debug.c

Linux Kernel 2.6.9 for OMAP1710

	up(&debug_lock);
	return rc;
}

/*
 * debug_unregister:
 * - give back debug area
 */

void debug_unregister(debug_info_t * id)
{
	if (!id)
		goto out;
	down(&debug_lock);
#ifdef DEBUG
	printk(KERN_INFO "debug: unregistering %s\n", id->name);
#endif
	debug_info_put(id);
	up(&debug_lock);

      out:
	return;
}

/*
 * debug_set_level:
 * - set actual debug level
 */

void debug_set_level(debug_info_t* id, int new_level)
{
	unsigned long flags;
	if(!id)
		return;	
	spin_lock_irqsave(&id->lock,flags);
        if(new_level == DEBUG_OFF_LEVEL){
                id->level = DEBUG_OFF_LEVEL;
                printk(KERN_INFO "debug: %s: switched off\n",id->name);
        } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
                printk(KERN_INFO
                        "debug: %s: level %i is out of range (%i - %i)\n",
                        id->name, new_level, 0, DEBUG_MAX_LEVEL);
        } else {
                id->level = new_level;
#ifdef DEBUG
                printk(KERN_INFO 
			"debug: %s: new level %i\n",id->name,id->level);
#endif
        }
	spin_unlock_irqrestore(&id->lock,flags);
}


/*
 * proceed_active_entry:
 * - set active entry to next in the ring buffer
 */

extern inline void proceed_active_entry(debug_info_t * id)
{
	if ((id->active_entry[id->active_area] += id->entry_size)
	    > ((PAGE_SIZE << (id->page_order)) - id->entry_size))
		id->active_entry[id->active_area] = 0;
}

/*
 * proceed_active_area:
 * - set active area to next in the ring buffer
 */

extern inline void proceed_active_area(debug_info_t * id)
{
	id->active_area++;
	id->active_area = id->active_area % id->nr_areas;
}

/*
 * get_active_entry:
 */

extern inline debug_entry_t *get_active_entry(debug_info_t * id)
{
	return (debug_entry_t *) ((char *) id->areas[id->active_area] +
				  id->active_entry[id->active_area]);
}

/*
 * debug_finish_entry:
 * - set timestamp, caller address, cpu number etc.
 */

extern inline void debug_finish_entry(debug_info_t * id, debug_entry_t* active,
		int level, int exception)
{
	STCK(active->id.stck);
	active->id.fields.cpuid = smp_processor_id();
	active->caller = __builtin_return_address(0);
	active->id.fields.exception = exception;
	active->id.fields.level     = level;
	proceed_active_entry(id);
	if(exception)
		proceed_active_area(id);
}

/*
 * debug_event_common:
 * - write debug entry with given size
 */

debug_entry_t *debug_event_common(debug_info_t * id, int level, const void *buf,
			          int len)
{
	unsigned long flags;
	debug_entry_t *active;

	spin_lock_irqsave(&id->lock, flags);
	active = get_active_entry(id);
	memset(DEBUG_DATA(active), 0, id->buf_size);
	memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
	debug_finish_entry(id, active, level, 0);
	spin_unlock_irqrestore(&id->lock, flags);

	return active;
}

/*
 * debug_exception_common:
 * - write debug entry with given size and switch to next debug area
 */

debug_entry_t *debug_exception_common(debug_info_t * id, int level, 
                                      const void *buf, int len)
{
	unsigned long flags;
	debug_entry_t *active;

	spin_lock_irqsave(&id->lock, flags);
	active = get_active_entry(id);
	memset(DEBUG_DATA(active), 0, id->buf_size);
	memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
	debug_finish_entry(id, active, level, 1);
	spin_unlock_irqrestore(&id->lock, flags);

	return active;
}

/*
 * counts arguments in format string for sprintf view
 */

extern inline int debug_count_numargs(char *string)
{
	int numargs=0;

	while(*string) {
		if(*string++=='%')
			numargs++;
	}
	return(numargs);
}

/*
 * debug_sprintf_event:
 */

debug_entry_t *debug_sprintf_event(debug_info_t* id,
                                   int level,char *string,...)
{
	va_list   ap;
	int numargs,idx;
	unsigned long flags;
	debug_sprintf_entry_t *curr_event;
	debug_entry_t *active;

	if((!id) || (level > id->level))
		return NULL;

	numargs=debug_count_numargs(string);

	spin_lock_irqsave(&id->lock, flags);
	active = get_active_entry(id);
	curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
	va_start(ap,string);
	curr_event->string=string;
	for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
		curr_event->args[idx]=va_arg(ap,long);
	va_end(ap);
	debug_finish_entry(id, active, level, 0);
	spin_unlock_irqrestore(&id->lock, flags);

	return active;
}

/*
 * debug_sprintf_exception:
 */

debug_entry_t *debug_sprintf_exception(debug_info_t* id,
                                       int level,char *string,...)
{
	va_list   ap;
	int numargs,idx;
	unsigned long flags;
	debug_sprintf_entry_t *curr_event;
	debug_entry_t *active;

	if((!id) || (level > id->level))
		return NULL;

	numargs=debug_count_numargs(string);

	spin_lock_irqsave(&id->lock, flags);
	active = get_active_entry(id);
	curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
	va_start(ap,string);
	curr_event->string=string;
	for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
		curr_event->args[idx]=va_arg(ap,long);
	va_end(ap);
	debug_finish_entry(id, active, level, 1);
	spin_unlock_irqrestore(&id->lock, flags);

	return active;
}

/*
 * debug_init:
 * - is called exactly once to initialize the debug feature
 */

static int __init debug_init(void)
{
	int rc = 0;

	down(&debug_lock);
#ifdef CONFIG_PROC_FS
	debug_proc_root_entry = proc_mkdir(DEBUG_DIR_ROOT, NULL);
#endif /* CONFIG_PROC_FS */
	printk(KERN_INFO "debug: Initialization complete\n");
	initialized = 1;
	up(&debug_lock);

	return rc;
}

/*
 * debug_register_view:
 */

int debug_register_view(debug_info_t * id, struct debug_view *view)
{
	int rc = 0;
	int i;
	unsigned long flags;
	mode_t mode = S_IFREG;
	struct proc_dir_entry *pde;

	if (!id)
		goto out;
	pde = create_proc_entry(view->name, mode, id->proc_root_entry);
	if (!pde){
		printk(KERN_WARNING "debug: create_proc_entry() failed! Cannot register view %s/%s\n", id->name,view->name);
		rc = -1;
		goto out;
	}

	spin_lock_irqsave(&id->lock, flags);
	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
		if (id->views[i] == NULL)
			break;
	}
	if (i == DEBUG_MAX_VIEWS) {
		printk(KERN_WARNING "debug: cannot register view %s/%s\n",
			id->name,view->name);
		printk(KERN_WARNING 
			"debug: maximum number of views reached (%i)!\n", i);
		remove_proc_entry(pde->name, id->proc_root_entry);
		rc = -1;
	}
	else {
		id->views[i] = view;
		if (view->prolog_proc || view->format_proc || view->header_proc)
			mode |= S_IRUSR;
		if (view->input_proc)
			mode |= S_IWUSR;
		pde->proc_fops = &debug_file_ops;
		id->proc_entries[i] = pde;
	}
	spin_unlock_irqrestore(&id->lock, flags);
      out:
	return rc;
}

/*
 * debug_unregister_view:
 */

int debug_unregister_view(debug_info_t * id, struct debug_view *view)
{
	int rc = 0;
	int i;
	unsigned long flags;

	if (!id)
		goto out;
	spin_lock_irqsave(&id->lock, flags);
	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
		if (id->views[i] == view)
			break;
	}
	if (i == DEBUG_MAX_VIEWS)
		rc = -1;
	else {
#ifdef CONFIG_PROC_FS
		remove_proc_entry(id->proc_entries[i]->name,
				  id->proc_root_entry);
#endif
		id->views[i] = NULL;
		rc = 0;
	}
	spin_unlock_irqrestore(&id->lock, flags);
      out:
	return rc;
}

/*
 * functions for debug-views
 ***********************************
*/

/*
 * prints out actual debug level
 */

static int debug_prolog_level_fn(debug_info_t * id,
				 struct debug_view *view, char *out_buf)
{
	int rc = 0;

	if(id->level == -1) rc = sprintf(out_buf,"-\n");
	else rc = sprintf(out_buf, "%i\n", id->level);
	return rc;
}

/*
 * reads new debug level
 */

static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
				struct file *file, const char __user *user_buf,
				size_t in_buf_size, loff_t * offset)
{
	char input_buf[1];
	int rc = in_buf_size;

	if (*offset != 0)
		goto out;
	if (copy_from_user(input_buf, user_buf, 1)){
		rc = -EFAULT;
		goto out;
	}
	if (isdigit(input_buf[0])) {
		int new_level = ((int) input_buf[0] - (int) '0');
		debug_set_level(id, new_level);
	} else if(input_buf[0] == '-') {
		debug_set_level(id, DEBUG_OFF_LEVEL);
	} else {
		printk(KERN_INFO "debug: level `%c` is not valid\n",
		       input_buf[0]);
	}
      out:
	*offset += in_buf_size;
	return rc;		/* number of input characters */
}


/*
 * flushes debug areas
 */
 
void debug_flush(debug_info_t* id, int area)
{
        unsigned long flags;
        int i;

        if(!id)
                return;
        spin_lock_irqsave(&id->lock,flags);
        if(area == DEBUG_FLUSH_ALL){
                id->active_area = 0;
                memset(id->active_entry, 0, id->nr_areas * sizeof(int));
                for (i = 0; i < id->nr_areas; i++) 
                        memset(id->areas[i], 0, PAGE_SIZE << id->page_order);
                printk(KERN_INFO "debug: %s: all areas flushed\n",id->name);
        } else if(area >= 0 && area < id->nr_areas) {
                id->active_entry[area] = 0;
                memset(id->areas[area], 0, PAGE_SIZE << id->page_order);
                printk(KERN_INFO
                        "debug: %s: area %i has been flushed\n",
                        id->name, area);
        } else {
                printk(KERN_INFO
                        "debug: %s: area %i cannot be flushed (range: %i - %i)\n",
                        id->name, area, 0, id->nr_areas-1);
        }
        spin_unlock_irqrestore(&id->lock,flags);
}

/*
 * view function: flushes debug areas 
 */

static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
                                struct file *file, const char __user *user_buf,
                                size_t in_buf_size, loff_t * offset)
{
        char input_buf[1];
        int rc = in_buf_size;
 
        if (*offset != 0)
                goto out;
        if (copy_from_user(input_buf, user_buf, 1)){
                rc = -EFAULT;
                goto out;
        }
        if(input_buf[0] == '-') { 
                debug_flush(id, DEBUG_FLUSH_ALL);
                goto out;
        }
        if (isdigit(input_buf[0])) {
                int area = ((int) input_buf[0] - (int) '0');
                debug_flush(id, area);
                goto out;
        }

        printk(KERN_INFO "debug: area `%c` is not valid\n", input_buf[0]);

      out:
        *offset += in_buf_size;
        return rc;              /* number of input characters */
}

/*
 * prints debug header in raw format
 */

int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
                         int area, debug_entry_t * entry, char *out_buf)
{
        int rc;

	rc = sizeof(debug_entry_t);
	memcpy(out_buf,entry,sizeof(debug_entry_t));
        return rc;
}

/*
 * prints debug data in raw format
 */

static int debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
			       char *out_buf, const char *in_buf)
{
	int rc;

	rc = id->buf_size;
	memcpy(out_buf, in_buf, id->buf_size);
	return rc;
}

/*
 * prints debug data in hex/ascii format
 */

static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
		    		  char *out_buf, const char *in_buf)
{
	int i, rc = 0;

	for (i = 0; i < id->buf_size; i++) {
                rc += sprintf(out_buf + rc, "%02x ",
                              ((unsigned char *) in_buf)[i]);
        }
	rc += sprintf(out_buf + rc, "| ");
	for (i = 0; i < id->buf_size; i++) {
		unsigned char c = in_buf[i];
		if (!isprint(c))
			rc += sprintf(out_buf + rc, ".");
		else
			rc += sprintf(out_buf + rc, "%c", c);
	}
	rc += sprintf(out_buf + rc, "\n");
	return rc;
}

/*
 * prints header for debug entry
 */

int debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
			 int area, debug_entry_t * entry, char *out_buf)
{
	struct timeval time_val;
	unsigned long long time;
	char *except_str;
	unsigned long caller;
	int rc = 0;
	unsigned int level;

	level = entry->id.fields.level;
	time = entry->id.stck;
	/* adjust todclock to 1970 */
	time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
	tod_to_timeval(time, &time_val);

	if (entry->id.fields.exception)
		except_str = "*";
	else
		except_str = "-";
	caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
	rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
		      area, time_val.tv_sec, time_val.tv_usec, level,
		      except_str, entry->id.fields.cpuid, (void *) caller);
	return rc;
}

/*
 * prints debug data sprintf-formated:
 * debug_sprinf_event/exception calls must be used together with this view
 */

#define DEBUG_SPRINTF_MAX_ARGS 10

int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
                            char *out_buf, debug_sprintf_entry_t *curr_event)
{
	int num_longs, num_used_args = 0,i, rc = 0;
	int index[DEBUG_SPRINTF_MAX_ARGS];

	/* count of longs fit into one entry */
	num_longs = id->buf_size /  sizeof(long); 

	if(num_longs < 1)
		goto out; /* bufsize of entry too small */
	if(num_longs == 1) {
		/* no args, we use only the string */
		strcpy(out_buf, curr_event->string);
		rc = strlen(curr_event->string);
		goto out;
	}

	/* number of arguments used for sprintf (without the format string) */
	num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));

	memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));

	for(i = 0; i < num_used_args; i++)
		index[i] = i;

	rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
		curr_event->args[index[1]], curr_event->args[index[2]],
		curr_event->args[index[3]], curr_event->args[index[4]],
		curr_event->args[index[5]], curr_event->args[index[6]],
		curr_event->args[index[7]], curr_event->args[index[8]],
		curr_event->args[index[9]]);

out:

	return rc;
}

/*
 * clean up module
 */
void __exit debug_exit(void)
{
#ifdef DEBUG
	printk("debug_cleanup_module: \n");
#endif
#ifdef CONFIG_PROC_FS
	remove_proc_entry(debug_proc_root_entry->name, NULL);
#endif /* CONFIG_PROC_FS */
	return;
}

/*
 * module definitions
 */
core_initcall(debug_init);
module_exit(debug_exit);
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(debug_register);
EXPORT_SYMBOL(debug_unregister); 
EXPORT_SYMBOL(debug_set_level);
EXPORT_SYMBOL(debug_register_view);
EXPORT_SYMBOL(debug_unregister_view);
EXPORT_SYMBOL(debug_event_common);
EXPORT_SYMBOL(debug_exception_common);
EXPORT_SYMBOL(debug_hex_ascii_view);
EXPORT_SYMBOL(debug_raw_view);
EXPORT_SYMBOL(debug_dflt_header_fn);
EXPORT_SYMBOL(debug_sprintf_view);
EXPORT_SYMBOL(debug_sprintf_exception);
EXPORT_SYMBOL(debug_sprintf_event);