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-rw-r--r--arch/powerpc/crypto/aes-spe-glue.c522
1 files changed, 522 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/aes-spe-glue.c b/arch/powerpc/crypto/aes-spe-glue.c
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index 0000000000..efab78a3a8
--- /dev/null
+++ b/arch/powerpc/crypto/aes-spe-glue.c
@@ -0,0 +1,522 @@
+// 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/internal/skcipher.h>
+#include <crypto/xts.h>
+#include <crypto/gf128mul.h>
+#include <crypto/scatterwalk.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 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);
+
+ 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;
+ default:
+ return -EINVAL;
+ }
+
+ ppc_generate_decrypt_key(ctx->key_dec, ctx->key_enc, key_len);
+
+ return 0;
+}
+
+static int ppc_aes_setkey_skcipher(struct crypto_skcipher *tfm,
+ const u8 *in_key, unsigned int key_len)
+{
+ return ppc_aes_setkey(crypto_skcipher_tfm(tfm), in_key, key_len);
+}
+
+static int ppc_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
+ int err;
+
+ err = xts_verify_key(tfm, in_key, key_len);
+ if (err)
+ return err;
+
+ key_len >>= 1;
+
+ 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;
+ default:
+ return -EINVAL;
+ }
+
+ 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_crypt(struct skcipher_request *req, bool enc)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ppc_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct skcipher_walk walk;
+ unsigned int nbytes;
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+
+ while ((nbytes = walk.nbytes) != 0) {
+ nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
+ nbytes = round_down(nbytes, AES_BLOCK_SIZE);
+
+ spe_begin();
+ if (enc)
+ ppc_encrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_enc, ctx->rounds, nbytes);
+ else
+ ppc_decrypt_ecb(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_dec, ctx->rounds, nbytes);
+ spe_end();
+
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+ return err;
+}
+
+static int ppc_ecb_encrypt(struct skcipher_request *req)
+{
+ return ppc_ecb_crypt(req, true);
+}
+
+static int ppc_ecb_decrypt(struct skcipher_request *req)
+{
+ return ppc_ecb_crypt(req, false);
+}
+
+static int ppc_cbc_crypt(struct skcipher_request *req, bool enc)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ppc_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct skcipher_walk walk;
+ unsigned int nbytes;
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+
+ while ((nbytes = walk.nbytes) != 0) {
+ nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
+ nbytes = round_down(nbytes, AES_BLOCK_SIZE);
+
+ spe_begin();
+ if (enc)
+ ppc_encrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_enc, ctx->rounds, nbytes,
+ walk.iv);
+ else
+ ppc_decrypt_cbc(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_dec, ctx->rounds, nbytes,
+ walk.iv);
+ spe_end();
+
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+ return err;
+}
+
+static int ppc_cbc_encrypt(struct skcipher_request *req)
+{
+ return ppc_cbc_crypt(req, true);
+}
+
+static int ppc_cbc_decrypt(struct skcipher_request *req)
+{
+ return ppc_cbc_crypt(req, false);
+}
+
+static int ppc_ctr_crypt(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ppc_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct skcipher_walk walk;
+ unsigned int nbytes;
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+
+ while ((nbytes = walk.nbytes) != 0) {
+ nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
+ if (nbytes < walk.total)
+ nbytes = round_down(nbytes, AES_BLOCK_SIZE);
+
+ spe_begin();
+ ppc_crypt_ctr(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_enc, ctx->rounds, nbytes, walk.iv);
+ spe_end();
+
+ err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+ return err;
+}
+
+static int ppc_xts_crypt(struct skcipher_request *req, bool enc)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct skcipher_walk walk;
+ unsigned int nbytes;
+ int err;
+ u32 *twk;
+
+ err = skcipher_walk_virt(&walk, req, false);
+ twk = ctx->key_twk;
+
+ while ((nbytes = walk.nbytes) != 0) {
+ nbytes = min_t(unsigned int, nbytes, MAX_BYTES);
+ nbytes = round_down(nbytes, AES_BLOCK_SIZE);
+
+ spe_begin();
+ if (enc)
+ ppc_encrypt_xts(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_enc, ctx->rounds, nbytes,
+ walk.iv, twk);
+ else
+ 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 = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+ }
+
+ return err;
+}
+
+static int ppc_xts_encrypt(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
+ int tail = req->cryptlen % AES_BLOCK_SIZE;
+ int offset = req->cryptlen - tail - AES_BLOCK_SIZE;
+ struct skcipher_request subreq;
+ u8 b[2][AES_BLOCK_SIZE];
+ int err;
+
+ if (req->cryptlen < AES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (tail) {
+ subreq = *req;
+ skcipher_request_set_crypt(&subreq, req->src, req->dst,
+ req->cryptlen - tail, req->iv);
+ req = &subreq;
+ }
+
+ err = ppc_xts_crypt(req, true);
+ if (err || !tail)
+ return err;
+
+ scatterwalk_map_and_copy(b[0], req->dst, offset, AES_BLOCK_SIZE, 0);
+ memcpy(b[1], b[0], tail);
+ scatterwalk_map_and_copy(b[0], req->src, offset + AES_BLOCK_SIZE, tail, 0);
+
+ spe_begin();
+ ppc_encrypt_xts(b[0], b[0], ctx->key_enc, ctx->rounds, AES_BLOCK_SIZE,
+ req->iv, NULL);
+ spe_end();
+
+ scatterwalk_map_and_copy(b[0], req->dst, offset, AES_BLOCK_SIZE + tail, 1);
+
+ return 0;
+}
+
+static int ppc_xts_decrypt(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ppc_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
+ int tail = req->cryptlen % AES_BLOCK_SIZE;
+ int offset = req->cryptlen - tail - AES_BLOCK_SIZE;
+ struct skcipher_request subreq;
+ u8 b[3][AES_BLOCK_SIZE];
+ le128 twk;
+ int err;
+
+ if (req->cryptlen < AES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (tail) {
+ subreq = *req;
+ skcipher_request_set_crypt(&subreq, req->src, req->dst,
+ offset, req->iv);
+ req = &subreq;
+ }
+
+ err = ppc_xts_crypt(req, false);
+ if (err || !tail)
+ return err;
+
+ scatterwalk_map_and_copy(b[1], req->src, offset, AES_BLOCK_SIZE + tail, 0);
+
+ spe_begin();
+ if (!offset)
+ ppc_encrypt_ecb(req->iv, req->iv, ctx->key_twk, ctx->rounds,
+ AES_BLOCK_SIZE);
+
+ gf128mul_x_ble(&twk, (le128 *)req->iv);
+
+ ppc_decrypt_xts(b[1], b[1], ctx->key_dec, ctx->rounds, AES_BLOCK_SIZE,
+ (u8 *)&twk, NULL);
+ memcpy(b[0], b[2], tail);
+ memcpy(b[0] + tail, b[1] + tail, AES_BLOCK_SIZE - tail);
+ ppc_decrypt_xts(b[0], b[0], ctx->key_dec, ctx->rounds, AES_BLOCK_SIZE,
+ req->iv, NULL);
+ spe_end();
+
+ scatterwalk_map_and_copy(b[0], req->dst, offset, AES_BLOCK_SIZE + tail, 1);
+
+ return 0;
+}
+
+/*
+ * Algorithm definitions. Disabling alignment (cra_alignmask=0) was chosen
+ * because the e500 platform can handle unaligned reads/writes very efficiently.
+ * 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_cipher_alg = {
+ .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
+ }
+ }
+};
+
+static struct skcipher_alg aes_skcipher_algs[] = {
+ {
+ .base.cra_name = "ecb(aes)",
+ .base.cra_driver_name = "ecb-ppc-spe",
+ .base.cra_priority = 300,
+ .base.cra_blocksize = AES_BLOCK_SIZE,
+ .base.cra_ctxsize = sizeof(struct ppc_aes_ctx),
+ .base.cra_module = THIS_MODULE,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .setkey = ppc_aes_setkey_skcipher,
+ .encrypt = ppc_ecb_encrypt,
+ .decrypt = ppc_ecb_decrypt,
+ }, {
+ .base.cra_name = "cbc(aes)",
+ .base.cra_driver_name = "cbc-ppc-spe",
+ .base.cra_priority = 300,
+ .base.cra_blocksize = AES_BLOCK_SIZE,
+ .base.cra_ctxsize = sizeof(struct ppc_aes_ctx),
+ .base.cra_module = THIS_MODULE,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ppc_aes_setkey_skcipher,
+ .encrypt = ppc_cbc_encrypt,
+ .decrypt = ppc_cbc_decrypt,
+ }, {
+ .base.cra_name = "ctr(aes)",
+ .base.cra_driver_name = "ctr-ppc-spe",
+ .base.cra_priority = 300,
+ .base.cra_blocksize = 1,
+ .base.cra_ctxsize = sizeof(struct ppc_aes_ctx),
+ .base.cra_module = THIS_MODULE,
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = ppc_aes_setkey_skcipher,
+ .encrypt = ppc_ctr_crypt,
+ .decrypt = ppc_ctr_crypt,
+ .chunksize = AES_BLOCK_SIZE,
+ }, {
+ .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");