dm crypt: remove obsolete references to per-CPU state

dm-crypt used to use separate crypto transforms for each CPU, but this
is no longer the case.  To avoid confusion, fix up obsolete comments and
rename setup_essiv_cpu().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-crypt.c

@@ -225,7 +225,7 @@ static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
 					     struct scatterlist *sg);
 
 /*
- * Use this to access cipher attributes that are the same for each CPU.
+ * Use this to access cipher attributes that are independent of the key.
  */
 static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
 {
@@ -349,10 +349,11 @@ static int crypt_iv_essiv_wipe(struct crypt_config *cc)
 	return err;
 }
 
-/* Set up per cpu cipher state */
-static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
-					     struct dm_target *ti,
-					     u8 *salt, unsigned saltsize)
+/* Allocate the cipher for ESSIV */
+static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
+						struct dm_target *ti,
+						const u8 *salt,
+						unsigned int saltsize)
 {
 	struct crypto_cipher *essiv_tfm;
 	int err;
@@ -431,9 +432,8 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 	cc->iv_gen_private.essiv.salt = salt;
 	cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
 
-	essiv_tfm = setup_essiv_cpu(cc, ti, salt,
-				crypto_ahash_digestsize(hash_tfm));
-
+	essiv_tfm = alloc_essiv_cipher(cc, ti, salt,
+				       crypto_ahash_digestsize(hash_tfm));
 	if (IS_ERR(essiv_tfm)) {
 		crypt_iv_essiv_dtr(cc);
 		return PTR_ERR(essiv_tfm);