Add support for selecting encryption backend

- Add two new module parameters to icp (icp_aes_impl, icp_gcm_impl)
  that control the crypto implementation.  At the moment there is a
  choice between generic and aesni (on platforms that support it).
- This enables support for AES-NI and PCLMULQDQ-NI on AMD Family
  15h (bulldozer) and newer CPUs (zen).
- Modify aes_key_t to track what implementation it was generated
  with as key schedules generated with various implementations
  are not necessarily interchangable.

Reviewed by: Gvozden Neskovic <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Tom Caputi <[email protected]>
Reviewed-by: Richard Laager <[email protected]>
Signed-off-by: Nathaniel R. Lewis <[email protected]>
Closes #7102 
Closes #7103 

1 files changed, 46 insertions, 4 deletions

diff --git a/module/icp/include/aes/aes_impl.h b/module/icp/include/aes/aes_impl.h
index ed15f74e7..95cfddf9e 100644
--- a/module/icp/include/aes/aes_impl.h
+++ b/module/icp/include/aes/aes_impl.h
@@ -106,17 +106,15 @@ typedef union {
 	uint32_t	ks32[((MAX_AES_NR) + 1) * (MAX_AES_NB)];
 } aes_ks_t;
 
-/* aes_key.flags value: */
-#define	INTEL_AES_NI_CAPABLE	0x1	/* AES-NI instructions present */
-
+typedef struct aes_impl_ops aes_impl_ops_t;
 typedef struct aes_key aes_key_t;
 struct aes_key {
 	aes_ks_t	encr_ks;  /* encryption key schedule */
 	aes_ks_t	decr_ks;  /* decryption key schedule */
 #ifdef __amd64
 	long double	align128; /* Align fields above for Intel AES-NI */
-	int		flags;	  /* implementation-dependent flags */
 #endif	/* __amd64 */
+	const aes_impl_ops_t	*ops;	/* ops associated with this schedule */
 	int		nr;	  /* number of rounds (10, 12, or 14) */
 	int		type;	  /* key schedule size (32 or 64 bits) */
 };
@@ -163,6 +161,50 @@ typedef enum aes_mech_type {
 
 #endif /* _AES_IMPL */
 
+/*
+ * Methods used to define aes implementation
+ *
+ * @aes_gen_f Key generation
+ * @aes_enc_f Function encrypts one block
+ * @aes_dec_f Function decrypts one block
+ * @aes_will_work_f Function tests whether method will function
+ */
+typedef void 		(*aes_generate_f)(aes_key_t *, const uint32_t *, int);
+typedef void		(*aes_encrypt_f)(const uint32_t[], int,
+    const uint32_t[4], uint32_t[4]);
+typedef void		(*aes_decrypt_f)(const uint32_t[], int,
+    const uint32_t[4], uint32_t[4]);
+typedef boolean_t	(*aes_will_work_f)(void);
+
+#define	AES_IMPL_NAME_MAX (16)
+
+struct aes_impl_ops {
+	aes_generate_f generate;
+	aes_encrypt_f encrypt;
+	aes_decrypt_f decrypt;
+	aes_will_work_f is_supported;
+	boolean_t needs_byteswap;
+	char name[AES_IMPL_NAME_MAX];
+};
+
+extern const aes_impl_ops_t aes_generic_impl;
+#if defined(__x86_64)
+extern const aes_impl_ops_t aes_x86_64_impl;
+#endif
+#if defined(__x86_64) && defined(HAVE_AES)
+extern const aes_impl_ops_t aes_aesni_impl;
+#endif
+
+/*
+ * Initializes fastest implementation
+ */
+void aes_impl_init(void);
+
+/*
+ * Get selected aes implementation
+ */
+struct aes_impl_ops *aes_impl_get_ops(void);
+
 #ifdef	__cplusplus
 }
 #endif