/**
 * \file debug.c
 *  License details are found in the file LICENSE.
 * \brief
 *  Output to kmsg
 * \author Taku Shimosawa  <shimosawa@is.s.u-tokyo.ac.jp> \par
 * Copyright (C) 2011 - 2012  Taku Shimosawa
 */
/*
 * HISTORY:
 */

#include <stdarg.h>
#include <string.h>
#include <kmsg.h>
#include <ihk/debug.h>
#include <ihk/lock.h>

struct ihk_kmsg_buf kmsg_buf IHK_KMSG_ALIGN;

extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
extern int sprintf(char * buf, const char *fmt, ...);
static ihk_spinlock_t kmsg_lock;

/* TODO: lock */
void kputs(char *buf)
{
	int len = strlen(buf);
	unsigned long flags;

	flags = __ihk_mc_spinlock_lock(&kmsg_lock);

	if (len + kmsg_buf.tail > kmsg_buf.len) {
		kmsg_buf.tail = 0;
		if(len > kmsg_buf.len) {
			len = kmsg_buf.len;
		}
	}
	
	memcpy(kmsg_buf.str + kmsg_buf.tail, buf, len);
	kmsg_buf.tail += len;

	__ihk_mc_spinlock_unlock(&kmsg_lock, flags);
}

#define KPRINTF_LOCAL_BUF_LEN 1024

unsigned long kprintf_lock(void)
{
	return __ihk_mc_spinlock_lock(&kmsg_lock);
}

void kprintf_unlock(unsigned long irqflags)
{
	__ihk_mc_spinlock_unlock(&kmsg_lock, irqflags);
}

/* Caller must hold kmsg_lock! */
int __kprintf(const char *format, ...)
{
	int len = 0;
	va_list va;
	char buf[KPRINTF_LOCAL_BUF_LEN];

	/* Copy into the local buf */
	va_start(va, format);
	len += vsnprintf(buf + len, KPRINTF_LOCAL_BUF_LEN - len - 2, format, va);
	va_end(va);

	/* Append to kmsg buffer */
	if (kmsg_buf.tail + len > kmsg_buf.len) {
		kmsg_buf.tail = 0;
	}

	memcpy(kmsg_buf.str + kmsg_buf.tail, buf, len);
	kmsg_buf.tail += len;

	return len;
}

int kprintf(const char *format, ...)
{
	int len = 0;
	va_list va;
	unsigned long flags;
	char buf[KPRINTF_LOCAL_BUF_LEN];

	flags = __ihk_mc_spinlock_lock(&kmsg_lock);

	/* Copy into the local buf */
	len = sprintf(buf, "[%3d]: ", ihk_mc_get_processor_id());
	va_start(va, format);
	len += vsnprintf(buf + len, KPRINTF_LOCAL_BUF_LEN - len - 2, format, va);
	va_end(va);

	/* Append to kmsg buffer */
	if (kmsg_buf.tail + len > kmsg_buf.len) {
		kmsg_buf.tail = 0;
	}

	memcpy(kmsg_buf.str + kmsg_buf.tail, buf, len);
	kmsg_buf.tail += len;

	__ihk_mc_spinlock_unlock(&kmsg_lock, flags);

	return len;
}

void kmsg_init(void)
{
	ihk_mc_spinlock_init(&kmsg_lock);
	kmsg_buf.tail = 0;
	kmsg_buf.len = sizeof(kmsg_buf.str);
	memset(kmsg_buf.str, 0, kmsg_buf.len);
}