lib/crc: x86: Migrate optimized CRC code into lib/crc/

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.  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/20250607200454.73587-12-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

1 files changed, 0 insertions, 111 deletions

diff --git a/arch/x86/lib/crc32.c b/arch/x86/lib/crc32.c
deleted file mode 100644
index d09343e2cea9..000000000000
--- a/arch/x86/lib/crc32.c
+++ /dev/null
@@ -1,111 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * x86-optimized CRC32 functions
- *
- * 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)
-{
-	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"
-#endif
-
-/*
- * Use carryless multiply version of crc32c when buffer size is >= 512 to
- * account for FPU state save/restore overhead.
- */
-#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)
-{
-	size_t num_longs;
-
-	if (!static_branch_likely(&have_crc32))
-		return crc32c_base(crc, p, len);
-
-	if (IS_ENABLED(CONFIG_X86_64) && len >= CRC32C_PCLMUL_BREAKEVEN &&
-	    static_branch_likely(&have_pclmulqdq) && crypto_simd_usable()) {
-		kernel_fpu_begin();
-		crc = crc32c_x86_3way(crc, p, len);
-		kernel_fpu_end();
-		return crc;
-	}
-
-	for (num_longs = len / sizeof(unsigned long);
-	     num_longs != 0; num_longs--, p += sizeof(unsigned long))
-		asm(CRC32_INST : "+r" (crc) : ASM_INPUT_RM (*(unsigned long *)p));
-
-	if (sizeof(unsigned long) > 4 && (len & 4)) {
-		asm("crc32l %1, %0" : "+r" (crc) : ASM_INPUT_RM (*(u32 *)p));
-		p += 4;
-	}
-	if (len & 2) {
-		asm("crc32w %1, %0" : "+r" (crc) : ASM_INPUT_RM (*(u16 *)p));
-		p += 2;
-	}
-	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)
-{
-	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)
-{
-	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");