523 lines
14 KiB
C
523 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Glue code for AES implementation for SPE instructions (PPC)
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*
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* Based on generic implementation. The assembler module takes care
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* about the SPE registers so it can run from interrupt context.
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*
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* Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
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*/
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#include <crypto/aes.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/crypto.h>
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#include <asm/byteorder.h>
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#include <asm/switch_to.h>
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#include <crypto/algapi.h>
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#include <crypto/internal/skcipher.h>
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#include <crypto/xts.h>
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#include <crypto/gf128mul.h>
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#include <crypto/scatterwalk.h>
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/*
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* MAX_BYTES defines the number of bytes that are allowed to be processed
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* between preempt_disable() and preempt_enable(). e500 cores can issue two
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* instructions per clock cycle using one 32/64 bit unit (SU1) and one 32
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* bit unit (SU2). One of these can be a memory access that is executed via
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* a single load and store unit (LSU). XTS-AES-256 takes ~780 operations per
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* 16 byte block or 25 cycles per byte. Thus 768 bytes of input data
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* will need an estimated maximum of 20,000 cycles. Headroom for cache misses
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* included. Even with the low end model clocked at 667 MHz this equals to a
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* critical time window of less than 30us. The value has been chosen to
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* process a 512 byte disk block in one or a large 1400 bytes IPsec network
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* packet in two runs.
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*
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*/
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#define MAX_BYTES 768
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struct ppc_aes_ctx {
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u32 key_enc[AES_MAX_KEYLENGTH_U32];
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u32 key_dec[AES_MAX_KEYLENGTH_U32];
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u32 rounds;
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};
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struct ppc_xts_ctx {
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u32 key_enc[AES_MAX_KEYLENGTH_U32];
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u32 key_dec[AES_MAX_KEYLENGTH_U32];
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u32 key_twk[AES_MAX_KEYLENGTH_U32];
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u32 rounds;
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};
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extern void ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc, u32 rounds);
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extern void ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec, u32 rounds);
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extern void ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
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u32 bytes);
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extern void ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
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u32 bytes);
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extern void ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
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u32 bytes, u8 *iv);
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extern void ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
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u32 bytes, u8 *iv);
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extern void ppc_crypt_ctr (u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
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u32 bytes, u8 *iv);
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extern void ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc, u32 rounds,
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u32 bytes, u8 *iv, u32 *key_twk);
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extern void ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec, u32 rounds,
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u32 bytes, u8 *iv, u32 *key_twk);
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extern void ppc_expand_key_128(u32 *key_enc, const u8 *key);
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extern void ppc_expand_key_192(u32 *key_enc, const u8 *key);
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extern void ppc_expand_key_256(u32 *key_enc, const u8 *key);
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extern void ppc_generate_decrypt_key(u32 *key_dec,u32 *key_enc,
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unsigned int key_len);
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static void spe_begin(void)
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{
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/* disable preemption and save users SPE registers if required */
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preempt_disable();
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enable_kernel_spe();
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}
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static void spe_end(void)
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{
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disable_kernel_spe();
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/* reenable preemption */
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preempt_enable();
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}
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static int ppc_aes_setkey(struct crypto_tfm *tfm, const u8 *in_key,
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unsigned int key_len)
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{
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struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
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switch (key_len) {
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case AES_KEYSIZE_128:
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ctx->rounds = 4;
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ppc_expand_key_128(ctx->key_enc, in_key);
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break;
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case AES_KEYSIZE_192:
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ctx->rounds = 5;
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ppc_expand_key_192(ctx->key_enc, in_key);
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break;
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case AES_KEYSIZE_256:
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ctx->rounds = 6;
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ppc_expand_key_256(ctx->key_enc, in_key);
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break;
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default:
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return -EINVAL;
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}
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ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
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return 0;
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}
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static int ppc_aes_setkey_skcipher(struct crypto_skcipher *tfm,
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const u8 *in_key, unsigned int key_len)
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{
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return ppc_aes_setkey(crypto_skcipher_tfm(tfm), in_key, key_len);
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}
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static int ppc_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
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unsigned int key_len)
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{
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struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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int err;
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err = xts_verify_key(tfm, in_key, key_len);
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if (err)
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return err;
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key_len >>= 1;
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switch (key_len) {
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case AES_KEYSIZE_128:
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ctx->rounds = 4;
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ppc_expand_key_128(ctx->key_enc, in_key);
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ppc_expand_key_128(ctx->key_twk, in_key + AES_KEYSIZE_128);
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break;
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case AES_KEYSIZE_192:
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ctx->rounds = 5;
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ppc_expand_key_192(ctx->key_enc, in_key);
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ppc_expand_key_192(ctx->key_twk, in_key + AES_KEYSIZE_192);
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break;
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case AES_KEYSIZE_256:
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ctx->rounds = 6;
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ppc_expand_key_256(ctx->key_enc, in_key);
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ppc_expand_key_256(ctx->key_twk, in_key + AES_KEYSIZE_256);
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break;
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default:
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return -EINVAL;
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}
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ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
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return 0;
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}
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static void ppc_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
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{
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struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
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spe_begin();
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ppc_encrypt_aes(out, in, ctx->key_enc, ctx->rounds);
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spe_end();
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}
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static void ppc_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
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{
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struct ppc_aes_ctx *ctx = crypto_tfm_ctx(tfm);
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spe_begin();
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ppc_decrypt_aes(out, in, ctx->key_dec, ctx->rounds);
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spe_end();
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}
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static int ppc_ecb_crypt(struct skcipher_request *req, bool enc)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct ppc_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
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struct skcipher_walk walk;
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unsigned int nbytes;
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int err;
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err = skcipher_walk_virt(&walk, req, false);
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while ((nbytes = walk.nbytes) != 0) {
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nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
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nbytes = round_down(nbytes, AES_BLOCK_SIZE);
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spe_begin();
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if (enc)
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ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_enc, ctx->rounds, nbytes);
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else
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ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_dec, ctx->rounds, nbytes);
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spe_end();
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err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
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}
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return err;
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}
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static int ppc_ecb_encrypt(struct skcipher_request *req)
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{
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return ppc_ecb_crypt(req, true);
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}
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static int ppc_ecb_decrypt(struct skcipher_request *req)
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{
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return ppc_ecb_crypt(req, false);
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}
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static int ppc_cbc_crypt(struct skcipher_request *req, bool enc)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct ppc_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
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struct skcipher_walk walk;
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unsigned int nbytes;
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int err;
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err = skcipher_walk_virt(&walk, req, false);
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while ((nbytes = walk.nbytes) != 0) {
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nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
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nbytes = round_down(nbytes, AES_BLOCK_SIZE);
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spe_begin();
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if (enc)
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ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_enc, ctx->rounds, nbytes,
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walk.iv);
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else
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ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_dec, ctx->rounds, nbytes,
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walk.iv);
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spe_end();
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err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
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}
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return err;
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}
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static int ppc_cbc_encrypt(struct skcipher_request *req)
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{
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return ppc_cbc_crypt(req, true);
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}
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static int ppc_cbc_decrypt(struct skcipher_request *req)
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{
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return ppc_cbc_crypt(req, false);
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}
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static int ppc_ctr_crypt(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct ppc_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
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struct skcipher_walk walk;
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unsigned int nbytes;
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int err;
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err = skcipher_walk_virt(&walk, req, false);
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while ((nbytes = walk.nbytes) != 0) {
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nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
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if (nbytes < walk.total)
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nbytes = round_down(nbytes, AES_BLOCK_SIZE);
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spe_begin();
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ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_enc, ctx->rounds, nbytes, walk.iv);
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spe_end();
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err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
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}
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return err;
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}
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static int ppc_xts_crypt(struct skcipher_request *req, bool enc)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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struct skcipher_walk walk;
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unsigned int nbytes;
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int err;
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u32 *twk;
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err = skcipher_walk_virt(&walk, req, false);
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twk = ctx->key_twk;
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while ((nbytes = walk.nbytes) != 0) {
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nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
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nbytes = round_down(nbytes, AES_BLOCK_SIZE);
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spe_begin();
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if (enc)
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ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_enc, ctx->rounds, nbytes,
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walk.iv, twk);
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else
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ppc_decrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
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ctx->key_dec, ctx->rounds, nbytes,
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walk.iv, twk);
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spe_end();
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twk = NULL;
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err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
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}
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return err;
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}
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static int ppc_xts_encrypt(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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int tail = req->cryptlen % AES_BLOCK_SIZE;
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int offset = req->cryptlen - tail - AES_BLOCK_SIZE;
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struct skcipher_request subreq;
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u8 b[2][AES_BLOCK_SIZE];
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int err;
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if (req->cryptlen < AES_BLOCK_SIZE)
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return -EINVAL;
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if (tail) {
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subreq = *req;
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skcipher_request_set_crypt(&subreq, req->src, req->dst,
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req->cryptlen - tail, req->iv);
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req = &subreq;
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}
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err = ppc_xts_crypt(req, true);
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if (err || !tail)
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return err;
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scatterwalk_map_and_copy(b[0], req->dst, offset, AES_BLOCK_SIZE, 0);
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memcpy(b[1], b[0], tail);
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scatterwalk_map_and_copy(b[0], req->src, offset + AES_BLOCK_SIZE, tail, 0);
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spe_begin();
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ppc_encrypt_xts(b[0], b[0], ctx->key_enc, ctx->rounds, AES_BLOCK_SIZE,
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req->iv, NULL);
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spe_end();
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scatterwalk_map_and_copy(b[0], req->dst, offset, AES_BLOCK_SIZE + tail, 1);
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return 0;
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}
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static int ppc_xts_decrypt(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
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int tail = req->cryptlen % AES_BLOCK_SIZE;
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int offset = req->cryptlen - tail - AES_BLOCK_SIZE;
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struct skcipher_request subreq;
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u8 b[3][AES_BLOCK_SIZE];
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le128 twk;
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int err;
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if (req->cryptlen < AES_BLOCK_SIZE)
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return -EINVAL;
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if (tail) {
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subreq = *req;
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skcipher_request_set_crypt(&subreq, req->src, req->dst,
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offset, req->iv);
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req = &subreq;
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}
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err = ppc_xts_crypt(req, false);
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if (err || !tail)
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return err;
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scatterwalk_map_and_copy(b[1], req->src, offset, AES_BLOCK_SIZE + tail, 0);
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spe_begin();
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if (!offset)
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ppc_encrypt_ecb(req->iv, req->iv, ctx->key_twk, ctx->rounds,
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AES_BLOCK_SIZE);
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gf128mul_x_ble(&twk, (le128 *)req->iv);
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ppc_decrypt_xts(b[1], b[1], ctx->key_dec, ctx->rounds, AES_BLOCK_SIZE,
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(u8 *)&twk, NULL);
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memcpy(b[0], b[2], tail);
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memcpy(b[0] + tail, b[1] + tail, AES_BLOCK_SIZE - tail);
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ppc_decrypt_xts(b[0], b[0], ctx->key_dec, ctx->rounds, AES_BLOCK_SIZE,
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req->iv, NULL);
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spe_end();
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scatterwalk_map_and_copy(b[0], req->dst, offset, AES_BLOCK_SIZE + tail, 1);
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return 0;
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}
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/*
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* Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
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* because the e500 platform can handle unaligned reads/writes very efficiently.
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* This improves IPsec thoughput by another few percent. Additionally we assume
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* that AES context is always aligned to at least 8 bytes because it is created
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* with kmalloc() in the crypto infrastructure
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*/
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static struct crypto_alg aes_cipher_alg = {
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.cra_name = "aes",
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.cra_driver_name = "aes-ppc-spe",
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.cra_priority = 300,
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.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
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.cra_blocksize = AES_BLOCK_SIZE,
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.cra_ctxsize = sizeof(struct ppc_aes_ctx),
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.cra_alignmask = 0,
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.cra_module = THIS_MODULE,
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.cra_u = {
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.cipher = {
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.cia_min_keysize = AES_MIN_KEY_SIZE,
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.cia_max_keysize = AES_MAX_KEY_SIZE,
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.cia_setkey = ppc_aes_setkey,
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.cia_encrypt = ppc_aes_encrypt,
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.cia_decrypt = ppc_aes_decrypt
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}
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}
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};
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static struct skcipher_alg aes_skcipher_algs[] = {
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{
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.base.cra_name = "ecb(aes)",
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.base.cra_driver_name = "ecb-ppc-spe",
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.base.cra_priority = 300,
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.base.cra_blocksize = AES_BLOCK_SIZE,
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.base.cra_ctxsize = sizeof(struct ppc_aes_ctx),
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.base.cra_module = THIS_MODULE,
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.min_keysize = AES_MIN_KEY_SIZE,
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.max_keysize = AES_MAX_KEY_SIZE,
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.setkey = ppc_aes_setkey_skcipher,
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.encrypt = ppc_ecb_encrypt,
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.decrypt = ppc_ecb_decrypt,
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}, {
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.base.cra_name = "cbc(aes)",
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.base.cra_driver_name = "cbc-ppc-spe",
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.base.cra_priority = 300,
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.base.cra_blocksize = AES_BLOCK_SIZE,
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.base.cra_ctxsize = sizeof(struct ppc_aes_ctx),
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.base.cra_module = THIS_MODULE,
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.min_keysize = AES_MIN_KEY_SIZE,
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.max_keysize = AES_MAX_KEY_SIZE,
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.ivsize = AES_BLOCK_SIZE,
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.setkey = ppc_aes_setkey_skcipher,
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.encrypt = ppc_cbc_encrypt,
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.decrypt = ppc_cbc_decrypt,
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}, {
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.base.cra_name = "ctr(aes)",
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.base.cra_driver_name = "ctr-ppc-spe",
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.base.cra_priority = 300,
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.base.cra_blocksize = 1,
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.base.cra_ctxsize = sizeof(struct ppc_aes_ctx),
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.base.cra_module = THIS_MODULE,
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.min_keysize = AES_MIN_KEY_SIZE,
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.max_keysize = AES_MAX_KEY_SIZE,
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.ivsize = AES_BLOCK_SIZE,
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.setkey = ppc_aes_setkey_skcipher,
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.encrypt = ppc_ctr_crypt,
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.decrypt = ppc_ctr_crypt,
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.chunksize = AES_BLOCK_SIZE,
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}, {
|
|
.base.cra_name = "xts(aes)",
|
|
.base.cra_driver_name = "xts-ppc-spe",
|
|
.base.cra_priority = 300,
|
|
.base.cra_blocksize = AES_BLOCK_SIZE,
|
|
.base.cra_ctxsize = sizeof(struct ppc_xts_ctx),
|
|
.base.cra_module = THIS_MODULE,
|
|
.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)
|
|
{
|
|
int err;
|
|
|
|
err = crypto_register_alg(&aes_cipher_alg);
|
|
if (err)
|
|
return err;
|
|
|
|
err = crypto_register_skciphers(aes_skcipher_algs,
|
|
ARRAY_SIZE(aes_skcipher_algs));
|
|
if (err)
|
|
crypto_unregister_alg(&aes_cipher_alg);
|
|
return err;
|
|
}
|
|
|
|
static void __exit ppc_aes_mod_fini(void)
|
|
{
|
|
crypto_unregister_alg(&aes_cipher_alg);
|
|
crypto_unregister_skciphers(aes_skcipher_algs,
|
|
ARRAY_SIZE(aes_skcipher_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");
|