+DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL(rtc_lock);
+
+/*
+ * This is a special lock that is owned by the CPU and holds the index
+ * register we are working with. It is required for NMI access to the
+ * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details.
+ */
+volatile unsigned long cmos_lock = 0;
+EXPORT_SYMBOL(cmos_lock);
+
+/* Routines for accessing the CMOS RAM/RTC. */
+unsigned char rtc_cmos_read(unsigned char addr)
+{
+ unsigned char val;
+
+ lock_cmos_prefix(addr);
+ outb_p(addr, RTC_PORT(0));
+ val = inb_p(RTC_PORT(1));
+ lock_cmos_suffix(addr);
+ return val;
+}
+EXPORT_SYMBOL(rtc_cmos_read);
+
+void rtc_cmos_write(unsigned char val, unsigned char addr)
+{
+ lock_cmos_prefix(addr);
+ outb_p(addr, RTC_PORT(0));
+ outb_p(val, RTC_PORT(1));
+ lock_cmos_suffix(addr);
+}
+EXPORT_SYMBOL(rtc_cmos_write);
+
+static int set_rtc_mmss(unsigned long nowtime)
+{
+ int retval;
+ unsigned long flags;
+
+ /* gets recalled with irq locally disabled */
+ /* XXX - does irqsave resolve this? -johnstul */
+ spin_lock_irqsave(&rtc_lock, flags);
+ retval = set_wallclock(nowtime);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ return retval;
+}
+
+/* not static: needed by APM */
+unsigned long read_persistent_clock(void)
+{
+ unsigned long retval;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ retval = get_wallclock();
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ return retval;
+}
+
+int update_persistent_clock(struct timespec now)
+{
+ return set_rtc_mmss(now.tv_sec);
+}