lib/crypto: powerpc/sha1: Migrate optimized code into library

Eric Biggers · Eric Biggers · commit 6b9ae8cfaa7a · 2025-07-14T11:11:49.000-07:00
Instead of exposing the powerpc-optimized SHA-1 code via powerpc-specific crypto_shash algorithms, instead just implement the sha1_blocks() library function. This is much simpler, it makes the SHA-1 library functions be powerpc-optimized, and it fixes the longstanding issue where the powerpc-optimized SHA-1 code was disabled by default. SHA-1 still remains available through crypto_shash, but individual architectures no longer need to handle it. Note: to see the diff from arch/powerpc/crypto/sha1-spe-glue.c to lib/crypto/powerpc/sha1.h, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250712232329.818226-11-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
diff --git a/arch/powerpc/configs/44x/akebono_defconfig b/arch/powerpc/configs/44x/akebono_defconfig
@@ -128,6 +128,5 @@ CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW=0x00010000
 CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH=0x33f
 CONFIG_CRYPTO_PCBC=y
 CONFIG_CRYPTO_MD5=y
-CONFIG_CRYPTO_SHA1_PPC=y
 CONFIG_CRYPTO_DES=y
 # CONFIG_CRYPTO_HW is not set
diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig
@@ -322,7 +322,6 @@ CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MD5_PPC=m
 CONFIG_CRYPTO_MICHAEL_MIC=m
-CONFIG_CRYPTO_SHA1_PPC=m
 CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
@@ -388,7 +388,6 @@ CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_LZO=m
 CONFIG_CRYPTO_MD5_PPC=m
-CONFIG_CRYPTO_SHA1_PPC=m
 CONFIG_CRYPTO_AES_GCM_P10=m
 CONFIG_CRYPTO_DEV_NX=y
 CONFIG_CRYPTO_DEV_NX_ENCRYPT=m
diff --git a/arch/powerpc/crypto/Kconfig b/arch/powerpc/crypto/Kconfig
@@ -23,22 +23,6 @@ config CRYPTO_MD5_PPC
 
 	  Architecture: powerpc
 
-config CRYPTO_SHA1_PPC
-	tristate "Hash functions: SHA-1"
-	help
-	  SHA-1 secure hash algorithm (FIPS 180)
-
-	  Architecture: powerpc
-
-config CRYPTO_SHA1_PPC_SPE
-	tristate "Hash functions: SHA-1 (SPE)"
-	depends on SPE
-	help
-	  SHA-1 secure hash algorithm (FIPS 180)
-
-	  Architecture: powerpc using
-	  - SPE (Signal Processing Engine) extensions
-
 config CRYPTO_AES_PPC_SPE
 	tristate "Ciphers: AES, modes: ECB/CBC/CTR/XTS (SPE)"
 	depends on SPE
diff --git a/arch/powerpc/crypto/Makefile b/arch/powerpc/crypto/Makefile
@@ -7,16 +7,12 @@
 
 obj-$(CONFIG_CRYPTO_AES_PPC_SPE) += aes-ppc-spe.o
 obj-$(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-$(CONFIG_CRYPTO_AES_GCM_P10) += aes-gcm-p10-crypto.o
 obj-$(CONFIG_CRYPTO_DEV_VMX_ENCRYPT) += vmx-crypto.o
 obj-$(CONFIG_CRYPTO_CURVE25519_PPC64) += curve25519-ppc64le.o
 
 aes-ppc-spe-y := aes-spe-core.o aes-spe-keys.o aes-tab-4k.o aes-spe-modes.o aes-spe-glue.o
 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
 aes-gcm-p10-crypto-y := aes-gcm-p10-glue.o aes-gcm-p10.o ghashp10-ppc.o aesp10-ppc.o
 vmx-crypto-objs := vmx.o aesp8-ppc.o ghashp8-ppc.o aes.o aes_cbc.o aes_ctr.o aes_xts.o ghash.o
 curve25519-ppc64le-y := curve25519-ppc64le-core.o curve25519-ppc64le_asm.o
diff --git a/arch/powerpc/crypto/sha1-spe-glue.c b/arch/powerpc/crypto/sha1-spe-glue.c
diff --git a/arch/powerpc/crypto/sha1.c b/arch/powerpc/crypto/sha1.c
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
@@ -149,6 +149,7 @@ config CRYPTO_LIB_SHA1_ARCH
 	default y if ARM
 	default y if ARM64 && KERNEL_MODE_NEON
 	default y if MIPS && CPU_CAVIUM_OCTEON
+	default y if PPC
 
 config CRYPTO_LIB_SHA256
 	tristate
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
@@ -77,6 +77,10 @@ libsha1-$(CONFIG_KERNEL_MODE_NEON) += arm/sha1-armv7-neon.o \
 				      arm/sha1-ce-core.o
 endif
 libsha1-$(CONFIG_ARM64) += arm64/sha1-ce-core.o
+ifeq ($(CONFIG_PPC),y)
+libsha1-y += powerpc/sha1-powerpc-asm.o
+libsha1-$(CONFIG_SPE) += powerpc/sha1-spe-asm.o
+endif
 endif # CONFIG_CRYPTO_LIB_SHA1_ARCH
 
 ################################################################################
diff --git a/lib/crypto/powerpc/sha1-powerpc-asm.S b/lib/crypto/powerpc/sha1-powerpc-asm.S
diff --git a/lib/crypto/powerpc/sha1-spe-asm.S b/lib/crypto/powerpc/sha1-spe-asm.S
diff --git a/lib/crypto/powerpc/sha1.h b/lib/crypto/powerpc/sha1.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * SHA-1 optimized for PowerPC
+ *
+ * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
+ */
+
+#include <asm/switch_to.h>
+#include <linux/preempt.h>
+
+#ifdef CONFIG_SPE
+/*
+ * MAX_BYTES defines the number of bytes that are allowed to be processed
+ * between preempt_disable() and preempt_enable(). SHA1 takes ~1000
+ * operations per 64 bytes. e500 cores can issue two arithmetic instructions
+ * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2).
+ * Thus 2KB of input data will need an estimated maximum of 18,000 cycles.
+ * Headroom for cache misses included. Even with the low end model clocked
+ * at 667 MHz this equals to a critical time window of less than 27us.
+ *
+ */
+#define MAX_BYTES 2048
+
+asmlinkage void ppc_spe_sha1_transform(struct sha1_block_state *state,
+				       const u8 *data, u32 nblocks);
+
+static void spe_begin(void)
+{
+	/* We just start SPE operations and will save SPE registers later. */
+	preempt_disable();
+	enable_kernel_spe();
+}
+
+static void spe_end(void)
+{
+	disable_kernel_spe();
+	/* reenable preemption */
+	preempt_enable();
+}
+
+static void sha1_blocks(struct sha1_block_state *state,
+			const u8 *data, size_t nblocks)
+{
+	do {
+		u32 unit = min_t(size_t, nblocks, MAX_BYTES / SHA1_BLOCK_SIZE);
+
+		spe_begin();
+		ppc_spe_sha1_transform(state, data, unit);
+		spe_end();
+
+		data += unit * SHA1_BLOCK_SIZE;
+		nblocks -= unit;
+	} while (nblocks);
+}
+#else /* CONFIG_SPE */
+asmlinkage void powerpc_sha_transform(struct sha1_block_state *state,
+				      const u8 data[SHA1_BLOCK_SIZE]);
+
+static void sha1_blocks(struct sha1_block_state *state,
+			const u8 *data, size_t nblocks)
+{
+	do {
+		powerpc_sha_transform(state, data);
+		data += SHA1_BLOCK_SIZE;
+	} while (--nblocks);
+}
+#endif /* !CONFIG_SPE */
