This module registers crc32 and crc32c algorithms that use the
optional CRC32[bhwd] and CRC32C[bhwd] instructions in MIPSr6 cores.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
---
v2:
- minor code refactoring as suggested by JamesH which produces
a better assembly output for 32-bit builds
---
arch/mips/Kconfig | 4 +
arch/mips/Makefile | 3 +
arch/mips/crypto/Makefile | 5 +
arch/mips/crypto/crc32-mips.c | 364 ++++++++++++++++++++++++++++++++++++++++++
crypto/Kconfig | 9 ++
5 files changed, 385 insertions(+)
create mode 100644 arch/mips/crypto/Makefile
create mode 100644 arch/mips/crypto/crc32-mips.c
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index cb7fcc4..0f96812 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2036,6 +2036,7 @@ config CPU_MIPSR6
select CPU_HAS_RIXI
select HAVE_ARCH_BITREVERSE
select MIPS_ASID_BITS_VARIABLE
+ select MIPS_CRC_SUPPORT
select MIPS_SPRAM
config EVA
@@ -2503,6 +2504,9 @@ config MIPS_ASID_BITS
config MIPS_ASID_BITS_VARIABLE
bool
+config MIPS_CRC_SUPPORT
+ bool
+
#
# - Highmem only makes sense for the 32-bit kernel.
# - The current highmem code will only work properly on physically indexed
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index a96d97a..aa77536 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -216,6 +216,8 @@ cflags-$(toolchain-msa) += -DTOOLCHAIN_SUPPORTS_MSA
endif
toolchain-virt := $(call cc-option-yn,$(mips-cflags) -mvirt)
cflags-$(toolchain-virt) += -DTOOLCHAIN_SUPPORTS_VIRT
+toolchain-crc := $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mcrc)
+cflags-$(toolchain-crc) += -DTOOLCHAIN_SUPPORTS_CRC
#
# Firmware support
@@ -324,6 +326,7 @@ libs-y += arch/mips/math-emu/
# See arch/mips/Kbuild for content of core part of the kernel
core-y += arch/mips/
+drivers-$(CONFIG_MIPS_CRC_SUPPORT) += arch/mips/crypto/
drivers-$(CONFIG_OPROFILE) += arch/mips/oprofile/
# suspend and hibernation support
diff --git a/arch/mips/crypto/Makefile b/arch/mips/crypto/Makefile
new file mode 100644
index 0000000..665c725
--- /dev/null
+++ b/arch/mips/crypto/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for MIPS crypto files..
+#
+
+obj-$(CONFIG_CRYPTO_CRC32_MIPS) += crc32-mips.o
diff --git a/arch/mips/crypto/crc32-mips.c b/arch/mips/crypto/crc32-mips.c
new file mode 100644
index 0000000..f2f5db0
--- /dev/null
+++ b/arch/mips/crypto/crc32-mips.c
@@ -0,0 +1,364 @@
+/*
+ * crc32-mips.c - CRC32 and CRC32C using optional MIPSr6 instructions
+ *
+ * Module based on arm64/crypto/crc32-arm.c
+ *
+ * Copyright (C) 2014 Linaro Ltd <yazen.ghannam@xxxxxxxxxx>
+ * Copyright (C) 2017 Imagination Technologies, Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/unaligned/access_ok.h>
+#include <linux/cpufeature.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <asm/mipsregs.h>
+
+#include <crypto/internal/hash.h>
+
+enum crc_op_size {
+ b, h, w, d,
+};
+
+enum crc_type {
+ crc32,
+ crc32c,
+};
+
+#ifdef TOOLCHAIN_SUPPORTS_CRC
+
+#define _CRC32(crc, value, size, type) \
+do { \
+ __asm__ __volatile__( \
+ ".set push\n\t" \
+ ".set crc\n\t" \
+ #type #size " %0, %1, %0\n\t" \
+ ".set pop" \
+ : "+r" (crc) \
+ : "r" (value) \
+); \
+} while(0)
+
+#define CRC_REGISTER
+
+#else /* TOOLCHAIN_SUPPORTS_CRC */
+/*
+ * Crc argument is currently ignored and the assembly below assumes
+ * the crc is stored in $2. As the register number is encoded in the
+ * instruction we can't let the compiler chose the register it wants.
+ * An alternative is to change the code to do
+ * move $2, %0
+ * crc32
+ * move %0, $2
+ * but that adds unnecessary operations that the crc32 operation is
+ * designed to avoid. This issue can go away once the assembler
+ * is extended to support this operation and the compiler can make
+ * the right register choice automatically
+ */
+
+#define _CRC32(crc, value, size, type) \
+do { \
+ __asm__ __volatile__( \
+ ".set push\n\t" \
+ ".set noat\n\t" \
+ "move $at, %1\n\t" \
+ "# " #type #size " %0, $at, %0\n\t" \
+ _ASM_INSN_IF_MIPS(0x7c00000f | (2 << 16) | (1 << 21) | (%2 << 6) | (%3 << 8)) \
+ _ASM_INSN32_IF_MM(0x00000030 | (1 << 16) | (2 << 21) | (%2 << 14) | (%3 << 3)) \
+ ".set pop" \
+ : "+r" (crc) \
+ : "r" (value), "i" (size), "i" (type) \
+); \
+} while(0)
+
+#define CRC_REGISTER __asm__("$2")
+#endif /* !TOOLCHAIN_SUPPORTS_CRC */
+
+#define CRC32(crc, value, size) \
+ _CRC32(crc, value, size, crc32)
+
+#define CRC32C(crc, value, size) \
+ _CRC32(crc, value, size, crc32c)
+
+static u32 crc32_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
+{
+ register u32 crc CRC_REGISTER = crc_;
+
+#ifdef CONFIG_64BIT
+ while (len >= sizeof(u64)) {
+ register u64 value = get_unaligned_le64(p);
+
+ CRC32(crc, value, d);
+ p += sizeof(u64);
+ len -= sizeof(u64);
+ }
+
+ if (len & sizeof(u32)) {
+#else /* !CONFIG_64BIT */
+ while (len >= sizeof(u32)) {
+#endif
+ register u32 value = get_unaligned_le32(p);
+
+ CRC32(crc, value, w);
+ p += sizeof(u32);
+ len -= sizeof(u32);
+ }
+
+ if (len & sizeof(u16)) {
+ register u16 value = get_unaligned_le16(p);
+
+ CRC32(crc, value, h);
+ p += sizeof(u16);
+ }
+
+ if (len & sizeof(u8)) {
+ register u8 value = *p++;
+
+ CRC32(crc, value, b);
+ }
+
+ return crc;
+}
+
+static u32 crc32c_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
+{
+ register u32 crc CRC_REGISTER = crc_;
+
+#ifdef CONFIG_64BIT
+ while (len >= sizeof(u64)) {
+ register u64 value = get_unaligned_le64(p);
+
+ CRC32C(crc, value, d);
+ p += sizeof(u64);
+ len -= sizeof(u64);
+ }
+
+ if (len & sizeof(u32)) {
+#else /* !CONFIG_64BIT */
+ while (len >= sizeof(u32)) {
+#endif
+ register u32 value = get_unaligned_le32(p);
+
+ CRC32C(crc, value, w);
+ p += sizeof(u32);
+ len -= sizeof(u32);
+ }
+
+ if (len & sizeof(u16)) {
+ register u16 value = get_unaligned_le16(p);
+
+ CRC32C(crc, value, h);
+ p += sizeof(u16);
+ }
+
+ if (len & sizeof(u8)) {
+ register u8 value = *p++;
+
+ CRC32C(crc, value, b);
+ }
+ return crc;
+}
+
+#define CHKSUM_BLOCK_SIZE 1
+#define CHKSUM_DIGEST_SIZE 4
+
+struct chksum_ctx {
+ u32 key;
+};
+
+struct chksum_desc_ctx {
+ u32 crc;
+};
+
+static int chksum_init(struct shash_desc *desc)
+{
+ struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ ctx->crc = mctx->key;
+
+ return 0;
+}
+
+/*
+ * Setting the seed allows arbitrary accumulators and flexible XOR policy
+ * If your algorithm starts with ~0, then XOR with ~0 before you set
+ * the seed.
+ */
+static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
+ unsigned int keylen)
+{
+ struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
+
+ if (keylen != sizeof(mctx->key)) {
+ crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+ return -EINVAL;
+ }
+ mctx->key = get_unaligned_le32(key);
+ return 0;
+}
+
+static int chksum_update(struct shash_desc *desc, const u8 *data,
+ unsigned int length)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ ctx->crc = crc32_mips_le_hw(ctx->crc, data, length);
+ return 0;
+}
+
+static int chksumc_update(struct shash_desc *desc, const u8 *data,
+ unsigned int length)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ ctx->crc = crc32c_mips_le_hw(ctx->crc, data, length);
+ return 0;
+}
+
+static int chksum_final(struct shash_desc *desc, u8 *out)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ put_unaligned_le32(ctx->crc, out);
+ return 0;
+}
+
+static int chksumc_final(struct shash_desc *desc, u8 *out)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ put_unaligned_le32(~ctx->crc, out);
+ return 0;
+}
+
+static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
+{
+ put_unaligned_le32(crc32_mips_le_hw(crc, data, len), out);
+ return 0;
+}
+
+static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
+{
+ put_unaligned_le32(~crc32c_mips_le_hw(crc, data, len), out);
+ return 0;
+}
+
+static int chksum_finup(struct shash_desc *desc, const u8 *data,
+ unsigned int len, u8 *out)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ return __chksum_finup(ctx->crc, data, len, out);
+}
+
+static int chksumc_finup(struct shash_desc *desc, const u8 *data,
+ unsigned int len, u8 *out)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ return __chksumc_finup(ctx->crc, data, len, out);
+}
+
+static int chksum_digest(struct shash_desc *desc, const u8 *data,
+ unsigned int length, u8 *out)
+{
+ struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
+
+ return __chksum_finup(mctx->key, data, length, out);
+}
+
+static int chksumc_digest(struct shash_desc *desc, const u8 *data,
+ unsigned int length, u8 *out)
+{
+ struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
+
+ return __chksumc_finup(mctx->key, data, length, out);
+}
+
+static int chksum_cra_init(struct crypto_tfm *tfm)
+{
+ struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
+
+ mctx->key = ~0;
+ return 0;
+}
+
+static struct shash_alg crc32_alg = {
+ .digestsize = CHKSUM_DIGEST_SIZE,
+ .setkey = chksum_setkey,
+ .init = chksum_init,
+ .update = chksum_update,
+ .final = chksum_final,
+ .finup = chksum_finup,
+ .digest = chksum_digest,
+ .descsize = sizeof(struct chksum_desc_ctx),
+ .base = {
+ .cra_name = "crc32",
+ .cra_driver_name = "crc32-mips-hw",
+ .cra_priority = 300,
+ .cra_blocksize = CHKSUM_BLOCK_SIZE,
+ .cra_alignmask = 0,
+ .cra_ctxsize = sizeof(struct chksum_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = chksum_cra_init,
+ }
+};
+
+static struct shash_alg crc32c_alg = {
+ .digestsize = CHKSUM_DIGEST_SIZE,
+ .setkey = chksum_setkey,
+ .init = chksum_init,
+ .update = chksumc_update,
+ .final = chksumc_final,
+ .finup = chksumc_finup,
+ .digest = chksumc_digest,
+ .descsize = sizeof(struct chksum_desc_ctx),
+ .base = {
+ .cra_name = "crc32c",
+ .cra_driver_name = "crc32c-mips-hw",
+ .cra_priority = 300,
+ .cra_blocksize = CHKSUM_BLOCK_SIZE,
+ .cra_alignmask = 0,
+ .cra_ctxsize = sizeof(struct chksum_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_init = chksum_cra_init,
+ }
+};
+
+static int __init crc32_mod_init(void)
+{
+ int err;
+
+ err = crypto_register_shash(&crc32_alg);
+
+ if (err)
+ return err;
+
+ err = crypto_register_shash(&crc32c_alg);
+
+ if (err) {
+ crypto_unregister_shash(&crc32_alg);
+ return err;
+ }
+
+ return 0;
+}
+
+static void __exit crc32_mod_exit(void)
+{
+ crypto_unregister_shash(&crc32_alg);
+ crypto_unregister_shash(&crc32c_alg);
+}
+
+MODULE_AUTHOR("Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx");
+MODULE_DESCRIPTION("CRC32 and CRC32C using optional MIPS instructions");
+MODULE_LICENSE("GPL v2");
+
+module_cpu_feature_match(MIPS_CRC32, crc32_mod_init);
+module_exit(crc32_mod_exit);
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 28b1a0d..661971a 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -494,6 +494,15 @@ config CRYPTO_CRC32_PCLMUL
which will enable any routine to use the CRC-32-IEEE 802.3 checksum
and gain better performance as compared with the table implementation.
+config CRYPTO_CRC32_MIPS
+ tristate "CRC32c and CRC32 CRC algorithm (MIPS)"
+ depends on MIPS_CRC_SUPPORT
+ select CRYPTO_HASH
+ help
+ CRC32c and CRC32 CRC algorithms implemented using mips crypto
+ instructions, when available.
+
+
config CRYPTO_CRCT10DIF
tristate "CRCT10DIF algorithm"
select CRYPTO_HASH
--
2.7.4
