1 files changed, 240 insertions, 0 deletions
diff --git a/lib/crypto/powerpc/aes.h b/lib/crypto/powerpc/aes.h
new file mode 100644
index 000000000..5a36b637e
--- /dev/null
+++ b/lib/crypto/powerpc/aes.h
@@ -0,0 +1,240 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
+ * Copyright (C) 2015 International Business Machines Inc.
+ * Copyright 2026 Google LLC
+ */
+#include <asm/simd.h>
+#include <asm/switch_to.h>
+#include <linux/cpufeature.h>
+#include <linux/jump_label.h>
+#include <linux/preempt.h>
+#include <linux/uaccess.h>
+
+#ifdef CONFIG_SPE
+
+EXPORT_SYMBOL_GPL(ppc_expand_key_128);
+EXPORT_SYMBOL_GPL(ppc_expand_key_192);
+EXPORT_SYMBOL_GPL(ppc_expand_key_256);
+EXPORT_SYMBOL_GPL(ppc_generate_decrypt_key);
+EXPORT_SYMBOL_GPL(ppc_encrypt_ecb);
+EXPORT_SYMBOL_GPL(ppc_decrypt_ecb);
+EXPORT_SYMBOL_GPL(ppc_encrypt_cbc);
+EXPORT_SYMBOL_GPL(ppc_decrypt_cbc);
+EXPORT_SYMBOL_GPL(ppc_crypt_ctr);
+EXPORT_SYMBOL_GPL(ppc_encrypt_xts);
+EXPORT_SYMBOL_GPL(ppc_decrypt_xts);
+
+void ppc_encrypt_aes(u8 *out, const u8 *in, const u32 *key_enc, u32 rounds);
+void ppc_decrypt_aes(u8 *out, const u8 *in, const u32 *key_dec, u32 rounds);
+
+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 void aes_preparekey_arch(union aes_enckey_arch *k,
+				union aes_invkey_arch *inv_k,
+				const u8 *in_key, int key_len, int nrounds)
+{
+	if (key_len == AES_KEYSIZE_128)
+		ppc_expand_key_128(k->spe_enc_key, in_key);
+	else if (key_len == AES_KEYSIZE_192)
+		ppc_expand_key_192(k->spe_enc_key, in_key);
+	else
+		ppc_expand_key_256(k->spe_enc_key, in_key);
+
+	if (inv_k)
+		ppc_generate_decrypt_key(inv_k->spe_dec_key, k->spe_enc_key,
+					 key_len);
+}
+
+static void aes_encrypt_arch(const struct aes_enckey *key,
+			     u8 out[AES_BLOCK_SIZE],
+			     const u8 in[AES_BLOCK_SIZE])
+{
+	spe_begin();
+	ppc_encrypt_aes(out, in, key->k.spe_enc_key, key->nrounds / 2 - 1);
+	spe_end();
+}
+
+static void aes_decrypt_arch(const struct aes_key *key,
+			     u8 out[AES_BLOCK_SIZE],
+			     const u8 in[AES_BLOCK_SIZE])
+{
+	spe_begin();
+	ppc_decrypt_aes(out, in, key->inv_k.spe_dec_key, key->nrounds / 2 - 1);
+	spe_end();
+}
+
+#else /* CONFIG_SPE */
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_vec_crypto);
+
+EXPORT_SYMBOL_GPL(aes_p8_set_encrypt_key);
+EXPORT_SYMBOL_GPL(aes_p8_set_decrypt_key);
+EXPORT_SYMBOL_GPL(aes_p8_encrypt);
+EXPORT_SYMBOL_GPL(aes_p8_decrypt);
+EXPORT_SYMBOL_GPL(aes_p8_cbc_encrypt);
+EXPORT_SYMBOL_GPL(aes_p8_ctr32_encrypt_blocks);
+EXPORT_SYMBOL_GPL(aes_p8_xts_encrypt);
+EXPORT_SYMBOL_GPL(aes_p8_xts_decrypt);
+
+static inline bool is_vsx_format(const struct p8_aes_key *key)
+{
+	return key->nrounds != 0;
+}
+
+/*
+ * Convert a round key from VSX to generic format by reflecting all 16 bytes (if
+ * little endian) or reflecting the bytes in each 4-byte word (if big endian),
+ * and (if apply_inv_mix=true) applying InvMixColumn to each column.
+ *
+ * It would be nice if the VSX and generic key formats would be compatible.  But
+ * that's very difficult to do, with the assembly code having been borrowed from
+ * OpenSSL and also targeted to POWER8 rather than POWER9.
+ *
+ * Fortunately, this conversion should only be needed in extremely rare cases,
+ * possibly not at all in practice.  It's just included for full correctness.
+ */
+static void rndkey_from_vsx(u32 out[4], const u32 in[4], bool apply_inv_mix)
+{
+	const bool be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
+	u32 k0 = swab32(in[0]);
+	u32 k1 = swab32(in[1]);
+	u32 k2 = swab32(in[2]);
+	u32 k3 = swab32(in[3]);
+
+	if (apply_inv_mix) {
+		k0 = inv_mix_columns(k0);
+		k1 = inv_mix_columns(k1);
+		k2 = inv_mix_columns(k2);
+		k3 = inv_mix_columns(k3);
+	}
+	out[0] = be ? k0 : k3;
+	out[1] = be ? k1 : k2;
+	out[2] = be ? k2 : k1;
+	out[3] = be ? k3 : k0;
+}
+
+static void aes_preparekey_arch(union aes_enckey_arch *k,
+				union aes_invkey_arch *inv_k,
+				const u8 *in_key, int key_len, int nrounds)
+{
+	const int keybits = 8 * key_len;
+	int ret;
+
+	if (static_branch_likely(&have_vec_crypto) && likely(may_use_simd())) {
+		preempt_disable();
+		pagefault_disable();
+		enable_kernel_vsx();
+		ret = aes_p8_set_encrypt_key(in_key, keybits, &k->p8);
+		/*
+		 * aes_p8_set_encrypt_key() should never fail here, since the
+		 * key length was already validated.
+		 */
+		WARN_ON_ONCE(ret);
+		if (inv_k) {
+			ret = aes_p8_set_decrypt_key(in_key, keybits,
+						     &inv_k->p8);
+			/* ... and likewise for aes_p8_set_decrypt_key(). */
+			WARN_ON_ONCE(ret);
+		}
+		disable_kernel_vsx();
+		pagefault_enable();
+		preempt_enable();
+	} else {
+		aes_expandkey_generic(k->rndkeys,
+				      inv_k ? inv_k->inv_rndkeys : NULL,
+				      in_key, key_len);
+		/* Mark the key as using the generic format. */
+		k->p8.nrounds = 0;
+		if (inv_k)
+			inv_k->p8.nrounds = 0;
+	}
+}
+
+static void aes_encrypt_arch(const struct aes_enckey *key,
+			     u8 out[AES_BLOCK_SIZE],
+			     const u8 in[AES_BLOCK_SIZE])
+{
+	if (static_branch_likely(&have_vec_crypto) &&
+	    likely(is_vsx_format(&key->k.p8) && may_use_simd())) {
+		preempt_disable();
+		pagefault_disable();
+		enable_kernel_vsx();
+		aes_p8_encrypt(in, out, &key->k.p8);
+		disable_kernel_vsx();
+		pagefault_enable();
+		preempt_enable();
+	} else if (unlikely(is_vsx_format(&key->k.p8))) {
+		/*
+		 * This handles (the hopefully extremely rare) case where a key
+		 * was prepared using the VSX optimized format, then encryption
+		 * is done in a context that cannot use VSX instructions.
+		 */
+		u32 rndkeys[AES_MAX_KEYLENGTH_U32];
+
+		for (int i = 0; i < 4 * (key->nrounds + 1); i += 4)
+			rndkey_from_vsx(&rndkeys[i],
+					&key->k.p8.rndkeys[i], false);
+		aes_encrypt_generic(rndkeys, key->nrounds, out, in);
+	} else {
+		aes_encrypt_generic(key->k.rndkeys, key->nrounds, out, in);
+	}
+}
+
+static void aes_decrypt_arch(const struct aes_key *key, u8 out[AES_BLOCK_SIZE],
+			     const u8 in[AES_BLOCK_SIZE])
+{
+	if (static_branch_likely(&have_vec_crypto) &&
+	    likely(is_vsx_format(&key->inv_k.p8) && may_use_simd())) {
+		preempt_disable();
+		pagefault_disable();
+		enable_kernel_vsx();
+		aes_p8_decrypt(in, out, &key->inv_k.p8);
+		disable_kernel_vsx();
+		pagefault_enable();
+		preempt_enable();
+	} else if (unlikely(is_vsx_format(&key->inv_k.p8))) {
+		/*
+		 * This handles (the hopefully extremely rare) case where a key
+		 * was prepared using the VSX optimized format, then decryption
+		 * is done in a context that cannot use VSX instructions.
+		 */
+		u32 inv_rndkeys[AES_MAX_KEYLENGTH_U32];
+		int i;
+
+		rndkey_from_vsx(&inv_rndkeys[0],
+				&key->inv_k.p8.rndkeys[0], false);
+		for (i = 4; i < 4 * key->nrounds; i += 4) {
+			rndkey_from_vsx(&inv_rndkeys[i],
+					&key->inv_k.p8.rndkeys[i], true);
+		}
+		rndkey_from_vsx(&inv_rndkeys[i],
+				&key->inv_k.p8.rndkeys[i], false);
+		aes_decrypt_generic(inv_rndkeys, key->nrounds, out, in);
+	} else {
+		aes_decrypt_generic(key->inv_k.inv_rndkeys, key->nrounds,
+				    out, in);
+	}
+}
+
+#define aes_mod_init_arch aes_mod_init_arch
+static void aes_mod_init_arch(void)
+{
+	if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
+	    (cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_VEC_CRYPTO))
+		static_branch_enable(&have_vec_crypto);
+}
+
+#endif /* !CONFIG_SPE */