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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [n_r3964.c] - Rev 1275
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/* r3964 linediscipline for linux * * ----------------------------------------------------------- * Copyright by * Philips Automation Projects * Kassel (Germany) * http://www.pap-philips.de * ----------------------------------------------------------- * This software may be used and distributed according to the terms of * the GNU General Public License, incorporated herein by reference. * * Author: * L. Haag * * $Log: not supported by cvs2svn $ * Revision 1.8 2000/03/23 14:14:54 dwmw2 * Fix race in sleeping in r3964_read() * * Revision 1.7 1999/28/08 11:41:50 dwmw2 * Port to 2.3 kernel * * Revision 1.6 1998/09/30 00:40:40 dwmw2 * Fixed compilation on 2.0.x kernels * Updated to newly registered tty-ldisc number 9 * * Revision 1.5 1998/09/04 21:57:36 dwmw2 * Signal handling bug fixes, port to 2.1.x. * * Revision 1.4 1998/04/02 20:26:59 lhaag * select, blocking, ... * * Revision 1.3 1998/02/12 18:58:43 root * fixed some memory leaks * calculation of checksum characters * * Revision 1.2 1998/02/07 13:03:34 root * ioctl read_telegram * * Revision 1.1 1998/02/06 19:21:03 root * Initial revision * * */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/types.h> #include <linux/fcntl.h> #include <linux/interrupt.h> #include <linux/ptrace.h> #include <linux/ioport.h> #include <linux/in.h> #include <linux/slab.h> #include <linux/tty.h> #include <linux/errno.h> #include <linux/string.h> /* used in new tty drivers */ #include <linux/signal.h> /* used in new tty drivers */ #include <linux/ioctl.h> #include <linux/n_r3964.h> #include <linux/poll.h> #include <linux/init.h> #include <asm/uaccess.h> //#define DEBUG_QUEUE /* Log successful handshake and protocol operations */ //#define DEBUG_PROTO_S /* Log handshake and protocol errors: */ //#define DEBUG_PROTO_E /* Log Linediscipline operations (open, close, read, write...): */ //#define DEBUG_LDISC /* Log module and memory operations (init, cleanup; kmalloc, kfree): */ //#define DEBUG_MODUL /* Macro helpers for debug output: */ #define TRACE(format, args...) printk("r3964: " format "\n" , ## args); #ifdef DEBUG_MODUL #define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args); #else #define TRACE_M(fmt, arg...) /**/ #endif #ifdef DEBUG_PROTO_S #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args); #else #define TRACE_PS(fmt, arg...) /**/ #endif #ifdef DEBUG_PROTO_E #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args); #else #define TRACE_PE(fmt, arg...) /**/ #endif #ifdef DEBUG_LDISC #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args); #else #define TRACE_L(fmt, arg...) /**/ #endif #ifdef DEBUG_QUEUE #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args); #else #define TRACE_Q(fmt, arg...) /**/ #endif static void on_timer_1(void*); static void on_timer_2(void*); static void add_tx_queue(struct r3964_info *, struct r3964_block_header *); static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code); static void put_char(struct r3964_info *pInfo, unsigned char ch); static void trigger_transmit(struct r3964_info *pInfo); static void retry_transmit(struct r3964_info *pInfo); static void transmit_block(struct r3964_info *pInfo); static void receive_char(struct r3964_info *pInfo, const unsigned char c); static void receive_error(struct r3964_info *pInfo, const char flag); static void on_timeout(struct r3964_info *pInfo); static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg); static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char *buf); static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg, int error_code, struct r3964_block_header *pBlock); static struct r3964_message* remove_msg(struct r3964_info *pInfo, struct r3964_client_info *pClient); static void remove_client_block(struct r3964_info *pInfo, struct r3964_client_info *pClient); static int r3964_open(struct tty_struct *tty); static void r3964_close(struct tty_struct *tty); static ssize_t r3964_read(struct tty_struct *tty, struct file *file, unsigned char *buf, size_t nr); static ssize_t r3964_write(struct tty_struct * tty, struct file * file, const unsigned char * buf, size_t nr); static int r3964_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg); static void r3964_set_termios(struct tty_struct *tty, struct termios * old); static unsigned int r3964_poll(struct tty_struct * tty, struct file * file, struct poll_table_struct *wait); static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count); static int r3964_receive_room(struct tty_struct *tty); static struct tty_ldisc tty_ldisc_N_R3964 = { TTY_LDISC_MAGIC, /* magic */ "R3964", /* name */ 0, /* num */ 0, /* flags */ r3964_open, /* open */ r3964_close, /* close */ 0, /* flush_buffer */ 0, /* chars_in_buffer */ r3964_read, /* read */ r3964_write, /* write */ r3964_ioctl, /* ioctl */ r3964_set_termios, /* set_termios */ r3964_poll, /* poll */ r3964_receive_buf, /* receive_buf */ r3964_receive_room, /* receive_room */ 0 /* write_wakeup */ }; static void dump_block(const unsigned char *block, unsigned int length) { unsigned int i,j; char linebuf[16*3+1]; for(i=0;i<length;i+=16) { for(j=0;(j<16) && (j+i<length);j++) { sprintf(linebuf+3*j,"%02x ",block[i+j]); } linebuf[3*j]='\0'; TRACE_PS("%s",linebuf); } } /************************************************************* * Driver initialisation *************************************************************/ /************************************************************* * Module support routines *************************************************************/ static void __exit r3964_exit(void) { int status; TRACE_M ("cleanup_module()"); status=tty_register_ldisc(N_R3964, NULL); if(status!=0) { printk(KERN_ERR "r3964: error unregistering linediscipline: %d\n", status); } else { TRACE_L("linediscipline successfully unregistered"); } } static int __init r3964_init(void) { int status; printk ("r3964: Philips r3964 Driver $Revision: 1.1.1.1 $\n"); /* * Register the tty line discipline */ status = tty_register_ldisc (N_R3964, &tty_ldisc_N_R3964); if (status == 0) { TRACE_L("line discipline %d registered", N_R3964); TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags, tty_ldisc_N_R3964.num); TRACE_L("open=%x", (int)tty_ldisc_N_R3964.open); TRACE_L("tty_ldisc_N_R3964 = %x", (int)&tty_ldisc_N_R3964); } else { printk (KERN_ERR "r3964: error registering line discipline: %d\n", status); } return status; } module_init(r3964_init); module_exit(r3964_exit); /************************************************************* * Protocol implementation routines *************************************************************/ static void on_timer_1(void *arg) { struct r3964_info *pInfo = (struct r3964_info *)arg; if(pInfo->count_down) { if(!--pInfo->count_down) { on_timeout(pInfo); } } queue_task(&pInfo->bh_2, &tq_timer); } static void on_timer_2(void *arg) { struct r3964_info *pInfo = (struct r3964_info *)arg; if(pInfo->count_down) { if(!--pInfo->count_down) { on_timeout(pInfo); } } queue_task(&pInfo->bh_1, &tq_timer); } static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) { unsigned long flags; save_flags(flags); cli(); pHeader->next = NULL; if(pInfo->tx_last == NULL) { pInfo->tx_first = pInfo->tx_last = pHeader; } else { pInfo->tx_last->next = pHeader; pInfo->tx_last = pHeader; } restore_flags(flags); TRACE_Q("add_tx_queue %x, length %d, tx_first = %x", (int)pHeader, pHeader->length, (int)pInfo->tx_first ); } static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code) { struct r3964_block_header *pHeader; unsigned long flags; #ifdef DEBUG_QUEUE struct r3964_block_header *pDump; #endif pHeader = pInfo->tx_first; if(pHeader==NULL) return; #ifdef DEBUG_QUEUE printk("r3964: remove_from_tx_queue: %x, length %d - ", (int)pHeader, (int)pHeader->length ); for(pDump=pHeader;pDump;pDump=pDump->next) printk("%x ", (int)pDump); printk("\n"); #endif if(pHeader->owner) { if(error_code) { add_msg(pHeader->owner, R3964_MSG_ACK, 0, error_code, NULL); } else { add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length, error_code, NULL); } wake_up_interruptible (&pInfo->read_wait); } save_flags(flags); cli(); pInfo->tx_first = pHeader->next; if(pInfo->tx_first==NULL) { pInfo->tx_last = NULL; } restore_flags(flags); kfree(pHeader); TRACE_M("remove_from_tx_queue - kfree %x",(int)pHeader); TRACE_Q("remove_from_tx_queue: tx_first = %x, tx_last = %x", (int)pInfo->tx_first, (int)pInfo->tx_last ); } static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) { unsigned long flags; save_flags(flags); cli(); pHeader->next = NULL; if(pInfo->rx_last == NULL) { pInfo->rx_first = pInfo->rx_last = pHeader; } else { pInfo->rx_last->next = pHeader; pInfo->rx_last = pHeader; } pInfo->blocks_in_rx_queue++; restore_flags(flags); TRACE_Q("add_rx_queue: %x, length = %d, rx_first = %x, count = %d", (int)pHeader, pHeader->length, (int)pInfo->rx_first, pInfo->blocks_in_rx_queue); } static void remove_from_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) { unsigned long flags; struct r3964_block_header *pFind; if(pHeader==NULL) return; TRACE_Q("remove_from_rx_queue: rx_first = %x, rx_last = %x, count = %d", (int)pInfo->rx_first, (int)pInfo->rx_last, pInfo->blocks_in_rx_queue ); TRACE_Q("remove_from_rx_queue: %x, length %d", (int)pHeader, (int)pHeader->length ); save_flags(flags); cli(); if(pInfo->rx_first == pHeader) { /* Remove the first block in the linked list: */ pInfo->rx_first = pHeader->next; if(pInfo->rx_first==NULL) { pInfo->rx_last = NULL; } pInfo->blocks_in_rx_queue--; } else { /* Find block to remove: */ for(pFind=pInfo->rx_first; pFind; pFind=pFind->next) { if(pFind->next == pHeader) { /* Got it. */ pFind->next = pHeader->next; pInfo->blocks_in_rx_queue--; if(pFind->next==NULL) { /* Oh, removed the last one! */ pInfo->rx_last = pFind; } break; } } } restore_flags(flags); kfree(pHeader); TRACE_M("remove_from_rx_queue - kfree %x",(int)pHeader); TRACE_Q("remove_from_rx_queue: rx_first = %x, rx_last = %x, count = %d", (int)pInfo->rx_first, (int)pInfo->rx_last, pInfo->blocks_in_rx_queue ); } static void put_char(struct r3964_info *pInfo, unsigned char ch) { struct tty_struct *tty = pInfo->tty; if(tty==NULL) return; if(tty->driver.put_char) { tty->driver.put_char(tty, ch); } pInfo->bcc ^= ch; } static void flush(struct r3964_info *pInfo) { struct tty_struct *tty = pInfo->tty; if(tty==NULL) return; if(tty->driver.flush_chars) { tty->driver.flush_chars(tty); } } static void trigger_transmit(struct r3964_info *pInfo) { unsigned long flags; save_flags(flags); cli(); if((pInfo->state == R3964_IDLE) && (pInfo->tx_first!=NULL)) { pInfo->state = R3964_TX_REQUEST; pInfo->count_down = R3964_TO_QVZ; pInfo->nRetry=0; pInfo->flags &= ~R3964_ERROR; restore_flags(flags); TRACE_PS("trigger_transmit - sent STX"); put_char(pInfo, STX); flush(pInfo); pInfo->bcc = 0; } else { restore_flags(flags); } } static void retry_transmit(struct r3964_info *pInfo) { if(pInfo->nRetry<R3964_MAX_RETRIES) { TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry); pInfo->bcc = 0; put_char(pInfo, STX); flush(pInfo); pInfo->state = R3964_TX_REQUEST; pInfo->count_down = R3964_TO_QVZ; pInfo->nRetry++; } else { TRACE_PE("transmission failed after %d retries", R3964_MAX_RETRIES); remove_from_tx_queue(pInfo, R3964_TX_FAIL); put_char(pInfo, NAK); flush(pInfo); pInfo->state = R3964_IDLE; trigger_transmit(pInfo); } } static void transmit_block(struct r3964_info *pInfo) { struct tty_struct *tty = pInfo->tty; struct r3964_block_header *pBlock = pInfo->tx_first; int room=0; if((tty==NULL) || (pBlock==NULL)) { return; } if(tty->driver.write_room) room=tty->driver.write_room(tty); TRACE_PS("transmit_block %x, room %d, length %d", (int)pBlock, room, pBlock->length); while(pInfo->tx_position < pBlock->length) { if(room<2) break; if(pBlock->data[pInfo->tx_position]==DLE) { /* send additional DLE char: */ put_char(pInfo, DLE); } put_char(pInfo, pBlock->data[pInfo->tx_position++]); room--; } if((pInfo->tx_position == pBlock->length) && (room>=3)) { put_char(pInfo, DLE); put_char(pInfo, ETX); if(pInfo->flags & R3964_BCC) { put_char(pInfo, pInfo->bcc); } pInfo->state = R3964_WAIT_FOR_TX_ACK; pInfo->count_down = R3964_TO_QVZ; } flush(pInfo); } static void on_receive_block(struct r3964_info *pInfo) { unsigned int length; struct r3964_client_info *pClient; struct r3964_block_header *pBlock; length=pInfo->rx_position; /* compare byte checksum characters: */ if(pInfo->flags & R3964_BCC) { if(pInfo->bcc!=pInfo->last_rx) { TRACE_PE("checksum error - got %x but expected %x", pInfo->last_rx, pInfo->bcc); pInfo->flags |= R3964_CHECKSUM; } } /* check for errors (parity, overrun,...): */ if(pInfo->flags & R3964_ERROR) { TRACE_PE("on_receive_block - transmission failed error %x", pInfo->flags & R3964_ERROR); put_char(pInfo, NAK); flush(pInfo); if(pInfo->nRetry<R3964_MAX_RETRIES) { pInfo->state=R3964_WAIT_FOR_RX_REPEAT; pInfo->count_down = R3964_TO_RX_PANIC; pInfo->nRetry++; } else { TRACE_PE("on_receive_block - failed after max retries"); pInfo->state=R3964_IDLE; } return; } /* received block; submit DLE: */ put_char(pInfo, DLE); flush(pInfo); pInfo->count_down=0; TRACE_PS(" rx success: got %d chars", length); /* prepare struct r3964_block_header: */ pBlock = kmalloc(length+sizeof(struct r3964_block_header), GFP_KERNEL); TRACE_M("on_receive_block - kmalloc %x",(int)pBlock); if(pBlock==NULL) return; pBlock->length = length; pBlock->data = ((unsigned char*)pBlock)+sizeof(struct r3964_block_header); pBlock->locks = 0; pBlock->next = NULL; pBlock->owner = NULL; memcpy(pBlock->data, pInfo->rx_buf, length); /* queue block into rx_queue: */ add_rx_queue(pInfo, pBlock); /* notify attached client processes: */ for(pClient=pInfo->firstClient; pClient; pClient=pClient->next) { if(pClient->sig_flags & R3964_SIG_DATA) { add_msg(pClient, R3964_MSG_DATA, length, R3964_OK, pBlock); } } wake_up_interruptible (&pInfo->read_wait); pInfo->state = R3964_IDLE; trigger_transmit(pInfo); } static void receive_char(struct r3964_info *pInfo, const unsigned char c) { switch(pInfo->state) { case R3964_TX_REQUEST: if(c==DLE) { TRACE_PS("TX_REQUEST - got DLE"); pInfo->state = R3964_TRANSMITTING; pInfo->tx_position = 0; transmit_block(pInfo); } else if(c==STX) { if(pInfo->nRetry==0) { TRACE_PE("TX_REQUEST - init conflict"); if(pInfo->priority == R3964_SLAVE) { goto start_receiving; } } else { TRACE_PE("TX_REQUEST - secondary init conflict!?" " Switching to SLAVE mode for next rx."); goto start_receiving; } } else { TRACE_PE("TX_REQUEST - char != DLE: %x", c); retry_transmit(pInfo); } break; case R3964_TRANSMITTING: if(c==NAK) { TRACE_PE("TRANSMITTING - got NAK"); retry_transmit(pInfo); } else { TRACE_PE("TRANSMITTING - got illegal char"); pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY; pInfo->count_down = R3964_TO_ZVZ; } break; case R3964_WAIT_FOR_TX_ACK: if(c==DLE) { TRACE_PS("WAIT_FOR_TX_ACK - got DLE"); remove_from_tx_queue(pInfo, R3964_OK); pInfo->state = R3964_IDLE; trigger_transmit(pInfo); } else { retry_transmit(pInfo); } break; case R3964_WAIT_FOR_RX_REPEAT: /* FALLTROUGH */ case R3964_IDLE: if(c==STX) { /* Prevent rx_queue from overflow: */ if(pInfo->blocks_in_rx_queue >= R3964_MAX_BLOCKS_IN_RX_QUEUE) { TRACE_PE("IDLE - got STX but no space in rx_queue!"); pInfo->state=R3964_WAIT_FOR_RX_BUF; pInfo->count_down = R3964_TO_NO_BUF; break; } start_receiving: /* Ok, start receiving: */ TRACE_PS("IDLE - got STX"); pInfo->rx_position = 0; pInfo->last_rx = 0; pInfo->flags &= ~R3964_ERROR; pInfo->state=R3964_RECEIVING; pInfo->count_down = R3964_TO_ZVZ; pInfo->nRetry = 0; put_char(pInfo, DLE); flush(pInfo); pInfo->bcc = 0; } break; case R3964_RECEIVING: if(pInfo->rx_position < RX_BUF_SIZE) { pInfo->bcc ^= c; if(c==DLE) { if(pInfo->last_rx==DLE) { pInfo->last_rx = 0; goto char_to_buf; } pInfo->last_rx = DLE; break; } else if((c==ETX) && (pInfo->last_rx==DLE)) { if(pInfo->flags & R3964_BCC) { pInfo->state = R3964_WAIT_FOR_BCC; pInfo->count_down = R3964_TO_ZVZ; } else { on_receive_block(pInfo); } } else { pInfo->last_rx = c; char_to_buf: pInfo->rx_buf[pInfo->rx_position++] = c; pInfo->count_down = R3964_TO_ZVZ; } } /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */ break; case R3964_WAIT_FOR_BCC: pInfo->last_rx = c; on_receive_block(pInfo); break; } } static void receive_error(struct r3964_info *pInfo, const char flag) { switch (flag) { case TTY_NORMAL: break; case TTY_BREAK: TRACE_PE("received break") pInfo->flags |= R3964_BREAK; break; case TTY_PARITY: TRACE_PE("parity error") pInfo->flags |= R3964_PARITY; break; case TTY_FRAME: TRACE_PE("frame error") pInfo->flags |= R3964_FRAME; break; case TTY_OVERRUN: TRACE_PE("frame overrun") pInfo->flags |= R3964_OVERRUN; break; default: TRACE_PE("receive_error - unknown flag %d", flag); pInfo->flags |= R3964_UNKNOWN; break; } } static void on_timeout(struct r3964_info *pInfo) { switch(pInfo->state) { case R3964_TX_REQUEST: TRACE_PE("TX_REQUEST - timeout"); retry_transmit(pInfo); break; case R3964_WAIT_ZVZ_BEFORE_TX_RETRY: put_char(pInfo, NAK); flush(pInfo); retry_transmit(pInfo); break; case R3964_WAIT_FOR_TX_ACK: TRACE_PE("WAIT_FOR_TX_ACK - timeout"); retry_transmit(pInfo); break; case R3964_WAIT_FOR_RX_BUF: TRACE_PE("WAIT_FOR_RX_BUF - timeout"); put_char(pInfo, NAK); flush(pInfo); pInfo->state=R3964_IDLE; break; case R3964_RECEIVING: TRACE_PE("RECEIVING - timeout after %d chars", pInfo->rx_position); put_char(pInfo, NAK); flush(pInfo); pInfo->state=R3964_IDLE; break; case R3964_WAIT_FOR_RX_REPEAT: TRACE_PE("WAIT_FOR_RX_REPEAT - timeout"); pInfo->state=R3964_IDLE; break; case R3964_WAIT_FOR_BCC: TRACE_PE("WAIT_FOR_BCC - timeout"); put_char(pInfo, NAK); flush(pInfo); pInfo->state=R3964_IDLE; break; } } static struct r3964_client_info *findClient( struct r3964_info *pInfo, pid_t pid) { struct r3964_client_info *pClient; for(pClient=pInfo->firstClient; pClient; pClient=pClient->next) { if(pClient->pid == pid) { return pClient; } } return NULL; } static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg) { struct r3964_client_info *pClient; struct r3964_client_info **ppClient; struct r3964_message *pMsg; if((arg & R3964_SIG_ALL)==0) { /* Remove client from client list */ for(ppClient=&pInfo->firstClient; *ppClient; ppClient=&(*ppClient)->next) { pClient = *ppClient; if(pClient->pid == pid) { TRACE_PS("removing client %d from client list", pid); *ppClient = pClient->next; while(pClient->msg_count) { pMsg=remove_msg(pInfo, pClient); if(pMsg) { kfree(pMsg); TRACE_M("enable_signals - msg kfree %x",(int)pMsg); } } kfree(pClient); TRACE_M("enable_signals - kfree %x",(int)pClient); return 0; } } return -EINVAL; } else { pClient=findClient(pInfo, pid); if(pClient) { /* update signal options */ pClient->sig_flags=arg; } else { /* add client to client list */ pClient=kmalloc(sizeof(struct r3964_client_info), GFP_KERNEL); TRACE_M("enable_signals - kmalloc %x",(int)pClient); if(pClient==NULL) return -ENOMEM; TRACE_PS("add client %d to client list", pid); pClient->sig_flags=arg; pClient->pid = pid; pClient->next=pInfo->firstClient; pClient->first_msg = NULL; pClient->last_msg = NULL; pClient->next_block_to_read = NULL; pClient->msg_count = 0; pInfo->firstClient=pClient; } } return 0; } static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char *buf) { struct r3964_client_info *pClient; struct r3964_block_header *block; if(!buf) { return -EINVAL; } pClient=findClient(pInfo,pid); if(pClient==NULL) { return -EINVAL; } block=pClient->next_block_to_read; if(!block) { return 0; } else { if (copy_to_user (buf, block->data, block->length)) return -EFAULT; remove_client_block(pInfo, pClient); return block->length; } return -EINVAL; } static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg, int error_code, struct r3964_block_header *pBlock) { struct r3964_message *pMsg; unsigned long flags; if(pClient->msg_count<R3964_MAX_MSG_COUNT-1) { queue_the_message: pMsg = kmalloc(sizeof(struct r3964_message), GFP_KERNEL); TRACE_M("add_msg - kmalloc %x",(int)pMsg); if(pMsg==NULL) { return; } save_flags(flags); cli(); pMsg->msg_id = msg_id; pMsg->arg = arg; pMsg->error_code = error_code; pMsg->block = pBlock; pMsg->next = NULL; if(pClient->last_msg==NULL) { pClient->first_msg=pClient->last_msg=pMsg; } else { pClient->last_msg->next = pMsg; pClient->last_msg=pMsg; } pClient->msg_count++; if(pBlock!=NULL) { pBlock->locks++; } restore_flags(flags); } else { if((pClient->last_msg->msg_id == R3964_MSG_ACK) && (pClient->last_msg->error_code==R3964_OVERFLOW)) { pClient->last_msg->arg++; TRACE_PE("add_msg - inc prev OVERFLOW-msg"); } else { msg_id = R3964_MSG_ACK; arg = 0; error_code = R3964_OVERFLOW; pBlock = NULL; TRACE_PE("add_msg - queue OVERFLOW-msg"); goto queue_the_message; } } /* Send SIGIO signal to client process: */ if(pClient->sig_flags & R3964_USE_SIGIO) { kill_proc(pClient->pid, SIGIO, 1); } } static struct r3964_message *remove_msg(struct r3964_info *pInfo, struct r3964_client_info *pClient) { struct r3964_message *pMsg=NULL; unsigned long flags; if(pClient->first_msg) { save_flags(flags); cli(); pMsg = pClient->first_msg; pClient->first_msg = pMsg->next; if(pClient->first_msg==NULL) { pClient->last_msg = NULL; } pClient->msg_count--; if(pMsg->block) { remove_client_block(pInfo, pClient); pClient->next_block_to_read = pMsg->block; } restore_flags(flags); } return pMsg; } static void remove_client_block(struct r3964_info *pInfo, struct r3964_client_info *pClient) { struct r3964_block_header *block; TRACE_PS("remove_client_block PID %d", pClient->pid); block=pClient->next_block_to_read; if(block) { block->locks--; if(block->locks==0) { remove_from_rx_queue(pInfo, block); } } pClient->next_block_to_read = NULL; } /************************************************************* * Line discipline routines *************************************************************/ static int r3964_open(struct tty_struct *tty) { struct r3964_info *pInfo; MOD_INC_USE_COUNT; TRACE_L("open"); TRACE_L("tty=%x, PID=%d, disc_data=%x", (int)tty, current->pid, (int)tty->disc_data); pInfo=kmalloc(sizeof(struct r3964_info), GFP_KERNEL); TRACE_M("r3964_open - info kmalloc %x",(int)pInfo); if(!pInfo) { printk(KERN_ERR "r3964: failed to alloc info structure\n"); return -ENOMEM; } pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL); TRACE_M("r3964_open - rx_buf kmalloc %x",(int)pInfo->rx_buf); if(!pInfo->rx_buf) { printk(KERN_ERR "r3964: failed to alloc receive buffer\n"); kfree(pInfo); TRACE_M("r3964_open - info kfree %x",(int)pInfo); return -ENOMEM; } pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL); TRACE_M("r3964_open - tx_buf kmalloc %x",(int)pInfo->tx_buf); if(!pInfo->tx_buf) { printk(KERN_ERR "r3964: failed to alloc transmit buffer\n"); kfree(pInfo->rx_buf); TRACE_M("r3964_open - rx_buf kfree %x",(int)pInfo->rx_buf); kfree(pInfo); TRACE_M("r3964_open - info kfree %x",(int)pInfo); return -ENOMEM; } pInfo->tty = tty; init_waitqueue_head (&pInfo->read_wait); pInfo->priority = R3964_MASTER; pInfo->rx_first = pInfo->rx_last = NULL; pInfo->tx_first = pInfo->tx_last = NULL; pInfo->rx_position = 0; pInfo->tx_position = 0; pInfo->last_rx = 0; pInfo->blocks_in_rx_queue = 0; pInfo->firstClient=NULL; pInfo->state=R3964_IDLE; pInfo->flags = R3964_DEBUG; pInfo->count_down = 0; pInfo->nRetry = 0; tty->disc_data = pInfo; /* * Add 'on_timer' to timer task queue * (will be called from timer bh) */ INIT_LIST_HEAD(&pInfo->bh_1.list); pInfo->bh_1.sync = 0; pInfo->bh_1.routine = &on_timer_1; pInfo->bh_1.data = pInfo; INIT_LIST_HEAD(&pInfo->bh_2.list); pInfo->bh_2.sync = 0; pInfo->bh_2.routine = &on_timer_2; pInfo->bh_2.data = pInfo; queue_task(&pInfo->bh_1, &tq_timer); return 0; } static void r3964_close(struct tty_struct *tty) { struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; struct r3964_client_info *pClient, *pNext; struct r3964_message *pMsg; struct r3964_block_header *pHeader, *pNextHeader; unsigned long flags; TRACE_L("close"); /* * Make sure that our task queue isn't activated. If it * is, take it out of the linked list. */ spin_lock_irqsave(&tqueue_lock, flags); if (pInfo->bh_1.sync) list_del(&pInfo->bh_1.list); if (pInfo->bh_2.sync) list_del(&pInfo->bh_2.list); spin_unlock_irqrestore(&tqueue_lock, flags); /* Remove client-structs and message queues: */ pClient=pInfo->firstClient; while(pClient) { pNext=pClient->next; while(pClient->msg_count) { pMsg=remove_msg(pInfo, pClient); if(pMsg) { kfree(pMsg); TRACE_M("r3964_close - msg kfree %x",(int)pMsg); } } kfree(pClient); TRACE_M("r3964_close - client kfree %x",(int)pClient); pClient=pNext; } /* Remove jobs from tx_queue: */ save_flags(flags); cli(); pHeader=pInfo->tx_first; pInfo->tx_first=pInfo->tx_last=NULL; restore_flags(flags); while(pHeader) { pNextHeader=pHeader->next; kfree(pHeader); pHeader=pNextHeader; } /* Free buffers: */ wake_up_interruptible(&pInfo->read_wait); kfree(pInfo->rx_buf); TRACE_M("r3964_close - rx_buf kfree %x",(int)pInfo->rx_buf); kfree(pInfo->tx_buf); TRACE_M("r3964_close - tx_buf kfree %x",(int)pInfo->tx_buf); kfree(pInfo); TRACE_M("r3964_close - info kfree %x",(int)pInfo); MOD_DEC_USE_COUNT; } static ssize_t r3964_read(struct tty_struct *tty, struct file *file, unsigned char *buf, size_t nr) { struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; struct r3964_client_info *pClient; struct r3964_message *pMsg; struct r3964_client_message theMsg; DECLARE_WAITQUEUE (wait, current); int pid = current->pid; int count; TRACE_L("read()"); pClient=findClient(pInfo, pid); if(pClient) { pMsg = remove_msg(pInfo, pClient); if(pMsg==NULL) { /* no messages available. */ if (file->f_flags & O_NONBLOCK) { return -EAGAIN; } /* block until there is a message: */ add_wait_queue(&pInfo->read_wait, &wait); repeat: current->state = TASK_INTERRUPTIBLE; pMsg = remove_msg(pInfo, pClient); if (!pMsg && !signal_pending(current)) { schedule(); goto repeat; } current->state = TASK_RUNNING; remove_wait_queue(&pInfo->read_wait, &wait); } /* If we still haven't got a message, we must have been signalled */ if (!pMsg) return -EINTR; /* deliver msg to client process: */ theMsg.msg_id = pMsg->msg_id; theMsg.arg = pMsg->arg; theMsg.error_code = pMsg->error_code; count = sizeof(struct r3964_client_message); kfree(pMsg); TRACE_M("r3964_read - msg kfree %x",(int)pMsg); if (copy_to_user(buf,&theMsg, count)) return -EFAULT; TRACE_PS("read - return %d", count); return count; } return -EPERM; } static ssize_t r3964_write(struct tty_struct * tty, struct file * file, const unsigned char *data, size_t count) { struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; struct r3964_block_header *pHeader; struct r3964_client_info *pClient; unsigned char *new_data; int status; int pid; TRACE_L("write request, %d characters", count); /* * Verify the pointers */ if(!pInfo) return -EIO; status = verify_area (VERIFY_READ, data, count); if (status != 0) { return status; } /* * Ensure that the caller does not wish to send too much. */ if (count > R3964_MTU) { if (pInfo->flags & R3964_DEBUG) { TRACE_L (KERN_WARNING "r3964_write: truncating user packet " "from %u to mtu %d", count, R3964_MTU); } count = R3964_MTU; } /* * Allocate a buffer for the data and fetch it from the user space. */ new_data = kmalloc (count+sizeof(struct r3964_block_header), GFP_KERNEL); TRACE_M("r3964_write - kmalloc %x",(int)new_data); if (new_data == NULL) { if (pInfo->flags & R3964_DEBUG) { printk (KERN_ERR "r3964_write: no memory\n"); } return -ENOSPC; } pHeader = (struct r3964_block_header *)new_data; pHeader->data = new_data + sizeof(struct r3964_block_header); pHeader->length = count; pHeader->locks = 0; pHeader->owner = NULL; pid=current->pid; pClient=findClient(pInfo, pid); if(pClient) { pHeader->owner = pClient; } __copy_from_user(pHeader->data, data, count); /* We already verified this */ if(pInfo->flags & R3964_DEBUG) { dump_block(pHeader->data, count); } /* * Add buffer to transmit-queue: */ add_tx_queue(pInfo, pHeader); trigger_transmit(pInfo); return 0; } static int r3964_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg) { struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; if(pInfo==NULL) return -EINVAL; switch(cmd) { case R3964_ENABLE_SIGNALS: return enable_signals(pInfo, current->pid, arg); case R3964_SETPRIORITY: if(arg<R3964_MASTER || arg>R3964_SLAVE) return -EINVAL; pInfo->priority = arg & 0xff; return 0; case R3964_USE_BCC: if(arg) pInfo->flags |= R3964_BCC; else pInfo->flags &= ~R3964_BCC; return 0; case R3964_READ_TELEGRAM: return read_telegram(pInfo, current->pid, (unsigned char *)arg); default: return -ENOIOCTLCMD; } } static void r3964_set_termios(struct tty_struct *tty, struct termios * old) { TRACE_L("set_termios"); } /* Called without the kernel lock held - fine */ static unsigned int r3964_poll(struct tty_struct * tty, struct file * file, struct poll_table_struct *wait) { struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; int pid=current->pid; struct r3964_client_info *pClient; struct r3964_message *pMsg=NULL; unsigned long flags; int result = POLLOUT; TRACE_L("POLL"); pClient=findClient(pInfo,pid); if(pClient) { poll_wait(file, &pInfo->read_wait, wait); save_flags(flags); cli(); pMsg=pClient->first_msg; restore_flags(flags); if(pMsg) result |= POLLIN | POLLRDNORM; } else { result = -EINVAL; } return result; } static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data; const unsigned char *p; char *f, flags = 0; int i; for (i=count, p = cp, f = fp; i; i--, p++) { if (f) flags = *f++; if(flags==TTY_NORMAL) { receive_char(pInfo, *p); } else { receive_error(pInfo, flags); } } } static int r3964_receive_room(struct tty_struct *tty) { TRACE_L("receive_room"); return -1; } MODULE_LICENSE("GPL"); EXPORT_NO_SYMBOLS;
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