diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index f6a14c186b4ec..e87e3bc9b6d5e 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -72,6 +72,16 @@ config CRYPTO_BLAKE2B_NEON
 	  Crypto Extensions, typically this BLAKE2b implementation is
 	  much faster than SHA-2 and slightly faster than SHA-1.
 
+config CRYPTO_BLAKE2S_ARM
+	tristate "BLAKE2s digest algorithm (ARM)"
+	select CRYPTO_ARCH_HAVE_LIB_BLAKE2S
+	select CRYPTO_BLAKE2S_HELPERS if CRYPTO_HASH
+	help
+	  BLAKE2s digest algorithm optimized with ARM scalar instructions.  This
+	  is faster than the generic implementations of BLAKE2s and BLAKE2b, but
+	  slower than the NEON implementation of BLAKE2b.  (There is no NEON
+	  implementation of BLAKE2s, since NEON doesn't really help with it.)
+
 config CRYPTO_AES_ARM
 	tristate "Scalar AES cipher for ARM"
 	select CRYPTO_ALGAPI
diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile
index ab835ceeb4f2e..fcd80f660b762 100644
--- a/arch/arm/crypto/Makefile
+++ b/arch/arm/crypto/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_CRYPTO_SHA1_ARM_NEON) += sha1-arm-neon.o
 obj-$(CONFIG_CRYPTO_SHA256_ARM) += sha256-arm.o
 obj-$(CONFIG_CRYPTO_SHA512_ARM) += sha512-arm.o
 obj-$(CONFIG_CRYPTO_BLAKE2B_NEON) += blake2b-neon.o
+obj-$(CONFIG_CRYPTO_BLAKE2S_ARM) += blake2s-arm.o
 obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha-neon.o
 obj-$(CONFIG_CRYPTO_POLY1305_ARM) += poly1305-arm.o
 obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
@@ -31,6 +32,7 @@ sha256-arm-y	:= sha256-core.o sha256_glue.o $(sha256-arm-neon-y)
 sha512-arm-neon-$(CONFIG_KERNEL_MODE_NEON) := sha512-neon-glue.o
 sha512-arm-y	:= sha512-core.o sha512-glue.o $(sha512-arm-neon-y)
 blake2b-neon-y  := blake2b-neon-core.o blake2b-neon-glue.o
+blake2s-arm-y   := blake2s-core.o blake2s-glue.o
 sha1-arm-ce-y	:= sha1-ce-core.o sha1-ce-glue.o
 sha2-arm-ce-y	:= sha2-ce-core.o sha2-ce-glue.o
 aes-arm-ce-y	:= aes-ce-core.o aes-ce-glue.o
diff --git a/arch/arm/crypto/blake2s-core.S b/arch/arm/crypto/blake2s-core.S
new file mode 100644
index 0000000000000..88aa1875911d8
--- /dev/null
+++ b/arch/arm/crypto/blake2s-core.S
@@ -0,0 +1,272 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * BLAKE2s digest algorithm, ARM scalar implementation
+ *
+ * Copyright 2020 Google LLC
+ *
+ * Author: Eric Biggers <ebiggers@google.com>
+ */
+
+#include <linux/linkage.h>
+
+	// Registers used to hold message words temporarily.  There aren't
+	// enough ARM registers to hold the whole message block, so we have to
+	// load the words on-demand.
+	M_0		.req	r12
+	M_1		.req	r14
+
+// The BLAKE2s initialization vector
+.Lblake2s_IV:
+	.word	0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A
+	.word	0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
+
+.macro __ldrd		a, b, src, offset
+#if __LINUX_ARM_ARCH__ >= 6
+	ldrd		\a, \b, [\src, #\offset]
+#else
+	ldr		\a, [\src, #\offset]
+	ldr		\b, [\src, #\offset + 4]
+#endif
+.endm
+
+.macro __strd		a, b, dst, offset
+#if __LINUX_ARM_ARCH__ >= 6
+	strd		\a, \b, [\dst, #\offset]
+#else
+	str		\a, [\dst, #\offset]
+	str		\b, [\dst, #\offset + 4]
+#endif
+.endm
+
+.macro _blake2s_quarterround  a0, b0, c0, d0,  a1, b1, c1, d1,  s0, s1, s2, s3
+
+	ldr		M_0, [sp, #32 + 4 * \s0]
+	ldr		M_1, [sp, #32 + 4 * \s2]
+
+	// a += b + m[blake2s_sigma[r][2 * i + 0]];
+	add		\a0, \a0, \b0, ror #brot
+	add		\a1, \a1, \b1, ror #brot
+	add		\a0, \a0, M_0
+	add		\a1, \a1, M_1
+
+	// d = ror32(d ^ a, 16);
+	eor		\d0, \a0, \d0, ror #drot
+	eor		\d1, \a1, \d1, ror #drot
+
+	// c += d;
+	add		\c0, \c0, \d0, ror #16
+	add		\c1, \c1, \d1, ror #16
+
+	// b = ror32(b ^ c, 12);
+	eor		\b0, \c0, \b0, ror #brot
+	eor		\b1, \c1, \b1, ror #brot
+
+	ldr		M_0, [sp, #32 + 4 * \s1]
+	ldr		M_1, [sp, #32 + 4 * \s3]
+
+	// a += b + m[blake2s_sigma[r][2 * i + 1]];
+	add		\a0, \a0, \b0, ror #12
+	add		\a1, \a1, \b1, ror #12
+	add		\a0, \a0, M_0
+	add		\a1, \a1, M_1
+
+	// d = ror32(d ^ a, 8);
+	eor		\d0, \a0, \d0, ror#16
+	eor		\d1, \a1, \d1, ror#16
+
+	// c += d;
+	add		\c0, \c0, \d0, ror#8
+	add		\c1, \c1, \d1, ror#8
+
+	// b = ror32(b ^ c, 7);
+	eor		\b0, \c0, \b0, ror#12
+	eor		\b1, \c1, \b1, ror#12
+.endm
+
+// Execute one round of BLAKE2s by updating the state matrix v[0..15].  v[0..9]
+// are in r0..r9.  The stack pointer points to 8 bytes of scratch space for
+// spilling v[8..9], then to v[9..15], then to the message block.  r10-r12 and
+// r14 are free to use.  The macro arguments s0-s15 give the order in which the
+// message words are used in this round.
+//
+// All rotates are performed using the implicit rotate operand accepted by the
+// 'add' and 'eor' instructions.  This is faster than using explicit rotate
+// instructions.  To make this work, we allow the values in the second and last
+// rows of the BLAKE2s state matrix (rows 'b' and 'd') to temporarily have the
+// wrong rotation amount.  The rotation amount is then fixed up just in time
+// when the values are used.  'brot' is the number of bits the values in row 'b'
+// need to be rotated right to arrive at the correct values, and 'drot'
+// similarly for row 'd'.  (brot, drot) start out as (0, 0) but we make it such
+// that they end up as (7, 8) after every round.
+.macro	_blake2s_round	s0, s1, s2, s3, s4, s5, s6, s7, \
+			s8, s9, s10, s11, s12, s13, s14, s15
+
+	// Mix first two columns:
+	// (v[0], v[4], v[8], v[12]) and (v[1], v[5], v[9], v[13]).
+	__ldrd		r10, r11, sp, 16	// load v[12] and v[13]
+	_blake2s_quarterround	r0, r4, r8, r10,  r1, r5, r9, r11, \
+				\s0, \s1, \s2, \s3
+	__strd		r8, r9, sp, 0
+	__strd		r10, r11, sp, 16
+
+	// Mix second two columns:
+	// (v[2], v[6], v[10], v[14]) and (v[3], v[7], v[11], v[15]).
+	__ldrd		r8, r9, sp, 8		// load v[10] and v[11]
+	__ldrd		r10, r11, sp, 24	// load v[14] and v[15]
+	_blake2s_quarterround	r2, r6, r8, r10,  r3, r7, r9, r11, \
+				\s4, \s5, \s6, \s7
+	str		r10, [sp, #24]		// store v[14]
+	// v[10], v[11], and v[15] are used below, so no need to store them yet.
+
+	.set brot, 7
+	.set drot, 8
+
+	// Mix first two diagonals:
+	// (v[0], v[5], v[10], v[15]) and (v[1], v[6], v[11], v[12]).
+	ldr		r10, [sp, #16]		// load v[12]
+	_blake2s_quarterround	r0, r5, r8, r11,  r1, r6, r9, r10, \
+				\s8, \s9, \s10, \s11
+	__strd		r8, r9, sp, 8
+	str		r11, [sp, #28]
+	str		r10, [sp, #16]
+
+	// Mix second two diagonals:
+	// (v[2], v[7], v[8], v[13]) and (v[3], v[4], v[9], v[14]).
+	__ldrd		r8, r9, sp, 0		// load v[8] and v[9]
+	__ldrd		r10, r11, sp, 20	// load v[13] and v[14]
+	_blake2s_quarterround	r2, r7, r8, r10,  r3, r4, r9, r11, \
+				\s12, \s13, \s14, \s15
+	__strd		r10, r11, sp, 20
+.endm
+
+//
+// void blake2s_compress_arch(struct blake2s_state *state,
+//			      const u8 *block, size_t nblocks, u32 inc);
+//
+// Only the first three fields of struct blake2s_state are used:
+//	u32 h[8];	(inout)
+//	u32 t[2];	(in)
+//	u32 f[2];	(in)
+//
+	.align		5
+ENTRY(blake2s_compress_arch)
+	push		{r0-r2,r4-r11,lr}	// keep this an even number
+
+.Lnext_block:
+	// r0 is 'state'
+	// r1 is 'block'
+	// r3 is counter increment amount
+
+	// Load and increment the counter t[0..1].
+	__ldrd		r10, r11, r0, 32
+	adds		r10, r10, r3
+	adc		r11, r11, #0
+	__strd		r10, r11, r0, 32
+
+	// _blake2s_round is very short on registers, so copy the message block
+	// to the stack to save a register during the rounds.  This also has the
+	// advantage that misalignment only needs to be dealt with in one place.
+	sub		sp, sp, #64
+	mov		r12, sp
+	tst		r1, #3
+	bne		.Lcopy_block_misaligned
+	ldmia		r1!, {r2-r9}
+	stmia		r12!, {r2-r9}
+	ldmia		r1!, {r2-r9}
+	stmia		r12, {r2-r9}
+.Lcopy_block_done:
+	str		r1, [sp, #68]		// Update message pointer
+
+	// Calculate v[8..15].  Push v[9..15] onto the stack, and leave space
+	// for spilling v[8..9].  Leave v[8..9] in r8-r9.
+	mov		r14, r0			// r14 = state
+	adr		r12, .Lblake2s_IV
+	ldmia		r12!, {r8-r9}		// load IV[0..1]
+	__ldrd		r0, r1, r14, 40		// load f[0..1]
+	ldm		r12, {r2-r7}		// load IV[3..7]
+	eor		r4, r4, r10		// v[12] = IV[4] ^ t[0]
+	eor		r5, r5, r11		// v[13] = IV[5] ^ t[1]
+	eor		r6, r6, r0		// v[14] = IV[6] ^ f[0]
+	eor		r7, r7, r1		// v[15] = IV[7] ^ f[1]
+	push		{r2-r7}
+	sub		sp, sp, #8
+
+	// Load h[0..7] == v[0..7].
+	ldm		r14, {r0-r7}
+
+	// Execute the rounds.  Each round is provided the order in which it
+	// needs to use the message words.
+	.set brot, 0
+	.set drot, 0
+	_blake2s_round	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
+	_blake2s_round	14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3
+	_blake2s_round	11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4
+	_blake2s_round	7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8
+	_blake2s_round	9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13
+	_blake2s_round	2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9
+	_blake2s_round	12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11
+	_blake2s_round	13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10
+	_blake2s_round	6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5
+	_blake2s_round	10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0
+
+	// Fold the final state matrix into the hash chaining value:
+	//
+	//	for (i = 0; i < 8; i++)
+	//		h[i] ^= v[i] ^ v[i + 8];
+	//
+	ldr		r14, [sp, #96]		// r14 = &h[0]
+	add		sp, sp, #8		// v[8..9] are already loaded.
+	pop		{r10-r11}		// load v[10..11]
+	eor		r0, r0, r8
+	eor		r1, r1, r9
+	eor		r2, r2, r10
+	eor		r3, r3, r11
+	ldm		r14, {r8-r11}		// load h[0..3]
+	eor		r0, r0, r8
+	eor		r1, r1, r9
+	eor		r2, r2, r10
+	eor		r3, r3, r11
+	stmia		r14!, {r0-r3}		// store new h[0..3]
+	ldm		r14, {r0-r3}		// load old h[4..7]
+	pop		{r8-r11}		// load v[12..15]
+	eor		r0, r0, r4, ror #brot
+	eor		r1, r1, r5, ror #brot
+	eor		r2, r2, r6, ror #brot
+	eor		r3, r3, r7, ror #brot
+	eor		r0, r0, r8, ror #drot
+	eor		r1, r1, r9, ror #drot
+	eor		r2, r2, r10, ror #drot
+	eor		r3, r3, r11, ror #drot
+	  add		sp, sp, #64		// skip copy of message block
+	stm		r14, {r0-r3}		// store new h[4..7]
+
+	ldm		sp, {r0, r1, r2}	// load (state, block, nblocks)
+	mov		r3, #64			// set counter increment amount
+	subs		r2, r2, #1		// nblocks--
+	str		r2, [sp, #8]
+	bne		.Lnext_block		// nblocks != 0?
+
+	pop		{r0-r2,r4-r11,pc}
+
+	// The message block isn't 4-byte aligned, so it can't be loaded using
+	// ldmia.  Copy it to the stack using an alternative method.
+.Lcopy_block_misaligned:
+	mov		r2, #64
+1:
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+	ldr		r3, [r1], #4
+#else
+	ldrb		r3, [r1, #0]
+	ldrb		r4, [r1, #1]
+	ldrb		r5, [r1, #2]
+	ldrb		r6, [r1, #3]
+	add		r1, r1, #4
+	orr		r3, r3, r4, lsl #8
+	orr		r3, r3, r5, lsl #16
+	orr		r3, r3, r6, lsl #24
+#endif
+	subs		r2, r2, #4
+	str		r3, [r12], #4
+	bne		1b
+	b		.Lcopy_block_done
+ENDPROC(blake2s_compress_arch)
diff --git a/arch/arm/crypto/blake2s-glue.c b/arch/arm/crypto/blake2s-glue.c
new file mode 100644
index 0000000000000..f2cc1e5fc9ec1
--- /dev/null
+++ b/arch/arm/crypto/blake2s-glue.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * BLAKE2s digest algorithm, ARM scalar implementation
+ *
+ * Copyright 2020 Google LLC
+ */
+
+#include <crypto/internal/blake2s.h>
+#include <crypto/internal/hash.h>
+
+#include <linux/module.h>
+
+/* defined in blake2s-core.S */
+EXPORT_SYMBOL(blake2s_compress_arch);
+
+static int crypto_blake2s_update_arm(struct shash_desc *desc,
+				     const u8 *in, unsigned int inlen)
+{
+	return crypto_blake2s_update(desc, in, inlen, blake2s_compress_arch);
+}
+
+static int crypto_blake2s_final_arm(struct shash_desc *desc, u8 *out)
+{
+	return crypto_blake2s_final(desc, out, blake2s_compress_arch);
+}
+
+#define BLAKE2S_ALG(name, driver_name, digest_size)			\
+	{								\
+		.base.cra_name		= name,				\
+		.base.cra_driver_name	= driver_name,			\
+		.base.cra_priority	= 200,				\
+		.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,	\
+		.base.cra_blocksize	= BLAKE2S_BLOCK_SIZE,		\
+		.base.cra_ctxsize	= sizeof(struct blake2s_tfm_ctx), \
+		.base.cra_module	= THIS_MODULE,			\
+		.digestsize		= digest_size,			\
+		.setkey			= crypto_blake2s_setkey,	\
+		.init			= crypto_blake2s_init,		\
+		.update			= crypto_blake2s_update_arm,	\
+		.final			= crypto_blake2s_final_arm,	\
+		.descsize		= sizeof(struct blake2s_state),	\
+	}
+
+static struct shash_alg blake2s_arm_algs[] = {
+	BLAKE2S_ALG("blake2s-128", "blake2s-128-arm", BLAKE2S_128_HASH_SIZE),
+	BLAKE2S_ALG("blake2s-160", "blake2s-160-arm", BLAKE2S_160_HASH_SIZE),
+	BLAKE2S_ALG("blake2s-224", "blake2s-224-arm", BLAKE2S_224_HASH_SIZE),
+	BLAKE2S_ALG("blake2s-256", "blake2s-256-arm", BLAKE2S_256_HASH_SIZE),
+};
+
+static int __init blake2s_arm_mod_init(void)
+{
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
+		crypto_register_shashes(blake2s_arm_algs,
+					ARRAY_SIZE(blake2s_arm_algs)) : 0;
+}
+
+static void __exit blake2s_arm_mod_exit(void)
+{
+	if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
+		crypto_unregister_shashes(blake2s_arm_algs,
+					  ARRAY_SIZE(blake2s_arm_algs));
+}
+
+module_init(blake2s_arm_mod_init);
+module_exit(blake2s_arm_mod_exit);
+
+MODULE_DESCRIPTION("BLAKE2s digest algorithm, ARM scalar implementation");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
+MODULE_ALIAS_CRYPTO("blake2s-128");
+MODULE_ALIAS_CRYPTO("blake2s-128-arm");
+MODULE_ALIAS_CRYPTO("blake2s-160");
+MODULE_ALIAS_CRYPTO("blake2s-160-arm");
+MODULE_ALIAS_CRYPTO("blake2s-224");
+MODULE_ALIAS_CRYPTO("blake2s-224-arm");
+MODULE_ALIAS_CRYPTO("blake2s-256");
+MODULE_ALIAS_CRYPTO("blake2s-256-arm");
