iop.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

 * into the buffer, setting the channel state to MSG_COMPLETE and
 * notifying the IOP.
 */

void iop_complete_message(struct iop_msg *msg)
{
	int iop_num = msg->iop_num;
	int chan = msg->channel;
	int i,offset;

#ifdef DEBUG_IOP
	printk("iop_complete(%p): iop %d chan %d\n", msg, msg->iop_num, msg->channel);
#endif

	offset = IOP_ADDR_RECV_MSG + (msg->channel * IOP_MSG_LEN);

	for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
		iop_writeb(iop_base[iop_num], offset, msg->reply[i]);
	}

	iop_writeb(iop_base[iop_num],
		   IOP_ADDR_RECV_STATE + chan, IOP_MSG_COMPLETE);
	iop_interrupt(iop_base[msg->iop_num]);

	iop_free_msg(msg);
}

/*
 * Actually put a message into a send channel buffer
 */

static void iop_do_send(struct iop_msg *msg)
{
	volatile struct mac_iop *iop = iop_base[msg->iop_num];
	int i,offset;

	offset = IOP_ADDR_SEND_MSG + (msg->channel * IOP_MSG_LEN);

	for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
		iop_writeb(iop, offset, msg->message[i]);
	}

	iop_writeb(iop, IOP_ADDR_SEND_STATE + msg->channel, IOP_MSG_NEW);

	iop_interrupt(iop);
}

/*
 * Handle sending a message on a channel that
 * has gone into the IOP_MSG_COMPLETE state.
 */

static void iop_handle_send(uint iop_num, uint chan, struct pt_regs *regs)
{
	volatile struct mac_iop *iop = iop_base[iop_num];
	struct iop_msg *msg,*msg2;
	int i,offset;

#ifdef DEBUG_IOP
	printk("iop_handle_send: iop %d channel %d\n", iop_num, chan);
#endif

	iop_writeb(iop, IOP_ADDR_SEND_STATE + chan, IOP_MSG_IDLE);

	if (!(msg = iop_send_queue[iop_num][chan])) return;

	msg->status = IOP_MSGSTATUS_COMPLETE;
	offset = IOP_ADDR_SEND_MSG + (chan * IOP_MSG_LEN);
	for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
		msg->reply[i] = iop_readb(iop, offset);
	}
	if (msg->handler) (*msg->handler)(msg, regs);
	msg2 = msg;
	msg = msg->next;
	iop_free_msg(msg2);

	iop_send_queue[iop_num][chan] = msg;
	if (msg) iop_do_send(msg);
}

/*
 * Handle reception of a message on a channel that has
 * gone into the IOP_MSG_NEW state.
 */

static void iop_handle_recv(uint iop_num, uint chan, struct pt_regs *regs)
{
	volatile struct mac_iop *iop = iop_base[iop_num];
	int i,offset;
	struct iop_msg *msg;

#ifdef DEBUG_IOP
	printk("iop_handle_recv: iop %d channel %d\n", iop_num, chan);
#endif

	msg = iop_alloc_msg();
	msg->iop_num = iop_num;
	msg->channel = chan;
	msg->status = IOP_MSGSTATUS_UNSOL;
	msg->handler = iop_listeners[iop_num][chan].handler;

	offset = IOP_ADDR_RECV_MSG + (chan * IOP_MSG_LEN);

	for (i = 0 ; i < IOP_MSG_LEN ; i++, offset++) {
		msg->message[i] = iop_readb(iop, offset);
	}

	iop_writeb(iop, IOP_ADDR_RECV_STATE + chan, IOP_MSG_RCVD);

	/* If there is a listener, call it now. Otherwise complete */
	/* the message ourselves to avoid possible stalls.         */

	if (msg->handler) {
		(*msg->handler)(msg, regs);
	} else {
#ifdef DEBUG_IOP
		printk("iop_handle_recv: unclaimed message on iop %d channel %d\n", iop_num, chan);
		printk("iop_handle_recv:");
		for (i = 0 ; i < IOP_MSG_LEN ; i++) {
			printk(" %02X", (uint) msg->message[i]);
		}
		printk("\n");
#endif
		iop_complete_message(msg);
	}
}

/*
 * Send a message
 * 
 * The message is placed at the end of the send queue. Afterwards if the
 * channel is idle we force an immediate send of the next message in the
 * queue.
 */

int iop_send_message(uint iop_num, uint chan, void *privdata,
		      uint msg_len, __u8 *msg_data,
		      void (*handler)(struct iop_msg *, struct pt_regs *))
{
	struct iop_msg *msg, *q;

	if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return -EINVAL;
	if (chan >= NUM_IOP_CHAN) return -EINVAL;
	if (msg_len > IOP_MSG_LEN) return -EINVAL;

	msg = iop_alloc_msg();
	if (!msg) return -ENOMEM;

	msg->next = NULL;
	msg->status = IOP_MSGSTATUS_WAITING;
	msg->iop_num = iop_num;
	msg->channel = chan;
	msg->caller_priv = privdata;
	memcpy(msg->message, msg_data, msg_len);
	msg->handler = handler;

	if (!(q = iop_send_queue[iop_num][chan])) {
		iop_send_queue[iop_num][chan] = msg;
	} else {
		while (q->next) q = q->next;
		q->next = msg;
	}

	if (iop_readb(iop_base[iop_num],
	    IOP_ADDR_SEND_STATE + chan) == IOP_MSG_IDLE) {
		iop_do_send(msg);
	}

	return 0;
}

/*
 * Upload code to the shared RAM of an IOP.
 */

void iop_upload_code(uint iop_num, __u8 *code_start,
		     uint code_len, __u16 shared_ram_start)
{
	if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;

	iop_loadaddr(iop_base[iop_num], shared_ram_start);
	
	while (code_len--) {
		iop_base[iop_num]->ram_data = *code_start++;
	}
}

/*
 * Download code from the shared RAM of an IOP.
 */

void iop_download_code(uint iop_num, __u8 *code_start,
		       uint code_len, __u16 shared_ram_start)
{
	if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return;

	iop_loadaddr(iop_base[iop_num], shared_ram_start);
	
	while (code_len--) {
		*code_start++ = iop_base[iop_num]->ram_data;
	}
}

/*
 * Compare the code in the shared RAM of an IOP with a copy in system memory
 * and return 0 on match or the first nonmatching system memory address on
 * failure.
 */

__u8 *iop_compare_code(uint iop_num, __u8 *code_start,
		       uint code_len, __u16 shared_ram_start)
{
	if ((iop_num >= NUM_IOPS) || !iop_base[iop_num]) return code_start;

	iop_loadaddr(iop_base[iop_num], shared_ram_start);
	
	while (code_len--) {
		if (*code_start != iop_base[iop_num]->ram_data) {
			return code_start;
		}
		code_start++;
	}
	return (__u8 *) 0;
}

/*
 * Handle an ISM IOP interrupt
 */

void iop_ism_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	uint iop_num = (uint) dev_id;
	volatile struct mac_iop *iop = iop_base[iop_num];
	int i,state;

#ifdef DEBUG_IOP
	printk("iop_ism_irq: status = %02X\n", (uint) iop->status_ctrl);
#endif

	/* INT0 indicates a state change on an outgoing message channel */

	if (iop->status_ctrl & IOP_INT0) {
		iop->status_ctrl = IOP_INT0 | IOP_RUN | IOP_AUTOINC;
#ifdef DEBUG_IOP
		printk("iop_ism_irq: new status = %02X, send states",
			(uint) iop->status_ctrl);
#endif
		for (i = 0 ; i < NUM_IOP_CHAN  ; i++) {
			state = iop_readb(iop, IOP_ADDR_SEND_STATE + i);
#ifdef DEBUG_IOP
			printk(" %02X", state);
#endif
			if (state == IOP_MSG_COMPLETE) {
				iop_handle_send(iop_num, i, regs);
			}
		}
#ifdef DEBUG_IOP
		printk("\n");
#endif
	}

	if (iop->status_ctrl & IOP_INT1) {	/* INT1 for incoming msgs */
		iop->status_ctrl = IOP_INT1 | IOP_RUN | IOP_AUTOINC;
#ifdef DEBUG_IOP
		printk("iop_ism_irq: new status = %02X, recv states",
			(uint) iop->status_ctrl);
#endif
		for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
			state = iop_readb(iop, IOP_ADDR_RECV_STATE + i);
#ifdef DEBUG_IOP
			printk(" %02X", state);
#endif
			if (state == IOP_MSG_NEW) {
				iop_handle_recv(iop_num, i, regs);
			}
		}
#ifdef DEBUG_IOP
		printk("\n");
#endif
	}

}

#ifdef CONFIG_PROC_FS

char *iop_chan_state(int state)
{
	switch(state) {
		case IOP_MSG_IDLE	: return "idle      ";
		case IOP_MSG_NEW	: return "new       ";
		case IOP_MSG_RCVD	: return "received  ";
		case IOP_MSG_COMPLETE	: return "completed ";
		default			: return "unknown   ";
	}
}

int iop_dump_one_iop(char *buf, int iop_num, char *iop_name)
{
	int i,len = 0;
	volatile struct mac_iop *iop = iop_base[iop_num];

	len += sprintf(buf+len, "%s IOP channel states:\n\n", iop_name);
	len += sprintf(buf+len, "##  send_state  recv_state  device\n");
	len += sprintf(buf+len, "------------------------------------------------\n");
	for (i = 0 ; i < NUM_IOP_CHAN ; i++) {
		len += sprintf(buf+len, "%2d  %10s  %10s  %s\n", i,
			iop_chan_state(iop_readb(iop, IOP_ADDR_SEND_STATE+i)),
			iop_chan_state(iop_readb(iop, IOP_ADDR_RECV_STATE+i)),
			iop_listeners[iop_num][i].handler?
				      iop_listeners[iop_num][i].devname : "");
			
	}
	len += sprintf(buf+len, "\n");
	return len;
}
 
static int iop_get_proc_info(char *buf, char **start, off_t pos, int count)
{
	int len, cnt;

	cnt = 0;
	len =  sprintf(buf, "IOPs detected:\n\n");

	if (iop_scc_present) {
		len += sprintf(buf+len, "SCC IOP (%p): status %02X\n",
				iop_base[IOP_NUM_SCC],
				(uint) iop_base[IOP_NUM_SCC]->status_ctrl);
	}
	if (iop_ism_present) {
		len += sprintf(buf+len, "ISM IOP (%p): status %02X\n\n",
				iop_base[IOP_NUM_ISM],
				(uint) iop_base[IOP_NUM_ISM]->status_ctrl);
	}

	if (iop_scc_present) {
		len += iop_dump_one_iop(buf+len, IOP_NUM_SCC, "SCC");

	}

	if (iop_ism_present) {
		len += iop_dump_one_iop(buf+len, IOP_NUM_ISM, "ISM");

	}

	if (len >= pos) {
		if (!*start) {
			*start = buf + pos;
			cnt = len - pos;
		} else {
			cnt += len;
		}
	}
	return (count > cnt) ? cnt : count;
}

#endif /* CONFIG_PROC_FS */