powerpc/crc-t10dif: expose CRC-T10DIF function through lib

Move the powerpc CRC-T10DIF 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/powerpc/crypto/crct10dif-vpmsum_glue.c
to arch/powerpc/lib/crc-t10dif-glue.c, view this commit with
'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241202012056.209768-8-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

8 files changed, 23 insertions, 71 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b5050a09a27f..da0ac6697ac5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -128,6 +128,7 @@ config PPC
 	select ARCH_ENABLE_MEMORY_HOTREMOVE
 	select ARCH_HAS_COPY_MC			if PPC64
 	select ARCH_HAS_CRC32			if PPC64 && ALTIVEC
+	select ARCH_HAS_CRC_T10DIF		if PPC64 && ALTIVEC
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE
diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig
index 4a7ddea05b4d..6b6d7467fecf 100644
--- a/arch/powerpc/configs/powernv_defconfig
+++ b/arch/powerpc/configs/powernv_defconfig
@@ -320,7 +320,6 @@ CONFIG_XMON=y
 CONFIG_CRYPTO_TEST=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
-CONFIG_CRYPTO_CRCT10DIF_VPMSUM=m
 CONFIG_CRYPTO_MD5_PPC=m
 CONFIG_CRYPTO_MICHAEL_MIC=m
 CONFIG_CRYPTO_SHA1_PPC=m
diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index 58e5f4488da4..15101f5c3238 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -389,7 +389,6 @@ CONFIG_CRYPTO_MICHAEL_MIC=m
 CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_LZO=m
-CONFIG_CRYPTO_CRCT10DIF_VPMSUM=m
 CONFIG_CRYPTO_VPMSUM_TESTER=m
 CONFIG_CRYPTO_MD5_PPC=m
 CONFIG_CRYPTO_SHA1_PPC=m
diff --git a/arch/powerpc/crypto/Kconfig b/arch/powerpc/crypto/Kconfig
index 2d89e35b3cdd..45376f1a43bd 100644
--- a/arch/powerpc/crypto/Kconfig
+++ b/arch/powerpc/crypto/Kconfig
@@ -13,21 +13,10 @@ config CRYPTO_CURVE25519_PPC64
 	  Architecture: PowerPC64
 	  - Little-endian
 
-config CRYPTO_CRCT10DIF_VPMSUM
-	tristate "CRC32T10DIF"
-	depends on PPC64 && ALTIVEC && CRC_T10DIF
-	select CRYPTO_HASH
-	help
-	  CRC16 CRC algorithm used for the T10 (SCSI) Data Integrity Field (DIF)
-
-	  Architecture: powerpc64 using
-	  - AltiVec extensions
-
-	  Enable on POWER8 and newer processors for improved performance.
-
 config CRYPTO_VPMSUM_TESTER
 	tristate "CRC32c and CRC32T10DIF hardware acceleration tester"
-	depends on CRYPTO_CRCT10DIF_VPMSUM && CRYPTO_CRC32C && CRC32_ARCH
+	depends on CRYPTO_CRC32C && CRC32_ARCH
+	depends on CRYPTO_CRCT10DIF && CRC_T10DIF_ARCH
 	help
 	  Stress test for CRC32c and CRCT10DIF algorithms implemented with
 	  powerpc64 AltiVec extensions (POWER8 vpmsum instructions).
diff --git a/arch/powerpc/crypto/Makefile b/arch/powerpc/crypto/Makefile
index 54486192273c..d2238ac7e52c 100644
--- a/arch/powerpc/crypto/Makefile
+++ b/arch/powerpc/crypto/Makefile
@@ -10,7 +10,6 @@ obj-$(CONFIG_CRYPTO_MD5_PPC) += md5-ppc.o
 obj-$(CONFIG_CRYPTO_SHA1_PPC) += sha1-powerpc.o
 obj-$(CONFIG_CRYPTO_SHA1_PPC_SPE) += sha1-ppc-spe.o
 obj-$(CONFIG_CRYPTO_SHA256_PPC_SPE) += sha256-ppc-spe.o
-obj-$(CONFIG_CRYPTO_CRCT10DIF_VPMSUM) += crct10dif-vpmsum.o
 obj-$(CONFIG_CRYPTO_VPMSUM_TESTER) += crc-vpmsum_test.o
 obj-$(CONFIG_CRYPTO_AES_GCM_P10) += aes-gcm-p10-crypto.o
 obj-$(CONFIG_CRYPTO_CHACHA20_P10) += chacha-p10-crypto.o
@@ -23,7 +22,6 @@ md5-ppc-y := md5-asm.o md5-glue.o
 sha1-powerpc-y := sha1-powerpc-asm.o sha1.o
 sha1-ppc-spe-y := sha1-spe-asm.o sha1-spe-glue.o
 sha256-ppc-spe-y := sha256-spe-asm.o sha256-spe-glue.o
-crct10dif-vpmsum-y := crct10dif-vpmsum_asm.o crct10dif-vpmsum_glue.o
 aes-gcm-p10-crypto-y := aes-gcm-p10-glue.o aes-gcm-p10.o ghashp10-ppc.o aesp10-ppc.o
 chacha-p10-crypto-y := chacha-p10-glue.o chacha-p10le-8x.o
 poly1305-p10-crypto-y := poly1305-p10-glue.o poly1305-p10le_64.o
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index da9381a1c95b..dd8a4b52a0cc 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -81,4 +81,7 @@ CFLAGS_xor_vmx.o += -isystem $(shell $(CC) -print-file-name=include)
 obj-$(CONFIG_CRC32_ARCH) += crc32-powerpc.o
 crc32-powerpc-y := crc32-glue.o crc32c-vpmsum_asm.o
 
+obj-$(CONFIG_CRC_T10DIF_ARCH) += crc-t10dif-powerpc.o
+crc-t10dif-powerpc-y := crc-t10dif-glue.o crct10dif-vpmsum_asm.o
+
 obj-$(CONFIG_PPC64) += $(obj64-y)
diff --git a/arch/powerpc/crypto/crct10dif-vpmsum_glue.c b/arch/powerpc/lib/crc-t10dif-glue.c
index 1dc8b6915178..730850dbc51d 100644
--- a/arch/powerpc/crypto/crct10dif-vpmsum_glue.c
+++ b/arch/powerpc/lib/crc-t10dif-glue.c
@@ -7,7 +7,6 @@
  */
 
 #include <linux/crc-t10dif.h>
-#include <crypto/internal/hash.h>
 #include <crypto/internal/simd.h>
 #include <linux/init.h>
 #include <linux/module.h>
@@ -22,15 +21,18 @@
 
 #define VECTOR_BREAKPOINT	64
 
+static DEFINE_STATIC_KEY_FALSE(have_vec_crypto);
+
 u32 __crct10dif_vpmsum(u32 crc, unsigned char const *p, size_t len);
 
-static u16 crct10dif_vpmsum(u16 crci, unsigned char const *p, size_t len)
+u16 crc_t10dif_arch(u16 crci, const u8 *p, size_t len)
 {
 	unsigned int prealign;
 	unsigned int tail;
 	u32 crc = crci;
 
-	if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || !crypto_simd_usable())
+	if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) ||
+	    !static_branch_likely(&have_vec_crypto) || !crypto_simd_usable())
 		return crc_t10dif_generic(crc, p, len);
 
 	if ((unsigned long)p & VMX_ALIGN_MASK) {
@@ -60,67 +62,28 @@ static u16 crct10dif_vpmsum(u16 crci, unsigned char const *p, size_t len)
 
 	return crc & 0xffff;
 }
+EXPORT_SYMBOL(crc_t10dif_arch);
 
-static int crct10dif_vpmsum_init(struct shash_desc *desc)
-{
-	u16 *crc = shash_desc_ctx(desc);
-
-	*crc = 0;
-	return 0;
-}
-
-static int crct10dif_vpmsum_update(struct shash_desc *desc, const u8 *data,
-			    unsigned int length)
-{
-	u16 *crc = shash_desc_ctx(desc);
-
-	*crc = crct10dif_vpmsum(*crc, data, length);
-
-	return 0;
-}
-
-
-static int crct10dif_vpmsum_final(struct shash_desc *desc, u8 *out)
+static int __init crc_t10dif_powerpc_init(void)
 {
-	u16 *crcp = shash_desc_ctx(desc);
-
-	*(u16 *)out = *crcp;
+	if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
+	    (cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_VEC_CRYPTO))
+		static_branch_enable(&have_vec_crypto);
 	return 0;
 }
+arch_initcall(crc_t10dif_powerpc_init);
 
-static struct shash_alg alg = {
-	.init		= crct10dif_vpmsum_init,
-	.update		= crct10dif_vpmsum_update,
-	.final		= crct10dif_vpmsum_final,
-	.descsize	= CRC_T10DIF_DIGEST_SIZE,
-	.digestsize	= CRC_T10DIF_DIGEST_SIZE,
-	.base		= {
-		.cra_name		= "crct10dif",
-		.cra_driver_name	= "crct10dif-vpmsum",
-		.cra_priority		= 200,
-		.cra_blocksize		= CRC_T10DIF_BLOCK_SIZE,
-		.cra_module		= THIS_MODULE,
-	}
-};
-
-static int __init crct10dif_vpmsum_mod_init(void)
+static void __exit crc_t10dif_powerpc_exit(void)
 {
-	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
-		return -ENODEV;
-
-	return crypto_register_shash(&alg);
 }
+module_exit(crc_t10dif_powerpc_exit);
 
-static void __exit crct10dif_vpmsum_mod_fini(void)
+bool crc_t10dif_is_optimized(void)
 {
-	crypto_unregister_shash(&alg);
+	return static_key_enabled(&have_vec_crypto);
 }
-
-module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crct10dif_vpmsum_mod_init);
-module_exit(crct10dif_vpmsum_mod_fini);
+EXPORT_SYMBOL(crc_t10dif_is_optimized);
 
 MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
 MODULE_DESCRIPTION("CRCT10DIF using vector polynomial multiply-sum instructions");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_CRYPTO("crct10dif");
-MODULE_ALIAS_CRYPTO("crct10dif-vpmsum");
diff --git a/arch/powerpc/crypto/crct10dif-vpmsum_asm.S b/arch/powerpc/lib/crct10dif-vpmsum_asm.S
index 0a52261bf859..f0b93a0fe168 100644
--- a/arch/powerpc/crypto/crct10dif-vpmsum_asm.S
+++ b/arch/powerpc/lib/crct10dif-vpmsum_asm.S
@@ -842,4 +842,4 @@
 	.octa 0x0000000000000000000000018bb70000
 
 #define CRC_FUNCTION_NAME __crct10dif_vpmsum
-#include "../lib/crc32-vpmsum_core.S"
+#include "crc32-vpmsum_core.S"