/* 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: n_r3964.c,v $ * Revision 1.10 2001/03/18 13:02:24 dwmw2 * Fix timer usage, use spinlocks properly. * * Revision 1.9 2001/03/18 12:52:14 dwmw2 * Merge changes in 2.4.2 * * 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...) do {} while (0) #endif #ifdef DEBUG_PROTO_S #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args) #else #define TRACE_PS(fmt, arg...) do {} while (0) #endif #ifdef DEBUG_PROTO_E #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args) #else #define TRACE_PE(fmt, arg...) do {} while (0) #endif #ifdef DEBUG_LDISC #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args) #else #define TRACE_L(fmt, arg...) do {} while (0) #endif #ifdef DEBUG_QUEUE #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args) #else #define TRACE_Q(fmt, arg...) do {} while (0) #endif 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(unsigned long priv); static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg); static int read_telegram(struct r3964_info *pInfo, struct pid *pid, unsigned char __user * 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 __user * 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 ktermios *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 struct tty_ldisc tty_ldisc_N_R3964 = { .owner = THIS_MODULE, .magic = TTY_LDISC_MAGIC, .name = "R3964", .open = r3964_open, .close = r3964_close, .read = r3964_read, .write = r3964_write, .ioctl = r3964_ioctl, .set_termios = r3964_set_termios, .poll = r3964_poll, .receive_buf = r3964_receive_buf, }; 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_unregister_ldisc(N_R3964); 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: 1.10 $\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=%p", tty_ldisc_N_R3964.open); TRACE_L("tty_ldisc_N_R3964 = %p", &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 add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) { unsigned long flags; spin_lock_irqsave(&pInfo->lock, flags); 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; } spin_unlock_irqrestore(&pInfo->lock, flags); TRACE_Q("add_tx_queue %p, length %d, tx_first = %p", pHeader, pHeader->length, 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: %p, length %u - ", pHeader, pHeader->length); for (pDump = pHeader; pDump; pDump = pDump->next) printk("%p ", 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); } spin_lock_irqsave(&pInfo->lock, flags); pInfo->tx_first = pHeader->next; if (pInfo->tx_first == NULL) { pInfo->tx_last = NULL; } spin_unlock_irqrestore(&pInfo->lock, flags); kfree(pHeader); TRACE_M("remove_from_tx_queue - kfree %p", pHeader); TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p", pInfo->tx_first, pInfo->tx_last); } static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader) { unsigned long flags; spin_lock_irqsave(&pInfo->lock, flags); 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++; spin_unlock_irqrestore(&pInfo->lock, flags); TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d", pHeader, pHeader->length, 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 = %p, rx_last = %p, count = %d", pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue); TRACE_Q("remove_from_rx_queue: %p, length %u", pHeader, pHeader->length); spin_lock_irqsave(&pInfo->lock, flags); 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; } } } spin_unlock_irqrestore(&pInfo->lock, flags); kfree(pHeader); TRACE_M("remove_from_rx_queue - kfree %p", pHeader); TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d", pInfo->rx_first, 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; spin_lock_irqsave(&pInfo->lock, flags); if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) { pInfo->state = R3964_TX_REQUEST; pInfo->nRetry = 0; pInfo->flags &= ~R3964_ERROR; mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ); spin_unlock_irqrestore(&pInfo->lock, flags); TRACE_PS("trigger_transmit - sent STX"); put_char(pInfo, STX); flush(pInfo); pInfo->bcc = 0; } else { spin_unlock_irqrestore(&pInfo->lock, 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->nRetry++; mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ); } 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 %p, room %d, length %d", 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; mod_timer(&pInfo->tmr, jiffies + 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->nRetry++; mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC); } 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); del_timer_sync(&pInfo->tmr); 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 %p", 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 invalid char"); pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY; mod_timer(&pInfo->tmr, jiffies + 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; mod_timer(&pInfo->tmr, jiffies + 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; mod_timer(&pInfo->tmr, jiffies + 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; mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ); } else { on_receive_block(pInfo); } } else { pInfo->last_rx = c; char_to_buf: pInfo->rx_buf[pInfo->rx_position++] = c; mod_timer(&pInfo->tmr, jiffies + 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(unsigned long priv) { struct r3964_info *pInfo = (void *)priv; 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, struct pid *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, struct pid *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_nr(pid)); *ppClient = pClient->next; while (pClient->msg_count) { pMsg = remove_msg(pInfo, pClient); if (pMsg) { kfree(pMsg); TRACE_M("enable_signals - msg " "kfree %p", pMsg); } } put_pid(pClient->pid); kfree(pClient); TRACE_M("enable_signals - kfree %p", 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 %p", pClient); if (pClient == NULL) return -ENOMEM; TRACE_PS("add client %d to client list", pid_nr(pid)); spin_lock_init(&pClient->lock); pClient->sig_flags = arg; pClient->pid = get_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, struct pid *pid, unsigned char __user * 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), error_code ? GFP_ATOMIC : GFP_KERNEL); TRACE_M("add_msg - kmalloc %p", pMsg); if (pMsg == NULL) { return; } spin_lock_irqsave(&pClient->lock, flags); 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++; } spin_unlock_irqrestore(&pClient->lock, 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_pid(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) { spin_lock_irqsave(&pClient->lock, flags); 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; } spin_unlock_irqrestore(&pClient->lock, 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", pid_nr(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; TRACE_L("open"); TRACE_L("tty=%p, PID=%d, disc_data=%p", tty, current->pid, tty->disc_data); pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL); TRACE_M("r3964_open - info kmalloc %p", 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 %p", 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 %p", pInfo); return -ENOMEM; } pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL); TRACE_M("r3964_open - tx_buf kmalloc %p", 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 %p", pInfo->rx_buf); kfree(pInfo); TRACE_M("r3964_open - info kfree %p", pInfo); return -ENOMEM; } spin_lock_init(&pInfo->lock); 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->nRetry = 0; tty->disc_data = pInfo; tty->receive_room = 65536; setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo); 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. */ del_timer_sync(&pInfo->tmr); /* 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 %p", pMsg); } } put_pid(pClient->pid); kfree(pClient); TRACE_M("r3964_close - client kfree %p", pClient); pClient = pNext; } /* Remove jobs from tx_queue: */ spin_lock_irqsave(&pInfo->lock, flags); pHeader = pInfo->tx_first; pInfo->tx_first = pInfo->tx_last = NULL; spin_unlock_irqrestore(&pInfo->lock, 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 %p", pInfo->rx_buf); kfree(pInfo->tx_buf); TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf); kfree(pInfo); TRACE_M("r3964_close - info kfree %p", pInfo); } static ssize_t r3964_read(struct tty_struct *tty, struct file *file, unsigned char __user * 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 count; TRACE_L("read()"); pClient = findClient(pInfo, task_pid(current)); 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: __set_current_state(TASK_INTERRUPTIBLE); pMsg = remove_msg(pInfo, pClient); if (!pMsg && !signal_pending(current)) { schedule(); goto repeat; } __set_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 %p", 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; TRACE_L("write request, %d characters", count); /* * Verify the pointers */ if (!pInfo) return -EIO; /* * 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 copy it from the buffer with header prepended */ new_data = kmalloc(count + sizeof(struct r3964_block_header), GFP_KERNEL); TRACE_M("r3964_write - kmalloc %p", 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; pClient = findClient(pInfo, task_pid(current)); if (pClient) { pHeader->owner = pClient; } memcpy(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, task_pid(current), 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, task_pid(current), (unsigned char __user *)arg); default: return -ENOIOCTLCMD; } } static void r3964_set_termios(struct tty_struct *tty, struct ktermios *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; struct r3964_client_info *pClient; struct r3964_message *pMsg = NULL; unsigned long flags; int result = POLLOUT; TRACE_L("POLL"); pClient = findClient(pInfo, task_pid(current)); if (pClient) { poll_wait(file, &pInfo->read_wait, wait); spin_lock_irqsave(&pInfo->lock, flags); pMsg = pClient->first_msg; spin_unlock_irqrestore(&pInfo->lock, 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); } } } MODULE_LICENSE("GPL"); MODULE_ALIAS_LDISC(N_R3964);