lib/crc: s390: Migrate optimized CRC code into lib/crc/

Move the s390-optimized CRC code from arch/s390/lib/crc* into its new
location in lib/crc/s390/, and wire it up in the new way.  This new way
of organizing the CRC code eliminates the need to artificially split the
code for each CRC variant into separate arch and generic modules,
enabling better inlining and dead code elimination.  For more details,
see "lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/".

Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20250607200454.73587-10-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

arch/s390/Kconfig

@@ -75,7 +75,6 @@ config S390
 	select ARCH_ENABLE_MEMORY_HOTREMOVE
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
 	select ARCH_HAS_CPU_FINALIZE_INIT
-	select ARCH_HAS_CRC32
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE

arch/s390/lib/Makefile

@@ -25,6 +25,3 @@ obj-$(CONFIG_S390_MODULES_SANITY_TEST_HELPERS) += test_modules_helpers.o
 lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
 
 obj-$(CONFIG_EXPOLINE_EXTERN) += expoline.o
-
-obj-$(CONFIG_CRC32_ARCH) += crc32-s390.o
-crc32-s390-y := crc32.o crc32le-vx.o crc32be-vx.o

lib/crc/Kconfig

@@ -74,6 +74,7 @@ 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
 
 config CRC64
 	tristate

lib/crc/Makefile

@@ -27,6 +27,7 @@ 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
 endif
 
 obj-$(CONFIG_CRC64) += crc64.o

lib/crc/s390/crc32.h

@@ -5,12 +5,8 @@
  * Copyright IBM Corp. 2015
  * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  */
-#define KMSG_COMPONENT	"crc32-vx"
-#define pr_fmt(fmt)	KMSG_COMPONENT ": " fmt
 
-#include <linux/module.h>
 #include <linux/cpufeature.h>
-#include <linux/crc32.h>
 #include <asm/fpu.h>
 #include "crc32-vx.h"
 
@@ -27,7 +23,7 @@
  * operations of VECTOR LOAD MULTIPLE instructions.
  */
 #define DEFINE_CRC32_VX(___fname, ___crc32_vx, ___crc32_sw)		    \
-	u32 ___fname(u32 crc, const u8 *data, size_t datalen)		    \
+	static inline u32 ___fname(u32 crc, const u8 *data, size_t datalen) \
 	{								    \
 		unsigned long prealign, aligned, remaining;		    \
 		DECLARE_KERNEL_FPU_ONSTACK16(vxstate);			    \
@@ -54,14 +50,13 @@
 			crc = ___crc32_sw(crc, data + aligned, remaining);  \
 									    \
 		return crc;						    \
-	}								    \
-	EXPORT_SYMBOL(___fname);
+	}
 
 DEFINE_CRC32_VX(crc32_le_arch, crc32_le_vgfm_16, crc32_le_base)
 DEFINE_CRC32_VX(crc32_be_arch, crc32_be_vgfm_16, crc32_be_base)
 DEFINE_CRC32_VX(crc32c_arch, crc32c_le_vgfm_16, crc32c_base)
 
-u32 crc32_optimizations(void)
+static inline u32 crc32_optimizations_arch(void)
 {
 	if (cpu_has_vx()) {
 		return CRC32_LE_OPTIMIZATION |
@@ -70,8 +65,3 @@ u32 crc32_optimizations(void)
 	}
 	return 0;
 }
-EXPORT_SYMBOL(crc32_optimizations);
-
-MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");
-MODULE_DESCRIPTION("CRC-32 algorithms using z/Architecture Vector Extension Facility");
-MODULE_LICENSE("GPL");