s390/zcrypt: split ioctl function into smaller code units

The zcrpyt_unlocked_ioctl() function has become large. So split away
into new static functions the 4 ioctl ICARSAMODEXPO, ICARSACRT,
ZSECSENDCPRB and ZSENDEP11CPRB. This makes the code more readable and
is a preparation step for further improvements needed on these ioctls.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

drivers/s390/crypto/zcrypt_api.c

@@ -1298,99 +1298,119 @@ static int zcrypt_requestq_count(void)
 	return requestq_count;
 }
 
-static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
-				  unsigned long arg)
+static int icarsamodexpo_ioctl(struct ap_perms *perms, unsigned long arg)
 {
 	int rc;
-	struct ap_perms *perms =
-		(struct ap_perms *) filp->private_data;
+	struct ica_rsa_modexpo mex;
+	struct ica_rsa_modexpo __user *umex = (void __user *) arg;
 
-	rc = zcrypt_check_ioctl(perms, cmd);
-	if (rc)
-		return rc;
-
-	switch (cmd) {
-	case ICARSAMODEXPO: {
-		struct ica_rsa_modexpo __user *umex = (void __user *) arg;
-		struct ica_rsa_modexpo mex;
-
-		if (copy_from_user(&mex, umex, sizeof(mex)))
-			return -EFAULT;
+	if (copy_from_user(&mex, umex, sizeof(mex)))
+		return -EFAULT;
+	do {
+		rc = zcrypt_rsa_modexpo(perms, &mex);
+	} while (rc == -EAGAIN);
+	/* on failure: retry once again after a requested rescan */
+	if ((rc == -ENODEV) && (zcrypt_process_rescan()))
 		do {
 			rc = zcrypt_rsa_modexpo(perms, &mex);
 		} while (rc == -EAGAIN);
-		/* on failure: retry once again after a requested rescan */
-		if ((rc == -ENODEV) && (zcrypt_process_rescan()))
-			do {
-				rc = zcrypt_rsa_modexpo(perms, &mex);
-			} while (rc == -EAGAIN);
-		if (rc) {
-			ZCRYPT_DBF(DBF_DEBUG, "ioctl ICARSAMODEXPO rc=%d\n", rc);
-			return rc;
-		}
-		return put_user(mex.outputdatalength, &umex->outputdatalength);
+	if (rc) {
+		ZCRYPT_DBF(DBF_DEBUG, "ioctl ICARSAMODEXPO rc=%d\n", rc);
+		return rc;
 	}
-	case ICARSACRT: {
-		struct ica_rsa_modexpo_crt __user *ucrt = (void __user *) arg;
-		struct ica_rsa_modexpo_crt crt;
+	return put_user(mex.outputdatalength, &umex->outputdatalength);
+}
 
-		if (copy_from_user(&crt, ucrt, sizeof(crt)))
-			return -EFAULT;
+static int icarsacrt_ioctl(struct ap_perms *perms, unsigned long arg)
+{
+	int rc;
+	struct ica_rsa_modexpo_crt crt;
+	struct ica_rsa_modexpo_crt __user *ucrt = (void __user *) arg;
+
+	if (copy_from_user(&crt, ucrt, sizeof(crt)))
+		return -EFAULT;
+	do {
+		rc = zcrypt_rsa_crt(perms, &crt);
+	} while (rc == -EAGAIN);
+	/* on failure: retry once again after a requested rescan */
+	if ((rc == -ENODEV) && (zcrypt_process_rescan()))
 		do {
 			rc = zcrypt_rsa_crt(perms, &crt);
 		} while (rc == -EAGAIN);
-		/* on failure: retry once again after a requested rescan */
-		if ((rc == -ENODEV) && (zcrypt_process_rescan()))
-			do {
-				rc = zcrypt_rsa_crt(perms, &crt);
-			} while (rc == -EAGAIN);
-		if (rc) {
-			ZCRYPT_DBF(DBF_DEBUG, "ioctl ICARSACRT rc=%d\n", rc);
-			return rc;
-		}
-		return put_user(crt.outputdatalength, &ucrt->outputdatalength);
+	if (rc) {
+		ZCRYPT_DBF(DBF_DEBUG, "ioctl ICARSACRT rc=%d\n", rc);
+		return rc;
 	}
-	case ZSECSENDCPRB: {
-		struct ica_xcRB __user *uxcRB = (void __user *) arg;
-		struct ica_xcRB xcRB;
+	return put_user(crt.outputdatalength, &ucrt->outputdatalength);
+}
 
-		if (copy_from_user(&xcRB, uxcRB, sizeof(xcRB)))
-			return -EFAULT;
+static int zsecsendcprb_ioctl(struct ap_perms *perms, unsigned long arg)
+{
+	int rc;
+	struct ica_xcRB xcRB;
+	struct ica_xcRB __user *uxcRB = (void __user *) arg;
+
+	if (copy_from_user(&xcRB, uxcRB, sizeof(xcRB)))
+		return -EFAULT;
+	do {
+		rc = _zcrypt_send_cprb(perms, &xcRB);
+	} while (rc == -EAGAIN);
+	/* on failure: retry once again after a requested rescan */
+	if ((rc == -ENODEV) && (zcrypt_process_rescan()))
 		do {
 			rc = _zcrypt_send_cprb(perms, &xcRB);
 		} while (rc == -EAGAIN);
-		/* on failure: retry once again after a requested rescan */
-		if ((rc == -ENODEV) && (zcrypt_process_rescan()))
-			do {
-				rc = _zcrypt_send_cprb(perms, &xcRB);
-			} while (rc == -EAGAIN);
-		if (rc)
-			ZCRYPT_DBF(DBF_DEBUG, "ioctl ZSENDCPRB rc=%d status=0x%x\n",
-				   rc, xcRB.status);
-		if (copy_to_user(uxcRB, &xcRB, sizeof(xcRB)))
-			return -EFAULT;
-		return rc;
-	}
-	case ZSENDEP11CPRB: {
-		struct ep11_urb __user *uxcrb = (void __user *)arg;
-		struct ep11_urb xcrb;
+	if (rc)
+		ZCRYPT_DBF(DBF_DEBUG, "ioctl ZSENDCPRB rc=%d status=0x%x\n",
+			   rc, xcRB.status);
+	if (copy_to_user(uxcRB, &xcRB, sizeof(xcRB)))
+		return -EFAULT;
+	return rc;
+}
 
-		if (copy_from_user(&xcrb, uxcrb, sizeof(xcrb)))
-			return -EFAULT;
+static int zsendep11cprb_ioctl(struct ap_perms *perms, unsigned long arg)
+{
+	int rc;
+	struct ep11_urb xcrb;
+	struct ep11_urb __user *uxcrb = (void __user *)arg;
+
+	if (copy_from_user(&xcrb, uxcrb, sizeof(xcrb)))
+		return -EFAULT;
+	do {
+		rc = _zcrypt_send_ep11_cprb(perms, &xcrb);
+	} while (rc == -EAGAIN);
+	/* on failure: retry once again after a requested rescan */
+	if ((rc == -ENODEV) && (zcrypt_process_rescan()))
 		do {
 			rc = _zcrypt_send_ep11_cprb(perms, &xcrb);
 		} while (rc == -EAGAIN);
-		/* on failure: retry once again after a requested rescan */
-		if ((rc == -ENODEV) && (zcrypt_process_rescan()))
-			do {
-				rc = _zcrypt_send_ep11_cprb(perms, &xcrb);
-			} while (rc == -EAGAIN);
-		if (rc)
-			ZCRYPT_DBF(DBF_DEBUG, "ioctl ZSENDEP11CPRB rc=%d\n", rc);
-		if (copy_to_user(uxcrb, &xcrb, sizeof(xcrb)))
-			return -EFAULT;
+	if (rc)
+		ZCRYPT_DBF(DBF_DEBUG, "ioctl ZSENDEP11CPRB rc=%d\n", rc);
+	if (copy_to_user(uxcrb, &xcrb, sizeof(xcrb)))
+		return -EFAULT;
+	return rc;
+}
+
+static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
+				  unsigned long arg)
+{
+	int rc;
+	struct ap_perms *perms =
+		(struct ap_perms *) filp->private_data;
+
+	rc = zcrypt_check_ioctl(perms, cmd);
+	if (rc)
 		return rc;
-	}
+
+	switch (cmd) {
+	case ICARSAMODEXPO:
+		return icarsamodexpo_ioctl(perms, arg);
+	case ICARSACRT:
+		return icarsacrt_ioctl(perms, arg);
+	case ZSECSENDCPRB:
+		return zsecsendcprb_ioctl(perms, arg);
+	case ZSENDEP11CPRB:
+		return zsendep11cprb_ioctl(perms, arg);
 	case ZCRYPT_DEVICE_STATUS: {
 		struct zcrypt_device_status_ext *device_status;
 		size_t total_size = MAX_ZDEV_ENTRIES_EXT