[PATCH] first cut at scc.c for 2.5 locking

diff --git a/drivers/net/hamradio/scc.c b/drivers/net/hamradio/scc.c
index ebe175627dccb835b9b8b3f4cb60b81f01b67606..538e35c128e8924c5782b3bfc5256fcb77ad4c30 100644 (file)
--- a/drivers/net/hamradio/scc.c
+++ b/drivers/net/hamradio/scc.c
@@ -235,13 +235,14 @@ static io_port Vector_Latch;
 
 /* These provide interrupt save 2-step access to the Z8530 registers */
 
+static spinlock_t iolock;      /* Guards paired accesses */
+
 static inline unsigned char InReg(io_port port, unsigned char reg)
 {
        unsigned long flags;
        unsigned char r;
-       
-       save_flags(flags);
-       cli();
+
+       spin_lock_irqsave(&iolock, flags);      
 #ifdef SCC_LDELAY
        Outb(port, reg);
        udelay(SCC_LDELAY);
@@ -251,16 +252,15 @@ static inline unsigned char InReg(io_port port, unsigned char reg)
        Outb(port, reg);
        r=Inb(port);
 #endif
-       restore_flags(flags);
+       spin_unlock_irqrestore(&iolock, flags);
        return r;
 }
 
 static inline void OutReg(io_port port, unsigned char reg, unsigned char val)
 {
        unsigned long flags;
-       
-       save_flags(flags);
-       cli();
+
+       spin_lock_irqsave(&iolock, flags);
 #ifdef SCC_LDELAY
        Outb(port, reg); udelay(SCC_LDELAY);
        Outb(port, val); udelay(SCC_LDELAY);
@@ -268,7 +268,7 @@ static inline void OutReg(io_port port, unsigned char reg, unsigned char val)
        Outb(port, reg);
        Outb(port, val);
 #endif
-       restore_flags(flags);
+       spin_unlock_irqrestore(&iolock, flags);
 }
 
 static inline void wr(struct scc_channel *scc, unsigned char reg,
@@ -295,9 +295,7 @@ static inline void scc_discard_buffers(struct scc_channel *scc)
 {
        unsigned long flags;
        
-       save_flags(flags);
-       cli();
-       
+       spin_lock_irqsave(&scc->lock, flags);   
        if (scc->tx_buff != NULL)
        {
                dev_kfree_skb(scc->tx_buff);
@@ -307,7 +305,7 @@ static inline void scc_discard_buffers(struct scc_channel *scc)
        while (skb_queue_len(&scc->tx_queue))
                dev_kfree_skb(skb_dequeue(&scc->tx_queue));
 
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 
@@ -609,6 +607,7 @@ static inline void scc_spint(struct scc_channel *scc)
 
 static void scc_isr_dispatch(struct scc_channel *scc, int vector)
 {
+       spin_lock(&scc->lock);
        switch (vector & VECTOR_MASK)
        {
                case TXINT: scc_txint(scc); break;
@@ -616,6 +615,7 @@ static void scc_isr_dispatch(struct scc_channel *scc, int vector)
                case RXINT: scc_rxint(scc); break;
                case SPINT: scc_spint(scc); break;
        }
+       spin_unlock(&scc->lock);
 }
 
 /* If the card has a latch for the interrupt vector (like the PA0HZP card)
@@ -722,12 +722,13 @@ static inline void set_brg(struct scc_channel *scc, unsigned int tc)
 
 static inline void set_speed(struct scc_channel *scc)
 {
-       disable_irq(scc->irq);
+       unsigned long flags;
+       spin_lock_irqsave(&scc->lock, flags);
 
        if (scc->modem.speed > 0)       /* paranoia... */
                set_brg(scc, (unsigned) (scc->clock / (scc->modem.speed * 64)) - 2);
-
-       enable_irq(scc->irq);
+               
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 
@@ -988,14 +989,8 @@ static void scc_key_trx(struct scc_channel *scc, char tx)
 
 /* ----> SCC timer interrupt handler and friends. <---- */
 
-static void scc_start_tx_timer(struct scc_channel *scc, void (*handler)(unsigned long), unsigned long when)
+static void __scc_start_tx_timer(struct scc_channel *scc, void (*handler)(unsigned long), unsigned long when)
 {
-       unsigned long flags;
-       
-       
-       save_flags(flags);
-       cli();
-
        del_timer(&scc->tx_t);
 
        if (when == 0)
@@ -1009,17 +1004,22 @@ static void scc_start_tx_timer(struct scc_channel *scc, void (*handler)(unsigned
                scc->tx_t.expires = jiffies + (when*HZ)/100;
                add_timer(&scc->tx_t);
        }
+}
+
+static void scc_start_tx_timer(struct scc_channel *scc, void (*handler)(unsigned long), unsigned long when)
+{
+       unsigned long flags;
        
-       restore_flags(flags);
+       spin_lock_irqsave(&scc->lock, flags);
+       __scc_start_tx_timer(scc, handler, when);
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 static void scc_start_defer(struct scc_channel *scc)
 {
        unsigned long flags;
        
-       save_flags(flags);
-       cli();
-
+       spin_lock_irqsave(&scc->lock, flags);
        del_timer(&scc->tx_wdog);
        
        if (scc->kiss.maxdefer != 0 && scc->kiss.maxdefer != TIMER_OFF)
@@ -1029,16 +1029,14 @@ static void scc_start_defer(struct scc_channel *scc)
                scc->tx_wdog.expires = jiffies + HZ*scc->kiss.maxdefer;
                add_timer(&scc->tx_wdog);
        }
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 static void scc_start_maxkeyup(struct scc_channel *scc)
 {
        unsigned long flags;
        
-       save_flags(flags);
-       cli();
-
+       spin_lock_irqsave(&scc->lock, flags);
        del_timer(&scc->tx_wdog);
        
        if (scc->kiss.maxkeyup != 0 && scc->kiss.maxkeyup != TIMER_OFF)
@@ -1048,8 +1046,7 @@ static void scc_start_maxkeyup(struct scc_channel *scc)
                scc->tx_wdog.expires = jiffies + HZ*scc->kiss.maxkeyup;
                add_timer(&scc->tx_wdog);
        }
-       
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 /* 
@@ -1189,13 +1186,10 @@ static void t_tail(unsigned long channel)
        struct scc_channel *scc = (struct scc_channel *) channel;
        unsigned long flags;
        
-       save_flags(flags);
-       cli();
- 
+       spin_lock_irqsave(&scc->lock, flags); 
        del_timer(&scc->tx_wdog);       
        scc_key_trx(scc, TX_OFF);
-
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 
        if (scc->stat.tx_state == TXS_TIMEOUT)          /* we had a timeout? */
        {
@@ -1242,9 +1236,7 @@ static void t_maxkeyup(unsigned long channel)
        struct scc_channel *scc = (struct scc_channel *) channel;
        unsigned long flags;
 
-       save_flags(flags);
-       cli();
-
+       spin_lock_irqsave(&scc->lock, flags);
        /* 
         * let things settle down before we start to
         * accept new data.
@@ -1259,7 +1251,7 @@ static void t_maxkeyup(unsigned long channel)
        cl(scc, R15, TxUIE);            /* count it. */
        OutReg(scc->ctrl, R0, RES_Tx_P);
 
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 
        scc->stat.txerrs++;
        scc->stat.tx_state = TXS_TIMEOUT;
@@ -1289,13 +1281,10 @@ static void t_idle(unsigned long channel)
 static void scc_init_timer(struct scc_channel *scc)
 {
        unsigned long flags;
-       
-       save_flags(flags); 
-       cli();
-       
-       scc->stat.tx_state = TXS_IDLE;
 
-       restore_flags(flags);
+       spin_lock_irqsave(&scc->lock, flags);   
+       scc->stat.tx_state = TXS_IDLE;
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 
@@ -1414,9 +1403,7 @@ static void scc_stop_calibrate(unsigned long channel)
        struct scc_channel *scc = (struct scc_channel *) channel;
        unsigned long flags;
        
-       save_flags(flags);
-       cli();
-
+       spin_lock_irqsave(&scc->lock, flags);
        del_timer(&scc->tx_wdog);
        scc_key_trx(scc, TX_OFF);
        wr(scc, R6, 0);
@@ -1425,7 +1412,7 @@ static void scc_stop_calibrate(unsigned long channel)
        Outb(scc->ctrl,RES_EXT_INT);
 
        netif_wake_queue(scc->dev);
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 
@@ -1434,9 +1421,7 @@ scc_start_calibrate(struct scc_channel *scc, int duration, unsigned char pattern
 {
        unsigned long flags;
        
-       save_flags(flags);
-       cli();
-
+       spin_lock_irqsave(&scc->lock, flags);
        netif_stop_queue(scc->dev);
        scc_discard_buffers(scc);
 
@@ -1460,7 +1445,7 @@ scc_start_calibrate(struct scc_channel *scc, int duration, unsigned char pattern
        Outb(scc->ctrl,RES_EXT_INT);
 
        scc_key_trx(scc, TX_ON);
-       restore_flags(flags);
+       spin_unlock_irqrestore(&scc->lock, flags);
 }
 
 /* ******************************************************************* */
@@ -1508,16 +1493,14 @@ static void z8530_init(void)
                        
                /* Reset and pre-init Z8530 */
 
-               save_flags(flags);
-               cli();
-               
+               spin_lock_irqsave(&scc->lock, flags);
+                               
                Outb(scc->ctrl, 0);
                OutReg(scc->ctrl,R9,FHWRES);            /* force hardware reset */
                udelay(100);                            /* give it 'a bit' more time than required */
                wr(scc, R2, chip*16);                   /* interrupt vector */
                wr(scc, R9, VIS);                       /* vector includes status */
-               
-               restore_flags(flags);
+               spin_unlock_irqrestore(&scc->lock, flags);              
         }
 
  
@@ -1548,6 +1531,8 @@ static int scc_net_setup(struct scc_channel *scc, unsigned char *name, int addev
        dev->priv = (void *) scc;
        dev->init = scc_net_init;
 
+       spin_lock_init(&scc->lock);
+       
        if ((addev? register_netdevice(dev) : register_netdev(dev)) != 0) {
                kfree(dev);
                 return -EIO;
@@ -1625,17 +1610,14 @@ static int scc_net_close(struct net_device *dev)
 
        netif_stop_queue(dev);
 
-       save_flags(flags); 
-       cli();
-       
+       spin_lock_irqsave(&scc->lock, flags);   
        Outb(scc->ctrl,0);              /* Make sure pointer is written */
        wr(scc,R1,0);                   /* disable interrupts */
        wr(scc,R3,0);
+       spin_unlock_irqrestore(&scc->lock, flags);
 
-       del_timer(&scc->tx_t);
-       del_timer(&scc->tx_wdog);
-
-       restore_flags(flags);
+       del_timer_sync(&scc->tx_t);
+       del_timer_sync(&scc->tx_wdog);
        
        scc_discard_buffers(scc);
 
@@ -1689,9 +1671,8 @@ static int scc_net_tx(struct sk_buff *skb, struct net_device *dev)
                return 0;
        }
 
-       save_flags(flags);
-       cli();
-       
+       spin_lock_irqsave(&scc->lock, flags);
+               
        if (skb_queue_len(&scc->tx_queue) > scc->dev->tx_queue_len) {
                struct sk_buff *skb_del;
                skb_del = skb_dequeue(&scc->tx_queue);
@@ -1710,12 +1691,11 @@ static int scc_net_tx(struct sk_buff *skb, struct net_device *dev)
        if(scc->stat.tx_state == TXS_IDLE || scc->stat.tx_state == TXS_IDLE2) {
                scc->stat.tx_state = TXS_BUSY;
                if (scc->kiss.fulldup == KISS_DUPLEX_HALF)
-                       scc_start_tx_timer(scc, t_dwait, scc->kiss.waittime);
+                       __scc_start_tx_timer(scc, t_dwait, scc->kiss.waittime);
                else
-                       scc_start_tx_timer(scc, t_dwait, 0);
+                       __scc_start_tx_timer(scc, t_dwait, 0);
        }
-
-       restore_flags(flags);   
+       spin_unlock_irqrestore(&scc->lock, flags);
        return 0;
 }
 
@@ -1785,19 +1765,23 @@ static int scc_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                                hwcfg.clock = SCC_DEFAULT_CLOCK;
 
 #ifndef SCC_DONT_CHECK
-                       disable_irq(hwcfg.irq);
-
-                       check_region(scc->ctrl, 1);
-                       Outb(hwcfg.ctrl_a, 0);
-                       OutReg(hwcfg.ctrl_a, R9, FHWRES);
-                       udelay(100);
-                       OutReg(hwcfg.ctrl_a,R13,0x55);          /* is this chip really there? */
-                       udelay(5);
 
-                       if (InReg(hwcfg.ctrl_a,R13) != 0x55)
+                       if(request_region(scc->ctrl, 1, "scc-probe"))
+                       {
+                               disable_irq(hwcfg.irq);
+                               Outb(hwcfg.ctrl_a, 0);
+                               OutReg(hwcfg.ctrl_a, R9, FHWRES);
+                               udelay(100);
+                               OutReg(hwcfg.ctrl_a,R13,0x55);          /* is this chip really there? */
+                               udelay(5);
+
+                               if (InReg(hwcfg.ctrl_a,R13) != 0x55)
+                                       found = 0;
+                               enable_irq(hwcfg.irq);
+                               release_region(scc->ctrl, 1);
+                       }
+                       else
                                found = 0;
-
-                       enable_irq(hwcfg.irq);
 #endif
 
                        if (found)
@@ -2111,6 +2095,8 @@ static int __init scc_init_driver (void)
        
        printk(banner);
        
+       spin_lock_init(&iolock);
+       
        sprintf(devname,"%s0", SCC_DriverName);
        
        result = scc_net_setup(SCC_Info, devname, 0);
@@ -2127,20 +2113,19 @@ static int __init scc_init_driver (void)
 
 static void __exit scc_cleanup_driver(void)
 {
-       unsigned long flags;
        io_port ctrl;
        int k;
        struct scc_channel *scc;
        
-       save_flags(flags); 
-       cli();
-
        if (Nchips == 0)
        {
                unregister_netdev(SCC_Info[0].dev);
                kfree(SCC_Info[0].dev);
        }
 
+       /* Guard against chip prattle */
+       local_irq_disable();
+       
        for (k = 0; k < Nchips; k++)
                if ( (ctrl = SCC_ctrl[k].chan_A) )
                {
@@ -2149,6 +2134,13 @@ static void __exit scc_cleanup_driver(void)
                        udelay(50);
                }
                
+       /* To unload the port must be closed so no real IRQ pending */
+       for (k=0; k < NR_IRQS ; k++)
+               if (Ivec[k].used) free_irq(k, NULL);
+               
+       local_irq_enable();
+               
+       /* Now clean up */
        for (k = 0; k < Nchips*2; k++)
        {
                scc = &SCC_Info[k];
@@ -2164,14 +2156,10 @@ static void __exit scc_cleanup_driver(void)
                }
        }
        
-       for (k=0; k < NR_IRQS ; k++)
-               if (Ivec[k].used) free_irq(k, NULL);
                
        if (Vector_Latch)
                release_region(Vector_Latch, 1);
 
-       restore_flags(flags);
-
        proc_net_remove("z8530drv");
 }