diff options
Diffstat (limited to 'arch/powerpc/crypto/sha1-spe-glue.c')
| -rw-r--r-- | arch/powerpc/crypto/sha1-spe-glue.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/sha1-spe-glue.c b/arch/powerpc/crypto/sha1-spe-glue.c new file mode 100644 index 000000000000..3e1d22212521 --- /dev/null +++ b/arch/powerpc/crypto/sha1-spe-glue.c @@ -0,0 +1,210 @@ +/* + * Glue code for SHA-1 implementation for SPE instructions (PPC) + * + * Based on generic implementation. + * + * 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(). 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 + +extern void ppc_spe_sha1_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_sha1_clear_context(struct sha1_state *sctx) +{ + int count = sizeof(struct sha1_state) >> 2; + u32 *ptr = (u32 *)sctx; + + /* make sure we can clear the fast way */ + BUILD_BUG_ON(sizeof(struct sha1_state) % 4); + do { *ptr++ = 0; } while (--count); +} + +static int ppc_spe_sha1_init(struct shash_desc *desc) +{ + struct sha1_state *sctx = shash_desc_ctx(desc); + + sctx->state[0] = SHA1_H0; + sctx->state[1] = SHA1_H1; + sctx->state[2] = SHA1_H2; + sctx->state[3] = SHA1_H3; + sctx->state[4] = SHA1_H4; + sctx->count = 0; + + return 0; +} + +static int ppc_spe_sha1_update(struct shash_desc *desc, const u8 *data, + unsigned int len) +{ + struct sha1_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->buffer + offset, src, len); + return 0; + } + + sctx->count += len; + + if (offset) { + memcpy((char *)sctx->buffer + offset, src, avail); + + spe_begin(); + ppc_spe_sha1_transform(sctx->state, (const u8 *)sctx->buffer, 1); + spe_end(); + + len -= avail; + src += avail; + } + + while (len > 63) { + bytes = (len > MAX_BYTES) ? MAX_BYTES : len; + bytes = bytes & ~0x3f; + + spe_begin(); + ppc_spe_sha1_transform(sctx->state, src, bytes >> 6); + spe_end(); + + src += bytes; + len -= bytes; + }; + + memcpy((char *)sctx->buffer, src, len); + return 0; +} + +static int ppc_spe_sha1_final(struct shash_desc *desc, u8 *out) +{ + struct sha1_state *sctx = shash_desc_ctx(desc); + const unsigned int offset = sctx->count & 0x3f; + char *p = (char *)sctx->buffer + offset; + int padlen; + __be64 *pbits = (__be64 *)(((char *)&sctx->buffer) + 56); + __be32 *dst = (__be32 *)out; + + padlen = 55 - offset; + *p++ = 0x80; + + spe_begin(); + + if (padlen < 0) { + memset(p, 0x00, padlen + sizeof (u64)); + ppc_spe_sha1_transform(sctx->state, sctx->buffer, 1); + p = (char *)sctx->buffer; + padlen = 56; + } + + memset(p, 0, padlen); + *pbits = cpu_to_be64(sctx->count << 3); + ppc_spe_sha1_transform(sctx->state, sctx->buffer, 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]); + + ppc_sha1_clear_context(sctx); + return 0; +} + +static int ppc_spe_sha1_export(struct shash_desc *desc, void *out) +{ + struct sha1_state *sctx = shash_desc_ctx(desc); + + memcpy(out, sctx, sizeof(*sctx)); + return 0; +} + +static int ppc_spe_sha1_import(struct shash_desc *desc, const void *in) +{ + struct sha1_state *sctx = shash_desc_ctx(desc); + + memcpy(sctx, in, sizeof(*sctx)); + return 0; +} + +static struct shash_alg alg = { + .digestsize = SHA1_DIGEST_SIZE, + .init = ppc_spe_sha1_init, + .update = ppc_spe_sha1_update, + .final = ppc_spe_sha1_final, + .export = ppc_spe_sha1_export, + .import = ppc_spe_sha1_import, + .descsize = sizeof(struct sha1_state), + .statesize = sizeof(struct sha1_state), + .base = { + .cra_name = "sha1", + .cra_driver_name= "sha1-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_SHASH, + .cra_blocksize = SHA1_BLOCK_SIZE, + .cra_module = THIS_MODULE, + } +}; + +static int __init ppc_spe_sha1_mod_init(void) +{ + return crypto_register_shash(&alg); +} + +static void __exit ppc_spe_sha1_mod_fini(void) +{ + crypto_unregister_shash(&alg); +} + +module_init(ppc_spe_sha1_mod_init); +module_exit(ppc_spe_sha1_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm, SPE optimized"); + +MODULE_ALIAS_CRYPTO("sha1"); +MODULE_ALIAS_CRYPTO("sha1-ppc-spe"); |