[PATCH 4/8] lib/crc: Turn NEON intrinsics crc64 implementation into common code

Ard Biesheuvel
2026-04-22T17:17:35Z

From: Ard Biesheuvel <ardb@kernel.org>

Move and rename the CRC64 NEON intrinsics implementation source file and
rename the function name to reflect that it is NEON code that can be
shared. This will be wired up for 32-bit ARM in a subsequent patch.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
lib/crc/Makefile | 6 ++---
lib/crc/arm64/crc64-neon.h | 21 ++++++++++++++++
lib/crc/arm64/crc64.h | 4 +--
lib/crc/{arm64/crc64-neon-inner.c => crc64-neon.c} | 26 +++-----------------
4 files changed, 30 insertions(+), 27 deletions(-)

diff --git a/lib/crc/Makefile b/lib/crc/Makefile
index ff213590e4e3..193257ae466f 100644
--- a/lib/crc/Makefile
+++ b/lib/crc/Makefile
@@ -39,9 +39,9 @@ crc64-y := crc64-main.o
ifeq ($(CONFIG_CRC64_ARCH),y)
CFLAGS_crc64-main.o += -I$(src)/$(SRCARCH)

-CFLAGS_REMOVE_arm64/crc64-neon-inner.o += $(CC_FLAGS_NO_FPU)
-CFLAGS_arm64/crc64-neon-inner.o += $(CC_FLAGS_FPU) -march=armv8-a+crypto
-crc64-$(CONFIG_ARM64) += arm64/crc64-neon-inner.o
+CFLAGS_REMOVE_crc64-neon.o += $(CC_FLAGS_NO_FPU)
+CFLAGS_crc64-neon.o += $(CC_FLAGS_FPU) -I$(src)/$(SRCARCH) -march=armv8-a+crypto
+crc64-$(CONFIG_ARM64) += crc64-neon.o

crc64-$(CONFIG_RISCV) += riscv/crc64_lsb.o riscv/crc64_msb.o
crc64-$(CONFIG_X86) += x86/crc64-pclmul.o
diff --git a/lib/crc/arm64/crc64-neon.h b/lib/crc/arm64/crc64-neon.h
new file mode 100644
index 000000000000..fcd5b1e6f812
--- /dev/null
+++ b/lib/crc/arm64/crc64-neon.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+static inline uint64x2_t pmull64(uint64x2_t a, uint64x2_t b)
+{
+ return vreinterpretq_u64_p128(vmull_p64(vgetq_lane_u64(a, 0),
+ vgetq_lane_u64(b, 0)));
+}
+
+static inline uint64x2_t pmull64_high(uint64x2_t a, uint64x2_t b)
+{
+ poly64x2_t l = vreinterpretq_p64_u64(a);
+ poly64x2_t m = vreinterpretq_p64_u64(b);
+
+ return vreinterpretq_u64_p128(vmull_high_p64(l, m));
+}
+
+static inline uint64x2_t pmull64_hi_lo(uint64x2_t a, uint64x2_t b)
+{
+ return vreinterpretq_u64_p128(vmull_p64(vgetq_lane_u64(a, 1),
+ vgetq_lane_u64(b, 0)));
+}
diff --git a/lib/crc/arm64/crc64.h b/lib/crc/arm64/crc64.h
index 60151ec3035a..c7a69e1f3d8f 100644
--- a/lib/crc/arm64/crc64.h
+++ b/lib/crc/arm64/crc64.h
@@ -8,7 +8,7 @@
#include <linux/minmax.h>
#include <linux/sizes.h>

-u64 crc64_nvme_arm64_c(u64 crc, const u8 *p, size_t len);
+u64 crc64_nvme_neon(u64 crc, const u8 *p, size_t len);

#define crc64_be_arch crc64_be_generic

@@ -19,7 +19,7 @@ static inline u64 crc64_nvme_arch(u64 crc, const u8 *p, size_t len)
size_t chunk = len & ~15;

scoped_ksimd()
- crc = crc64_nvme_arm64_c(crc, p, chunk);
+ crc = crc64_nvme_neon(crc, p, chunk);

p += chunk;
len &= 15;
diff --git a/lib/crc/arm64/crc64-neon-inner.c b/lib/crc/crc64-neon.c
similarity index 62%
rename from lib/crc/arm64/crc64-neon-inner.c
rename to lib/crc/crc64-neon.c
index 28527e544ff6..4753fb94a4be 100644
--- a/lib/crc/arm64/crc64-neon-inner.c
+++ b/lib/crc/crc64-neon.c
@@ -6,7 +6,9 @@
#include <linux/types.h>
#include <asm/neon-intrinsics.h>

-u64 crc64_nvme_arm64_c(u64 crc, const u8 *p, size_t len);
+#include "crc64-neon.h"
+
+u64 crc64_nvme_neon(u64 crc, const u8 *p, size_t len);

/* x^191 mod G, x^127 mod G */
static const u64 fold_consts_val[2] = { 0xeadc41fd2ba3d420ULL,
@@ -15,27 +17,7 @@ static const u64 fold_consts_val[2] = { 0xeadc41fd2ba3d420ULL,
static const u64 bconsts_val[2] = { 0x27ecfa329aef9f77ULL,
0x34d926535897936aULL };

-static inline uint64x2_t pmull64(uint64x2_t a, uint64x2_t b)
-{
- return vreinterpretq_u64_p128(vmull_p64(vgetq_lane_u64(a, 0),
- vgetq_lane_u64(b, 0)));
-}
-
-static inline uint64x2_t pmull64_high(uint64x2_t a, uint64x2_t b)
-{
- poly64x2_t l = vreinterpretq_p64_u64(a);
- poly64x2_t m = vreinterpretq_p64_u64(b);
-
- return vreinterpretq_u64_p128(vmull_high_p64(l, m));
-}
-
-static inline uint64x2_t pmull64_hi_lo(uint64x2_t a, uint64x2_t b)
-{
- return vreinterpretq_u64_p128(vmull_p64(vgetq_lane_u64(a, 1),
- vgetq_lane_u64(b, 0)));
-}
-
-u64 crc64_nvme_arm64_c(u64 crc, const u8 *p, size_t len)
+u64 crc64_nvme_neon(u64 crc, const u8 *p, size_t len)
{
uint64x2_t fold_consts = vld1q_u64(fold_consts_val);
uint64x2_t v0 = { crc, 0 };
--
2.54.0.rc1.555.g9c883467ad-goog