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

Move the mips-optimized CRC code from arch/mips/lib/crc* into its new
location in lib/crc/mips/, 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/20250607200454.73587-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: Eric Biggers

arch/mips/Kconfig

@@ -2024,7 +2024,6 @@ config CPU_MIPSR5
 config CPU_MIPSR6
 	bool
 	default y if CPU_MIPS32_R6 || CPU_MIPS64_R6
-	select ARCH_HAS_CRC32
 	select CPU_HAS_RIXI
 	select CPU_HAS_DIEI if !CPU_DIEI_BROKEN
 	select HAVE_ARCH_BITREVERSE

arch/mips/lib/Makefile

@@ -16,7 +16,5 @@ lib-$(CONFIG_GENERIC_CSUM)	:= $(filter-out csum_partial.o, $(lib-y))
 obj-$(CONFIG_CPU_GENERIC_DUMP_TLB) += dump_tlb.o
 obj-$(CONFIG_CPU_R3000)		+= r3k_dump_tlb.o
 
-obj-$(CONFIG_CRC32_ARCH)	+= crc32-mips.o
-
 # libgcc-style stuff needed in the kernel
 obj-y += bswapsi.o bswapdi.o multi3.o

lib/crc/Kconfig

@@ -69,6 +69,7 @@ config CRC32_ARCH
 	default y if ARM && KERNEL_MODE_NEON
 	default y if ARM64
 	default y if LOONGARCH
+	default y if MIPS && CPU_MIPSR6
 
 config CRC64
 	tristate

arch/mips/lib/crc32-mips.c lib/crc/mips/crc32.harch/mips/lib/crc32-mips.c renamed to lib/crc/mips/crc32.h

@@ -9,10 +9,6 @@
  */
 
 #include <linux/cpufeature.h>
-#include <linux/crc32.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
 #include <asm/mipsregs.h>
 #include <linux/unaligned.h>
 
@@ -64,7 +60,7 @@ do {							\
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_crc32);
 
-u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
+static inline u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
 {
 	if (!static_branch_likely(&have_crc32))
 		return crc32_le_base(crc, p, len);
@@ -106,9 +102,8 @@ u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
 
 	return crc;
 }
-EXPORT_SYMBOL(crc32_le_arch);
 
-u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
+static inline u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
 {
 	if (!static_branch_likely(&have_crc32))
 		return crc32c_base(crc, p, len);
@@ -149,35 +144,19 @@ u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
 	}
 	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);
+#define crc32_be_arch crc32_be_base /* not implemented on this arch */
 
-static int __init crc32_mips_init(void)
+#define crc32_mod_init_arch crc32_mod_init_arch
+static inline void crc32_mod_init_arch(void)
 {
 	if (cpu_have_feature(cpu_feature(MIPS_CRC32)))
 		static_branch_enable(&have_crc32);
-	return 0;
 }
-subsys_initcall(crc32_mips_init);
 
-static void __exit crc32_mips_exit(void)
-{
-}
-module_exit(crc32_mips_exit);
-
-u32 crc32_optimizations(void)
+static inline u32 crc32_optimizations_arch(void)
 {
 	if (static_key_enabled(&have_crc32))
 		return CRC32_LE_OPTIMIZATION | CRC32C_OPTIMIZATION;
 	return 0;
 }
-EXPORT_SYMBOL(crc32_optimizations);
-
-MODULE_AUTHOR("Marcin Nowakowski <marcin.nowakowski@mips.com");
-MODULE_DESCRIPTION("CRC32 and CRC32C using optional MIPS instructions");
-MODULE_LICENSE("GPL v2");