| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * 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> |
| */ |
| |
| #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> |
| #include <crypto/xts.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 chosen 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) |
| { |
| disable_kernel_spe(); |
| /* 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); |
| int err; |
| |
| err = xts_check_key(tfm, in_key, key_len); |
| if (err) |
| return err; |
| |
| 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"); |