patch-2.3.99-pre8 linux/drivers/s390/net/ctc.c

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diff -u --recursive --new-file v2.3.99-pre7/linux/drivers/s390/net/ctc.c linux/drivers/s390/net/ctc.c
@@ -0,0 +1,1581 @@
+/*
+ *  drivers/s390/net/ctc.c 
+ *    CTC / ESCON network driver
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Dieter Wellerdiek (wel@de.ibm.com)
+ *
+ *     2.3 Updates Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *                 Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
+ *
+ *
+ *  Description of the Kernel Parameter
+ *    Normally the CTC driver selects the channels in order (automatic channel 
+ *    selection). If your installation needs to use the channels in a different 
+ *    order or doesn't want to have automatic channel selection on, you can do 
+ *    this with the "ctc= kernel keyword". 
+ *
+ *       ctc=0,0xrrrr,0xwwww,ddddd
+ *
+ *     Where:
+ *
+ *       "rrrr" is the read channel address
+ *       "wwww" is the write channel address
+ *       "dddd" is the network device (ctc0 to ctc7 for a parallel channel, escon0
+ *              to escon7 for ESCON channels).
+ *
+ *     To switch the automatic channel selection off use the ctc= keyword with 
+ *     parameter "noauto". This may be necessary if you 3271 devices or other devices 
+ *     which use the ctc device type and model, but operate with a different protocol. 
+ *     
+ *       ctc=noauto
+ *
+ *  Change History
+ *    0.50  Initial release shipped
+ *    0.51  Bug fixes
+ *          - CTC / ESCON network device can now handle up to 64 channels 
+ *          - 3088-61 info message supperssed - CISCO 7206 - CLAW - ESCON 
+ *          - 3088-62 info message suppressed - OSA/D   
+ *          - channel: def ffffffed ... error message suppressed 
+ *          - CTC / ESCON device was not recoverable after a lost connection with 
+ *            IFCONFIG dev DOWN and IFCONFIG dev UP 
+ *          - Possibility to switch the automatic selection off
+ *          - Minor bug fixes 
+ */
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/malloc.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+
+#include <linux/signal.h>
+#include <linux/string.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ip.h>
+#include <linux/if_arp.h>
+#include <linux/tcp.h>
+#include <linux/skbuff.h>
+
+#include <asm/io.h>
+#include <asm/bitops.h>
+ 
+#include <asm/irq.h>
+
+
+//#define DEBUG 
+
+/* Redefine message level, so that all messages occur on 3215 console in DEBUG mode */
+#ifdef DEBUG                
+        #undef  KERN_INFO
+        #undef  KERN_WARNING
+        #undef  KERN_DEBUG
+        #define KERN_INFO    KERN_EMERG
+        #define KERN_WARNING KERN_EMERG
+        #define KERN_DEBUG   KERN_EMERG
+#endif  
+//#undef DEBUG
+
+#define CCW_CMD_WRITE           0x01
+#define CCW_CMD_READ            0x02
+#define CCW_CMD_SET_EXTENDED    0xc3
+#define CCW_CMD_PREPARE         0xe3
+
+#define MAX_CHANNEL_DEVICES     64 
+#define MAX_ADAPTERS            8
+#define CTC_DEFAULT_MTU_SIZE    1500
+#define READ                    0
+#define WRITE                   1
+#define CTC                     0
+#define ESCON                   1
+#define CHANNEL_MEDIA           2
+#define CTC_BLOCKS              8          /* 8 blocks * 2 times * 64k = 1M */
+
+#define TB_TX                   0          /* sk buffer handling in process */
+#define TB_STOP                 1          /* network device stop in process */
+#define TB_RETRY                2          /* retry in process */
+#define TB_NOBUFFER             3          /* no buffer on free queue */ 
+
+/* state machine codes used in ctc_irq_handler */
+#define CTC_STOP                0
+#define CTC_START_HALT_IO       1
+#define CTC_START_SET_X_MODE    2
+#define CTC_START_SELECT        4 
+#define CTC_START_READ_TEST     32
+#define CTC_START_READ          33
+#define CTC_START_WRITE_TEST    64
+#define CTC_START_WRITE         65
+
+
+typedef enum { 
+        channel_type_none,           /* Device is not a channel */
+        channel_type_undefined,      /* Device is a channel but we don't know anything about it */
+        channel_type_ctca,           /* Device is a CTC/A and we can deal with it */
+        channel_type_escon,          /* Device is a ESCON channel and we can deal with it */
+        channel_type_unsupported     /* Device is a unsupported model */
+} channel_type_t; 
+  
+
+
+/* 
+ *   Structures needed in the initial phase 
+ *
+ */  
+
+static int channel_tab_initialized = 0;     /* channel[] structure initialized */
+
+struct devicelist {  
+        unsigned int  devno;
+        __u8          flag;
+#define CHANNEL_IN_USE   0x08               /* - Show that channel is in use */
+}; 
+
+static struct {
+        struct devicelist  list[MAX_CHANNEL_DEVICES]; 
+        int                count;
+        int                left;
+} channel[CHANNEL_MEDIA];
+
+
+
+static int ctc_no_auto = 0;
+
+struct adapterlist{ 
+        unsigned int       devno[2];
+        __u16              protocol;
+};
+
+static struct adapterlist ctc_adapter[CHANNEL_MEDIA][MAX_ADAPTERS];  /* 0 = CTC  / 1 = ESCON */
+
+
+/* 
+ *   Structure used after the initial phase 
+ *
+ */
+    
+struct buffer {
+        struct buffer       *next;
+        int                 packets;
+        struct block        *block;
+};
+
+#if LINUX_VERSION_CODE>=0x020300
+typedef struct net_device  net_device;
+#else
+typedef struct device  net_device;
+typedef struct wait_queue* wait_queue_head_t;
+#define DECLARE_WAITQUEUE(waitqname,waitqtask) struct wait_queue  waitqname = {waitqtask, NULL }
+#define init_waitqueue_head(nothing)
+#endif
+
+
+struct channel {
+        unsigned int        devno;
+        int                 irq;
+        unsigned long       IO_active;
+        ccw1_t              ccw[3];
+        __u32               state; 
+        int                 buffer_count;
+        struct buffer       *free_anchor;
+        struct buffer       *proc_anchor;
+        devstat_t           *devstat;
+        net_device   *dev;      /* backward pointer to the network device */ 
+	wait_queue_head_t   wait;
+        struct tq_struct    tq;
+        struct timer_list   timer;
+        unsigned long       flag_a;    /* atomic flags */
+#define CTC_BH_ACTIVE       0   
+        __u8                last_dstat;
+        __u8                flag;
+#define CTC_WRITE            0x01      /* - Set if this is a write channel */
+#define CTC_TIMER            0x80      /* - Set if timer made the wake_up  */ 
+};
+
+
+struct ctc_priv {                                                                    
+        struct net_device_stats  stats;
+#if LINUX_VERSION_CODE>=0x02032D
+	int                      tbusy;
+#endif
+        struct channel           channel[2]; 
+        __u16                    protocol;
+};  
+
+/*
+ *   This structure works as shuttle between two systems 
+ *    - A block can contain one or more packets 
+ */
+
+#define PACKET_HEADER_LENGTH  6
+struct packet {
+        __u16         length;
+        __u16         type;
+        __u16         unused;
+        __u8          data;
+}; 
+
+#define BLOCK_HEADER_LENGTH   2
+struct block {
+        __u16         length;
+        struct packet data;
+};
+
+#if LINUX_VERSION_CODE>=0x02032D
+#define ctc_protect_busy(dev) \
+s390irq_spin_lock(((struct ctc_priv *)dev->priv)->channel[WRITE].irq)
+#define ctc_unprotect_busy(dev) \
+s390irq_spin_unlock(((struct ctc_priv *)dev->priv)->channel[WRITE].irq)
+
+#define ctc_protect_busy_irqsave(dev,flags) \
+s390irq_spin_lock_irqsave(((struct ctc_priv *)dev->priv)->channel[WRITE].irq,flags)
+#define ctc_unprotect_busy_irqrestore(dev,flags) \
+s390irq_spin_unlock_irqrestore(((struct ctc_priv *)dev->priv)->channel[WRITE].irq,flags)
+
+static __inline__ void ctc_set_busy(net_device *dev)
+{
+	((struct ctc_priv *)dev->priv)->tbusy=1;
+	netif_stop_queue(dev);
+}
+
+static __inline__ void ctc_clear_busy(net_device *dev)
+{
+	((struct ctc_priv *)dev->priv)->tbusy=0;
+	netif_start_queue(dev);
+}
+
+static __inline__ int ctc_check_busy(net_device *dev)
+{
+	eieio();
+	return(((struct ctc_priv *)dev->priv)->tbusy);
+}
+
+
+static __inline__ void ctc_setbit_busy(int nr,net_device *dev)
+{
+	set_bit(nr,&(((struct ctc_priv *)dev->priv)->tbusy));
+	netif_stop_queue(dev);	
+}
+
+static __inline__ void ctc_clearbit_busy(int nr,net_device *dev)
+{
+	clear_bit(nr,&(((struct ctc_priv *)dev->priv)->tbusy));
+	if(((struct ctc_priv *)dev->priv)->tbusy==0)
+		netif_start_queue(dev);
+}
+
+static __inline__ int ctc_test_and_setbit_busy(int nr,net_device *dev)
+{
+	netif_stop_queue(dev);
+	return(test_and_set_bit(nr,&((struct ctc_priv *)dev->priv)->tbusy));
+}
+#else
+
+#define ctc_protect_busy(dev)
+#define ctc_unprotect_busy(dev)
+#define ctc_protect_busy_irqsave(dev,flags)
+#define ctc_unprotect_busy_irqrestore(dev,flags)
+
+static __inline__ void ctc_set_busy(net_device *dev)
+{
+	dev->tbusy=1;
+	eieio();
+}
+
+static __inline__ void ctc_clear_busy(net_device *dev)
+{
+	dev->tbusy=0;
+	eieio();
+}
+
+static __inline__ int ctc_check_busy(net_device *dev)
+{
+	eieio();
+	return(dev->tbusy);
+}
+
+
+static __inline__ void ctc_setbit_busy(int nr,net_device *dev)
+{
+	set_bit(nr,(void *)&dev->tbusy);
+}
+
+static __inline__ void ctc_clearbit_busy(int nr,net_device *dev)
+{
+	clear_bit(nr,(void *)&dev->tbusy);
+}
+
+static __inline__ int ctc_test_and_setbit_busy(int nr,net_device *dev)
+{
+	return(test_and_set_bit(nr,(void *)&dev->tbusy));
+}
+#endif
+
+
+
+
+
+/* Interrupt handler */
+static void ctc_irq_handler(int irq, void *initparm, struct pt_regs *regs);
+static void ctc_irq_bh(struct channel *ctc); 
+static void ctc_read_retry (struct channel *ctc);
+static void ctc_write_retry (struct channel *ctc);
+
+
+/* Functions for the DEV methods */
+int ctc_probe(net_device *dev);
+ 
+
+static int ctc_open(net_device *dev); 
+static void ctc_timer (struct channel *ctc);
+static int ctc_release(net_device *dev);
+static int ctc_tx(struct sk_buff *skb, net_device *dev);
+static int ctc_change_mtu(net_device *dev, int new_mtu);
+struct net_device_stats* ctc_stats(net_device *dev); 
+
+
+/*
+ *   Channel Routines 
+ *
+ */ 
+
+static void channel_init(void);
+static void channel_scan(void);
+static int channel_get(int media, int devno);
+static int channel_get_next(int media); 
+static int channel_free(int media, int devno);
+static channel_type_t channel_check_for_type (senseid_t *id);
+static void channel_sort(struct devicelist list[], int n);
+
+
+/*
+ * initialize the channel[].list 
+ */   
+static void channel_init(void) 
+{
+        int     m;
+#ifdef DEBUG
+        int     c;
+#endif
+
+        if (!test_and_set_bit(0, (void *)& channel_tab_initialized)){
+                channel_scan(); 
+                for (m = 0; m < CHANNEL_MEDIA; m++) { 
+                        channel_sort (channel[m].list, MAX_CHANNEL_DEVICES); 
+                        channel[m].left = channel[m].count;   
+                }
+                if (channel[CTC].count == 0 && channel[ESCON].count == 0) 
+                        printk(KERN_INFO "channel: no Channel devices recognized\n");
+                else
+                        printk(KERN_INFO "channel: %d Parallel channel found - %d ESCON channel found\n",
+                            channel[CTC].count, channel[ESCON].count);  
+#ifdef DEBUG 
+                for (m = 0; m < CHANNEL_MEDIA;  m++) { 
+                        for (c = 0; c < MAX_CHANNEL_DEVICES; c++){
+                                printk(KERN_DEBUG "channel: Adapter=%x Entry=%x devno=%04x\n", 
+                                     m, c, channel[m].list[c].devno);
+                        }
+                }
+#endif
+         }
+}
+
+
+/*
+* scan for all channels and put the device numbers into the channel[].list 
+*/  
+static void channel_scan(void)
+{
+        int        m;
+        int        c;
+        int        irq;
+        dev_info_t temp;
+        
+        for (m = 0; m < CHANNEL_MEDIA;  m++) { 
+                for (c = 0; c < MAX_CHANNEL_DEVICES; c++){
+                        channel[m].list[c].devno = -ENODEV;
+                }
+        }
+        
+        for (irq = 0; irq < NR_IRQS; irq++) {
+                /* CTC/A */
+                if (channel[CTC].count < MAX_CHANNEL_DEVICES ) {
+                        if (get_dev_info(irq, &temp) == 0 && 
+                            channel_check_for_type(&temp.sid_data) == channel_type_ctca) {
+                                channel[CTC].list[channel[CTC].count].devno = temp.devno; 
+                                channel[CTC].count++; 
+                        }
+                }
+
+                /* ESCON */
+                if (channel[ESCON].count < MAX_CHANNEL_DEVICES ) {
+                        if (get_dev_info(irq, &temp) == 0 && 
+                            channel_check_for_type(&temp.sid_data) == channel_type_escon) {
+                                channel[ESCON].list[channel[ESCON].count].devno = temp.devno; 
+                                channel[ESCON].count++; 
+
+                        }
+                }
+        }
+} 
+ 
+
+/*
+ * free specific channel from the channel[].list 
+ */  
+static int channel_free(int media, int devno)
+{
+        int     i;
+
+        for (i = 0; i < channel[media].count; i++) {       
+                if ((devno == channel[media].list[i].devno) &&
+                    ((channel[media].list[i].flag & CHANNEL_IN_USE) != 0x00)) {
+                        channel[media].list[i].flag &= ~CHANNEL_IN_USE;
+                        return 0;
+                }
+        }
+        printk(KERN_WARNING "channel: dev %04x is not a channel or in use\n", devno);
+        return -ENODEV; 
+}
+
+
+/*
+ * get specific channel from the channel[].list 
+ */  
+static int channel_get(int media, int devno)
+{
+        int     i;
+
+        for (i = 0; i < channel[media].count; i++) {       
+                if ((devno == channel[media].list[i].devno) &&
+                    ((channel[media].list[i].flag & CHANNEL_IN_USE) == 0x00)) {
+                        channel[media].list[i].flag |= CHANNEL_IN_USE;
+                        return channel[media].list[i].devno;             
+                }
+        }
+        printk(KERN_WARNING "channel: dev %04x is not a channel or in use\n", devno);
+        return -ENODEV; 
+
+}
+
+
+/*
+ * get the next free channel from the channel[].list 
+ */  
+static int channel_get_next(int media)
+{
+        int     i;
+
+        for (i = 0; i < channel[media].count; i++) {
+                if ((channel[media].list[i].flag & CHANNEL_IN_USE) == 0x00) {
+#ifdef DEBUG
+                        printk(KERN_DEBUG "channel: picked=%04x\n", channel[media].list[i].devno);
+#endif
+                        channel[media].list[i].flag |= CHANNEL_IN_USE;
+                        return channel[media].list[i].devno;        
+                }
+        }
+        return -ENODEV; 
+}
+ 
+
+/*
+ * picks the next free channel from the channel[].list 
+ */  
+static int channel_left(int media)
+{
+        return channel[media].left; 
+}
+
+
+/*
+ * defines all devices which are channels
+ */
+static channel_type_t channel_check_for_type (senseid_t *id)
+ {
+        channel_type_t type;
+
+        switch (id->cu_type) {
+                case 0x3088: 
+
+                        switch (id->cu_model) {
+                                case 0x08:    
+                                        type = channel_type_ctca;  /* 3088-08  ==> CTCA */
+                                        break; 
+
+                                case 0x1F:   
+                                        type = channel_type_escon; /* 3088-1F  ==> ESCON channel */
+                                        break;
+ 
+                                case 0x01:                         /* 3088-01  ==> P390 OSA emulation */
+                                case 0x60:                         /* 3088-60  ==> OSA/2 adapter */
+                                case 0x61:                         /* 3088-61  ==> CISCO 7206 CLAW protocol ESCON connected */
+                                case 0x62:                         /* 3088-62  ==> OSA/D device */ 
+                                        type = channel_type_unsupported;
+                                         break; 
+
+                                default:
+                                        type = channel_type_undefined;
+                                        printk(KERN_INFO "channel: Unknown model found 3088-%02x\n",id->cu_model);
+                        }
+                        break;
+
+                default:
+                        type = channel_type_none;
+
+        }
+        return type;
+}
+
+
+/*
+ *  sort the channel[].list
+ */
+static void channel_sort(struct devicelist list[], int n)
+{
+        int               i;
+        int               sorted = 0;
+        struct devicelist tmp;
+
+        while (!sorted) { 
+                sorted = 1;
+
+                for (i = 0; i < n-1; i++) {  
+                        if (list[i].devno > list[i+1].devno) {  
+                                tmp = list[i];
+                                list[i] = list[i+1];
+                                list[i+1] = tmp;
+                                sorted = 0;
+                        }
+                }
+        }
+} 
+
+
+/*
+ *   General routines 
+ *
+ */
+
+static int inline extract_channel_id(char *name)
+{
+        if (name[0] == 'c') 
+                return (name[3]-'0');
+        else
+                return (name[5]-'0');
+}
+
+
+static int inline extract_channel_media(char *name)
+{
+        if (name[0] == 'c') 
+                return CTC;
+        else
+                return ESCON;
+}
+
+
+static void ctc_tab_init(void)
+{                                    
+        int          m;
+        int          i;
+        static int   t;
+
+        if (t == 0){
+                for (m = 0; m < CHANNEL_MEDIA;  m++) {
+                        for (i = 0; i < MAX_ADAPTERS;  i++) {
+                                ctc_adapter[m][i].devno[WRITE] = -ENODEV;
+                                ctc_adapter[m][i].devno[READ] = -ENODEV;
+                        }
+                }
+                t = 1; 
+        }
+} 
+
+
+static int ctc_buffer_alloc(struct channel *ctc) {
+        
+        struct buffer    *p;
+        struct buffer    *q;
+
+        p = kmalloc(sizeof(p), GFP_KERNEL);
+        if (p == NULL) 
+                return -ENOMEM;
+        else {  
+                p->next = NULL;  
+                p->packets = 0;
+                p->block = (struct block *) __get_free_pages(GFP_KERNEL+GFP_DMA, 4);
+                if (p->block == NULL) {
+                        kfree(p);
+                        return -ENOMEM;
+                }
+        }
+   
+        if (ctc->free_anchor == NULL) 
+                ctc->free_anchor = p;  
+        else {  
+                 q = ctc->free_anchor;
+                 while (q->next != NULL) 
+                        q = q->next;
+                 q->next = p;
+        }
+        ctc->buffer_count++;   
+   return 0;
+}
+
+
+static int ctc_buffer_free(struct channel *ctc) {
+        
+        struct buffer    *p;
+
+           
+        if (ctc->free_anchor == NULL)
+                return -ENOMEM;
+        
+        p = ctc->free_anchor; 
+        ctc->free_anchor = p->next;
+        free_pages((__u32)p->block, 4);
+        kfree(p);
+
+        return 0;
+}
+
+
+static int inline ctc_buffer_swap(struct buffer **from, struct buffer **to) {
+        
+        struct buffer    *p = NULL;
+        struct buffer    *q = NULL;
+ 
+        if (*from == NULL)
+                return -ENOMEM; 
+
+        p = *from;
+        *from = p->next;
+        p->next = NULL;
+
+        if (*to == NULL)
+                *to = p;
+        else {
+                q = *to;
+                while (q->next != NULL)
+                        q = q->next;
+                q->next = p;
+
+        }
+        return 0;
+}
+
+
+/*
+ *   ctc_setup function 
+ *     this function is called for each ctc= keyword passed into the kernel 
+ *
+ *     valid parameter are: ctc=n,0xnnnn,0xnnnn,ctcx 
+ *     where n      is the channel protocol always 0 
+ *           0xnnnn is the cu number  read 
+ *           0xnnnn is the cu number  write 
+ *           ctcx can be ctc0 to ctc7 or escon0 to escon7 
+ */
+#if LINUX_VERSION_CODE>=0x020300
+static int __init ctc_setup(char *dev_name)
+#else
+__initfunc(void ctc_setup(char *dev_name,int *ints))
+#endif
+{
+        struct adapterlist tmp;
+#if  LINUX_VERSION_CODE>=0x020300
+	#define CTC_MAX_PARMS 4
+	int ints[CTC_MAX_PARMS+1];	
+	get_options(dev_name,CTC_MAX_PARMS,ints);
+	#define ctc_setup_return return(1)
+#else
+	#define ctc_setup_return return
+#endif
+        ctc_tab_init();
+        
+        ctc_no_auto = 1;
+
+        if (!strcmp(dev_name,"noauto")) { 
+                printk(KERN_INFO "ctc: automatic channel selection deactivated\n"); 
+                ctc_setup_return;
+        }
+
+        tmp.devno[WRITE] = -ENODEV;
+        tmp.devno[READ] = -ENODEV; 
+
+        switch (ints[0]) {
+              
+                case 3: /* write channel passed */
+                        tmp.devno[WRITE] = ints[3]; 
+                        
+                case 2: /* read channel passed */
+                        tmp.devno[READ] = ints[2];
+                        if (tmp.devno[WRITE] == -ENODEV)
+                                tmp.devno[WRITE] = tmp.devno[READ] + 1; 
+
+                case 1: /* protocol type passed */
+                        tmp.protocol    = ints[1];
+                        if (tmp.protocol == 0) {
+                                break;    
+                        } else {
+                                printk(KERN_WARNING "%s: wrong Channel protocol type passed\n", dev_name);
+                                ctc_setup_return;
+                        }
+			break;
+
+                default: 
+                        printk(KERN_WARNING "ctc: wrong number of parameter passed\n");
+                        ctc_setup_return;
+        }
+        ctc_adapter[extract_channel_media(dev_name)][extract_channel_id(dev_name)] = tmp; 
+#ifdef DEBUG
+        printk(DEBUG "%s: protocol=%x read=%04x write=%04x\n",
+             dev_name, tmp.protocol, tmp.devno[READ], tmp.devno[WRITE]);
+#endif  
+        ctc_setup_return;
+        
+}
+#if LINUX_VERSION_CODE>=0x020300
+__setup("ctc=", ctc_setup);
+#endif
+
+/*
+ *   ctc_probe 
+ *      this function is called for each channel network device, 
+ *      which is defined in the /init/main.c 
+ */
+int ctc_probe(net_device *dev)
+{       
+        int                rc;
+        int                c;
+        int                i;
+        int                m;
+
+        struct ctc_priv    *privptr;
+
+        /* Only the first time the ctc_probe gets control */
+        if (channel_tab_initialized == 0) {  
+                channel_init();  
+
+
+        }
+        
+        ctc_tab_init();
+
+        m = extract_channel_media(dev->name);
+        i = extract_channel_id(dev->name);
+        
+        if (channel_left(m) <=1) 
+                return -ENODEV;
+
+        if (ctc_no_auto == 1 && (ctc_adapter[m][i].devno[READ] == -ENODEV || ctc_adapter[m][i].devno[WRITE] == -ENODEV))
+                return -ENODEV;
+
+        dev->priv = kmalloc(sizeof(struct ctc_priv), GFP_KERNEL);
+        if (dev->priv == NULL)
+                return -ENOMEM;
+        memset(dev->priv, 0, sizeof(struct ctc_priv));  
+        privptr = (struct ctc_priv *) (dev->priv);
+
+        
+        for (c = 0; c < 2; c++) {
+
+                privptr->channel[c].devstat = kmalloc(sizeof(devstat_t), GFP_KERNEL);
+                if (privptr->channel[c].devstat == NULL){
+                        if (i == WRITE)
+                                kfree(privptr->channel[READ].devstat);
+                        return -ENOMEM;  
+                }
+                memset(privptr->channel[c].devstat, 0, sizeof(devstat_t));
+
+                if (ctc_no_auto == 0) 
+                         ctc_adapter[m][i].devno[c] = channel_get_next(m);
+                else 
+                         ctc_adapter[m][i].devno[c] = channel_get(m, ctc_adapter[m][i].devno[c]);
+
+                if ( ctc_adapter[m][i].devno[c] != -ENODEV){
+                         rc = request_irq(get_irq_by_devno(ctc_adapter[m][i].devno[c]),
+                              (void *)ctc_irq_handler, SA_INTERRUPT, dev->name, 
+                              privptr->channel[c].devstat);
+                         if (rc) { 
+                                 printk(KERN_WARNING "%s: requested device busy %02x\n", dev->name, rc);
+                                 return -EBUSY;
+                         }
+                } else {        
+                        if (i == WRITE) {
+                                free_irq(get_irq_by_devno(ctc_adapter[m][i].devno[c]), privptr->channel[i].devstat);
+                                channel_free(m, ctc_adapter[m][i].devno[READ]);
+                                kfree(privptr->channel[READ].devstat);
+                        } 
+                        kfree(privptr->channel[i].devstat);
+                        return -ENODEV;
+                }
+        }
+
+        privptr->channel[READ].devno = ctc_adapter[m][i].devno[READ];
+        privptr->channel[READ].irq = get_irq_by_devno(ctc_adapter[m][i].devno[READ]);
+        privptr->channel[WRITE].devno = ctc_adapter[m][i].devno[WRITE];
+        privptr->channel[WRITE].irq = get_irq_by_devno(ctc_adapter[m][i].devno[WRITE]);
+        privptr->protocol = ctc_adapter[m][i].protocol;
+        channel[m].left = channel[m].left - 2;
+
+        printk(KERN_INFO "%s: read dev: %04x irq: %04x - write dev: %04x irq: %04x \n",
+            dev->name, privptr->channel[READ].devno,   privptr->channel[READ].irq,
+            privptr->channel[WRITE].devno,  privptr->channel[WRITE].irq); 
+
+        dev->mtu             = CTC_DEFAULT_MTU_SIZE;
+        dev->hard_start_xmit = ctc_tx;
+        dev->open            = ctc_open;
+        dev->stop            = ctc_release;
+        dev->get_stats       = ctc_stats;
+        dev->change_mtu      = ctc_change_mtu;
+        dev->hard_header_len = 0;
+        dev->addr_len        = 0;
+        dev->type            = ARPHRD_SLIP;
+        dev->tx_queue_len    = 100;
+        dev_init_buffers(dev);
+        dev->flags           = IFF_POINTOPOINT | IFF_NOARP;   
+
+        return 0;
+} 
+
+
+/*
+ *   Interrupt processing 
+ *
+ */
+
+static void inline ccw_check_return_code (net_device *dev, int return_code)
+{
+        if (return_code != 0) {
+                switch (return_code) {
+                        case -EBUSY:  
+                                printk(KERN_INFO "%s: Busy !\n", dev->name);
+                                break;
+                        case -ENODEV:
+                                printk(KERN_EMERG "%s: Invalid device called for IO\n", dev->name);
+                                break;
+                        case -EIO:
+                                printk(KERN_EMERG "%s: Status pending... \n", dev->name);
+                                break;
+                        default:
+                                printk(KERN_EMERG "%s: Unknown error in Do_IO %04x\n", 
+                                    dev->name, return_code);
+                }
+        }
+} 
+
+
+static void inline ccw_check_unit_check (net_device *dev, char sense)
+{
+#ifdef DEBUG
+        printk(KERN_INFO "%s: Unit Check with sense code: %02x\n",
+            dev->name, sense);
+#endif
+
+        if (sense & 0x40) {
+#ifdef DEBUG
+                if (sense & 0x01) 
+                        printk(KERN_DEBUG "%s: Interface disconnect or Selective reset occurred (remote side)\n", dev->name);
+                else 
+                        printk(KERN_DEBUG "%s: System reset occured (remote side)\n", dev->name);
+#endif
+        } else if (sense & 0x20) {
+                if (sense & 0x04)
+                        printk(KERN_WARNING "%s: Data-streaming timeout)\n", dev->name);
+                else 
+                        printk(KERN_WARNING "%s: Data-transfer parity error\n", dev->name);
+        } else if (sense & 0x10) {
+                if (sense & 0x20)
+                        printk(KERN_WARNING "%s: Hardware malfunction (remote side)\n", dev->name);
+                else 
+                        printk(KERN_WARNING "%s: Read-data parity error (remote side)\n", dev->name);
+        }
+
+} 
+
+
+static void ctc_irq_handler (int irq, void *initparm, struct pt_regs *regs)
+{
+        int               rc = 0;
+        __u32             parm;
+        __u8              flags = 0x00;
+        struct  channel   *ctc = NULL;
+        struct  ctc_priv  *privptr = NULL;
+        net_device        *dev = NULL;    
+        
+        ccw1_t            ccw_set_x_mode[2] = {{CCW_CMD_SET_EXTENDED, CCW_FLAG_SLI | CCW_FLAG_CC, 0, NULL},
+                                               {CCW_CMD_NOOP, CCW_FLAG_SLI, 0, NULL}}; 
+
+        devstat_t *devstat = ((devstat_t *)initparm);
+
+        /* Bypass all 'unsolited interrupts' */
+        if (devstat->intparm == 0) {
+#ifdef DEBUG
+                printk(KERN_DEBUG "ctc: unsolited interrupt for device: %04x received c-%02x d-%02x f-%02x\n",
+                    devstat->devno, devstat->cstat, devstat->dstat, devstat->flag);
+#endif 
+                /* FIXME - find the related intparm!!! No IO outstanding!!!! */
+                return;
+        }
+
+        ctc = (struct channel *) (devstat->intparm);
+        dev = (net_device *) ctc->dev;
+        privptr = dev->priv;
+
+#ifdef DEBUG
+        printk(KERN_DEBUG "%s: interrupt for device: %04x received c-%02x d-%02x f-%02x state-%02x\n",
+            dev->name, ctc->devno, devstat->cstat, devstat->dstat, devstat->flag, ctc->state);
+#endif 
+
+        /* Check for good subchannel return code, otherwise error message */
+        if (devstat->cstat) {
+                printk(KERN_WARNING "%s: subchannel check for device: %04x - %02x\n", 
+                    dev->name, ctc->devno, devstat->cstat);
+                return;
+        }
+
+
+        /* Check the reason-code of a unit check */
+        if (devstat->dstat & DEV_STAT_UNIT_CHECK)
+                ccw_check_unit_check(dev, devstat->ii.sense.data[0]);
+
+
+        /* State machine to bring the connection up / down and to restart */ 
+
+        ctc->last_dstat = devstat->dstat;
+
+        switch (ctc->state) {   
+
+                case CTC_STOP:           /* HALT_IO issued by ctc_release (halt sequence) */
+                        if (!devstat->flag & DEVSTAT_FINAL_STATUS)
+                                return;
+                        wake_up(&ctc->wait);   /* wake up ctc_release */
+                        return;
+ 
+
+                case CTC_START_HALT_IO:  /* HALT_IO issued by ctc_open (start sequence) */
+                        if (!devstat->flag & DEVSTAT_FINAL_STATUS)
+                                return;
+
+                        ctc->state = CTC_START_SET_X_MODE;
+                        parm = (__u32) ctc;
+                        rc = do_IO (ctc->irq, &ccw_set_x_mode[0], parm, 0xff, flags);
+                        if (rc != 0)
+                                ccw_check_return_code(dev, rc);
+                        return;
+ 
+        
+                case CTC_START_SET_X_MODE:
+                        if (devstat->dstat & DEV_STAT_UNIT_CHECK) {
+                                if ((devstat->ii.sense.data[0] & 0x41) != 0x41 ||
+                                    (devstat->ii.sense.data[0] & 0x40) != 0x40) {
+                                        wake_up(&ctc->wait);  /* wake up ctc_open (READ or WRITE) */
+                                        return; 
+                                }        
+                        }
+                        if (!devstat->flag & DEVSTAT_FINAL_STATUS)
+                                return;
+                        ctc->state =  CTC_START_SELECT;
+ 
+
+                case CTC_START_SELECT:
+                        if (!ctc->flag & CTC_WRITE) {
+                                ctc->state = CTC_START_READ_TEST;
+                                ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->free_anchor->block);
+                                parm = (__u32) ctc;
+                                rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+                                if (rc != 0) 
+                                        ccw_check_return_code(dev, rc);
+                                wake_up(&ctc->wait);  /* wake up ctc_open (READ) */
+
+                        } else {
+                                ctc->state = CTC_START_WRITE_TEST;
+                                /* ADD HERE THE RIGHT PACKET TO ISSUE A ROUND TRIP - PART 1 */
+                                ctc->ccw[1].count = 0;
+                                ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->free_anchor->block);
+                                parm = (__u32) ctc; 
+                                rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags);
+                                if (rc != 0)
+                                        ccw_check_return_code(dev, rc);
+                        }
+                        return;
+
+
+                case CTC_START_READ_TEST:
+                        if (devstat->dstat & DEV_STAT_UNIT_CHECK) {
+                                if ((devstat->ii.sense.data[0] & 0x41) == 0x41 ||
+                                    (devstat->ii.sense.data[0] & 0x40) == 0x40 ||
+                                    devstat->ii.sense.data[0] == 0                ) {
+                                        init_timer(&ctc->timer);
+                                        ctc->timer.function = (void *)ctc_read_retry; 
+                                        ctc->timer.data = (__u32)ctc;
+                                        ctc->timer.expires = jiffies + 10*HZ;
+                                        add_timer(&ctc->timer);
+#ifdef DEBUG 
+                                        printk(KERN_DEBUG "%s: read connection restarted\n",dev->name); 
+#endif
+                                }
+                                return;
+                        }
+
+                        if ((devstat->dstat &  ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) != 0x00) {
+                                if ((devstat->dstat & DEV_STAT_ATTENTION) && 
+                                    (devstat->dstat & DEV_STAT_BUSY)) {
+                                        printk(KERN_WARNING "%s: read channel is connected with the remote side read channel\n", dev->name);
+                                } 
+                                wake_up(&privptr->channel[WRITE].wait);  /* wake up ctc_open (WRITE) */
+                                return;
+                        }
+
+                        ctc->state = CTC_START_READ;
+                        set_bit(0, (void *)&ctc->IO_active);
+
+                        /* ADD HERE THE RIGHT PACKET TO ISSUE A ROUND TRIP - PART 2 */
+                        /* wake_up(&privptr->channel[WRITE].wait);*/  /* wake up ctc_open (WRITE) */
+
+
+                case CTC_START_READ: 
+                        if (devstat->dstat & DEV_STAT_UNIT_CHECK) {
+                                if ((devstat->ii.sense.data[0] & 0x41) == 0x41 ||
+                                    (devstat->ii.sense.data[0] & 0x40) == 0x40 ||
+                                    devstat->ii.sense.data[0] == 0               ) {
+                                        privptr->stats.rx_errors++;
+					/* Need protection here cos we are in the read irq */
+					/*  handler the tbusy is for the write subchannel */
+					ctc_protect_busy(dev);
+				        ctc_setbit_busy(TB_RETRY,dev);
+					ctc_unprotect_busy(dev);
+				        init_timer(&ctc->timer);
+                                        ctc->timer.function = (void *)ctc_read_retry; 
+                                        ctc->timer.data = (__u32)ctc;
+                                        ctc->timer.expires = jiffies + 30*HZ;
+                                        add_timer(&ctc->timer); 
+                                        printk(KERN_INFO "%s: connection restarted!! problem on remote side\n",dev->name);
+                                }
+                                return;
+                        }
+
+                        if(!devstat->flag & DEVSTAT_FINAL_STATUS)
+                                return; 
+			ctc_protect_busy(dev);
+			ctc_clearbit_busy(TB_RETRY,dev);
+			ctc_unprotect_busy(dev);
+                        ctc_buffer_swap(&ctc->free_anchor, &ctc->proc_anchor);
+
+                        if (ctc->free_anchor != NULL) {  
+                                ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->free_anchor->block);
+                                parm = (__u32) ctc;
+                                rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+                                if (rc != 0) 
+                                        ccw_check_return_code(dev, rc);
+                        } else {
+                                clear_bit(0, (void *)&ctc->IO_active);    
+#ifdef DEBUG
+                                printk(KERN_DEBUG "%s: No HOT READ started in IRQ\n",dev->name);
+#endif
+                        }
+                        
+                        if (test_and_set_bit(CTC_BH_ACTIVE, (void *)&ctc->flag_a) == 0) {
+                                queue_task(&ctc->tq, &tq_immediate);
+                                mark_bh(IMMEDIATE_BH);
+                        }
+                        return;
+
+
+                case CTC_START_WRITE_TEST:
+                        if (devstat->dstat & DEV_STAT_UNIT_CHECK) {
+                                if ((devstat->ii.sense.data[0] & 0x41) == 0x41 ||
+                                    (devstat->ii.sense.data[0] & 0x40) == 0x40 ||
+                                    devstat->ii.sense.data[0] == 0                ) {
+                                        init_timer(&ctc->timer);
+                                        ctc->timer.function = (void *)ctc_write_retry; 
+                                        ctc->timer.data = (__u32)ctc;
+                                        ctc->timer.expires = jiffies + 10*HZ;
+                                        add_timer(&ctc->timer);
+#ifdef DEBUG
+                                        printk(KERN_DEBUG "%s: write connection restarted\n",dev->name);
+#endif
+                                }
+                                return;
+                        }
+
+                        ctc->state = CTC_START_WRITE;
+                        wake_up(&ctc->wait);  /* wake up ctc_open (WRITE) */
+                        return;
+ 
+
+                case CTC_START_WRITE:
+                        if (devstat->dstat & DEV_STAT_UNIT_CHECK) {
+                                privptr->stats.tx_errors += ctc->proc_anchor->packets;
+#ifdef DEBUG
+                                printk(KERN_DEBUG "%s: Unit Check on write channel\n",dev->name);
+#endif
+                        } else { 
+                                if (!devstat->flag & DEVSTAT_FINAL_STATUS)
+                                        return; 
+                                privptr->stats.tx_packets += ctc->proc_anchor->packets;
+                        } 
+
+                        ctc->proc_anchor->block->length = 0;
+                        ctc_buffer_swap(&ctc->proc_anchor, &ctc->free_anchor);
+                        ctc_clearbit_busy(TB_NOBUFFER,dev);      
+                        if (ctc->proc_anchor != NULL) {  
+#ifdef DEBUG
+                                printk(KERN_DEBUG "%s: IRQ early swap buffer\n",dev->name); 
+#endif
+                                ctc->ccw[1].count = ctc->proc_anchor->block->length;
+                                ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->proc_anchor->block);
+                                parm = (__u32) ctc;
+                                rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+                                if (rc != 0) 
+                                        ccw_check_return_code(dev, rc);
+                                dev->trans_start = jiffies;
+                                return;
+
+                        }
+
+                        if (ctc->free_anchor->block->length != 0) {
+                                if (ctc_test_and_setbit_busy(TB_TX,dev) == 0) {     
+                                       /* set transmission to busy */
+                                        ctc_buffer_swap(&ctc->free_anchor, &ctc->proc_anchor);
+                                        ctc_clearbit_busy(TB_TX,dev);
+#ifdef DEBUG
+                                        printk(KERN_DEBUG "%s: last buffer move in IRQ\n",dev->name); 
+#endif
+                                        ctc->ccw[1].count = ctc->proc_anchor->block->length;
+                                        ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->proc_anchor->block);
+                                        parm = (__u32) ctc;
+                                        rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+                                        if (rc != 0) 
+                                                ccw_check_return_code(dev, rc);
+                                        dev->trans_start = jiffies;
+                                        return;
+                                }
+                        } 
+
+                        clear_bit(0, (void *)&ctc->IO_active);              /* set by ctc_tx or ctc_bh */
+                        return;
+
+ 
+                default: 
+                        printk(KERN_WARNING "%s: wrong selection code - irq\n",dev->name);
+                        return;  
+        }
+} 
+
+
+static void ctc_irq_bh (struct channel *ctc)
+{
+        int                rc = 0;
+        __u16              data_len;
+        __u32              parm;
+
+        __u8               flags = 0x00;
+        __u32              saveflags;
+        net_device  *dev;
+        struct ctc_priv    *privptr;             
+        struct packet      *lp;
+        struct sk_buff     *skb;
+
+        dev = (net_device *) ctc->dev; 
+        privptr = (struct ctc_priv *) dev->priv; 
+   
+#ifdef DEBUG
+        printk(KERN_DEBUG "%s: bh routine - state-%02x\n" ,dev->name, ctc->state);
+#endif 
+
+        while (ctc->proc_anchor != NULL) { 
+
+                lp = &ctc->proc_anchor->block->data;
+
+                while ((__u8 *) lp < (__u8 *) &ctc->proc_anchor->block->length + ctc->proc_anchor->block->length) {
+                        data_len = lp->length - PACKET_HEADER_LENGTH;
+                        skb = dev_alloc_skb(data_len); 
+                        if (skb) { 
+                                memcpy(skb_put(skb, data_len),&lp->data, data_len);
+                                skb->mac.raw = skb->data;
+                                skb->dev = dev;
+                                skb->protocol = htons(ETH_P_IP);
+                                skb->ip_summed = CHECKSUM_UNNECESSARY; /* no UC happened!!! */
+                                netif_rx(skb);
+                                privptr->stats.rx_packets++;
+                        } else {
+                                privptr->stats.rx_dropped++; 
+                                printk(KERN_WARNING "%s: is low on memory\n",dev->name);
+                        }
+                        (__u8 *)lp += lp->length;
+                }
+
+                s390irq_spin_lock_irqsave(ctc->irq, saveflags);
+                ctc_buffer_swap(&ctc->proc_anchor, &ctc->free_anchor);
+
+                if (test_and_set_bit(0, (void *)&ctc->IO_active) == 0) {
+#ifdef DEBUG
+                        printk(KERN_DEBUG "%s: HOT READ started in bh routine\n" ,dev->name);
+#endif 
+                        ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->free_anchor->block);
+                        parm = (__u32) ctc; 
+                        rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+                        if (rc != 0) 
+                                 ccw_check_return_code(dev, rc);
+                } 
+                s390irq_spin_unlock_irqrestore(ctc->irq, saveflags); 
+        }
+        clear_bit(CTC_BH_ACTIVE, (void *)&ctc->flag_a);
+        return;
+}  
+
+
+static void ctc_read_retry (struct channel *ctc)
+{
+        int                rc = 0;
+        __u32              parm;
+        __u8               flags = 0x00;
+        __u32              saveflags;
+        net_device  *dev;
+
+        dev = (net_device *) ctc->dev; 
+   
+#ifdef DEBUG
+        printk(KERN_DEBUG "%s: read retry - state-%02x\n" ,dev->name, ctc->state);
+#endif 
+        s390irq_spin_lock_irqsave(ctc->irq, saveflags);
+        ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->free_anchor->block);
+        parm = (__u32) ctc; 
+        rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+        s390irq_spin_unlock_irqrestore(ctc->irq, saveflags);
+        if (rc != 0) 
+                ccw_check_return_code(dev, rc);
+        return;
+}  
+ 
+
+static void ctc_write_retry (struct channel *ctc)
+{
+        int                rc = 0;
+        __u32              parm;
+        __u8               flags = 0x00;
+        __u32              saveflags;
+        net_device  *dev;
+
+        dev = (net_device *) ctc->dev; 
+   
+#ifdef DEBUG
+        printk(KERN_DEBUG "%s: write retry - state-%02x\n" ,dev->name, ctc->state);
+#endif 
+        s390irq_spin_lock_irqsave(ctc->irq, saveflags);
+        ctc->ccw[1].count = 0;
+        ctc->ccw[1].cda  = (char *)virt_to_phys(ctc->proc_anchor->block);
+        parm = (__u32) ctc; 
+        rc = do_IO (ctc->irq, &ctc->ccw[0], parm, 0xff, flags );
+        s390irq_spin_unlock_irqrestore(ctc->irq, saveflags);
+        if (rc != 0) 
+                ccw_check_return_code(dev, rc);
+        return;
+}  
+
+
+
+/*
+ *   ctc_open
+ *
+ */
+static int ctc_open(net_device *dev)
+{
+        int                rc;
+        int                i;
+        int                j;
+        __u8               flags = 0x00;
+        __u32              saveflags;
+        __u32              parm;
+        struct ctc_priv    *privptr;
+	DECLARE_WAITQUEUE(wait, current);
+        struct timer_list  timer;
+
+
+        ctc_set_busy(dev);
+
+        privptr = (struct ctc_priv *) (dev->priv);
+        
+        privptr->channel[READ].flag  = 0x00;
+        privptr->channel[WRITE].flag = CTC_WRITE;
+
+        for (i = 0; i < 2;  i++) { 
+                for (j = 0; j < CTC_BLOCKS;  j++) { 
+                        rc = ctc_buffer_alloc(&privptr->channel[i]);
+                        if (rc != 0)
+                                return -ENOMEM;
+                }
+                init_waitqueue_head(&privptr->channel[i].wait);
+                privptr->channel[i].tq.next = NULL;
+                privptr->channel[i].tq.sync = 0;
+                privptr->channel[i].tq.routine = (void *)(void *)ctc_irq_bh;
+                privptr->channel[i].tq.data = &privptr->channel[i]; 
+
+                privptr->channel[i].dev = dev;
+                
+                privptr->channel[i].flag_a = 0;
+                privptr->channel[i].IO_active = 0;
+
+                privptr->channel[i].ccw[0].cmd_code  = CCW_CMD_PREPARE;
+                privptr->channel[i].ccw[0].flags     = CCW_FLAG_SLI | CCW_FLAG_CC;
+                privptr->channel[i].ccw[0].count     = 0;
+                privptr->channel[i].ccw[0].cda       = NULL;
+                if (i == READ) {  
+                        privptr->channel[i].ccw[1].cmd_code  = CCW_CMD_READ;
+                        privptr->channel[i].ccw[1].flags     = CCW_FLAG_SLI;
+                        privptr->channel[i].ccw[1].count     = 0xffff;   /* MAX size */
+                        privptr->channel[i].ccw[1].cda       = NULL;
+                } else {
+                        privptr->channel[i].ccw[1].cmd_code = CCW_CMD_WRITE;
+                        privptr->channel[i].ccw[1].flags    = CCW_FLAG_SLI | CCW_FLAG_CC;
+                        privptr->channel[i].ccw[1].count    = 0;
+                        privptr->channel[i].ccw[1].cda      = NULL;
+                }
+                privptr->channel[i].ccw[2].cmd_code = CCW_CMD_NOOP;      /* jointed CE+DE */
+                privptr->channel[i].ccw[2].flags    = CCW_FLAG_SLI;
+                privptr->channel[i].ccw[2].count    = 0;
+                privptr->channel[i].ccw[2].cda      = NULL;
+                
+                privptr->channel[i].flag  &= ~CTC_TIMER;
+                init_timer(&timer);
+                timer.function = (void *)ctc_timer; 
+                timer.data = (__u32)&privptr->channel[i];
+                timer.expires = jiffies + 150*HZ;                        /* time to connect with the remote side */
+                add_timer(&timer);
+
+                s390irq_spin_lock_irqsave(privptr->channel[i].irq, saveflags);
+                parm = (unsigned long) &privptr->channel[i]; 
+                privptr->channel[i].state = CTC_START_HALT_IO;
+                rc = halt_IO(privptr->channel[i].irq, parm, flags);
+                add_wait_queue(&privptr->channel[i].wait, &wait);
+                current->state = TASK_INTERRUPTIBLE;
+                s390irq_spin_unlock_irqrestore(privptr->channel[i].irq, saveflags);
+                schedule();
+                remove_wait_queue(&privptr->channel[i].wait, &wait);
+                if(rc != 0)
+                        ccw_check_return_code(dev, rc);
+                if((privptr->channel[i].flag & CTC_TIMER) == 0x00)
+                        del_timer(&timer);
+        }
+
+        if ((((privptr->channel[READ].last_dstat | privptr->channel[WRITE].last_dstat) & 
+               ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) != 0x00) ||
+            (((privptr->channel[READ].flag | privptr->channel[WRITE].flag) & CTC_TIMER) != 0x00)) {
+#ifdef DEBUG
+                printk(KERN_DEBUG "%s: channel problems during open - read: %02x -  write: %02x\n",
+                    dev->name, privptr->channel[READ].last_dstat, privptr->channel[WRITE].last_dstat);
+#endif 
+                printk(KERN_INFO "%s: remote side is currently not ready\n", dev->name);
+                
+                for (i = 0; i < 2;  i++) {
+                        s390irq_spin_lock_irqsave(privptr->channel[i].irq, saveflags);
+                        parm = (unsigned long) &privptr->channel[i];
+                        privptr->channel[i].state = CTC_STOP;
+                        rc = halt_IO(privptr->channel[i].irq, parm, flags);
+                        s390irq_spin_unlock_irqrestore(privptr->channel[i].irq, saveflags);
+                        if (rc != 0)
+                                ccw_check_return_code(dev, rc);
+                        for (j = 0; j < CTC_BLOCKS;  j++) 
+                                ctc_buffer_free(&privptr->channel[i]);
+                }
+                return -EIO;
+        }
+
+        printk(KERN_INFO "%s: connected with remote side\n",dev->name);
+        ctc_clear_busy(dev);
+        return 0;
+}
+
+
+static void ctc_timer (struct channel *ctc)
+{
+#ifdef DEBUG
+        net_device  *dev;
+
+        dev = (net_device *) ctc->dev; 
+        printk(KERN_DEBUG "%s: timer return\n" ,dev->name);
+#endif
+        ctc->flag |= CTC_TIMER;
+        wake_up(&ctc->wait);  
+        return;
+}  
+
+/*
+ *   ctc_release 
+ *
+ */
+static int ctc_release(net_device *dev)
+{   
+        int                rc;
+        int                i;
+        int                j;
+        __u8               flags = 0x00;
+        __u32              saveflags;
+        __u32              parm;
+        struct ctc_priv    *privptr;
+	DECLARE_WAITQUEUE(wait, current);
+
+        privptr = (struct ctc_priv *) dev->priv;  
+   
+	ctc_protect_busy_irqsave(dev,saveflags);
+        ctc_setbit_busy(TB_STOP,dev);    
+	ctc_unprotect_busy_irqrestore(dev,flags);
+        for (i = 0; i < 2;  i++) {
+                s390irq_spin_lock_irqsave(privptr->channel[i].irq, saveflags);
+                privptr->channel[i].state = CTC_STOP;
+                parm = (__u32) &privptr->channel[i]; 
+                rc = halt_IO (privptr->channel[i].irq, parm, flags );
+                add_wait_queue(&privptr->channel[i].wait, &wait);
+                current->state = TASK_INTERRUPTIBLE;
+                s390irq_spin_unlock_irqrestore(privptr->channel[i].irq, saveflags); 
+                schedule();
+                remove_wait_queue(&privptr->channel[i].wait, &wait);
+                if (rc != 0) {
+                        ccw_check_return_code(dev, rc);
+                }
+                 
+                for (j = 0; j < CTC_BLOCKS;  j++) {  
+                        ctc_buffer_swap(&privptr->channel[i].proc_anchor, &privptr->channel[i].free_anchor);
+                        ctc_buffer_free(&privptr->channel[i]); 
+                }
+        }
+
+        if (((privptr->channel[READ].last_dstat | privptr->channel[WRITE].last_dstat) &
+            ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) != 0x00) {
+                printk(KERN_WARNING "%s: channel problems during close - read: %02x -  write: %02x\n",
+                    dev->name, privptr->channel[READ].last_dstat, privptr->channel[WRITE].last_dstat);
+                return -EIO;
+        }
+
+        return 0;
+}  
+
+
+/*
+ *   ctc_tx 
+ *
+ *
+ */
+static int ctc_tx(struct sk_buff *skb, net_device *dev)
+{
+        int                rc=0,rc2;
+        __u32              parm;
+        __u8               flags = 0x00;
+        __u32              saveflags;
+        struct ctc_priv    *privptr;
+        struct packet      *lp;
+
+   
+        privptr = (struct ctc_priv *) (dev->priv);
+
+        if (skb == NULL) { 
+                printk(KERN_WARNING "%s: NULL pointer as sk_buffer passed\n", dev->name);
+                privptr->stats.tx_dropped++;
+                return -EIO;
+        }
+        
+        s390irq_spin_lock_irqsave(privptr->channel[WRITE].irq, saveflags);
+        if (ctc_check_busy(dev)) {
+                rc=-EBUSY;
+		goto Done;
+        } 
+
+        if (ctc_test_and_setbit_busy(TB_TX,dev)) {                /* set transmission to busy */
+                rc=-EBUSY;
+		goto Done;
+        } 
+
+        if (65535 - privptr->channel[WRITE].free_anchor->block->length - PACKET_HEADER_LENGTH <= skb->len + PACKET_HEADER_LENGTH + 2) {
+#ifdef DEBUG
+                printk(KERN_DEBUG "%s: early swap\n", dev->name);
+#endif
+               
+                ctc_buffer_swap(&privptr->channel[WRITE].free_anchor, &privptr->channel[WRITE].proc_anchor);
+                if (privptr->channel[WRITE].free_anchor == NULL){
+                        ctc_setbit_busy(TB_NOBUFFER,dev);
+                        rc=-EBUSY;
+			goto Done2;
+                }
+        }
+        
+        if (privptr->channel[WRITE].free_anchor->block->length == 0) {
+                privptr->channel[WRITE].free_anchor->block->length = BLOCK_HEADER_LENGTH; 
+                privptr->channel[WRITE].free_anchor->packets = 0;
+        } 
+
+
+        (__u8 *)lp = (__u8 *) &privptr->channel[WRITE].free_anchor->block->length + privptr->channel[WRITE].free_anchor->block->length;
+        privptr->channel[WRITE].free_anchor->block->length += skb->len + PACKET_HEADER_LENGTH;
+        lp->length = skb->len + PACKET_HEADER_LENGTH; 
+        lp->type = 0x0800; 
+        lp->unused = 0;
+        memcpy(&lp->data, skb->data, skb->len); 
+        (__u8 *) lp += lp->length; 
+        lp->length = 0;
+        dev_kfree_skb(skb);
+        privptr->channel[WRITE].free_anchor->packets++;
+
+        if (test_and_set_bit(0, (void *)&privptr->channel[WRITE].IO_active) == 0) {
+	       ctc_buffer_swap(&privptr->channel[WRITE].free_anchor,&privptr->channel[WRITE].proc_anchor); 
+                privptr->channel[WRITE].ccw[1].count = privptr->channel[WRITE].proc_anchor->block->length;
+                privptr->channel[WRITE].ccw[1].cda   = (char *)virt_to_phys(privptr->channel[WRITE].proc_anchor->block);
+                parm = (__u32) &privptr->channel[WRITE];  
+                rc2 = do_IO (privptr->channel[WRITE].irq, &privptr->channel[WRITE].ccw[0], parm, 0xff, flags );
+                if (rc2 != 0) 
+                        ccw_check_return_code(dev, rc2);
+                dev->trans_start = jiffies;
+        }
+        if (privptr->channel[WRITE].free_anchor == NULL)
+                ctc_setbit_busy(TB_NOBUFFER,dev);
+Done2:
+        ctc_clearbit_busy(TB_TX,dev);
+Done:
+	s390irq_spin_unlock_irqrestore(privptr->channel[WRITE].irq, saveflags);
+        return(rc);
+} 
+
+
+/*
+ *   ctc_change_mtu 
+ *
+ *   S/390 can handle MTU sizes from 576 to 32760 for VM, VSE
+ *                                   576 to 65527 for OS/390
+ *
+ */
+static int ctc_change_mtu(net_device *dev, int new_mtu)
+{
+        if ((new_mtu < 576) || (new_mtu > 65528))
+                return -EINVAL;
+        dev->mtu = new_mtu;
+        return 0;
+}
+
+
+/*
+ *   ctc_stats
+ *
+ */
+struct net_device_stats *ctc_stats(net_device *dev)
+{
+         struct ctc_priv *privptr;
+   
+         privptr = dev->priv;
+         return &privptr->stats;
+}  
+
+
+/* Module code goes here */
+
+/*
+                free_irq(privptr->channel[i].irq, privptr->channel[i].devstat);
+                kfree(privptr->channel[i].devstat); 
+
+*/
+/* --- This is the END my friend --- */

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)