USB: option: convert interface blacklisting to bitfields

It's cleaner than the array stuff, and we're about to add a bunch
more blacklist entries.  Second, there are devices that need both
the sendsetup and the reserved interface blacklists, which the
current code can't accommodate.
Signed-off-by: NDan Williams <dcbw@redhat.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/option.c

@@ -475,31 +475,24 @@ enum option_blacklist_reason {
 		OPTION_BLACKLIST_RESERVED_IF = 2
 };
 
+#define MAX_BL_NUM  8
 struct option_blacklist_info {
-	const u32 infolen;	/* number of interface numbers on blacklist */
-	const u8  *ifaceinfo;	/* pointer to the array holding the numbers */
-	enum option_blacklist_reason reason;
+	/* bitfield of interface numbers for OPTION_BLACKLIST_SENDSETUP */
+	const unsigned long sendsetup;
+	/* bitfield of interface numbers for OPTION_BLACKLIST_RESERVED_IF */
+	const unsigned long reserved;
 };
 
-static const u8 four_g_w14_no_sendsetup[] = { 0, 1 };
 static const struct option_blacklist_info four_g_w14_blacklist = {
-	.infolen = ARRAY_SIZE(four_g_w14_no_sendsetup),
-	.ifaceinfo = four_g_w14_no_sendsetup,
-	.reason = OPTION_BLACKLIST_SENDSETUP
+	.sendsetup = BIT(0) | BIT(1),
 };
 
-static const u8 alcatel_x200_no_sendsetup[] = { 0, 1 };
 static const struct option_blacklist_info alcatel_x200_blacklist = {
-	.infolen = ARRAY_SIZE(alcatel_x200_no_sendsetup),
-	.ifaceinfo = alcatel_x200_no_sendsetup,
-	.reason = OPTION_BLACKLIST_SENDSETUP
+	.sendsetup = BIT(0) | BIT(1),
 };
 
-static const u8 zte_k3765_z_no_sendsetup[] = { 0, 1, 2 };
 static const struct option_blacklist_info zte_k3765_z_blacklist = {
-	.infolen = ARRAY_SIZE(zte_k3765_z_no_sendsetup),
-	.ifaceinfo = zte_k3765_z_no_sendsetup,
-	.reason = OPTION_BLACKLIST_SENDSETUP
+	.sendsetup = BIT(0) | BIT(1) | BIT(2),
 };
 
 static const struct usb_device_id option_ids[] = {
@@ -1255,21 +1248,28 @@ static int option_probe(struct usb_serial *serial,
 	return 0;
 }
 
-static enum option_blacklist_reason is_blacklisted(const u8 ifnum,
-				const struct option_blacklist_info *blacklist)
+static bool is_blacklisted(const u8 ifnum, enum option_blacklist_reason reason,
+			   const struct option_blacklist_info *blacklist)
 {
-	const u8  *info;
-	int i;
+	unsigned long num;
+	const unsigned long *intf_list;
 
 	if (blacklist) {
-		info = blacklist->ifaceinfo;
+		if (reason == OPTION_BLACKLIST_SENDSETUP)
+			intf_list = &blacklist->sendsetup;
+		else if (reason == OPTION_BLACKLIST_RESERVED_IF)
+			intf_list = &blacklist->reserved;
+		else {
+			BUG_ON(reason);
+			return false;
+		}
 
-		for (i = 0; i < blacklist->infolen; i++) {
-			if (info[i] == ifnum)
-				return blacklist->reason;
+		for_each_set_bit(num, intf_list, MAX_BL_NUM + 1) {
+			if (num == ifnum)
+				return true;
 		}
 	}
-	return OPTION_BLACKLIST_NONE;
+	return false;
 }
 
 static void option_instat_callback(struct urb *urb)
@@ -1343,9 +1343,8 @@ static int option_send_setup(struct usb_serial_port *port)
 	int val = 0;
 	dbg("%s", __func__);
 
-	if (is_blacklisted(ifNum,
-			   (struct option_blacklist_info *) intfdata->private)
-	    == OPTION_BLACKLIST_SENDSETUP) {
+	if (is_blacklisted(ifNum, OPTION_BLACKLIST_SENDSETUP,
+			(struct option_blacklist_info *) intfdata->private)) {
 		dbg("No send_setup on blacklisted interface #%d\n", ifNum);
 		return -EIO;
 	}