Char: moxa, centralize board readiness

The only relevant sign of port being ready is its board->ready since now.
Remove all other flags for this purpose which are set almost on the same
place.  Move ports inside the board to be sure that nobody will grab reference
to the port without being sure that it exists.

[jirislaby@gmail.com: fix unused var warning]
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Tested-by: NOyvind Aabling <Oyvind.Aabling@uni-c.dk>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/char/moxa.c

@@ -104,7 +104,7 @@ static struct moxa_board_conf {
 	int numPorts;
 	int busType;
 
-	int loadstat;
+	unsigned int ready;
 
 	struct moxa_port *ports;
 
@@ -142,7 +142,6 @@ struct moxa_port {
 
 	struct timer_list emptyTimer;
 
-	char chkPort;
 	char lineCtrl;
 	void __iomem *tableAddr;
 	char DCDState;
@@ -162,7 +161,6 @@ struct moxa_port {
 #define WAKEUP_CHARS		256
 
 static int ttymajor = MOXAMAJOR;
-static int moxaCard;
 /* Variables for insmod */
 #ifdef MODULE
 static unsigned long baseaddr[MAX_BOARDS];
@@ -218,7 +216,6 @@ static void moxa_receive_data(struct moxa_port *);
 static int MoxaDriverIoctl(struct tty_struct *, unsigned int, unsigned long);
 static int MoxaDriverPoll(void);
 static int MoxaPortsOfCard(int);
-static int MoxaPortIsValid(int);
 static void MoxaPortEnable(struct moxa_port *);
 static void MoxaPortDisable(struct moxa_port *);
 static int MoxaPortSetTermio(struct moxa_port *, struct ktermios *, speed_t);
@@ -263,7 +260,6 @@ static const struct tty_operations moxa_ops = {
 };
 
 static struct tty_driver *moxaDriver;
-static struct moxa_port moxa_ports[MAX_PORTS];
 static DEFINE_TIMER(moxaTimer, moxa_poll, 0, 0);
 static DEFINE_SPINLOCK(moxa_lock);
 
@@ -480,7 +476,6 @@ static int moxa_real_load_code(struct moxa_board_conf *brd, const void *ptr,
 		if (readw(baseAddr + Magic_no) != Magic_code)
 			return -EIO;
 	}
-	moxaCard = 1;
 	brd->intNdx = baseAddr + IRQindex;
 	brd->intPend = baseAddr + IRQpending;
 	brd->intTable = baseAddr + IRQtable;
@@ -511,7 +506,6 @@ static int moxa_load_code(struct moxa_board_conf *brd, const void *ptr,
 		port = brd->ports;
 		for (i = 0; i < brd->numPorts; i++, port++) {
 			port->board = brd;
-			port->chkPort = 1;
 			port->DCDState = 0;
 			port->tableAddr = baseAddr + Extern_table +
 					Extern_size * i;
@@ -530,7 +524,6 @@ static int moxa_load_code(struct moxa_board_conf *brd, const void *ptr,
 		port = brd->ports;
 		for (i = 0; i < brd->numPorts; i++, port++) {
 			port->board = brd;
-			port->chkPort = 1;
 			port->DCDState = 0;
 			port->tableAddr = baseAddr + Extern_table +
 					Extern_size * i;
@@ -575,7 +568,6 @@ static int moxa_load_code(struct moxa_board_conf *brd, const void *ptr,
 		}
 		break;
 	}
-	brd->loadstat = 1;
 	return 0;
 }
 
@@ -672,8 +664,29 @@ static int moxa_init_board(struct moxa_board_conf *brd, struct device *dev)
 {
 	const struct firmware *fw;
 	const char *file;
+	struct moxa_port *p;
+	unsigned int i;
 	int ret;
 
+	brd->ports = kcalloc(MAX_PORTS_PER_BOARD, sizeof(*brd->ports),
+			GFP_KERNEL);
+	if (brd->ports == NULL) {
+		printk(KERN_ERR "cannot allocate memory for ports\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	for (i = 0, p = brd->ports; i < MAX_PORTS_PER_BOARD; i++, p++) {
+		p->type = PORT_16550A;
+		p->close_delay = 5 * HZ / 10;
+		p->cflag = B9600 | CS8 | CREAD | CLOCAL | HUPCL;
+		init_waitqueue_head(&p->open_wait);
+		init_completion(&p->close_wait);
+
+		setup_timer(&p->emptyTimer, moxa_check_xmit_empty,
+				(unsigned long)p);
+	}
+
 	switch (brd->boardType) {
 	case MOXA_BOARD_C218_ISA:
 	case MOXA_BOARD_C218_PCI:
@@ -690,16 +703,38 @@ static int moxa_init_board(struct moxa_board_conf *brd, struct device *dev)
 	ret = request_firmware(&fw, file, dev);
 	if (ret) {
 		printk(KERN_ERR "request_firmware failed\n");
-		goto end;
+		goto err_free;
 	}
 
 	ret = moxa_load_fw(brd, fw);
 
 	release_firmware(fw);
-end:
+
+	if (ret)
+		goto err_free;
+
+	brd->ready = 1;
+
+	return 0;
+err_free:
+	kfree(brd->ports);
+err:
 	return ret;
 }
 
+static void moxa_board_deinit(struct moxa_board_conf *brd)
+{
+	unsigned int i;
+
+	brd->ready = 0;
+	for (i = 0; i < MAX_PORTS_PER_BOARD; i++)
+		del_timer_sync(&brd->ports[i].emptyTimer);
+
+	iounmap(brd->basemem);
+	brd->basemem = NULL;
+	kfree(brd->ports);
+}
+
 #ifdef CONFIG_PCI
 static int __devinit moxa_pci_probe(struct pci_dev *pdev,
 		const struct pci_device_id *ent)
@@ -727,7 +762,6 @@ static int __devinit moxa_pci_probe(struct pci_dev *pdev,
 	}
 
 	board = &moxa_boards[i];
-	board->ports = &moxa_ports[i * MAX_PORTS_PER_BOARD];
 
 	retval = pci_request_region(pdev, 2, "moxa-base");
 	if (retval) {
@@ -777,8 +811,8 @@ static void __devexit moxa_pci_remove(struct pci_dev *pdev)
 {
 	struct moxa_board_conf *brd = pci_get_drvdata(pdev);
 
-	iounmap(brd->basemem);
-	brd->basemem = NULL;
+	moxa_board_deinit(brd);
+
 	pci_release_region(pdev, 2);
 }
 
@@ -792,8 +826,7 @@ static struct pci_driver moxa_pci_driver = {
 
 static int __init moxa_init(void)
 {
-	struct moxa_port *ch;
-	unsigned int i, isabrds = 0;
+	unsigned int isabrds = 0;
 	int retval = 0;
 
 	printk(KERN_INFO "MOXA Intellio family driver version %s\n",
@@ -815,17 +848,6 @@ static int __init moxa_init(void)
 	moxaDriver->flags = TTY_DRIVER_REAL_RAW;
 	tty_set_operations(moxaDriver, &moxa_ops);
 
-	for (i = 0, ch = moxa_ports; i < MAX_PORTS; i++, ch++) {
-		ch->type = PORT_16550A;
-		ch->close_delay = 5 * HZ / 10;
-		ch->cflag = B9600 | CS8 | CREAD | CLOCAL | HUPCL;
-		init_waitqueue_head(&ch->open_wait);
-		init_completion(&ch->close_wait);
-
-		setup_timer(&ch->emptyTimer, moxa_check_xmit_empty,
-				(unsigned long)ch);
-	}
-
 	pr_debug("Moxa tty devices major number = %d\n", ttymajor);
 
 	if (tty_register_driver(moxaDriver)) {
@@ -840,6 +862,7 @@ static int __init moxa_init(void)
 #ifdef MODULE
 	{
 	struct moxa_board_conf *brd = moxa_boards;
+	unsigned int i;
 	for (i = 0; i < MAX_BOARDS; i++) {
 		if (!baseaddr[i])
 			break;
@@ -849,7 +872,6 @@ static int __init moxa_init(void)
 					isabrds + 1, moxa_brdname[type[i] - 1],
 					baseaddr[i]);
 			brd->boardType = type[i];
-			brd->ports = &moxa_ports[isabrds * MAX_PORTS_PER_BOARD];
 			brd->numPorts = type[i] == MOXA_BOARD_C218_ISA ? 8 :
 					numports[i];
 			brd->busType = MOXA_BUS_TYPE_ISA;
@@ -890,9 +912,6 @@ static void __exit moxa_exit(void)
 
 	del_timer_sync(&moxaTimer);
 
-	for (i = 0; i < MAX_PORTS; i++)
-		del_timer_sync(&moxa_ports[i].emptyTimer);
-
 	if (tty_unregister_driver(moxaDriver))
 		printk(KERN_ERR "Couldn't unregister MOXA Intellio family "
 				"serial driver\n");
@@ -902,9 +921,9 @@ static void __exit moxa_exit(void)
 	pci_unregister_driver(&moxa_pci_driver);
 #endif
 
-	for (i = 0; i < MAX_BOARDS; i++)
-		if (moxa_boards[i].basemem)
-			iounmap(moxa_boards[i].basemem);
+	for (i = 0; i < MAX_BOARDS; i++) /* ISA boards */
+		if (moxa_boards[i].ready)
+			moxa_board_deinit(&moxa_boards[i]);
 }
 
 module_init(moxa_init);
@@ -912,6 +931,7 @@ module_exit(moxa_exit);
 
 static int moxa_open(struct tty_struct *tty, struct file *filp)
 {
+	struct moxa_board_conf *brd;
 	struct moxa_port *ch;
 	int port;
 	int retval;
@@ -920,12 +940,11 @@ static int moxa_open(struct tty_struct *tty, struct file *filp)
 	if (port == MAX_PORTS) {
 		return (0);
 	}
-	if (!MoxaPortIsValid(port)) {
-		tty->driver_data = NULL;
-		return (-ENODEV);
-	}
+	brd = &moxa_boards[port / MAX_PORTS_PER_BOARD];
+	if (!brd->ready)
+		return -ENODEV;
 
-	ch = &moxa_ports[port];
+	ch = &brd->ports[port % MAX_PORTS_PER_BOARD];
 	ch->count++;
 	tty->driver_data = ch;
 	ch->tty = tty;
@@ -958,11 +977,6 @@ static void moxa_close(struct tty_struct *tty, struct file *filp)
 	if (port == MAX_PORTS) {
 		return;
 	}
-	if (!MoxaPortIsValid(port)) {
-		pr_debug("Invalid portno in moxa_close\n");
-		tty->driver_data = NULL;
-		return;
-	}
 	if (tty->driver_data == NULL) {
 		return;
 	}
@@ -1285,7 +1299,7 @@ static void moxa_poll(unsigned long ignored)
 	for (card = 0; card < MAX_BOARDS; card++) {
 		if ((ports = MoxaPortsOfCard(card)) <= 0)
 			continue;
-		ch = &moxa_ports[card * MAX_PORTS_PER_BOARD];
+		ch = moxa_boards[card].ports;
 		for (i = 0; i < ports; i++, ch++) {
 			if ((ch->asyncflags & ASYNC_INITIALIZED) == 0)
 				continue;
@@ -1589,17 +1603,22 @@ static int MoxaDriverIoctl(struct tty_struct *tty, unsigned int cmd,
 	case MOXA_GET_IOQUEUE: {
 		struct moxaq_str __user *argm = argp;
 		struct moxaq_str tmp;
-
-		for (i = 0; i < MAX_PORTS; i++, argm++) {
-			memset(&tmp, 0, sizeof(tmp));
-			if (moxa_ports[i].chkPort) {
-				tmp.inq = MoxaPortRxQueue(&moxa_ports[i]);
-				tmp.outq = MoxaPortTxQueue(&moxa_ports[i]);
+		struct moxa_port *p;
+		unsigned int j;
+
+		for (i = 0; i < MAX_BOARDS; i++) {
+			p = moxa_boards[i].ports;
+			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
+				memset(&tmp, 0, sizeof(tmp));
+				if (moxa_boards[i].ready) {
+					tmp.inq = MoxaPortRxQueue(p);
+					tmp.outq = MoxaPortTxQueue(p);
+				}
+				if (copy_to_user(argm, &tmp, sizeof(tmp)))
+					return -EFAULT;
 			}
-			if (copy_to_user(argm, &tmp, sizeof(tmp)))
-				return -EFAULT;
 		}
-		return (0);
+		return 0;
 	} case MOXA_GET_OQUEUE:
 		i = MoxaPortTxQueue(port);
 		return put_user(i, (unsigned long __user *)argp);
@@ -1619,13 +1638,15 @@ static int MoxaDriverIoctl(struct tty_struct *tty, unsigned int cmd,
 		struct mxser_mstatus __user *argm = argp;
 		struct mxser_mstatus tmp;
 		struct moxa_port *p;
+		unsigned int j;
+
+		for (i = 0; i < MAX_BOARDS; i++) {
+			p = moxa_boards[i].ports;
+			for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) {
+				memset(&tmp, 0, sizeof(tmp));
+				if (!moxa_boards[i].ready)
+					goto copy;
 
-		for (i = 0; i < MAX_PORTS; i++, argm++) {
-			p = &moxa_ports[i];
-			memset(&tmp, 0, sizeof(tmp));
-			if (!p->chkPort) {
-				goto copy;
-			} else {
 				status = MoxaPortLineStatus(p);
 				if (status & 1)
 					tmp.cts = 1;
@@ -1633,15 +1654,15 @@ static int MoxaDriverIoctl(struct tty_struct *tty, unsigned int cmd,
 					tmp.dsr = 1;
 				if (status & 4)
 					tmp.dcd = 1;
-			}
 
-			if (!p->tty || !p->tty->termios)
-				tmp.cflag = p->cflag;
-			else
-				tmp.cflag = p->tty->termios->c_cflag;
+				if (!p->tty || !p->tty->termios)
+					tmp.cflag = p->cflag;
+				else
+					tmp.cflag = p->tty->termios->c_cflag;
 copy:
-			if (copy_to_user(argm, &tmp, sizeof(tmp)))
-				return -EFAULT;
+				if (copy_to_user(argm, &tmp, sizeof(tmp)))
+					return -EFAULT;
+			}
 		}
 		return 0;
 	}
@@ -1653,53 +1674,55 @@ static int MoxaDriverIoctl(struct tty_struct *tty, unsigned int cmd,
 int MoxaDriverPoll(void)
 {
 	struct moxa_board_conf *brd;
+	struct moxa_port *p;
 	register ushort temp;
 	register int card;
 	void __iomem *ofsAddr;
 	void __iomem *ip;
-	int port, p, ports;
+	int port, ports;
 
-	if (moxaCard == 0)
-		return (-1);
 	for (card = 0; card < MAX_BOARDS; card++) {
 		brd = &moxa_boards[card];
-	        if (brd->loadstat == 0)
+	        if (brd->ready == 0)
 			continue;
 		if ((ports = brd->numPorts) == 0)
 			continue;
 		if (readb(brd->intPend) == 0xff) {
 			ip = brd->intTable + readb(brd->intNdx);
-			p = card * MAX_PORTS_PER_BOARD;
+			p = brd->ports;
 			ports <<= 1;
 			for (port = 0; port < ports; port += 2, p++) {
-				if ((temp = readw(ip + port)) != 0) {
-					writew(0, ip + port);
-					ofsAddr = moxa_ports[p].tableAddr;
-					if (temp & IntrTx)
-						writew(readw(ofsAddr + HostStat) & ~WakeupTx, ofsAddr + HostStat);
-					if (temp & IntrBreak) {
-						moxa_ports[p].breakCnt++;
-					}
-					if (temp & IntrLine) {
-						if (readb(ofsAddr + FlagStat) & DCD_state) {
-							if ((moxa_ports[p].DCDState & DCD_oldstate) == 0)
-								moxa_ports[p].DCDState = (DCD_oldstate |
-										   DCD_changed);
-						} else {
-							if (moxa_ports[p].DCDState & DCD_oldstate)
-								moxa_ports[p].DCDState = DCD_changed;
-						}
+				temp = readw(ip + port);
+				if (temp == 0)
+					continue;
+
+				writew(0, ip + port);
+				ofsAddr = p->tableAddr;
+				if (temp & IntrTx)
+					writew(readw(ofsAddr + HostStat) &
+						~WakeupTx, ofsAddr + HostStat);
+				if (temp & IntrBreak)
+					p->breakCnt++;
+
+				if (temp & IntrLine) {
+					if (readb(ofsAddr + FlagStat) & DCD_state) {
+						if ((p->DCDState & DCD_oldstate) == 0)
+							p->DCDState = (DCD_oldstate |
+									   DCD_changed);
+					} else {
+						if (p->DCDState & DCD_oldstate)
+							p->DCDState = DCD_changed;
 					}
 				}
 			}
 			writeb(0, brd->intPend);
 		}
 		if (moxaLowWaterChk) {
-			p = card * MAX_PORTS_PER_BOARD;
+			p = brd->ports;
 			for (port = 0; port < ports; port++, p++) {
-				if (moxa_ports[p].lowChkFlag) {
-					moxa_ports[p].lowChkFlag = 0;
-					ofsAddr = moxa_ports[p].tableAddr;
+				if (p->lowChkFlag) {
+					p->lowChkFlag = 0;
+					ofsAddr = p->tableAddr;
 					moxa_low_water_check(ofsAddr);
 				}
 			}
@@ -1723,7 +1746,6 @@ int MoxaPortsOfCard(int cardno)
 
 /*****************************************************************************
  *	Port level functions:						     *
- *	1.  MoxaPortIsValid(int port);					     *
  *	2.  MoxaPortEnable(int port);					     *
  *	3.  MoxaPortDisable(int port);					     *
  *	4.  MoxaPortGetMaxBaud(int port);				     *
@@ -1800,15 +1822,6 @@ int MoxaPortsOfCard(int cardno)
  *                      8/16/24/32
  *
  *
- *      Function 5:     Check this port is valid or invalid
- *      Syntax:
- *      int  MoxaPortIsValid(int port);
- *           int port           : port number (0 - 127, ref port description)
- *
- *           return:    0       : this port is invalid
- *                      1       : this port is valid
- *
- *
  *      Function 6:     Enable this port to start Tx/Rx data.
  *      Syntax:
  *      void MoxaPortEnable(int port);
@@ -2000,14 +2013,6 @@ int MoxaPortsOfCard(int cardno)
  *                                send out a about 250 ms BREAK signal.
  *
  */
-static int MoxaPortIsValid(int port)
-{
-	if (moxaCard == 0)
-		return (0);
-	if (moxa_ports[port].chkPort == 0)
-		return (0);
-	return (1);
-}
 
 static void MoxaPortEnable(struct moxa_port *port)
 {
@@ -2081,8 +2086,6 @@ static int MoxaPortSetTermio(struct moxa_port *port, struct ktermios *termio,
 	tcflag_t cflag;
 	tcflag_t mode = 0;
 
-	if (port->chkPort == 0 || termio == 0)
-		return (-1);
 	ofsAddr = port->tableAddr;
 	cflag = termio->c_cflag;	/* termio->c_cflag */
 
@@ -2135,8 +2138,6 @@ static int MoxaPortGetLineOut(struct moxa_port *port, int *dtrState,
 		int *rtsState)
 {
 
-	if (!MoxaPortIsValid(port->tty->index))
-		return (-1);
 	if (dtrState)
 		*dtrState = !!(port->lineCtrl & DTR_ON);
 	if (rtsState)
@@ -2205,8 +2206,6 @@ static int MoxaPortDCDChange(struct moxa_port *port)
 {
 	int n;
 
-	if (port->chkPort == 0)
-		return (0);
 	n = port->DCDState;
 	port->DCDState &= ~DCD_changed;
 	n &= DCD_changed;
@@ -2217,8 +2216,6 @@ static int MoxaPortDCDON(struct moxa_port *port)
 {
 	int n;
 
-	if (port->chkPort == 0)
-		return (0);
 	if (port->DCDState & DCD_oldstate)
 		n = 1;
 	else