[PATCH 13/13] lib/crc/x86: migrate x86-optimized CRC code into lib/crc/

Eric Biggers
2025-06-01T22:46:00Z

Move the x86-optimized CRC code from arch/x86/lib/crc* into its new
location in lib/crc/x86/, and wire it up in the new way. For a detailed
explanation of why this change is being made, see the commit that
introduced the new way of integrating arch-specific code into lib/crc/.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
arch/x86/Kconfig | 3 --
arch/x86/lib/Makefile | 10 ------
lib/crc/Kconfig | 3 ++
lib/crc/Makefile | 4 +++
.../lib => lib/crc/x86}/crc-pclmul-consts.h | 0
.../lib => lib/crc/x86}/crc-pclmul-template.S | 0
.../lib => lib/crc/x86}/crc-pclmul-template.h | 0
.../crc-t10dif.c => lib/crc/x86/crc-t10dif.h | 18 ++---------
.../lib => lib/crc/x86}/crc16-msb-pclmul.S | 0
{arch/x86/lib => lib/crc/x86}/crc32-pclmul.S | 0
arch/x86/lib/crc32.c => lib/crc/x86/crc32.h | 32 ++++---------------
{arch/x86/lib => lib/crc/x86}/crc32c-3way.S | 0
{arch/x86/lib => lib/crc/x86}/crc64-pclmul.S | 0
arch/x86/lib/crc64.c => lib/crc/x86/crc64.h | 21 +++---------
14 files changed, 21 insertions(+), 70 deletions(-)
rename {arch/x86/lib => lib/crc/x86}/crc-pclmul-consts.h (100%)
rename {arch/x86/lib => lib/crc/x86}/crc-pclmul-template.S (100%)
rename {arch/x86/lib => lib/crc/x86}/crc-pclmul-template.h (100%)
rename arch/x86/lib/crc-t10dif.c => lib/crc/x86/crc-t10dif.h (56%)
rename {arch/x86/lib => lib/crc/x86}/crc16-msb-pclmul.S (100%)
rename {arch/x86/lib => lib/crc/x86}/crc32-pclmul.S (100%)
rename arch/x86/lib/crc32.c => lib/crc/x86/crc32.h (76%)
rename {arch/x86/lib => lib/crc/x86}/crc32c-3way.S (100%)
rename {arch/x86/lib => lib/crc/x86}/crc64-pclmul.S (100%)
rename arch/x86/lib/crc64.c => lib/crc/x86/crc64.h (61%)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 340e5468980e0..6181f414f87ec 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -77,13 +77,10 @@ config X86
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_CACHE_LINE_SIZE
select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
select ARCH_HAS_CPU_FINALIZE_INIT
select ARCH_HAS_CPU_PASID if IOMMU_SVA
- select ARCH_HAS_CRC32
- select ARCH_HAS_CRC64 if X86_64
- select ARCH_HAS_CRC_T10DIF
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 4fa5c4e1ba8a0..dc5ee2a6938c4 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -38,20 +38,10 @@ lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
lib-$(CONFIG_MITIGATION_RETPOLINE) += retpoline.o

-obj-$(CONFIG_CRC32_ARCH) += crc32-x86.o
-crc32-x86-y := crc32.o crc32-pclmul.o
-crc32-x86-$(CONFIG_64BIT) += crc32c-3way.o
-
-obj-$(CONFIG_CRC64_ARCH) += crc64-x86.o
-crc64-x86-y := crc64.o crc64-pclmul.o
-
-obj-$(CONFIG_CRC_T10DIF_ARCH) += crc-t10dif-x86.o
-crc-t10dif-x86-y := crc-t10dif.o crc16-msb-pclmul.o
-
obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
obj-y += iomem.o

ifeq ($(CONFIG_X86_32),y)
obj-y += atomic64_32.o
diff --git a/lib/crc/Kconfig b/lib/crc/Kconfig
index c0b36d03b66dc..450c8290cbc1f 100644
--- a/lib/crc/Kconfig
+++ b/lib/crc/Kconfig
@@ -52,10 +52,11 @@ config CRC_T10DIF_ARCH
depends on CRC_T10DIF && CRC_OPTIMIZATIONS
default y if ARM && KERNEL_MODE_NEON
default y if ARM64 && KERNEL_MODE_NEON
default y if PPC64 && ALTIVEC
default y if RISCV && RISCV_ISA_ZBC
+ default y if X86

config CRC32
tristate
select BITREVERSE
help
@@ -71,10 +72,11 @@ config CRC32_ARCH
default y if MIPS && CPU_MIPSR6
default y if PPC64 && ALTIVEC
default y if RISCV && RISCV_ISA_ZBC
default y if S390
default y if SPARC64
+ default y if X86

config CRC64
tristate
help
The CRC64 library functions. Select this if your module uses any of
@@ -82,10 +84,11 @@ config CRC64

config CRC64_ARCH
bool
depends on CRC64 && CRC_OPTIMIZATIONS
default y if RISCV && RISCV_ISA_ZBC && 64BIT
+ default y if X86_64

config CRC_OPTIMIZATIONS
bool "Enable optimized CRC implementations" if EXPERT
default y
help
diff --git a/lib/crc/Makefile b/lib/crc/Makefile
index 37dd4a776d1b4..80cfc94f5180d 100644
--- a/lib/crc/Makefile
+++ b/lib/crc/Makefile
@@ -16,10 +16,11 @@ crc-t10dif-y := crc-t10dif-main.o
ifeq ($(CONFIG_CRC_T10DIF_ARCH),y)
crc-t10dif-$(CONFIG_ARM) += arm/crc-t10dif-core.o
crc-t10dif-$(CONFIG_ARM64) += arm64/crc-t10dif-core.o
crc-t10dif-$(CONFIG_PPC) += powerpc/crct10dif-vpmsum_asm.o
crc-t10dif-$(CONFIG_RISCV) += riscv/crc16_msb.o
+crc-t10dif-$(CONFIG_X86) += x86/crc16-msb-pclmul.o
endif

obj-$(CONFIG_CRC32) += crc32.o
crc32-y := crc32-main.o
ifeq ($(CONFIG_CRC32_ARCH),y)
@@ -27,16 +28,19 @@ crc32-$(CONFIG_ARM) += arm/crc32-core.o
crc32-$(CONFIG_ARM64) += arm64/crc32-core.o
crc32-$(CONFIG_PPC) += powerpc/crc32c-vpmsum_asm.o
crc32-$(CONFIG_RISCV) += riscv/crc32_lsb.o riscv/crc32_msb.o
crc32-$(CONFIG_S390) += s390/crc32le-vx.o s390/crc32be-vx.o
crc32-$(CONFIG_SPARC) += sparc/crc32c_asm.o
+crc32-$(CONFIG_X86) += x86/crc32-pclmul.o
+crc32-$(CONFIG_X86_64) += x86/crc32c-3way.o
endif

obj-$(CONFIG_CRC64) += crc64.o
crc64-y := crc64-main.o
ifeq ($(CONFIG_CRC64_ARCH),y)
crc64-$(CONFIG_RISCV) += riscv/crc64_lsb.o riscv/crc64_msb.o
+crc64-$(CONFIG_X86) += x86/crc64-pclmul.o
endif

obj-y += tests/

hostprogs := gen_crc32table gen_crc64table
diff --git a/arch/x86/lib/crc-pclmul-consts.h b/lib/crc/x86/crc-pclmul-consts.h
similarity index 100%
rename from arch/x86/lib/crc-pclmul-consts.h
rename to lib/crc/x86/crc-pclmul-consts.h
diff --git a/arch/x86/lib/crc-pclmul-template.S b/lib/crc/x86/crc-pclmul-template.S
similarity index 100%
rename from arch/x86/lib/crc-pclmul-template.S
rename to lib/crc/x86/crc-pclmul-template.S
diff --git a/arch/x86/lib/crc-pclmul-template.h b/lib/crc/x86/crc-pclmul-template.h
similarity index 100%
rename from arch/x86/lib/crc-pclmul-template.h
rename to lib/crc/x86/crc-pclmul-template.h
diff --git a/arch/x86/lib/crc-t10dif.c b/lib/crc/x86/crc-t10dif.h
similarity index 56%
rename from arch/x86/lib/crc-t10dif.c
rename to lib/crc/x86/crc-t10dif.h
index db7ce59c31ace..eb1f23db4daa1 100644
--- a/arch/x86/lib/crc-t10dif.c
+++ b/lib/crc/x86/crc-t10dif.h
@@ -3,38 +3,26 @@
* CRC-T10DIF using [V]PCLMULQDQ instructions
*
* Copyright 2024 Google LLC
*/

-#include <linux/crc-t10dif.h>
-#include <linux/module.h>
#include "crc-pclmul-template.h"

static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pclmulqdq);

DECLARE_CRC_PCLMUL_FUNCS(crc16_msb, u16);

-u16 crc_t10dif_arch(u16 crc, const u8 *p, size_t len)
+static inline u16 crc_t10dif_arch(u16 crc, const u8 *p, size_t len)
{
CRC_PCLMUL(crc, p, len, crc16_msb, crc16_msb_0x8bb7_consts,
have_pclmulqdq);
return crc_t10dif_generic(crc, p, len);
}
-EXPORT_SYMBOL(crc_t10dif_arch);

-static int __init crc_t10dif_x86_init(void)
+#define crc_t10dif_mod_init_arch crc_t10dif_mod_init_arch
+static inline void crc_t10dif_mod_init_arch(void)
{
if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
static_branch_enable(&have_pclmulqdq);
INIT_CRC_PCLMUL(crc16_msb);
}
- return 0;
}
-subsys_initcall(crc_t10dif_x86_init);
-
-static void __exit crc_t10dif_x86_exit(void)
-{
-}
-module_exit(crc_t10dif_x86_exit);
-
-MODULE_DESCRIPTION("CRC-T10DIF using [V]PCLMULQDQ instructions");
-MODULE_LICENSE("GPL");
diff --git a/arch/x86/lib/crc16-msb-pclmul.S b/lib/crc/x86/crc16-msb-pclmul.S
similarity index 100%
rename from arch/x86/lib/crc16-msb-pclmul.S
rename to lib/crc/x86/crc16-msb-pclmul.S
diff --git a/arch/x86/lib/crc32-pclmul.S b/lib/crc/x86/crc32-pclmul.S
similarity index 100%
rename from arch/x86/lib/crc32-pclmul.S
rename to lib/crc/x86/crc32-pclmul.S
diff --git a/arch/x86/lib/crc32.c b/lib/crc/x86/crc32.h
similarity index 76%
rename from arch/x86/lib/crc32.c
rename to lib/crc/x86/crc32.h
index d09343e2cea93..ad7fc96fd6bc9 100644
--- a/arch/x86/lib/crc32.c
+++ b/lib/crc/x86/crc32.h
@@ -5,26 +5,24 @@
* Copyright (C) 2008 Intel Corporation
* Copyright 2012 Xyratex Technology Limited
* Copyright 2024 Google LLC
*/

-#include <linux/crc32.h>
-#include <linux/module.h>
#include "crc-pclmul-template.h"

static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_crc32);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pclmulqdq);

DECLARE_CRC_PCLMUL_FUNCS(crc32_lsb, u32);

-u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
+#define crc32_le_arch crc32_le_arch
+static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
{
CRC_PCLMUL(crc, p, len, crc32_lsb, crc32_lsb_0xedb88320_consts,
have_pclmulqdq);
return crc32_le_base(crc, p, len);
}
-EXPORT_SYMBOL(crc32_le_arch);

#ifdef CONFIG_X86_64
#define CRC32_INST "crc32q %1, %q0"
#else
#define CRC32_INST "crc32l %1, %0"
@@ -36,11 +34,12 @@ EXPORT_SYMBOL(crc32_le_arch);
*/
#define CRC32C_PCLMUL_BREAKEVEN 512

asmlinkage u32 crc32c_x86_3way(u32 crc, const u8 *buffer, size_t len);

-u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
+#define crc32c_arch crc32c_arch
+static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
{
size_t num_longs;

if (!static_branch_likely(&have_crc32))
return crc32c_base(crc, p, len);
@@ -68,44 +67,27 @@ u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
if (len & 1)
asm("crc32b %1, %0" : "+r" (crc) : ASM_INPUT_RM (*p));

return crc;
}
-EXPORT_SYMBOL(crc32c_arch);

-u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
-{
- return crc32_be_base(crc, p, len);
-}
-EXPORT_SYMBOL(crc32_be_arch);
-
-static int __init crc32_x86_init(void)
+#define crc32_mod_init_arch crc32_mod_init_arch
+static inline void crc32_mod_init_arch(void)
{
if (boot_cpu_has(X86_FEATURE_XMM4_2))
static_branch_enable(&have_crc32);
if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
static_branch_enable(&have_pclmulqdq);
INIT_CRC_PCLMUL(crc32_lsb);
}
- return 0;
}
-subsys_initcall(crc32_x86_init);

-static void __exit crc32_x86_exit(void)
-{
-}
-module_exit(crc32_x86_exit);
-
-u32 crc32_optimizations(void)
+static inline u32 crc32_optimizations_arch(void)
{
u32 optimizations = 0;

if (static_key_enabled(&have_crc32))
optimizations |= CRC32C_OPTIMIZATION;
if (static_key_enabled(&have_pclmulqdq))
optimizations |= CRC32_LE_OPTIMIZATION;
return optimizations;
}
-EXPORT_SYMBOL(crc32_optimizations);
-
-MODULE_DESCRIPTION("x86-optimized CRC32 functions");
-MODULE_LICENSE("GPL");
diff --git a/arch/x86/lib/crc32c-3way.S b/lib/crc/x86/crc32c-3way.S
similarity index 100%
rename from arch/x86/lib/crc32c-3way.S
rename to lib/crc/x86/crc32c-3way.S
diff --git a/arch/x86/lib/crc64-pclmul.S b/lib/crc/x86/crc64-pclmul.S
similarity index 100%
rename from arch/x86/lib/crc64-pclmul.S
rename to lib/crc/x86/crc64-pclmul.S
diff --git a/arch/x86/lib/crc64.c b/lib/crc/x86/crc64.h
similarity index 61%
rename from arch/x86/lib/crc64.c
rename to lib/crc/x86/crc64.h
index 351a09f5813e2..54aca3a9475c9 100644
--- a/arch/x86/lib/crc64.c
+++ b/lib/crc/x86/crc64.h
@@ -3,48 +3,35 @@
* CRC64 using [V]PCLMULQDQ instructions
*
* Copyright 2025 Google LLC
*/

-#include <linux/crc64.h>
-#include <linux/module.h>
#include "crc-pclmul-template.h"

static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pclmulqdq);

DECLARE_CRC_PCLMUL_FUNCS(crc64_msb, u64);
DECLARE_CRC_PCLMUL_FUNCS(crc64_lsb, u64);

-u64 crc64_be_arch(u64 crc, const u8 *p, size_t len)
+static inline u64 crc64_be_arch(u64 crc, const u8 *p, size_t len)
{
CRC_PCLMUL(crc, p, len, crc64_msb, crc64_msb_0x42f0e1eba9ea3693_consts,
have_pclmulqdq);
return crc64_be_generic(crc, p, len);
}
-EXPORT_SYMBOL_GPL(crc64_be_arch);

-u64 crc64_nvme_arch(u64 crc, const u8 *p, size_t len)
+static inline u64 crc64_nvme_arch(u64 crc, const u8 *p, size_t len)
{
CRC_PCLMUL(crc, p, len, crc64_lsb, crc64_lsb_0x9a6c9329ac4bc9b5_consts,
have_pclmulqdq);
return crc64_nvme_generic(crc, p, len);
}
-EXPORT_SYMBOL_GPL(crc64_nvme_arch);

-static int __init crc64_x86_init(void)
+#define crc64_mod_init_arch crc64_mod_init_arch
+static inline void crc64_mod_init_arch(void)
{
if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
static_branch_enable(&have_pclmulqdq);
INIT_CRC_PCLMUL(crc64_msb);
INIT_CRC_PCLMUL(crc64_lsb);
}
- return 0;
}
-subsys_initcall(crc64_x86_init);
-
-static void __exit crc64_x86_exit(void)
-{
-}
-module_exit(crc64_x86_exit);
-
-MODULE_DESCRIPTION("CRC64 using [V]PCLMULQDQ instructions");
-MODULE_LICENSE("GPL");
--
2.49.0