diff options
Diffstat (limited to 'kernel/arch/powerpc/crypto/sha256-spe-glue.c')
| -rw-r--r-- | kernel/arch/powerpc/crypto/sha256-spe-glue.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/crypto/sha256-spe-glue.c b/kernel/arch/powerpc/crypto/sha256-spe-glue.c new file mode 100644 index 000000000..f4a616fe1 --- /dev/null +++ b/kernel/arch/powerpc/crypto/sha256-spe-glue.c @@ -0,0 +1,275 @@ +/* + * Glue code for SHA-256 implementation for SPE instructions (PPC) + * + * Based on generic implementation. The assembler module takes care + * about the SPE registers so it can run from interrupt context. + * + * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#include <crypto/internal/hash.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/cryptohash.h> +#include <linux/types.h> +#include <crypto/sha.h> +#include <asm/byteorder.h> +#include <asm/switch_to.h> +#include <linux/hardirq.h> + +/* + * MAX_BYTES defines the number of bytes that are allowed to be processed + * between preempt_disable() and preempt_enable(). SHA256 takes ~2,000 + * 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 1KB 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 1024 + +extern void ppc_spe_sha256_transform(u32 *state, const u8 *src, u32 blocks); + +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) +{ + /* reenable preemption */ + preempt_enable(); +} + +static inline void ppc_sha256_clear_context(struct sha256_state *sctx) +{ + int count = sizeof(struct sha256_state) >> 2; + u32 *ptr = (u32 *)sctx; + + /* make sure we can clear the fast way */ + BUILD_BUG_ON(sizeof(struct sha256_state) % 4); + do { *ptr++ = 0; } while (--count); +} + +static int ppc_spe_sha256_init(struct shash_desc *desc) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + + sctx->state[0] = SHA256_H0; + sctx->state[1] = SHA256_H1; + sctx->state[2] = SHA256_H2; + sctx->state[3] = SHA256_H3; + sctx->state[4] = SHA256_H4; + sctx->state[5] = SHA256_H5; + sctx->state[6] = SHA256_H6; + sctx->state[7] = SHA256_H7; + sctx->count = 0; + + return 0; +} + +static int ppc_spe_sha224_init(struct shash_desc *desc) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + + sctx->state[0] = SHA224_H0; + sctx->state[1] = SHA224_H1; + sctx->state[2] = SHA224_H2; + sctx->state[3] = SHA224_H3; + sctx->state[4] = SHA224_H4; + sctx->state[5] = SHA224_H5; + sctx->state[6] = SHA224_H6; + sctx->state[7] = SHA224_H7; + sctx->count = 0; + + return 0; +} + +static int ppc_spe_sha256_update(struct shash_desc *desc, const u8 *data, + unsigned int len) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + const unsigned int offset = sctx->count & 0x3f; + const unsigned int avail = 64 - offset; + unsigned int bytes; + const u8 *src = data; + + if (avail > len) { + sctx->count += len; + memcpy((char *)sctx->buf + offset, src, len); + return 0; + } + + sctx->count += len; + + if (offset) { + memcpy((char *)sctx->buf + offset, src, avail); + + spe_begin(); + ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1); + spe_end(); + + len -= avail; + src += avail; + } + + while (len > 63) { + /* cut input data into smaller blocks */ + bytes = (len > MAX_BYTES) ? MAX_BYTES : len; + bytes = bytes & ~0x3f; + + spe_begin(); + ppc_spe_sha256_transform(sctx->state, src, bytes >> 6); + spe_end(); + + src += bytes; + len -= bytes; + }; + + memcpy((char *)sctx->buf, src, len); + return 0; +} + +static int ppc_spe_sha256_final(struct shash_desc *desc, u8 *out) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + const unsigned int offset = sctx->count & 0x3f; + char *p = (char *)sctx->buf + offset; + int padlen; + __be64 *pbits = (__be64 *)(((char *)&sctx->buf) + 56); + __be32 *dst = (__be32 *)out; + + padlen = 55 - offset; + *p++ = 0x80; + + spe_begin(); + + if (padlen < 0) { + memset(p, 0x00, padlen + sizeof (u64)); + ppc_spe_sha256_transform(sctx->state, sctx->buf, 1); + p = (char *)sctx->buf; + padlen = 56; + } + + memset(p, 0, padlen); + *pbits = cpu_to_be64(sctx->count << 3); + ppc_spe_sha256_transform(sctx->state, sctx->buf, 1); + + spe_end(); + + dst[0] = cpu_to_be32(sctx->state[0]); + dst[1] = cpu_to_be32(sctx->state[1]); + dst[2] = cpu_to_be32(sctx->state[2]); + dst[3] = cpu_to_be32(sctx->state[3]); + dst[4] = cpu_to_be32(sctx->state[4]); + dst[5] = cpu_to_be32(sctx->state[5]); + dst[6] = cpu_to_be32(sctx->state[6]); + dst[7] = cpu_to_be32(sctx->state[7]); + + ppc_sha256_clear_context(sctx); + return 0; +} + +static int ppc_spe_sha224_final(struct shash_desc *desc, u8 *out) +{ + u32 D[SHA256_DIGEST_SIZE >> 2]; + __be32 *dst = (__be32 *)out; + + ppc_spe_sha256_final(desc, (u8 *)D); + + /* avoid bytewise memcpy */ + dst[0] = D[0]; + dst[1] = D[1]; + dst[2] = D[2]; + dst[3] = D[3]; + dst[4] = D[4]; + dst[5] = D[5]; + dst[6] = D[6]; + + /* clear sensitive data */ + memzero_explicit(D, SHA256_DIGEST_SIZE); + return 0; +} + +static int ppc_spe_sha256_export(struct shash_desc *desc, void *out) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + + memcpy(out, sctx, sizeof(*sctx)); + return 0; +} + +static int ppc_spe_sha256_import(struct shash_desc *desc, const void *in) +{ + struct sha256_state *sctx = shash_desc_ctx(desc); + + memcpy(sctx, in, sizeof(*sctx)); + return 0; +} + +static struct shash_alg algs[2] = { { + .digestsize = SHA256_DIGEST_SIZE, + .init = ppc_spe_sha256_init, + .update = ppc_spe_sha256_update, + .final = ppc_spe_sha256_final, + .export = ppc_spe_sha256_export, + .import = ppc_spe_sha256_import, + .descsize = sizeof(struct sha256_state), + .statesize = sizeof(struct sha256_state), + .base = { + .cra_name = "sha256", + .cra_driver_name= "sha256-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_SHASH, + .cra_blocksize = SHA256_BLOCK_SIZE, + .cra_module = THIS_MODULE, + } +}, { + .digestsize = SHA224_DIGEST_SIZE, + .init = ppc_spe_sha224_init, + .update = ppc_spe_sha256_update, + .final = ppc_spe_sha224_final, + .export = ppc_spe_sha256_export, + .import = ppc_spe_sha256_import, + .descsize = sizeof(struct sha256_state), + .statesize = sizeof(struct sha256_state), + .base = { + .cra_name = "sha224", + .cra_driver_name= "sha224-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_SHASH, + .cra_blocksize = SHA224_BLOCK_SIZE, + .cra_module = THIS_MODULE, + } +} }; + +static int __init ppc_spe_sha256_mod_init(void) +{ + return crypto_register_shashes(algs, ARRAY_SIZE(algs)); +} + +static void __exit ppc_spe_sha256_mod_fini(void) +{ + crypto_unregister_shashes(algs, ARRAY_SIZE(algs)); +} + +module_init(ppc_spe_sha256_mod_init); +module_exit(ppc_spe_sha256_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized"); + +MODULE_ALIAS_CRYPTO("sha224"); +MODULE_ALIAS_CRYPTO("sha224-ppc-spe"); +MODULE_ALIAS_CRYPTO("sha256"); +MODULE_ALIAS_CRYPTO("sha256-ppc-spe"); |