SYM_CODE_END(.Lbad_put_user_clac)
+SYM_CODE_END(__put_user_handle_exception)
- _ASM_EXTABLE(1b, .Lbad_put_user_clac)
- _ASM_EXTABLE(2b, .Lbad_put_user_clac)
- _ASM_EXTABLE(3b, .Lbad_put_user_clac)
- _ASM_EXTABLE(4b, .Lbad_put_user_clac)
- _ASM_EXTABLE(5b, .Lbad_put_user_clac)
- _ASM_EXTABLE(6b, .Lbad_put_user_clac)
- _ASM_EXTABLE(7b, .Lbad_put_user_clac)
- _ASM_EXTABLE(9b, .Lbad_put_user_clac)
+ _ASM_EXTABLE(1b, __put_user_handle_exception)
+ _ASM_EXTABLE(2b, __put_user_handle_exception)
+ _ASM_EXTABLE(3b, __put_user_handle_exception)
+ _ASM_EXTABLE(4b, __put_user_handle_exception)
+ _ASM_EXTABLE(5b, __put_user_handle_exception)
+ _ASM_EXTABLE(6b, __put_user_handle_exception)
+ _ASM_EXTABLE(7b, __put_user_handle_exception)
+ _ASM_EXTABLE(9b, __put_user_handle_exception)
#ifdef CONFIG_X86_32
- _ASM_EXTABLE(8b, .Lbad_put_user_clac)
- _ASM_EXTABLE(10b, .Lbad_put_user_clac)
+ _ASM_EXTABLE(8b, __put_user_handle_exception)
+ _ASM_EXTABLE(10b, __put_user_handle_exception)
#endif
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ce51d4dc6803ed..f2d6e9dd8021f1 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2453,6 +2453,23 @@ config BITFIELD_KUNIT
If unsure, say N.
+config CHECKSUM_KUNIT
+ tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ Enable this option to test the checksum functions at boot.
+
+ KUnit tests run during boot and output the results to the debug log
+ in TAP format (http://testanything.org/). Only useful for kernel devs
+ running the KUnit test harness, and not intended for inclusion into a
+ production build.
+
+ For more information on KUnit and unit tests in general please refer
+ to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
+
config HASH_KUNIT_TEST
tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
depends on KUNIT
diff --git a/lib/Makefile b/lib/Makefile
index 876fcdeae34ec7..cd37ec1d9a2f6e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -377,6 +377,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/
# KUnit tests
CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN)
obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o
+obj-$(CONFIG_CHECKSUM_KUNIT) += checksum_kunit.o
obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o
obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
diff --git a/lib/checksum_kunit.c b/lib/checksum_kunit.c
new file mode 100644
index 00000000000000..ace3c4799fe151
--- /dev/null
+++ b/lib/checksum_kunit.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test cases csum_partial and csum_fold
+ */
+
+#include <kunit/test.h>
+#include <asm/checksum.h>
+
+#define MAX_LEN 512
+#define MAX_ALIGN 64
+#define TEST_BUFLEN (MAX_LEN + MAX_ALIGN)
+
+static const __wsum random_init_sum = 0x2847aab;
+static const u8 random_buf[] = {
+ 0xac, 0xd7, 0x76, 0x69, 0x6e, 0xf2, 0x93, 0x2c, 0x1f, 0xe0, 0xde, 0x86,
+ 0x8f, 0x54, 0x33, 0x90, 0x95, 0xbf, 0xff, 0xb9, 0xea, 0x62, 0x6e, 0xb5,
+ 0xd3, 0x4f, 0xf5, 0x60, 0x50, 0x5c, 0xc7, 0xfa, 0x6d, 0x1a, 0xc7, 0xf0,
+ 0xd2, 0x2c, 0x12, 0x3d, 0x88, 0xe3, 0x14, 0x21, 0xb1, 0x5e, 0x45, 0x31,
+ 0xa2, 0x85, 0x36, 0x76, 0xba, 0xd8, 0xad, 0xbb, 0x9e, 0x49, 0x8f, 0xf7,
+ 0xce, 0xea, 0xef, 0xca, 0x2c, 0x29, 0xf7, 0x15, 0x5c, 0x1d, 0x4d, 0x09,
+ 0x1f, 0xe2, 0x14, 0x31, 0x8c, 0x07, 0x57, 0x23, 0x1f, 0x6f, 0x03, 0xe1,
+ 0x93, 0x19, 0x53, 0x03, 0x45, 0x49, 0x9a, 0x3b, 0x8e, 0x0c, 0x12, 0x5d,
+ 0x8a, 0xb8, 0x9b, 0x8c, 0x9a, 0x03, 0xe5, 0xa2, 0x43, 0xd2, 0x3b, 0x4e,
+ 0x7e, 0x30, 0x3c, 0x22, 0x2d, 0xc5, 0xfc, 0x9e, 0xdb, 0xc6, 0xf9, 0x69,
+ 0x12, 0x39, 0x1f, 0xa0, 0x11, 0x0c, 0x3f, 0xf5, 0x53, 0xc9, 0x30, 0xfb,
+ 0xb0, 0xdd, 0x21, 0x1d, 0x34, 0xe2, 0x65, 0x30, 0xf1, 0xe8, 0x1b, 0xe7,
+ 0x55, 0x0d, 0xeb, 0xbd, 0xcc, 0x9d, 0x24, 0xa4, 0xad, 0xa7, 0x93, 0x47,
+ 0x19, 0x2e, 0xc4, 0x5c, 0x3b, 0xc7, 0x6d, 0x95, 0x0c, 0x47, 0x60, 0xaf,
+ 0x5b, 0x47, 0xee, 0xdc, 0x31, 0x31, 0x14, 0x12, 0x7e, 0x9e, 0x45, 0xb1,
+ 0xc1, 0x69, 0x4b, 0x84, 0xfc, 0x88, 0xc1, 0x9e, 0x46, 0xb4, 0xc2, 0x25,
+ 0xc5, 0x6c, 0x4c, 0x22, 0x58, 0x5c, 0xbe, 0xff, 0xea, 0x88, 0x88, 0x7a,
+ 0xcb, 0x1c, 0x5d, 0x63, 0xa1, 0xf2, 0x33, 0x0c, 0xa2, 0x16, 0x0b, 0x6e,
+ 0x2b, 0x79, 0x58, 0xf7, 0xac, 0xd3, 0x6a, 0x3f, 0x81, 0x57, 0x48, 0x45,
+ 0xe3, 0x7c, 0xdc, 0xd6, 0x34, 0x7e, 0xe6, 0x73, 0xfa, 0xcb, 0x31, 0x18,
+ 0xa9, 0x0b, 0xee, 0x6b, 0x99, 0xb9, 0x2d, 0xde, 0x22, 0x0e, 0x71, 0x57,
+ 0x0e, 0x9b, 0x11, 0xd1, 0x15, 0x41, 0xd0, 0x6b, 0x50, 0x8a, 0x23, 0x64,
+ 0xe3, 0x9c, 0xb3, 0x55, 0x09, 0xe9, 0x32, 0x67, 0xf9, 0xe0, 0x73, 0xf1,
+ 0x60, 0x66, 0x0b, 0x88, 0x79, 0x8d, 0x4b, 0x52, 0x83, 0x20, 0x26, 0x78,
+ 0x49, 0x27, 0xe7, 0x3e, 0x29, 0xa8, 0x18, 0x82, 0x41, 0xdd, 0x1e, 0xcc,
+ 0x3b, 0xc4, 0x65, 0xd1, 0x21, 0x40, 0x72, 0xb2, 0x87, 0x5e, 0x16, 0x10,
+ 0x80, 0x3f, 0x4b, 0x58, 0x1c, 0xc2, 0x79, 0x20, 0xf0, 0xe0, 0x80, 0xd3,
+ 0x52, 0xa5, 0x19, 0x6e, 0x47, 0x90, 0x08, 0xf5, 0x50, 0xe2, 0xd6, 0xae,
+ 0xe9, 0x2e, 0xdc, 0xd5, 0xb4, 0x90, 0x1f, 0x79, 0x49, 0x82, 0x21, 0x84,
+ 0xa0, 0xb5, 0x2f, 0xff, 0x30, 0x71, 0xed, 0x80, 0x68, 0xb1, 0x6d, 0xef,
+ 0xf6, 0xcf, 0xb8, 0x41, 0x79, 0xf5, 0x01, 0xbc, 0x0c, 0x9b, 0x0e, 0x06,
+ 0xf3, 0xb0, 0xbb, 0x97, 0xb8, 0xb1, 0xfd, 0x51, 0x4e, 0xef, 0x0a, 0x3d,
+ 0x7a, 0x3d, 0xbd, 0x61, 0x00, 0xa2, 0xb3, 0xf0, 0x1d, 0x77, 0x7b, 0x6c,
+ 0x01, 0x61, 0xa5, 0xa3, 0xdb, 0xd5, 0xd5, 0xf4, 0xb5, 0x28, 0x9f, 0x0a,
+ 0xa3, 0x82, 0x5f, 0x4b, 0x40, 0x0f, 0x05, 0x0e, 0x78, 0xed, 0xbf, 0x17,
+ 0xf6, 0x5a, 0x8a, 0x7d, 0xf9, 0x45, 0xc1, 0xd7, 0x1b, 0x9d, 0x6c, 0x07,
+ 0x88, 0xf3, 0xbc, 0xf1, 0xea, 0x28, 0x1f, 0xb8, 0x7a, 0x60, 0x3c, 0xce,
+ 0x3e, 0x50, 0xb2, 0x0b, 0xcf, 0xe5, 0x08, 0x1f, 0x48, 0x04, 0xf9, 0x35,
+ 0x29, 0x15, 0xbe, 0x82, 0x96, 0xc2, 0x55, 0x04, 0x6c, 0x19, 0x45, 0x29,
+ 0x0b, 0xb6, 0x49, 0x12, 0xfb, 0x8d, 0x1b, 0x75, 0x8b, 0xd9, 0x6a, 0x5c,
+ 0xbe, 0x46, 0x2b, 0x41, 0xfe, 0x21, 0xad, 0x1f, 0x75, 0xe7, 0x90, 0x3d,
+ 0xe1, 0xdf, 0x4b, 0xe1, 0x81, 0xe2, 0x17, 0x02, 0x7b, 0x58, 0x8b, 0x92,
+ 0x1a, 0xac, 0x46, 0xdd, 0x2e, 0xce, 0x40, 0x09
+};
+static const __sum16 expected_results[] = {
+ 0x82d0, 0x8224, 0xab23, 0xaaad, 0x41ad, 0x413f, 0x4f3e, 0x4eab, 0x22ab,
+ 0x228c, 0x428b, 0x41ad, 0xbbac, 0xbb1d, 0x671d, 0x66ea, 0xd6e9, 0xd654,
+ 0x1754, 0x1655, 0x5d54, 0x5c6a, 0xfa69, 0xf9fb, 0x44fb, 0x4428, 0xf527,
+ 0xf432, 0x9432, 0x93e2, 0x37e2, 0x371b, 0x3d1a, 0x3cad, 0x22ad, 0x21e6,
+ 0x31e5, 0x3113, 0x0513, 0x0501, 0xc800, 0xc778, 0xe477, 0xe463, 0xc363,
+ 0xc2b2, 0x64b2, 0x646d, 0x336d, 0x32cb, 0xadca, 0xad94, 0x3794, 0x36da,
+ 0x5ed9, 0x5e2c, 0xa32b, 0xa28d, 0x598d, 0x58fe, 0x61fd, 0x612f, 0x772e,
+ 0x763f, 0xac3e, 0xac12, 0x8312, 0x821b, 0x6d1b, 0x6cbf, 0x4fbf, 0x4f72,
+ 0x4672, 0x4653, 0x6452, 0x643e, 0x333e, 0x32b2, 0x2bb2, 0x2b5b, 0x085b,
+ 0x083c, 0x993b, 0x9938, 0xb837, 0xb7a4, 0x9ea4, 0x9e51, 0x9b51, 0x9b0c,
+ 0x520c, 0x5172, 0x1672, 0x15e4, 0x09e4, 0x09d2, 0xacd1, 0xac47, 0xf446,
+ 0xf3ab, 0x67ab, 0x6711, 0x6411, 0x632c, 0xc12b, 0xc0e8, 0xeee7, 0xeeac,
+ 0xa0ac, 0xa02e, 0x702e, 0x6ff2, 0x4df2, 0x4dc5, 0x88c4, 0x87c8, 0xe9c7,
+ 0xe8ec, 0x22ec, 0x21f3, 0xb8f2, 0xb8e0, 0x7fe0, 0x7fc1, 0xdfc0, 0xdfaf,
+ 0xd3af, 0xd370, 0xde6f, 0xde1c, 0x151c, 0x14ec, 0x19eb, 0x193b, 0x3c3a,
+ 0x3c19, 0x1f19, 0x1ee5, 0x3ce4, 0x3c7f, 0x0c7f, 0x0b8e, 0x238d, 0x2372,
+ 0x3c71, 0x3c1c, 0x2f1c, 0x2e31, 0x7130, 0x7064, 0xd363, 0xd33f, 0x2f3f,
+ 0x2e92, 0x8791, 0x86fe, 0x3ffe, 0x3fe5, 0x11e5, 0x1121, 0xb520, 0xb4e5,
+ 0xede4, 0xed77, 0x5877, 0x586b, 0x116b, 0x110b, 0x620a, 0x61af, 0x1aaf,
+ 0x19c1, 0x3dc0, 0x3d8f, 0x0c8f, 0x0c7b, 0xfa7a, 0xf9fc, 0x5bfc, 0x5bb7,
+ 0xaab6, 0xa9f5, 0x40f5, 0x40aa, 0xbca9, 0xbbad, 0x33ad, 0x32ec, 0x94eb,
+ 0x94a5, 0xe0a4, 0xdfe2, 0xbae2, 0xba1d, 0x4e1d, 0x4dd1, 0x2bd1, 0x2b79,
+ 0xcf78, 0xceba, 0xcfb9, 0xcecf, 0x46cf, 0x4647, 0xcc46, 0xcb7b, 0xaf7b,
+ 0xaf1e, 0x4c1e, 0x4b7d, 0x597c, 0x5949, 0x4d49, 0x4ca7, 0x36a7, 0x369c,
+ 0xc89b, 0xc870, 0x4f70, 0x4f18, 0x5817, 0x576b, 0x846a, 0x8400, 0x4500,
+ 0x447f, 0xed7e, 0xed36, 0xa836, 0xa753, 0x2b53, 0x2a77, 0x5476, 0x5442,
+ 0xd641, 0xd55b, 0x625b, 0x6161, 0x9660, 0x962f, 0x7e2f, 0x7d86, 0x7286,
+ 0x7198, 0x0698, 0x05ff, 0x4cfe, 0x4cd1, 0x6ed0, 0x6eae, 0x60ae, 0x603d,
+ 0x093d, 0x092f, 0x6e2e, 0x6e1d, 0x9d1c, 0x9d07, 0x5c07, 0x5b37, 0xf036,
+ 0xefe6, 0x65e6, 0x65c3, 0x01c3, 0x00e0, 0x64df, 0x642c, 0x0f2c, 0x0f23,
+ 0x2622, 0x25f0, 0xbeef, 0xbdf6, 0xddf5, 0xdd82, 0xec81, 0xec21, 0x8621,
+ 0x8616, 0xfe15, 0xfd9c, 0x709c, 0x7051, 0x1e51, 0x1dce, 0xfdcd, 0xfda7,
+ 0x85a7, 0x855e, 0x5e5e, 0x5d77, 0x1f77, 0x1f4e, 0x774d, 0x7735, 0xf534,
+ 0xf4f3, 0x17f3, 0x17d5, 0x4bd4, 0x4b99, 0x8798, 0x8733, 0xb632, 0xb611,
+ 0x7611, 0x759f, 0xc39e, 0xc317, 0x6517, 0x6501, 0x5501, 0x5481, 0x1581,
+ 0x1536, 0xbd35, 0xbd19, 0xfb18, 0xfa9f, 0xda9f, 0xd9af, 0xf9ae, 0xf92e,
+ 0x262e, 0x25dc, 0x80db, 0x80c2, 0x12c2, 0x127b, 0x827a, 0x8272, 0x8d71,
+ 0x8d21, 0xab20, 0xaa4a, 0xfc49, 0xfb60, 0xcd60, 0xcc84, 0xf783, 0xf6cf,
+ 0x66cf, 0x66b0, 0xedaf, 0xed66, 0x6b66, 0x6b45, 0xe744, 0xe6a4, 0x31a4,
+ 0x3175, 0x3274, 0x3244, 0xc143, 0xc056, 0x4056, 0x3fee, 0x8eed, 0x8e80,
+ 0x9f7f, 0x9e89, 0xcf88, 0xced0, 0x8dd0, 0x8d57, 0x9856, 0x9855, 0xdc54,
+ 0xdc48, 0x4148, 0x413a, 0x3b3a, 0x3a47, 0x8a46, 0x898b, 0xf28a, 0xf1d2,
+ 0x40d2, 0x3fd5, 0xeed4, 0xee86, 0xff85, 0xff7b, 0xc27b, 0xc201, 0x8501,
+ 0x8444, 0x2344, 0x2344, 0x8143, 0x8090, 0x908f, 0x9072, 0x1972, 0x18f7,
+ 0xacf6, 0xacf5, 0x4bf5, 0x4b50, 0xa84f, 0xa774, 0xd273, 0xd19e, 0xdd9d,
+ 0xdce8, 0xb4e8, 0xb449, 0xaa49, 0xa9a6, 0x27a6, 0x2747, 0xdc46, 0xdc06,
+ 0xcd06, 0xcd01, 0xbf01, 0xbe89, 0xd188, 0xd0c9, 0xb9c9, 0xb8d3, 0x5ed3,
+ 0x5e49, 0xe148, 0xe04f, 0x9b4f, 0x9a8e, 0xc38d, 0xc372, 0x2672, 0x2606,
+ 0x1f06, 0x1e7e, 0x2b7d, 0x2ac1, 0x39c0, 0x38d6, 0x10d6, 0x10b7, 0x58b6,
+ 0x583c, 0xf83b, 0xf7ff, 0x29ff, 0x29c1, 0xd9c0, 0xd90e, 0xce0e, 0xcd3f,
+ 0xe83e, 0xe836, 0xc936, 0xc8ee, 0xc4ee, 0xc3f5, 0x8ef5, 0x8ecc, 0x79cc,
+ 0x790e, 0xf70d, 0xf677, 0x3477, 0x3422, 0x3022, 0x2fb6, 0x16b6, 0x1671,
+ 0xed70, 0xed65, 0x3765, 0x371c, 0x251c, 0x2421, 0x9720, 0x9705, 0x2205,
+ 0x217a, 0x4879, 0x480f, 0xec0e, 0xeb50, 0xa550, 0xa525, 0x6425, 0x6327,
+ 0x4227, 0x417a, 0x227a, 0x2205, 0x3b04, 0x3a74, 0xfd73, 0xfc92, 0x1d92,
+ 0x1d47, 0x3c46, 0x3bc5, 0x59c4, 0x59ad, 0x57ad, 0x5732, 0xff31, 0xfea6,
+ 0x6ca6, 0x6c8c, 0xc08b, 0xc045, 0xe344, 0xe316, 0x1516, 0x14d6,
+};
+static const __wsum init_sums_no_overflow[] = {
+ 0xffffffff, 0xfffffffb, 0xfffffbfb, 0xfffffbf7, 0xfffff7f7, 0xfffff7f3,
+ 0xfffff3f3, 0xfffff3ef, 0xffffefef, 0xffffefeb, 0xffffebeb, 0xffffebe7,
+ 0xffffe7e7, 0xffffe7e3, 0xffffe3e3, 0xffffe3df, 0xffffdfdf, 0xffffdfdb,
+ 0xffffdbdb, 0xffffdbd7, 0xffffd7d7, 0xffffd7d3, 0xffffd3d3, 0xffffd3cf,
+ 0xffffcfcf, 0xffffcfcb, 0xffffcbcb, 0xffffcbc7, 0xffffc7c7, 0xffffc7c3,
+ 0xffffc3c3, 0xffffc3bf, 0xffffbfbf, 0xffffbfbb, 0xffffbbbb, 0xffffbbb7,
+ 0xffffb7b7, 0xffffb7b3, 0xffffb3b3, 0xffffb3af, 0xffffafaf, 0xffffafab,
+ 0xffffabab, 0xffffaba7, 0xffffa7a7, 0xffffa7a3, 0xffffa3a3, 0xffffa39f,
+ 0xffff9f9f, 0xffff9f9b, 0xffff9b9b, 0xffff9b97, 0xffff9797, 0xffff9793,
+ 0xffff9393, 0xffff938f, 0xffff8f8f, 0xffff8f8b, 0xffff8b8b, 0xffff8b87,
+ 0xffff8787, 0xffff8783, 0xffff8383, 0xffff837f, 0xffff7f7f, 0xffff7f7b,
+ 0xffff7b7b, 0xffff7b77, 0xffff7777, 0xffff7773, 0xffff7373, 0xffff736f,
+ 0xffff6f6f, 0xffff6f6b, 0xffff6b6b, 0xffff6b67, 0xffff6767, 0xffff6763,
+ 0xffff6363, 0xffff635f, 0xffff5f5f, 0xffff5f5b, 0xffff5b5b, 0xffff5b57,
+ 0xffff5757, 0xffff5753, 0xffff5353, 0xffff534f, 0xffff4f4f, 0xffff4f4b,
+ 0xffff4b4b, 0xffff4b47, 0xffff4747, 0xffff4743, 0xffff4343, 0xffff433f,
+ 0xffff3f3f, 0xffff3f3b, 0xffff3b3b, 0xffff3b37, 0xffff3737, 0xffff3733,
+ 0xffff3333, 0xffff332f, 0xffff2f2f, 0xffff2f2b, 0xffff2b2b, 0xffff2b27,
+ 0xffff2727, 0xffff2723, 0xffff2323, 0xffff231f, 0xffff1f1f, 0xffff1f1b,
+ 0xffff1b1b, 0xffff1b17, 0xffff1717, 0xffff1713, 0xffff1313, 0xffff130f,
+ 0xffff0f0f, 0xffff0f0b, 0xffff0b0b, 0xffff0b07, 0xffff0707, 0xffff0703,
+ 0xffff0303, 0xffff02ff, 0xfffffefe, 0xfffffefa, 0xfffffafa, 0xfffffaf6,
+ 0xfffff6f6, 0xfffff6f2, 0xfffff2f2, 0xfffff2ee, 0xffffeeee, 0xffffeeea,
+ 0xffffeaea, 0xffffeae6, 0xffffe6e6, 0xffffe6e2, 0xffffe2e2, 0xffffe2de,
+ 0xffffdede, 0xffffdeda, 0xffffdada, 0xffffdad6, 0xffffd6d6, 0xffffd6d2,
+ 0xffffd2d2, 0xffffd2ce, 0xffffcece, 0xffffceca, 0xffffcaca, 0xffffcac6,
+ 0xffffc6c6, 0xffffc6c2, 0xffffc2c2, 0xffffc2be, 0xffffbebe, 0xffffbeba,
+ 0xffffbaba, 0xffffbab6, 0xffffb6b6, 0xffffb6b2, 0xffffb2b2, 0xffffb2ae,
+ 0xffffaeae, 0xffffaeaa, 0xffffaaaa, 0xffffaaa6, 0xffffa6a6, 0xffffa6a2,
+ 0xffffa2a2, 0xffffa29e, 0xffff9e9e, 0xffff9e9a, 0xffff9a9a, 0xffff9a96,
+ 0xffff9696, 0xffff9692, 0xffff9292, 0xffff928e, 0xffff8e8e, 0xffff8e8a,
+ 0xffff8a8a, 0xffff8a86, 0xffff8686, 0xffff8682, 0xffff8282, 0xffff827e,
+ 0xffff7e7e, 0xffff7e7a, 0xffff7a7a, 0xffff7a76, 0xffff7676, 0xffff7672,
+ 0xffff7272, 0xffff726e, 0xffff6e6e, 0xffff6e6a, 0xffff6a6a, 0xffff6a66,
+ 0xffff6666, 0xffff6662, 0xffff6262, 0xffff625e, 0xffff5e5e, 0xffff5e5a,
+ 0xffff5a5a, 0xffff5a56, 0xffff5656, 0xffff5652, 0xffff5252, 0xffff524e,
+ 0xffff4e4e, 0xffff4e4a, 0xffff4a4a, 0xffff4a46, 0xffff4646, 0xffff4642,
+ 0xffff4242, 0xffff423e, 0xffff3e3e, 0xffff3e3a, 0xffff3a3a, 0xffff3a36,
+ 0xffff3636, 0xffff3632, 0xffff3232, 0xffff322e, 0xffff2e2e, 0xffff2e2a,
+ 0xffff2a2a, 0xffff2a26, 0xffff2626, 0xffff2622, 0xffff2222, 0xffff221e,
+ 0xffff1e1e, 0xffff1e1a, 0xffff1a1a, 0xffff1a16, 0xffff1616, 0xffff1612,
+ 0xffff1212, 0xffff120e, 0xffff0e0e, 0xffff0e0a, 0xffff0a0a, 0xffff0a06,
+ 0xffff0606, 0xffff0602, 0xffff0202, 0xffff01fe, 0xfffffdfd, 0xfffffdf9,
+ 0xfffff9f9, 0xfffff9f5, 0xfffff5f5, 0xfffff5f1, 0xfffff1f1, 0xfffff1ed,
+ 0xffffeded, 0xffffede9, 0xffffe9e9, 0xffffe9e5, 0xffffe5e5, 0xffffe5e1,
+ 0xffffe1e1, 0xffffe1dd, 0xffffdddd, 0xffffddd9, 0xffffd9d9, 0xffffd9d5,
+ 0xffffd5d5, 0xffffd5d1, 0xffffd1d1, 0xffffd1cd, 0xffffcdcd, 0xffffcdc9,
+ 0xffffc9c9, 0xffffc9c5, 0xffffc5c5, 0xffffc5c1, 0xffffc1c1, 0xffffc1bd,
+ 0xffffbdbd, 0xffffbdb9, 0xffffb9b9, 0xffffb9b5, 0xffffb5b5, 0xffffb5b1,
+ 0xffffb1b1, 0xffffb1ad, 0xffffadad, 0xffffada9, 0xffffa9a9, 0xffffa9a5,
+ 0xffffa5a5, 0xffffa5a1, 0xffffa1a1, 0xffffa19d, 0xffff9d9d, 0xffff9d99,
+ 0xffff9999, 0xffff9995, 0xffff9595, 0xffff9591, 0xffff9191, 0xffff918d,
+ 0xffff8d8d, 0xffff8d89, 0xffff8989, 0xffff8985, 0xffff8585, 0xffff8581,
+ 0xffff8181, 0xffff817d, 0xffff7d7d, 0xffff7d79, 0xffff7979, 0xffff7975,
+ 0xffff7575, 0xffff7571, 0xffff7171, 0xffff716d, 0xffff6d6d, 0xffff6d69,
+ 0xffff6969, 0xffff6965, 0xffff6565, 0xffff6561, 0xffff6161, 0xffff615d,
+ 0xffff5d5d, 0xffff5d59, 0xffff5959, 0xffff5955, 0xffff5555, 0xffff5551,
+ 0xffff5151, 0xffff514d, 0xffff4d4d, 0xffff4d49, 0xffff4949, 0xffff4945,
+ 0xffff4545, 0xffff4541, 0xffff4141, 0xffff413d, 0xffff3d3d, 0xffff3d39,
+ 0xffff3939, 0xffff3935, 0xffff3535, 0xffff3531, 0xffff3131, 0xffff312d,
+ 0xffff2d2d, 0xffff2d29, 0xffff2929, 0xffff2925, 0xffff2525, 0xffff2521,
+ 0xffff2121, 0xffff211d, 0xffff1d1d, 0xffff1d19, 0xffff1919, 0xffff1915,
+ 0xffff1515, 0xffff1511, 0xffff1111, 0xffff110d, 0xffff0d0d, 0xffff0d09,
+ 0xffff0909, 0xffff0905, 0xffff0505, 0xffff0501, 0xffff0101, 0xffff00fd,
+ 0xfffffcfc, 0xfffffcf8, 0xfffff8f8, 0xfffff8f4, 0xfffff4f4, 0xfffff4f0,
+ 0xfffff0f0, 0xfffff0ec, 0xffffecec, 0xffffece8, 0xffffe8e8, 0xffffe8e4,
+ 0xffffe4e4, 0xffffe4e0, 0xffffe0e0, 0xffffe0dc, 0xffffdcdc, 0xffffdcd8,
+ 0xffffd8d8, 0xffffd8d4, 0xffffd4d4, 0xffffd4d0, 0xffffd0d0, 0xffffd0cc,
+ 0xffffcccc, 0xffffccc8, 0xffffc8c8, 0xffffc8c4, 0xffffc4c4, 0xffffc4c0,
+ 0xffffc0c0, 0xffffc0bc, 0xffffbcbc, 0xffffbcb8, 0xffffb8b8, 0xffffb8b4,
+ 0xffffb4b4, 0xffffb4b0, 0xffffb0b0, 0xffffb0ac, 0xffffacac, 0xffffaca8,
+ 0xffffa8a8, 0xffffa8a4, 0xffffa4a4, 0xffffa4a0, 0xffffa0a0, 0xffffa09c,
+ 0xffff9c9c, 0xffff9c98, 0xffff9898, 0xffff9894, 0xffff9494, 0xffff9490,
+ 0xffff9090, 0xffff908c, 0xffff8c8c, 0xffff8c88, 0xffff8888, 0xffff8884,
+ 0xffff8484, 0xffff8480, 0xffff8080, 0xffff807c, 0xffff7c7c, 0xffff7c78,
+ 0xffff7878, 0xffff7874, 0xffff7474, 0xffff7470, 0xffff7070, 0xffff706c,
+ 0xffff6c6c, 0xffff6c68, 0xffff6868, 0xffff6864, 0xffff6464, 0xffff6460,
+ 0xffff6060, 0xffff605c, 0xffff5c5c, 0xffff5c58, 0xffff5858, 0xffff5854,
+ 0xffff5454, 0xffff5450, 0xffff5050, 0xffff504c, 0xffff4c4c, 0xffff4c48,
+ 0xffff4848, 0xffff4844, 0xffff4444, 0xffff4440, 0xffff4040, 0xffff403c,
+ 0xffff3c3c, 0xffff3c38, 0xffff3838, 0xffff3834, 0xffff3434, 0xffff3430,
+ 0xffff3030, 0xffff302c, 0xffff2c2c, 0xffff2c28, 0xffff2828, 0xffff2824,
+ 0xffff2424, 0xffff2420, 0xffff2020, 0xffff201c, 0xffff1c1c, 0xffff1c18,
+ 0xffff1818, 0xffff1814, 0xffff1414, 0xffff1410, 0xffff1010, 0xffff100c,
+ 0xffff0c0c, 0xffff0c08, 0xffff0808, 0xffff0804, 0xffff0404, 0xffff0400,
+ 0xffff0000, 0xfffffffb,
+};
+
+static u8 tmp_buf[TEST_BUFLEN];
+
+#define full_csum(buff, len, sum) csum_fold(csum_partial(buff, len, sum))
+
+#define CHECK_EQ(lhs, rhs) KUNIT_ASSERT_EQ(test, lhs, rhs)
+
+static void assert_setup_correct(struct kunit *test)
+{
+ CHECK_EQ(sizeof(random_buf) / sizeof(random_buf[0]), MAX_LEN);
+ CHECK_EQ(sizeof(expected_results) / sizeof(expected_results[0]),
+ MAX_LEN);
+ CHECK_EQ(sizeof(init_sums_no_overflow) /
+ sizeof(init_sums_no_overflow[0]),
+ MAX_LEN);
+}
+
+/*
+ * Test with randomized input (pre determined random with known results).
+ */
+static void test_csum_fixed_random_inputs(struct kunit *test)
+{
+ int len, align;
+ __wsum result, expec, sum;
+
+ assert_setup_correct(test);
+ for (align = 0; align < TEST_BUFLEN; ++align) {
+ memcpy(&tmp_buf[align], random_buf,
+ min(MAX_LEN, TEST_BUFLEN - align));
+ for (len = 0; len < MAX_LEN && (align + len) < TEST_BUFLEN;
+ ++len) {
+ /*
+ * Test the precomputed random input.
+ */
+ sum = random_init_sum;
+ result = full_csum(&tmp_buf[align], len, sum);
+ expec = expected_results[len];
+ CHECK_EQ(result, expec);
+ }
+ }
+}
+
+/*
+ * All ones input test. If there are any missing carry operations, it fails.
+ */
+static void test_csum_all_carry_inputs(struct kunit *test)
+{
+ int len, align;
+ __wsum result, expec, sum;
+
+ assert_setup_correct(test);
+ memset(tmp_buf, 0xff, TEST_BUFLEN);
+ for (align = 0; align < TEST_BUFLEN; ++align) {
+ for (len = 0; len < MAX_LEN && (align + len) < TEST_BUFLEN;
+ ++len) {
+ /*
+ * All carries from input and initial sum.
+ */
+ sum = 0xffffffff;
+ result = full_csum(&tmp_buf[align], len, sum);
+ expec = (len & 1) ? 0xff00 : 0;
+ CHECK_EQ(result, expec);
+
+ /*
+ * All carries from input.
+ */
+ sum = 0;
+ result = full_csum(&tmp_buf[align], len, sum);
+ if (len & 1)
+ expec = 0xff00;
+ else if (len)
+ expec = 0;
+ else
+ expec = 0xffff;
+ CHECK_EQ(result, expec);
+ }
+ }
+}
+
+/*
+ * Test with input that alone doesn't cause any carries. By selecting the
+ * maximum initial sum, this allows us to test that there are no carries
+ * where there shouldn't be.
+ */
+static void test_csum_no_carry_inputs(struct kunit *test)
+{
+ int len, align;
+ __wsum result, expec, sum;
+
+ assert_setup_correct(test);
+ memset(tmp_buf, 0x4, TEST_BUFLEN);
+ for (align = 0; align < TEST_BUFLEN; ++align) {
+ for (len = 0; len < MAX_LEN && (align + len) < TEST_BUFLEN;
+ ++len) {
+ /*
+ * Expect no carries.
+ */
+ sum = init_sums_no_overflow[len];
+ result = full_csum(&tmp_buf[align], len, sum);
+ expec = 0;
+ CHECK_EQ(result, expec);
+
+ /*
+ * Expect one carry.
+ */
+ sum = init_sums_no_overflow[len] + 1;
+ result = full_csum(&tmp_buf[align], len, sum);
+ expec = len ? 0xfffe : 0xffff;
+ CHECK_EQ(result, expec);
+ }
+ }
+}
+
+static struct kunit_case __refdata checksum_test_cases[] = {
+ KUNIT_CASE(test_csum_fixed_random_inputs),
+ KUNIT_CASE(test_csum_all_carry_inputs),
+ KUNIT_CASE(test_csum_no_carry_inputs),
+ {}
+};
+
+static struct kunit_suite checksum_test_suite = {
+ .name = "checksum",
+ .test_cases = checksum_test_cases,
+};
+
+kunit_test_suites(&checksum_test_suite);
+
+MODULE_AUTHOR("Noah Goldstein <goldstein.w.n@gmail.com>");
+MODULE_LICENSE("GPL");
diff --git a/tools/arch/x86/kcpuid/.gitignore b/tools/arch/x86/kcpuid/.gitignore
new file mode 100644
index 00000000000000..1b8541bc8dd06d
--- /dev/null
+++ b/tools/arch/x86/kcpuid/.gitignore
@@ -0,0 +1 @@
+kcpuid
diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c
index 416f5b35dd8f43..24b7d017ec2c11 100644
--- a/tools/arch/x86/kcpuid/kcpuid.c
+++ b/tools/arch/x86/kcpuid/kcpuid.c
@@ -517,15 +517,16 @@ static void show_range(struct cpuid_range *range)
static inline struct cpuid_func *index_to_func(u32 index)
{
struct cpuid_range *range;
+ u32 func_idx;
range = (index & 0x80000000) ? leafs_ext : leafs_basic;
- index &= 0x7FFFFFFF;
+ func_idx = index & 0xffff;
- if (((index & 0xFFFF) + 1) > (u32)range->nr) {
+ if ((func_idx + 1) > (u32)range->nr) {
printf("ERR: invalid input index (0x%x)\n", index);
return NULL;
}
- return &range->funcs[index];
+ return &range->funcs[func_idx];
}
static void show_info(void)