1 files changed, 433 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/aes-gcm-p10-glue.c b/arch/powerpc/crypto/aes-gcm-p10-glue.c
new file mode 100644
index 000000000000..85f4fd4b1bdc
--- /dev/null
+++ b/arch/powerpc/crypto/aes-gcm-p10-glue.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Glue code for accelerated AES-GCM stitched implementation for ppc64le.
+ *
+ * Copyright 2022- IBM Inc. All rights reserved
+ */
+
+#include <linux/unaligned.h>
+#include <asm/simd.h>
+#include <asm/switch_to.h>
+#include <crypto/gcm.h>
+#include <crypto/aes.h>
+#include <crypto/algapi.h>
+#include <crypto/b128ops.h>
+#include <crypto/gf128mul.h>
+#include <crypto/internal/simd.h>
+#include <crypto/internal/aead.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+#include <linux/cpufeature.h>
+#include <linux/crypto.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#define	PPC_ALIGN		16
+#define GCM_IV_SIZE		12
+#define RFC4106_NONCE_SIZE	4
+
+MODULE_DESCRIPTION("PPC64le AES-GCM with Stitched implementation");
+MODULE_AUTHOR("Danny Tsen <dtsen@linux.ibm.com");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_CRYPTO("aes");
+
+asmlinkage int aes_p10_set_encrypt_key(const u8 *userKey, const int bits,
+				       void *key);
+asmlinkage void aes_p10_encrypt(const u8 *in, u8 *out, const void *key);
+asmlinkage void aes_p10_gcm_encrypt(const u8 *in, u8 *out, size_t len,
+				    void *rkey, u8 *iv, void *Xi);
+asmlinkage void aes_p10_gcm_decrypt(const u8 *in, u8 *out, size_t len,
+				    void *rkey, u8 *iv, void *Xi);
+asmlinkage void gcm_init_htable(unsigned char htable[], unsigned char Xi[]);
+asmlinkage void gcm_ghash_p10(unsigned char *Xi, unsigned char *Htable,
+			      unsigned char *aad, unsigned int alen);
+asmlinkage void gcm_update(u8 *iv, void *Xi);
+
+struct aes_key {
+	u8 key[AES_MAX_KEYLENGTH];
+	u64 rounds;
+};
+
+struct gcm_ctx {
+	u8 iv[16];
+	u8 ivtag[16];
+	u8 aad_hash[16];
+	u64 aadLen;
+	u64 Plen;	/* offset 56 - used in aes_p10_gcm_{en/de}crypt */
+	u8 pblock[16];
+};
+struct Hash_ctx {
+	u8 H[16];	/* subkey */
+	u8 Htable[256];	/* Xi, Hash table(offset 32) */
+};
+
+struct p10_aes_gcm_ctx {
+	struct aes_key enc_key;
+	u8 nonce[RFC4106_NONCE_SIZE];
+};
+
+static void vsx_begin(void)
+{
+	preempt_disable();
+	pagefault_disable();
+	enable_kernel_vsx();
+}
+
+static void vsx_end(void)
+{
+	disable_kernel_vsx();
+	pagefault_enable();
+	preempt_enable();
+}
+
+static void set_subkey(unsigned char *hash)
+{
+	*(u64 *)&hash[0] = be64_to_cpup((__be64 *)&hash[0]);
+	*(u64 *)&hash[8] = be64_to_cpup((__be64 *)&hash[8]);
+}
+
+/*
+ * Compute aad if any.
+ *   - Hash aad and copy to Xi.
+ */
+static void set_aad(struct gcm_ctx *gctx, struct Hash_ctx *hash,
+		    unsigned char *aad, int alen)
+{
+	int i;
+	u8 nXi[16] = {0, };
+
+	gctx->aadLen = alen;
+	i = alen & ~0xf;
+	if (i) {
+		gcm_ghash_p10(nXi, hash->Htable+32, aad, i);
+		aad += i;
+		alen -= i;
+	}
+	if (alen) {
+		for (i = 0; i < alen; i++)
+			nXi[i] ^= aad[i];
+
+		memset(gctx->aad_hash, 0, 16);
+		gcm_ghash_p10(gctx->aad_hash, hash->Htable+32, nXi, 16);
+	} else {
+		memcpy(gctx->aad_hash, nXi, 16);
+	}
+
+	memcpy(hash->Htable, gctx->aad_hash, 16);
+}
+
+static void gcmp10_init(struct gcm_ctx *gctx, u8 *iv, unsigned char *rdkey,
+			struct Hash_ctx *hash, u8 *assoc, unsigned int assoclen)
+{
+	__be32 counter = cpu_to_be32(1);
+
+	aes_p10_encrypt(hash->H, hash->H, rdkey);
+	set_subkey(hash->H);
+	gcm_init_htable(hash->Htable+32, hash->H);
+
+	*((__be32 *)(iv+12)) = counter;
+
+	gctx->Plen = 0;
+
+	/*
+	 * Encrypt counter vector as iv tag and increment counter.
+	 */
+	aes_p10_encrypt(iv, gctx->ivtag, rdkey);
+
+	counter = cpu_to_be32(2);
+	*((__be32 *)(iv+12)) = counter;
+	memcpy(gctx->iv, iv, 16);
+
+	gctx->aadLen = assoclen;
+	memset(gctx->aad_hash, 0, 16);
+	if (assoclen)
+		set_aad(gctx, hash, assoc, assoclen);
+}
+
+static void finish_tag(struct gcm_ctx *gctx, struct Hash_ctx *hash, int len)
+{
+	int i;
+	unsigned char len_ac[16 + PPC_ALIGN];
+	unsigned char *aclen = PTR_ALIGN((void *)len_ac, PPC_ALIGN);
+	__be64 clen = cpu_to_be64(len << 3);
+	__be64 alen = cpu_to_be64(gctx->aadLen << 3);
+
+	if (len == 0 && gctx->aadLen == 0) {
+		memcpy(hash->Htable, gctx->ivtag, 16);
+		return;
+	}
+
+	/*
+	 * Len is in bits.
+	 */
+	*((__be64 *)(aclen)) = alen;
+	*((__be64 *)(aclen+8)) = clen;
+
+	/*
+	 * hash (AAD len and len)
+	 */
+	gcm_ghash_p10(hash->Htable, hash->Htable+32, aclen, 16);
+
+	for (i = 0; i < 16; i++)
+		hash->Htable[i] ^= gctx->ivtag[i];
+}
+
+static int set_authsize(struct crypto_aead *tfm, unsigned int authsize)
+{
+	switch (authsize) {
+	case 4:
+	case 8:
+	case 12:
+	case 13:
+	case 14:
+	case 15:
+	case 16:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int p10_aes_gcm_setkey(struct crypto_aead *aead, const u8 *key,
+			      unsigned int keylen)
+{
+	struct crypto_tfm *tfm = crypto_aead_tfm(aead);
+	struct p10_aes_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
+	int ret;
+
+	vsx_begin();
+	ret = aes_p10_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
+	vsx_end();
+
+	return ret ? -EINVAL : 0;
+}
+
+static int p10_aes_gcm_crypt(struct aead_request *req, u8 *riv,
+			     int assoclen, int enc)
+{
+	struct crypto_tfm *tfm = req->base.tfm;
+	struct p10_aes_gcm_ctx *ctx = crypto_tfm_ctx(tfm);
+	u8 databuf[sizeof(struct gcm_ctx) + PPC_ALIGN];
+	struct gcm_ctx *gctx = PTR_ALIGN((void *)databuf, PPC_ALIGN);
+	u8 hashbuf[sizeof(struct Hash_ctx) + PPC_ALIGN];
+	struct Hash_ctx *hash = PTR_ALIGN((void *)hashbuf, PPC_ALIGN);
+	struct skcipher_walk walk;
+	u8 *assocmem = NULL;
+	u8 *assoc;
+	unsigned int cryptlen = req->cryptlen;
+	unsigned char ivbuf[AES_BLOCK_SIZE+PPC_ALIGN];
+	unsigned char *iv = PTR_ALIGN((void *)ivbuf, PPC_ALIGN);
+	int ret;
+	unsigned long auth_tag_len = crypto_aead_authsize(__crypto_aead_cast(tfm));
+	u8 otag[16];
+	int total_processed = 0;
+	int nbytes;
+
+	memset(databuf, 0, sizeof(databuf));
+	memset(hashbuf, 0, sizeof(hashbuf));
+	memset(ivbuf, 0, sizeof(ivbuf));
+	memcpy(iv, riv, GCM_IV_SIZE);
+
+	/* Linearize assoc, if not already linear */
+	if (req->src->length >= assoclen && req->src->length) {
+		assoc = sg_virt(req->src); /* ppc64 is !HIGHMEM */
+	} else {
+		gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
+			      GFP_KERNEL : GFP_ATOMIC;
+
+		/* assoc can be any length, so must be on heap */
+		assocmem = kmalloc(assoclen, flags);
+		if (unlikely(!assocmem))
+			return -ENOMEM;
+		assoc = assocmem;
+
+		scatterwalk_map_and_copy(assoc, req->src, 0, assoclen, 0);
+	}
+
+	vsx_begin();
+	gcmp10_init(gctx, iv, (unsigned char *) &ctx->enc_key, hash, assoc, assoclen);
+	vsx_end();
+
+	kfree(assocmem);
+
+	if (enc)
+		ret = skcipher_walk_aead_encrypt(&walk, req, false);
+	else
+		ret = skcipher_walk_aead_decrypt(&walk, req, false);
+	if (ret)
+		return ret;
+
+	while ((nbytes = walk.nbytes) > 0 && ret == 0) {
+		const u8 *src = walk.src.virt.addr;
+		u8 *dst = walk.dst.virt.addr;
+		u8 buf[AES_BLOCK_SIZE];
+
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
+			src = dst = memcpy(buf, src, nbytes);
+
+		vsx_begin();
+		if (enc)
+			aes_p10_gcm_encrypt(src, dst, nbytes,
+					    &ctx->enc_key, gctx->iv, hash->Htable);
+		else
+			aes_p10_gcm_decrypt(src, dst, nbytes,
+					    &ctx->enc_key, gctx->iv, hash->Htable);
+
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
+			memcpy(walk.dst.virt.addr, buf, nbytes);
+
+		vsx_end();
+
+		total_processed += walk.nbytes;
+		ret = skcipher_walk_done(&walk, 0);
+	}
+
+	if (ret)
+		return ret;
+
+	/* Finalize hash */
+	vsx_begin();
+	gcm_update(gctx->iv, hash->Htable);
+	finish_tag(gctx, hash, total_processed);
+	vsx_end();
+
+	/* copy Xi to end of dst */
+	if (enc)
+		scatterwalk_map_and_copy(hash->Htable, req->dst, req->assoclen + cryptlen,
+					 auth_tag_len, 1);
+	else {
+		scatterwalk_map_and_copy(otag, req->src,
+					 req->assoclen + cryptlen - auth_tag_len,
+					 auth_tag_len, 0);
+
+		if (crypto_memneq(otag, hash->Htable, auth_tag_len)) {
+			memzero_explicit(hash->Htable, 16);
+			return -EBADMSG;
+		}
+	}
+
+	return 0;
+}
+
+static int rfc4106_setkey(struct crypto_aead *tfm, const u8 *inkey,
+			  unsigned int keylen)
+{
+	struct p10_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
+	int err;
+
+	keylen -= RFC4106_NONCE_SIZE;
+	err = p10_aes_gcm_setkey(tfm, inkey, keylen);
+	if (err)
+		return err;
+
+	memcpy(ctx->nonce, inkey + keylen, RFC4106_NONCE_SIZE);
+	return 0;
+}
+
+static int rfc4106_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
+{
+	return crypto_rfc4106_check_authsize(authsize);
+}
+
+static int rfc4106_encrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct p10_aes_gcm_ctx *ctx = crypto_aead_ctx(aead);
+	u8 iv[AES_BLOCK_SIZE];
+
+	memcpy(iv, ctx->nonce, RFC4106_NONCE_SIZE);
+	memcpy(iv + RFC4106_NONCE_SIZE, req->iv, GCM_RFC4106_IV_SIZE);
+
+	return crypto_ipsec_check_assoclen(req->assoclen) ?:
+	       p10_aes_gcm_crypt(req, iv, req->assoclen - GCM_RFC4106_IV_SIZE, 1);
+}
+
+static int rfc4106_decrypt(struct aead_request *req)
+{
+	struct crypto_aead *aead = crypto_aead_reqtfm(req);
+	struct p10_aes_gcm_ctx *ctx = crypto_aead_ctx(aead);
+	u8 iv[AES_BLOCK_SIZE];
+
+	memcpy(iv, ctx->nonce, RFC4106_NONCE_SIZE);
+	memcpy(iv + RFC4106_NONCE_SIZE, req->iv, GCM_RFC4106_IV_SIZE);
+
+	return crypto_ipsec_check_assoclen(req->assoclen) ?:
+	       p10_aes_gcm_crypt(req, iv, req->assoclen - GCM_RFC4106_IV_SIZE, 0);
+}
+
+static int p10_aes_gcm_encrypt(struct aead_request *req)
+{
+	return p10_aes_gcm_crypt(req, req->iv, req->assoclen, 1);
+}
+
+static int p10_aes_gcm_decrypt(struct aead_request *req)
+{
+	return p10_aes_gcm_crypt(req, req->iv, req->assoclen, 0);
+}
+
+static struct aead_alg gcm_aes_algs[] = {{
+	.ivsize			= GCM_IV_SIZE,
+	.maxauthsize		= 16,
+
+	.setauthsize		= set_authsize,
+	.setkey			= p10_aes_gcm_setkey,
+	.encrypt		= p10_aes_gcm_encrypt,
+	.decrypt		= p10_aes_gcm_decrypt,
+
+	.base.cra_name		= "__gcm(aes)",
+	.base.cra_driver_name	= "__aes_gcm_p10",
+	.base.cra_priority	= 2100,
+	.base.cra_blocksize	= 1,
+	.base.cra_ctxsize	= sizeof(struct p10_aes_gcm_ctx)+
+				  4 * sizeof(u64[2]),
+	.base.cra_module	= THIS_MODULE,
+	.base.cra_flags		= CRYPTO_ALG_INTERNAL,
+}, {
+	.ivsize			= GCM_RFC4106_IV_SIZE,
+	.maxauthsize		= 16,
+	.setkey			= rfc4106_setkey,
+	.setauthsize		= rfc4106_setauthsize,
+	.encrypt		= rfc4106_encrypt,
+	.decrypt		= rfc4106_decrypt,
+
+	.base.cra_name		= "__rfc4106(gcm(aes))",
+	.base.cra_driver_name	= "__rfc4106_aes_gcm_p10",
+	.base.cra_priority	= 2100,
+	.base.cra_blocksize	= 1,
+	.base.cra_ctxsize	= sizeof(struct p10_aes_gcm_ctx) +
+				  4 * sizeof(u64[2]),
+	.base.cra_module	= THIS_MODULE,
+	.base.cra_flags		= CRYPTO_ALG_INTERNAL,
+}};
+
+static struct simd_aead_alg *p10_simd_aeads[ARRAY_SIZE(gcm_aes_algs)];
+
+static int __init p10_init(void)
+{
+	int ret;
+
+	if (!cpu_has_feature(CPU_FTR_ARCH_31))
+		return 0;
+
+	ret = simd_register_aeads_compat(gcm_aes_algs,
+					 ARRAY_SIZE(gcm_aes_algs),
+					 p10_simd_aeads);
+	if (ret) {
+		simd_unregister_aeads(gcm_aes_algs, ARRAY_SIZE(gcm_aes_algs),
+				      p10_simd_aeads);
+		return ret;
+	}
+	return 0;
+}
+
+static void __exit p10_exit(void)
+{
+	simd_unregister_aeads(gcm_aes_algs, ARRAY_SIZE(gcm_aes_algs),
+			      p10_simd_aeads);
+}
+
+module_init(p10_init);
+module_exit(p10_exit);