This integrates the accelerated MIPS 32r2 implementation of ChaCha
into both the API and library interfaces of the kernel crypto stack.
The significance of this is that, in addition to becoming available
as an accelerated library implementation, it can also be used by
existing crypto API code such as Adiantum (for block encryption on
ultra low performance cores) or IPsec using chacha20poly1305. These
are use cases that have already opted into using the abstract crypto
API. In order to support Adiantum, the core assembler routine has
been adapted to take the round count as a function argument rather
than hardcoding it to 20.
Co-developed-by: René van Dorst <opensource@xxxxxxxxxx>
Signed-off-by: René van Dorst <opensource@xxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/mips/Makefile | 2 +-
arch/mips/crypto/Makefile | 4 +
arch/mips/crypto/chacha-core.S | 159 +++++++++++++------
arch/mips/crypto/chacha-glue.c | 162 ++++++++++++++++++++
crypto/Kconfig | 6 +
5 files changed, 289 insertions(+), 44 deletions(-)
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index cdc09b71febe..8584c047ea59 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -323,7 +323,7 @@ libs-$(CONFIG_MIPS_FP_SUPPORT) += arch/mips/math-emu/
# See arch/mips/Kbuild for content of core part of the kernel
core-y += arch/mips/
-drivers-$(CONFIG_MIPS_CRC_SUPPORT) += arch/mips/crypto/
+drivers-y += arch/mips/crypto/
drivers-$(CONFIG_OPROFILE) += arch/mips/oprofile/
# suspend and hibernation support
diff --git a/arch/mips/crypto/Makefile b/arch/mips/crypto/Makefile
index e07aca572c2e..b528b9d300f1 100644
--- a/arch/mips/crypto/Makefile
+++ b/arch/mips/crypto/Makefile
@@ -4,3 +4,7 @@
#
obj-$(CONFIG_CRYPTO_CRC32_MIPS) += crc32-mips.o
+
+obj-$(CONFIG_CRYPTO_CHACHA_MIPS) += chacha-mips.o
+chacha-mips-y := chacha-core.o chacha-glue.o
+AFLAGS_chacha-core.o += -O2 # needed to fill branch delay slots
diff --git a/arch/mips/crypto/chacha-core.S b/arch/mips/crypto/chacha-core.S
index a81e02db95e7..991063fa016d 100644
--- a/arch/mips/crypto/chacha-core.S
+++ b/arch/mips/crypto/chacha-core.S
@@ -125,7 +125,7 @@
#define CONCAT3(a,b,c) _CONCAT3(a,b,c)
#define STORE_UNALIGNED(x) \
-CONCAT3(.Lchacha20_mips_xor_unaligned_, PLUS_ONE(x), _b: ;) \
+CONCAT3(.Lchacha_mips_xor_unaligned_, PLUS_ONE(x), _b: ;) \
.if (x != 12); \
lw T0, (x*4)(STATE); \
.endif; \
@@ -142,7 +142,7 @@ CONCAT3(.Lchacha20_mips_xor_unaligned_, PLUS_ONE(x), _b: ;) \
swr X ## x, (x*4)+LSB ## (OUT);
#define STORE_ALIGNED(x) \
-CONCAT3(.Lchacha20_mips_xor_aligned_, PLUS_ONE(x), _b: ;) \
+CONCAT3(.Lchacha_mips_xor_aligned_, PLUS_ONE(x), _b: ;) \
.if (x != 12); \
lw T0, (x*4)(STATE); \
.endif; \
@@ -162,9 +162,9 @@ CONCAT3(.Lchacha20_mips_xor_aligned_, PLUS_ONE(x), _b: ;) \
* Every jumptable entry must be equal in size.
*/
#define JMPTBL_ALIGNED(x) \
-.Lchacha20_mips_jmptbl_aligned_ ## x: ; \
+.Lchacha_mips_jmptbl_aligned_ ## x: ; \
.set noreorder; \
- b .Lchacha20_mips_xor_aligned_ ## x ## _b; \
+ b .Lchacha_mips_xor_aligned_ ## x ## _b; \
.if (x == 12); \
addu SAVED_X, X ## x, NONCE_0; \
.else; \
@@ -173,9 +173,9 @@ CONCAT3(.Lchacha20_mips_xor_aligned_, PLUS_ONE(x), _b: ;) \
.set reorder
#define JMPTBL_UNALIGNED(x) \
-.Lchacha20_mips_jmptbl_unaligned_ ## x: ; \
+.Lchacha_mips_jmptbl_unaligned_ ## x: ; \
.set noreorder; \
- b .Lchacha20_mips_xor_unaligned_ ## x ## _b; \
+ b .Lchacha_mips_xor_unaligned_ ## x ## _b; \
.if (x == 12); \
addu SAVED_X, X ## x, NONCE_0; \
.else; \
@@ -200,15 +200,18 @@ CONCAT3(.Lchacha20_mips_xor_aligned_, PLUS_ONE(x), _b: ;) \
.text
.set reorder
.set noat
-.globl chacha20_mips
-.ent chacha20_mips
-chacha20_mips:
+.globl chacha_crypt
+.ent chacha_crypt
+chacha_crypt:
.frame $sp, STACK_SIZE, $ra
+ /* Load number of rounds */
+ lw $at, 16($sp)
+
addiu $sp, -STACK_SIZE
/* Return bytes = 0. */
- beqz BYTES, .Lchacha20_mips_end
+ beqz BYTES, .Lchacha_mips_end
lw NONCE_0, 48(STATE)
@@ -228,18 +231,15 @@ chacha20_mips:
or IS_UNALIGNED, IN, OUT
andi IS_UNALIGNED, 0x3
- /* Set number of rounds */
- li $at, 20
-
- b .Lchacha20_rounds_start
+ b .Lchacha_rounds_start
.align 4
-.Loop_chacha20_rounds:
+.Loop_chacha_rounds:
addiu IN, CHACHA20_BLOCK_SIZE
addiu OUT, CHACHA20_BLOCK_SIZE
addiu NONCE_0, 1
-.Lchacha20_rounds_start:
+.Lchacha_rounds_start:
lw X0, 0(STATE)
lw X1, 4(STATE)
lw X2, 8(STATE)
@@ -259,7 +259,7 @@ chacha20_mips:
lw X14, 56(STATE)
lw X15, 60(STATE)
-.Loop_chacha20_xor_rounds:
+.Loop_chacha_xor_rounds:
addiu $at, -2
AXR( 0, 1, 2, 3, 4, 5, 6, 7, 12,13,14,15, 16);
AXR( 8, 9,10,11, 12,13,14,15, 4, 5, 6, 7, 12);
@@ -269,31 +269,31 @@ chacha20_mips:
AXR(10,11, 8, 9, 15,12,13,14, 5, 6, 7, 4, 12);
AXR( 0, 1, 2, 3, 5, 6, 7, 4, 15,12,13,14, 8);
AXR(10,11, 8, 9, 15,12,13,14, 5, 6, 7, 4, 7);
- bnez $at, .Loop_chacha20_xor_rounds
+ bnez $at, .Loop_chacha_xor_rounds
addiu BYTES, -(CHACHA20_BLOCK_SIZE)
/* Is data src/dst unaligned? Jump */
- bnez IS_UNALIGNED, .Loop_chacha20_unaligned
+ bnez IS_UNALIGNED, .Loop_chacha_unaligned
/* Set number rounds here to fill delayslot. */
- li $at, 20
+ lw $at, (STACK_SIZE+16)($sp)
/* BYTES < 0, it has no full block. */
- bltz BYTES, .Lchacha20_mips_no_full_block_aligned
+ bltz BYTES, .Lchacha_mips_no_full_block_aligned
FOR_EACH_WORD_REV(STORE_ALIGNED)
/* BYTES > 0? Loop again. */
- bgtz BYTES, .Loop_chacha20_rounds
+ bgtz BYTES, .Loop_chacha_rounds
/* Place this here to fill delay slot */
addiu NONCE_0, 1
/* BYTES < 0? Handle last bytes */
- bltz BYTES, .Lchacha20_mips_xor_bytes
+ bltz BYTES, .Lchacha_mips_xor_bytes
-.Lchacha20_mips_xor_done:
+.Lchacha_mips_xor_done:
/* Restore used registers */
lw $s0, 0($sp)
lw $s1, 4($sp)
@@ -307,11 +307,11 @@ chacha20_mips:
/* Write NONCE_0 back to right location in state */
sw NONCE_0, 48(STATE)
-.Lchacha20_mips_end:
+.Lchacha_mips_end:
addiu $sp, STACK_SIZE
jr $ra
-.Lchacha20_mips_no_full_block_aligned:
+.Lchacha_mips_no_full_block_aligned:
/* Restore the offset on BYTES */
addiu BYTES, CHACHA20_BLOCK_SIZE
@@ -319,7 +319,7 @@ chacha20_mips:
andi $at, BYTES, MASK_U32
/* Load upper half of jump table addr */
- lui T0, %hi(.Lchacha20_mips_jmptbl_aligned_0)
+ lui T0, %hi(.Lchacha_mips_jmptbl_aligned_0)
/* Calculate lower half jump table offset */
ins T0, $at, 1, 6
@@ -328,7 +328,7 @@ chacha20_mips:
addu T1, STATE, $at
/* Add lower half jump table addr */
- addiu T0, %lo(.Lchacha20_mips_jmptbl_aligned_0)
+ addiu T0, %lo(.Lchacha_mips_jmptbl_aligned_0)
/* Read value from STATE */
lw SAVED_CA, 0(T1)
@@ -342,31 +342,31 @@ chacha20_mips:
FOR_EACH_WORD(JMPTBL_ALIGNED)
-.Loop_chacha20_unaligned:
+.Loop_chacha_unaligned:
/* Set number rounds here to fill delayslot. */
- li $at, 20
+ lw $at, (STACK_SIZE+16)($sp)
/* BYTES > 0, it has no full block. */
- bltz BYTES, .Lchacha20_mips_no_full_block_unaligned
+ bltz BYTES, .Lchacha_mips_no_full_block_unaligned
FOR_EACH_WORD_REV(STORE_UNALIGNED)
/* BYTES > 0? Loop again. */
- bgtz BYTES, .Loop_chacha20_rounds
+ bgtz BYTES, .Loop_chacha_rounds
/* Write NONCE_0 back to right location in state */
sw NONCE_0, 48(STATE)
.set noreorder
/* Fall through to byte handling */
- bgez BYTES, .Lchacha20_mips_xor_done
-.Lchacha20_mips_xor_unaligned_0_b:
-.Lchacha20_mips_xor_aligned_0_b:
+ bgez BYTES, .Lchacha_mips_xor_done
+.Lchacha_mips_xor_unaligned_0_b:
+.Lchacha_mips_xor_aligned_0_b:
/* Place this here to fill delay slot */
addiu NONCE_0, 1
.set reorder
-.Lchacha20_mips_xor_bytes:
+.Lchacha_mips_xor_bytes:
addu IN, $at
addu OUT, $at
/* First byte */
@@ -376,22 +376,22 @@ chacha20_mips:
ROTR(SAVED_X)
xor T1, SAVED_X
sb T1, 0(OUT)
- beqz $at, .Lchacha20_mips_xor_done
+ beqz $at, .Lchacha_mips_xor_done
/* Second byte */
lbu T1, 1(IN)
addiu $at, BYTES, 2
ROTx SAVED_X, 8
xor T1, SAVED_X
sb T1, 1(OUT)
- beqz $at, .Lchacha20_mips_xor_done
+ beqz $at, .Lchacha_mips_xor_done
/* Third byte */
lbu T1, 2(IN)
ROTx SAVED_X, 8
xor T1, SAVED_X
sb T1, 2(OUT)
- b .Lchacha20_mips_xor_done
+ b .Lchacha_mips_xor_done
-.Lchacha20_mips_no_full_block_unaligned:
+.Lchacha_mips_no_full_block_unaligned:
/* Restore the offset on BYTES */
addiu BYTES, CHACHA20_BLOCK_SIZE
@@ -399,7 +399,7 @@ chacha20_mips:
andi $at, BYTES, MASK_U32
/* Load upper half of jump table addr */
- lui T0, %hi(.Lchacha20_mips_jmptbl_unaligned_0)
+ lui T0, %hi(.Lchacha_mips_jmptbl_unaligned_0)
/* Calculate lower half jump table offset */
ins T0, $at, 1, 6
@@ -408,7 +408,7 @@ chacha20_mips:
addu T1, STATE, $at
/* Add lower half jump table addr */
- addiu T0, %lo(.Lchacha20_mips_jmptbl_unaligned_0)
+ addiu T0, %lo(.Lchacha_mips_jmptbl_unaligned_0)
/* Read value from STATE */
lw SAVED_CA, 0(T1)
@@ -420,5 +420,78 @@ chacha20_mips:
/* Jump table */
FOR_EACH_WORD(JMPTBL_UNALIGNED)
-.end chacha20_mips
+.end chacha_crypt
+.set at
+
+/* Input arguments
+ * STATE $a0
+ * OUT $a1
+ * NROUND $a2
+ */
+
+#undef X12
+#undef X13
+#undef X14
+#undef X15
+
+#define X12 $a3
+#define X13 $at
+#define X14 $v0
+#define X15 STATE
+
+.set noat
+.globl hchacha_block
+.ent hchacha_block
+hchacha_block:
+ .frame $sp, STACK_SIZE, $ra
+
+ addiu $sp, -STACK_SIZE
+
+ /* Save X11(s6) */
+ sw X11, 0($sp)
+
+ lw X0, 0(STATE)
+ lw X1, 4(STATE)
+ lw X2, 8(STATE)
+ lw X3, 12(STATE)
+ lw X4, 16(STATE)
+ lw X5, 20(STATE)
+ lw X6, 24(STATE)
+ lw X7, 28(STATE)
+ lw X8, 32(STATE)
+ lw X9, 36(STATE)
+ lw X10, 40(STATE)
+ lw X11, 44(STATE)
+ lw X12, 48(STATE)
+ lw X13, 52(STATE)
+ lw X14, 56(STATE)
+ lw X15, 60(STATE)
+
+.Loop_hchacha_xor_rounds:
+ addiu $a2, -2
+ AXR( 0, 1, 2, 3, 4, 5, 6, 7, 12,13,14,15, 16);
+ AXR( 8, 9,10,11, 12,13,14,15, 4, 5, 6, 7, 12);
+ AXR( 0, 1, 2, 3, 4, 5, 6, 7, 12,13,14,15, 8);
+ AXR( 8, 9,10,11, 12,13,14,15, 4, 5, 6, 7, 7);
+ AXR( 0, 1, 2, 3, 5, 6, 7, 4, 15,12,13,14, 16);
+ AXR(10,11, 8, 9, 15,12,13,14, 5, 6, 7, 4, 12);
+ AXR( 0, 1, 2, 3, 5, 6, 7, 4, 15,12,13,14, 8);
+ AXR(10,11, 8, 9, 15,12,13,14, 5, 6, 7, 4, 7);
+ bnez $a2, .Loop_hchacha_xor_rounds
+
+ /* Restore used register */
+ lw X11, 0($sp)
+
+ sw X0, 0(OUT)
+ sw X1, 4(OUT)
+ sw X2, 8(OUT)
+ sw X3, 12(OUT)
+ sw X12, 16(OUT)
+ sw X13, 20(OUT)
+ sw X14, 24(OUT)
+ sw X15, 28(OUT)
+
+ addiu $sp, STACK_SIZE
+ jr $ra
+.end hchacha_block
.set at
diff --git a/arch/mips/crypto/chacha-glue.c b/arch/mips/crypto/chacha-glue.c
new file mode 100644
index 000000000000..5515b75ada24
--- /dev/null
+++ b/arch/mips/crypto/chacha-glue.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MIPS accelerated ChaCha and XChaCha stream ciphers,
+ * including ChaCha20 (RFC7539)
+ *
+ * Copyright (C) 2019 Linaro, Ltd. <ard.biesheuvel@xxxxxxxxxx>
+ */
+
+#include <asm/byteorder.h>
+#include <crypto/algapi.h>
+#include <crypto/internal/chacha.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+asmlinkage void chacha_crypt(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds);
+EXPORT_SYMBOL(chacha_crypt);
+
+asmlinkage void hchacha_block(const u32 *state, u32 *stream, int nrounds);
+EXPORT_SYMBOL(hchacha_block);
+
+void chacha_init(u32 *state, const u32 *key, const u8 *iv)
+{
+ chacha_init_generic(state, key, iv);
+}
+EXPORT_SYMBOL(chacha_init);
+
+static int chacha_mips_stream_xor(struct skcipher_request *req,
+ const struct chacha_ctx *ctx, const u8 *iv)
+{
+ struct skcipher_walk walk;
+ u32 state[16];
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+
+ chacha_init_generic(state, ctx->key, iv);
+
+ while (walk.nbytes > 0) {
+ unsigned int nbytes = walk.nbytes;
+
+ if (nbytes < walk.total)
+ nbytes = round_down(nbytes, walk.stride);
+
+ chacha_crypt(state, walk.dst.virt.addr, walk.src.virt.addr,
+ nbytes, ctx->nrounds);
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+ return err;
+}
+
+static int chacha_mips(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+ return chacha_mips_stream_xor(req, ctx, req->iv);
+}
+
+static int xchacha_mips(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct chacha_ctx subctx;
+ u32 state[16];
+ u8 real_iv[16];
+
+ chacha_init_generic(state, ctx->key, req->iv);
+
+ hchacha_block(state, subctx.key, ctx->nrounds);
+ subctx.nrounds = ctx->nrounds;
+
+ memcpy(&real_iv[0], req->iv + 24, 8);
+ memcpy(&real_iv[8], req->iv + 16, 8);
+ return chacha_mips_stream_xor(req, &subctx, real_iv);
+}
+
+static int chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize)
+{
+ return chacha_setkey(tfm, key, keysize, 20);
+}
+
+static int chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize)
+{
+ return chacha_setkey(tfm, key, keysize, 12);
+}
+
+static struct skcipher_alg algs[] = {
+ {
+ .base.cra_name = "chacha20",
+ .base.cra_driver_name = "chacha20-mips",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = CHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .setkey = chacha20_setkey,
+ .encrypt = chacha_mips,
+ .decrypt = chacha_mips,
+ }, {
+ .base.cra_name = "xchacha20",
+ .base.cra_driver_name = "xchacha20-mips",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = XCHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .setkey = chacha20_setkey,
+ .encrypt = xchacha_mips,
+ .decrypt = xchacha_mips,
+ }, {
+ .base.cra_name = "xchacha12",
+ .base.cra_driver_name = "xchacha12-mips",
+ .base.cra_priority = 200,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct chacha_ctx),
+ .base.cra_module = THIS_MODULE,
+
+ .min_keysize = CHACHA_KEY_SIZE,
+ .max_keysize = CHACHA_KEY_SIZE,
+ .ivsize = XCHACHA_IV_SIZE,
+ .chunksize = CHACHA_BLOCK_SIZE,
+ .setkey = chacha12_setkey,
+ .encrypt = xchacha_mips,
+ .decrypt = xchacha_mips,
+ }
+};
+
+static int __init chacha_simd_mod_init(void)
+{
+ return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
+}
+
+static void __exit chacha_simd_mod_fini(void)
+{
+ crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
+}
+
+module_init(chacha_simd_mod_init);
+module_exit(chacha_simd_mod_fini);
+
+MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (MIPS accelerated)");
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("chacha20");
+MODULE_ALIAS_CRYPTO("chacha20-mips");
+MODULE_ALIAS_CRYPTO("xchacha20");
+MODULE_ALIAS_CRYPTO("xchacha20-mips");
+MODULE_ALIAS_CRYPTO("xchacha12");
+MODULE_ALIAS_CRYPTO("xchacha12-mips");
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 3e5a6febc7ef..33ee76c82740 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1445,6 +1445,12 @@ config CRYPTO_CHACHA20_X86_64
SSSE3, AVX2, and AVX-512VL optimized implementations of the ChaCha20,
XChaCha20, and XChaCha12 stream ciphers.
+config CRYPTO_CHACHA_MIPS
+ tristate "ChaCha stream cipher algorithms (MIPS 32r2 optimized)"
+ depends on CPU_MIPS32_R2
+ select CRYPTO_BLKCIPHER
+ select CRYPTO_ARCH_HAVE_LIB_CHACHA
+
config CRYPTO_SEED
tristate "SEED cipher algorithm"
select CRYPTO_ALGAPI
--
2.20.1
