diff options
| -rw-r--r-- | arch/powerpc/crypto/aes_spe_glue.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/aes_spe_glue.c b/arch/powerpc/crypto/aes_spe_glue.c new file mode 100644 index 000000000000..bd5e63f72ad4 --- /dev/null +++ b/arch/powerpc/crypto/aes_spe_glue.c @@ -0,0 +1,512 @@ +/* + * Glue code for AES 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/aes.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/crypto.h> +#include <asm/byteorder.h> +#include <asm/switch_to.h> +#include <crypto/algapi.h> + +/* + * MAX_BYTES defines the number of bytes that are allowed to be processed + * between preempt_disable() and preempt_enable(). e500 cores can issue two + * instructions per clock cycle using one 32/64 bit unit (SU1) and one 32 + * bit unit (SU2). One of these can be a memory access that is executed via + * a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per + * 16 byte block block or 25 cycles per byte. Thus 768 bytes of input data + * will need an estimated maximum of 20,000 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 30us. The value has been choosen to + * process a 512 byte disk block in one or a large 1400 bytes IPsec network + * packet in two runs. + * + */ +#define MAX_BYTES 768 + +struct ppc_aes_ctx { + u32 key_enc[AES_MAX_KEYLENGTH_U32]; + u32 key_dec[AES_MAX_KEYLENGTH_U32]; + u32 rounds; +}; + +struct ppc_xts_ctx { + u32 key_enc[AES_MAX_KEYLENGTH_U32]; + u32 key_dec[AES_MAX_KEYLENGTH_U32]; + u32 key_twk[AES_MAX_KEYLENGTH_U32]; + u32 rounds; +}; + +extern void ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc, u32 rounds); +extern void ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec, u32 rounds); +extern void ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc, u32 rounds, + u32 bytes); +extern void ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec, u32 rounds, + u32 bytes); +extern void ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc, u32 rounds, + u32 bytes, u8 *iv); +extern void ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec, u32 rounds, + u32 bytes, u8 *iv); +extern void ppc_crypt_ctr (u8 *out, const u8 *in, u32 *key_enc, u32 rounds, + u32 bytes, u8 *iv); +extern void ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc, u32 rounds, + u32 bytes, u8 *iv, u32 *key_twk); +extern void ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec, u32 rounds, + u32 bytes, u8 *iv, u32 *key_twk); + +extern void ppc_expand_key_128(u32 *key_enc, const u8 *key); +extern void ppc_expand_key_192(u32 *key_enc, const u8 *key); +extern void ppc_expand_key_256(u32 *key_enc, const u8 *key); + +extern void ppc_generate_decrypt_key(u32 *key_dec,u32 *key_enc, + unsigned int key_len); + +static void spe_begin(void) +{ + /* disable preemption and save users SPE registers if required */ + preempt_disable(); + enable_kernel_spe(); +} + +static void spe_end(void) +{ + /* reenable preemption */ + preempt_enable(); +} + +static int ppc_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm); + + if (key_len != AES_KEYSIZE_128 && + key_len != AES_KEYSIZE_192 && + key_len != AES_KEYSIZE_256) { + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + switch (key_len) { + case AES_KEYSIZE_128: + ctx->rounds = 4; + ppc_expand_key_128(ctx->key_enc, in_key); + break; + case AES_KEYSIZE_192: + ctx->rounds = 5; + ppc_expand_key_192(ctx->key_enc, in_key); + break; + case AES_KEYSIZE_256: + ctx->rounds = 6; + ppc_expand_key_256(ctx->key_enc, in_key); + break; + } + + ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len); + + return 0; +} + +static int ppc_xts_setkey(struct crypto_tfm *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct ppc_xts_ctx *ctx = crypto_tfm_ctx(tfm); + + key_len >>= 1; + + if (key_len != AES_KEYSIZE_128 && + key_len != AES_KEYSIZE_192 && + key_len != AES_KEYSIZE_256) { + tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; + return -EINVAL; + } + + switch (key_len) { + case AES_KEYSIZE_128: + ctx->rounds = 4; + ppc_expand_key_128(ctx->key_enc, in_key); + ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128); + break; + case AES_KEYSIZE_192: + ctx->rounds = 5; + ppc_expand_key_192(ctx->key_enc, in_key); + ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192); + break; + case AES_KEYSIZE_256: + ctx->rounds = 6; + ppc_expand_key_256(ctx->key_enc, in_key); + ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256); + break; + } + + ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len); + + return 0; +} + +static void ppc_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ + struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm); + + spe_begin(); + ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds); + spe_end(); +} + +static void ppc_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ + struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm); + + spe_begin(); + ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds); + spe_end(); +} + +static int ppc_ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int ubytes; + int err; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + + while ((nbytes = walk.nbytes)) { + ubytes = nbytes > MAX_BYTES ? + nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1); + nbytes -= ubytes; + + spe_begin(); + ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_enc, ctx->rounds, nbytes); + spe_end(); + + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +static int ppc_ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int ubytes; + int err; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + + while ((nbytes = walk.nbytes)) { + ubytes = nbytes > MAX_BYTES ? + nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1); + nbytes -= ubytes; + + spe_begin(); + ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_dec, ctx->rounds, nbytes); + spe_end(); + + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +static int ppc_cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int ubytes; + int err; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + + while ((nbytes = walk.nbytes)) { + ubytes = nbytes > MAX_BYTES ? + nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1); + nbytes -= ubytes; + + spe_begin(); + ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_enc, ctx->rounds, nbytes, walk.iv); + spe_end(); + + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +static int ppc_cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int ubytes; + int err; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + + while ((nbytes = walk.nbytes)) { + ubytes = nbytes > MAX_BYTES ? + nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1); + nbytes -= ubytes; + + spe_begin(); + ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_dec, ctx->rounds, nbytes, walk.iv); + spe_end(); + + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +static int ppc_ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_aes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int pbytes, ubytes; + int err; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE); + + while ((pbytes = walk.nbytes)) { + pbytes = pbytes > MAX_BYTES ? MAX_BYTES : pbytes; + pbytes = pbytes == nbytes ? + nbytes : pbytes & ~(AES_BLOCK_SIZE - 1); + ubytes = walk.nbytes - pbytes; + + spe_begin(); + ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_enc, ctx->rounds, pbytes , walk.iv); + spe_end(); + + nbytes -= pbytes; + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +static int ppc_xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int ubytes; + int err; + u32 *twk; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + twk = ctx->key_twk; + + while ((nbytes = walk.nbytes)) { + ubytes = nbytes > MAX_BYTES ? + nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1); + nbytes -= ubytes; + + spe_begin(); + ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_enc, ctx->rounds, nbytes, walk.iv, twk); + spe_end(); + + twk = NULL; + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +static int ppc_xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct ppc_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm); + struct blkcipher_walk walk; + unsigned int ubytes; + int err; + u32 *twk; + + desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP; + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt(desc, &walk); + twk = ctx->key_twk; + + while ((nbytes = walk.nbytes)) { + ubytes = nbytes > MAX_BYTES ? + nbytes - MAX_BYTES : nbytes & (AES_BLOCK_SIZE - 1); + nbytes -= ubytes; + + spe_begin(); + ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr, + ctx->key_dec, ctx->rounds, nbytes, walk.iv, twk); + spe_end(); + + twk = NULL; + err = blkcipher_walk_done(desc, &walk, ubytes); + } + + return err; +} + +/* + * Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen + * because the e500 platform can handle unaligned reads/writes very efficently. + * This improves IPsec thoughput by another few percent. Additionally we assume + * that AES context is always aligned to at least 8 bytes because it is created + * with kmalloc() in the crypto infrastructure + * + */ +static struct crypto_alg aes_algs[] = { { + .cra_name = "aes", + .cra_driver_name = "aes-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct ppc_aes_ctx), + .cra_alignmask = 0, + .cra_module = THIS_MODULE, + .cra_u = { + .cipher = { + .cia_min_keysize = AES_MIN_KEY_SIZE, + .cia_max_keysize = AES_MAX_KEY_SIZE, + .cia_setkey = ppc_aes_setkey, + .cia_encrypt = ppc_aes_encrypt, + .cia_decrypt = ppc_aes_decrypt + } + } +}, { + .cra_name = "ecb(aes)", + .cra_driver_name = "ecb-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct ppc_aes_ctx), + .cra_alignmask = 0, + .cra_type = &crypto_blkcipher_type, + .cra_module = THIS_MODULE, + .cra_u = { + .blkcipher = { + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = ppc_aes_setkey, + .encrypt = ppc_ecb_encrypt, + .decrypt = ppc_ecb_decrypt, + } + } +}, { + .cra_name = "cbc(aes)", + .cra_driver_name = "cbc-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct ppc_aes_ctx), + .cra_alignmask = 0, + .cra_type = &crypto_blkcipher_type, + .cra_module = THIS_MODULE, + .cra_u = { + .blkcipher = { + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = ppc_aes_setkey, + .encrypt = ppc_cbc_encrypt, + .decrypt = ppc_cbc_decrypt, + } + } +}, { + .cra_name = "ctr(aes)", + .cra_driver_name = "ctr-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, + .cra_blocksize = 1, + .cra_ctxsize = sizeof(struct ppc_aes_ctx), + .cra_alignmask = 0, + .cra_type = &crypto_blkcipher_type, + .cra_module = THIS_MODULE, + .cra_u = { + .blkcipher = { + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = ppc_aes_setkey, + .encrypt = ppc_ctr_crypt, + .decrypt = ppc_ctr_crypt, + } + } +}, { + .cra_name = "xts(aes)", + .cra_driver_name = "xts-ppc-spe", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct ppc_xts_ctx), + .cra_alignmask = 0, + .cra_type = &crypto_blkcipher_type, + .cra_module = THIS_MODULE, + .cra_u = { + .blkcipher = { + .min_keysize = AES_MIN_KEY_SIZE * 2, + .max_keysize = AES_MAX_KEY_SIZE * 2, + .ivsize = AES_BLOCK_SIZE, + .setkey = ppc_xts_setkey, + .encrypt = ppc_xts_encrypt, + .decrypt = ppc_xts_decrypt, + } + } +} }; + +static int __init ppc_aes_mod_init(void) +{ + return crypto_register_algs(aes_algs, ARRAY_SIZE(aes_algs)); +} + +static void __exit ppc_aes_mod_fini(void) +{ + crypto_unregister_algs(aes_algs, ARRAY_SIZE(aes_algs)); +} + +module_init(ppc_aes_mod_init); +module_exit(ppc_aes_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS, SPE optimized"); + +MODULE_ALIAS_CRYPTO("aes"); +MODULE_ALIAS_CRYPTO("ecb(aes)"); +MODULE_ALIAS_CRYPTO("cbc(aes)"); +MODULE_ALIAS_CRYPTO("ctr(aes)"); +MODULE_ALIAS_CRYPTO("xts(aes)"); +MODULE_ALIAS_CRYPTO("aes-ppc-spe"); |