[PATCH] remove MOD_IN_USE

Another left-over from ancient module code, it was supposed to return
non-zero if the module has a use count, but currently it always
evaluates to 0.

There are a few users of different types:
(1)  ioctl that perform a while(MOD_IN_USE) MOD_DEC_USE_COUNT loop.
     Just rip them out, we now have forced module unloading.
(2)  printk's that moan if the use-count in not zero in the exitfunc.
     Just rip them out, this can't happen.
(3)  if(MOD_IN_USE) MOD_DEC_USE_COUNT constructs in ->close of a few
     serial drivers.  Just remove the conditional, we did a
     MOD_INC_USE_COUNT in ->open.
(4)  This one is interesting:  drivers/sbus/char/display7seg.c uses
     the module use count to track openers.  Replace this with an
     atomic_t.

In addition remove tons of stale comments in network driver that aren't
understandable for anyone who doesn't know ancient Linux module semantics.

drivers/atm/nicstar.c

@@ -345,9 +345,6 @@ static void __exit nicstar_module_exit(void)
    
    XPRINTK("nicstar: cleanup_module() called.\n");
 
-   if (MOD_IN_USE)
-      printk("nicstar: module in use, remove delayed.\n");
-
    del_timer(&ns_timer);
 
    for (i = 0; i < NS_MAX_CARDS; i++)

drivers/char/pcmcia/synclink_cs.c

@@ -2513,10 +2513,6 @@ int ioctl_common(MGSLPC_INFO *info, unsigned int cmd, unsigned long arg)
 		return get_stats(info,(struct mgsl_icount*)arg);
 	case MGSL_IOCWAITEVENT:
 		return wait_events(info,(int*)arg);
-	case MGSL_IOCCLRMODCOUNT:
-		while(MOD_IN_USE)
-			MOD_DEC_USE_COUNT;
-		return 0;
 	case TIOCMIWAIT:
 		return modem_input_wait(info,(int)arg);
 	case TIOCGICOUNT:
@@ -2694,7 +2690,6 @@ static void mgslpc_close(struct tty_struct *tty, struct file * filp)
 	if (debug_level >= DEBUG_LEVEL_INFO)
 		printk("%s(%d):mgslpc_close(%s) exit, count=%d\n", __FILE__,__LINE__,
 			tty->driver.name, info->count);
-	if(MOD_IN_USE)
 	MOD_DEC_USE_COUNT;
 }
 
@@ -3003,7 +2998,6 @@ static int mgslpc_open(struct tty_struct *tty, struct file * filp)
 	
 cleanup:			
 	if (retval) {
-		if(MOD_IN_USE)
 		MOD_DEC_USE_COUNT;
 		if(info->count)
 			info->count--;

drivers/char/synclink.c

@@ -3119,11 +3119,6 @@ int mgsl_ioctl_common(struct mgsl_struct *info, unsigned int cmd, unsigned long
 			return mgsl_wait_event(info,(int*)arg);
 		case MGSL_IOCLOOPTXDONE:
 			return mgsl_loopmode_send_done(info);
-		case MGSL_IOCCLRMODCOUNT:
-			while(MOD_IN_USE)
-				MOD_DEC_USE_COUNT;
-			return 0;
-
 		/* Wait for modem input (DCD,RI,DSR,CTS) change
 		 * as specified by mask in arg (TIOCM_RNG/DSR/CD/CTS)
 		 */
@@ -3328,7 +3323,6 @@ static void mgsl_close(struct tty_struct *tty, struct file * filp)
 	if (debug_level >= DEBUG_LEVEL_INFO)
 		printk("%s(%d):mgsl_close(%s) exit, count=%d\n", __FILE__,__LINE__,
 			tty->driver.name, info->count);
-	if(MOD_IN_USE)
 	MOD_DEC_USE_COUNT;
 			
 }	/* end of mgsl_close() */
@@ -3689,7 +3683,6 @@ static int mgsl_open(struct tty_struct *tty, struct file * filp)
 	
 cleanup:			
 	if (retval) {
-		if(MOD_IN_USE)
 		MOD_DEC_USE_COUNT;
 		if(info->count)
 			info->count--;

drivers/char/synclinkmp.c

@@ -826,7 +826,6 @@ static int open(struct tty_struct *tty, struct file *filp)
 
 cleanup:
 	if (retval) {
-		if(MOD_IN_USE)
 		MOD_DEC_USE_COUNT;
 		if(info->count)
 			info->count--;
@@ -926,7 +925,6 @@ static void close(struct tty_struct *tty, struct file *filp)
 	if (debug_level >= DEBUG_LEVEL_INFO)
 		printk("%s(%d):%s close() exit, count=%d\n", __FILE__,__LINE__,
 			tty->driver.name, info->count);
-	if(MOD_IN_USE)
 	MOD_DEC_USE_COUNT;
 }
 
@@ -1415,10 +1413,6 @@ static int ioctl(struct tty_struct *tty, struct file *file,
 		return wait_mgsl_event(info,(int*)arg);
 	case MGSL_IOCLOOPTXDONE:
 		return 0; // TODO: Not supported, need to document
-	case MGSL_IOCCLRMODCOUNT:
-		while(MOD_IN_USE)
-			MOD_DEC_USE_COUNT;
-		return 0;
 		/* Wait for modem input (DCD,RI,DSR,CTS) change
 		 * as specified by mask in arg (TIOCM_RNG/DSR/CD/CTS)
 		 */

drivers/net/3c501.c

@@ -981,10 +981,6 @@ int init_module(void)
  
 void cleanup_module(void)
 {
-	/*
-	 *	No need to check MOD_IN_USE, as sys_delete_module() checks.
-	 */
-
 	unregister_netdev(&dev_3c501);
 
 	/*

drivers/net/3c509.c

@@ -1558,7 +1558,6 @@ static void __exit el3_cleanup_module(void)
 {
 	struct net_device *next_dev;
 
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	while (el3_root_dev) {
 		struct el3_private *lp = (struct el3_private *)el3_root_dev->priv;
 

drivers/net/3c515.c

@@ -1666,7 +1666,6 @@ void cleanup_module(void)
 {
 	struct net_device *next_dev;
 
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	while (root_corkscrew_dev) {
 		next_dev =
 		    ((struct corkscrew_private *) root_corkscrew_dev->

drivers/net/3c527.c

@@ -1773,7 +1773,6 @@ void cleanup_module(void)
 {
 	int slot;
 	
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	unregister_netdev(&this_device);
 
 	/*

drivers/net/appletalk/cops.c

@@ -1043,7 +1043,6 @@ int init_module(void)
 
 void cleanup_module(void)
 {
-        /* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	unregister_netdev(&cops0_dev);
 	kfree(cops0_dev.priv);
 	if(cops0_dev.irq)

drivers/net/hamachi.c

@@ -1960,7 +1960,6 @@ static void __devexit hamachi_remove_one (struct pci_dev *pdev)
 {
 	struct net_device *dev = pci_get_drvdata(pdev);
 
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	if (dev) {
 		struct hamachi_private *hmp = dev->priv;
 

drivers/net/isa-skeleton.c

@@ -659,7 +659,6 @@ int init_module(void)
 void
 cleanup_module(void)
 {
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	unregister_netdev(&this_device);
 	/*
 	 * If we don't do this, we can't re-insmod it later.

drivers/net/myri_sbus.c

@@ -1137,7 +1137,6 @@ static int __init myri_sbus_probe(void)
 static void __exit myri_sbus_cleanup(void)
 {
 #ifdef MODULE
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	while (root_myri_dev) {
 		struct myri_eth *next = root_myri_dev->next_module;
 

drivers/net/pcnet32.c

@@ -1737,7 +1737,6 @@ static void __exit pcnet32_cleanup_module(void)
 {
     struct net_device *next_dev;
 
-    /* No need to check MOD_IN_USE, as sys_delete_module() checks. */
     while (pcnet32_dev) {
 	struct pcnet32_private *lp = pcnet32_dev->priv;
 	next_dev = lp->next;

drivers/net/ptifddi.c

@@ -247,7 +247,6 @@ cleanup_module(void)
 {
 	struct ptifddi *pp;
 
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	while (root_pti_dev) {
 		pp = root_pti_dev->next_module;
 

drivers/net/seeq8005.c

@@ -733,10 +733,6 @@ int init_module(void)
 
 void cleanup_module(void)
 {
-	/*
-	 *	No need to check MOD_IN_USE, as sys_delete_module() checks.
-	 */
-
 	unregister_netdev(&dev_seeq);
 
 	/*

drivers/net/sk_mca.c

@@ -1274,11 +1274,6 @@ void cleanup_module(void)
 	skmca_priv *priv;
 	int z;
 
-	if (MOD_IN_USE) {
-		printk("cannot unload, module in use\n");
-		return;
-	}
-
 	for (z = 0; z < DEVMAX; z++) {
 		dev = moddevs + z;
 		if (dev->priv != NULL) {

drivers/net/smc9194.c

@@ -1557,7 +1557,6 @@ int init_module(void)
 
 void cleanup_module(void)
 {
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	unregister_netdev(&devSMC9194);
 
 	free_irq(devSMC9194.irq, &devSMC9194);

drivers/net/sundance.c

@@ -1734,7 +1734,6 @@ static void __devexit sundance_remove1 (struct pci_dev *pdev)
 {
 	struct net_device *dev = pci_get_drvdata(pdev);
 
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	if (dev) {
 		struct netdev_private *np = dev->priv;
 

drivers/net/tc35815.c

@@ -1755,7 +1755,6 @@ static void __exit tc35815_cleanup_module(void)
 {
 	struct net_device *next_dev;
 
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	while (root_tc35815_dev) {
 		struct net_device *dev = root_tc35815_dev;
 		next_dev = ((struct tc35815_local *)dev->priv)->next_module;

drivers/net/tulip/winbond-840.c

@@ -1612,7 +1612,6 @@ static void __devexit w840_remove1 (struct pci_dev *pdev)
 {
 	struct net_device *dev = pci_get_drvdata(pdev);
 	
-	/* No need to check MOD_IN_USE, as sys_delete_module() checks. */
 	if (dev) {
 		unregister_netdev(dev);
 		pci_release_regions(pdev);

drivers/net/wan/sbni.c

@@ -1501,7 +1501,6 @@ cleanup_module( void )
 	struct net_device  *dev;
 	int  num;
 
-	/* No need to check MOD_IN_USE, as sys_delete_module( ) checks. */
 	for( num = 0;  num < SBNI_MAX_NUM_CARDS;  ++num )
 		if( (dev = sbni_cards[ num ]) != NULL ) {
 			unregister_netdev( dev );

drivers/sbus/char/display7seg.c

@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/miscdevice.h>
 #include <linux/ioport.h>		/* request_region, check_region */
+#include <asm/atomic.h>
 #include <asm/ebus.h>			/* EBus device					*/
 #include <asm/oplib.h>			/* OpenProm Library 			*/
 #include <asm/uaccess.h>		/* put_/get_user			*/
@@ -86,27 +87,23 @@ static inline int d7s_obpflipped(void)
 	return ((-1 != prom_getintdefault(opt_node, "d7s-flipped?", -1)) ? 0 : 1);
 }
 
+static atomic_t d7s_users = ATOMIC_INIT(0);
+
 static int d7s_open(struct inode *inode, struct file *f)
 {
 	if (D7S_MINOR != minor(inode->i_rdev))
 		return -ENODEV;
-
-	MOD_INC_USE_COUNT;
+	atomic_inc(&d7s_users);
 	return 0;
 }
 
 static int d7s_release(struct inode *inode, struct file *f)
 {
-	if (D7S_MINOR != minor(inode->i_rdev))
-		return -ENODEV;
-	
-	MOD_DEC_USE_COUNT;
-
 	/* Reset flipped state to OBP default only if
 	 * no other users have the device open and we
 	 * are not operating in solaris-compat mode
 	 */
-	if (0 == MOD_IN_USE && 0 == sol_compat) {
+	if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
 		int regval = 0;
 
 		regval = readb(d7s_regs);

include/linux/module.h

@@ -437,7 +437,6 @@ static inline void __deprecated _MOD_INC_USE_COUNT(struct module *module)
 #endif
 }
 #define EXPORT_NO_SYMBOLS
-#define MOD_IN_USE 0
 #define __MODULE_STRING(x) __stringify(x)
 
 /*

net/atm/mpc.c

@@ -1424,10 +1424,6 @@ void cleanup_module(void)
 	struct atm_mpoa_qos *qos, *nextqos;
 	struct lec_priv *priv;
 
-	if (MOD_IN_USE) {
-		printk("mpc.c: module in use\n");
-		return;
-	}
 #ifdef CONFIG_PROC_FS
 	mpc_proc_clean();
 #endif

sound/oss/soundcard.c

@@ -599,9 +599,6 @@ static void __exit oss_cleanup(void)
 {
 	int i, j;
 
-	if (MOD_IN_USE)
-		return;
-
 	for (i = 0; i < sizeof (dev_list) / sizeof *dev_list; i++) {
 		devfs_remove("snd/%s", dev_list[i].name);
 		if (!dev_list[i].num)