static int cpu_check_overtemp()

in windfarm_rm31.c [119:200]

• 59 lines of code
• 16 McCabe index (conditional complexity)

static int cpu_check_overtemp(s32 temp)
{
	int new_state = 0;
	s32 t_avg, t_old;
	static bool first = true;

	/* First check for immediate overtemps */
	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
		new_state |= FAILURE_LOW_OVERTEMP;
		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
			       " temperature !\n");
	}
	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
		new_state |= FAILURE_HIGH_OVERTEMP;
		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Critical overtemp due to"
			       " immediate CPU temperature !\n");
	}

	/*
	 * The first time around, initialize the array with the first
	 * temperature reading
	 */
	if (first) {
		int i;

		cpu_thist_total = 0;
		for (i = 0; i < CPU_TEMP_HIST_SIZE; i++) {
			cpu_thist[i] = temp;
			cpu_thist_total += temp;
		}
		first = false;
	}

	/*
	 * We calculate a history of max temperatures and use that for the
	 * overtemp management
	 */
	t_old = cpu_thist[cpu_thist_pt];
	cpu_thist[cpu_thist_pt] = temp;
	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
	cpu_thist_total -= t_old;
	cpu_thist_total += temp;
	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;

	DBG_LOTS("  t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));

	/* Now check for average overtemps */
	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
		new_state |= FAILURE_LOW_OVERTEMP;
		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
			       " temperature !\n");
	}
	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
		new_state |= FAILURE_HIGH_OVERTEMP;
		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Critical overtemp due to"
			       " average CPU temperature !\n");
	}

	/* Now handle overtemp conditions. We don't currently use the windfarm
	 * overtemp handling core as it's not fully suited to the needs of those
	 * new machine. This will be fixed later.
	 */
	if (new_state) {
		/* High overtemp -> immediate shutdown */
		if (new_state & FAILURE_HIGH_OVERTEMP)
			machine_power_off();
		if ((failure_state & new_state) != new_state)
			cpu_max_all_fans();
		failure_state |= new_state;
	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
		failure_state &= ~FAILURE_LOW_OVERTEMP;
	}

	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
}