sparc/crc32: expose CRC32 functions through lib

Move the sparc CRC32C assembly code into the lib directory and wire it
up to the library interface.  This allows it to be used without going
through the crypto API.  It remains usable via the crypto API too via
the shash algorithms that use the library interface.  Thus all the
arch-specific "shash" code becomes unnecessary and is removed.

Note: to see the diff from arch/sparc/crypto/crc32c_glue.c to
arch/sparc/lib/crc32_glue.c, view this commit with 'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20241202010844.144356-11-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

arch/sparc/Kconfig

@@ -110,6 +110,7 @@ config SPARC64
 	select HAVE_SETUP_PER_CPU_AREA
 	select NEED_PER_CPU_EMBED_FIRST_CHUNK
 	select NEED_PER_CPU_PAGE_FIRST_CHUNK
+	select ARCH_HAS_CRC32
 
 config ARCH_PROC_KCORE_TEXT
 	def_bool y

arch/sparc/crypto/Kconfig

@@ -16,16 +16,6 @@ config CRYPTO_DES_SPARC64
 
 	  Architecture: sparc64
 
-config CRYPTO_CRC32C_SPARC64
-	tristate "CRC32c"
-	depends on SPARC64
-	select CRYPTO_HASH
-	select CRC32
-	help
-	  CRC32c CRC algorithm with the iSCSI polynomial (RFC 3385 and RFC 3720)
-
-	  Architecture: sparc64
-
 config CRYPTO_MD5_SPARC64
 	tristate "Digests: MD5"
 	depends on SPARC64

arch/sparc/crypto/Makefile

@@ -12,8 +12,6 @@ obj-$(CONFIG_CRYPTO_AES_SPARC64) += aes-sparc64.o
 obj-$(CONFIG_CRYPTO_DES_SPARC64) += des-sparc64.o
 obj-$(CONFIG_CRYPTO_CAMELLIA_SPARC64) += camellia-sparc64.o
 
-obj-$(CONFIG_CRYPTO_CRC32C_SPARC64) += crc32c-sparc64.o
-
 sha1-sparc64-y := sha1_asm.o sha1_glue.o
 sha256-sparc64-y := sha256_asm.o sha256_glue.o
 sha512-sparc64-y := sha512_asm.o sha512_glue.o
@@ -22,5 +20,3 @@ md5-sparc64-y := md5_asm.o md5_glue.o
 aes-sparc64-y := aes_asm.o aes_glue.o
 des-sparc64-y := des_asm.o des_glue.o
 camellia-sparc64-y := camellia_asm.o camellia_glue.o
-
-crc32c-sparc64-y := crc32c_asm.o crc32c_glue.o

arch/sparc/lib/Makefile

@@ -53,3 +53,5 @@ lib-$(CONFIG_SPARC64) += mcount.o ipcsum.o xor.o hweight.o ffs.o
 obj-$(CONFIG_SPARC64) += iomap.o
 obj-$(CONFIG_SPARC32) += atomic32.o
 obj-$(CONFIG_SPARC64) += PeeCeeI.o
+obj-$(CONFIG_CRC32_ARCH) += crc32-sparc.o
+crc32-sparc-y := crc32_glue.o crc32c_asm.o

arch/sparc/lib/crc32_glue.c

@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Glue code for CRC32C optimized for sparc64 crypto opcodes.
+ *
+ * This is based largely upon arch/x86/crypto/crc32c-intel.c
+ *
+ * Copyright (C) 2008 Intel Corporation
+ * Authors: Austin Zhang <austin_zhang@linux.intel.com>
+ *          Kent Liu <kent.liu@intel.com>
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/crc32.h>
+#include <asm/pstate.h>
+#include <asm/elf.h>
+
+static DEFINE_STATIC_KEY_FALSE(have_crc32c_opcode);
+
+u32 crc32_le_arch(u32 crc, const u8 *data, size_t len)
+{
+	return crc32_le_base(crc, data, len);
+}
+EXPORT_SYMBOL(crc32_le_arch);
+
+void crc32c_sparc64(u32 *crcp, const u64 *data, size_t len);
+
+u32 crc32c_le_arch(u32 crc, const u8 *data, size_t len)
+{
+	size_t n = -(uintptr_t)data & 7;
+
+	if (!static_branch_likely(&have_crc32c_opcode))
+		return crc32c_le_base(crc, data, len);
+
+	if (n) {
+		/* Data isn't 8-byte aligned.  Align it. */
+		n = min(n, len);
+		crc = crc32c_le_base(crc, data, n);
+		data += n;
+		len -= n;
+	}
+	n = len & ~7U;
+	if (n) {
+		crc32c_sparc64(&crc, (const u64 *)data, n);
+		data += n;
+		len -= n;
+	}
+	if (len)
+		crc = crc32c_le_base(crc, data, len);
+	return crc;
+}
+EXPORT_SYMBOL(crc32c_le_arch);
+
+u32 crc32_be_arch(u32 crc, const u8 *data, size_t len)
+{
+	return crc32_be_base(crc, data, len);
+}
+EXPORT_SYMBOL(crc32_be_arch);
+
+static int __init crc32_sparc_init(void)
+{
+	unsigned long cfr;
+
+	if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
+		return 0;
+
+	__asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
+	if (!(cfr & CFR_CRC32C))
+		return 0;
+
+	static_branch_enable(&have_crc32c_opcode);
+	pr_info("Using sparc64 crc32c opcode optimized CRC32C implementation\n");
+	return 0;
+}
+arch_initcall(crc32_sparc_init);
+
+static void __exit crc32_sparc_exit(void)
+{
+}
+module_exit(crc32_sparc_exit);
+
+u32 crc32_optimizations(void)
+{
+	if (static_key_enabled(&have_crc32c_opcode))
+		return CRC32C_OPTIMIZATION;
+	return 0;
+}
+EXPORT_SYMBOL(crc32_optimizations);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CRC32c (Castagnoli), sparc64 crc32c opcode accelerated");

arch/sparc/crypto/crc32c_asm.S → arch/sparc/lib/crc32c_asm.S

@@ -3,7 +3,7 @@
 #include <asm/visasm.h>
 #include <asm/asi.h>
 
-#include "opcodes.h"
+#include "../crypto/opcodes.h"
 
 ENTRY(crc32c_sparc64)
 	/* %o0=crc32p, %o1=data_ptr, %o2=len */