1 files changed, 31 insertions, 74 deletions

diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 0aa29394ed6f..51a849a79c98 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -1,114 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * RTC related functions
  */
 #include <linux/platform_device.h>
 #include <linux/mc146818rtc.h>
-#include <linux/acpi.h>
-#include <linux/bcd.h>
 #include <linux/export.h>
 #include <linux/pnp.h>
-#include <linux/of.h>
 
 #include <asm/vsyscall.h>
 #include <asm/x86_init.h>
 #include <asm/time.h>
-#include <asm/mrst.h>
-#include <asm/rtc.h>
+#include <asm/setup.h>
 
 #ifdef CONFIG_X86_32
 /*
  * 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.
+ * CMOS/RTC registers.  See arch/x86/include/asm/mc146818rtc.h for details.
  */
 volatile unsigned long cmos_lock;
 EXPORT_SYMBOL(cmos_lock);
 #endif /* CONFIG_X86_32 */
 
-/* For two digit years assume time is always after that */
-#define CMOS_YEARS_OFFS 2000
-
 DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 
 /*
- * In order to set the CMOS clock precisely, set_rtc_mmss has to be
+ * In order to set the CMOS clock precisely, mach_set_cmos_time has to be
  * called 500 ms after the second nowtime has started, because when
  * nowtime is written into the registers of the CMOS clock, it will
  * jump to the next second precisely 500 ms later. Check the Motorola
  * MC146818A or Dallas DS12887 data sheet for details.
  */
-int mach_set_rtc_mmss(const struct timespec *now)
+int mach_set_cmos_time(const struct timespec64 *now)
 {
-	unsigned long nowtime = now->tv_sec;
+	unsigned long long nowtime = now->tv_sec;
 	struct rtc_time tm;
 	int retval = 0;
 
-	rtc_time_to_tm(nowtime, &tm);
+	rtc_time64_to_tm(nowtime, &tm);
 	if (!rtc_valid_tm(&tm)) {
-		retval = set_rtc_time(&tm);
+		retval = mc146818_set_time(&tm);
 		if (retval)
 			printk(KERN_ERR "%s: RTC write failed with error %d\n",
-			       __FUNCTION__, retval);
+			       __func__, retval);
 	} else {
 		printk(KERN_ERR
-		       "%s: Invalid RTC value: write of %lx to RTC failed\n",
-			__FUNCTION__, nowtime);
+		       "%s: Invalid RTC value: write of %llx to RTC failed\n",
+			__func__, nowtime);
 		retval = -EINVAL;
 	}
 	return retval;
 }
 
-void mach_get_cmos_time(struct timespec *now)
+void mach_get_cmos_time(struct timespec64 *now)
 {
-	unsigned int status, year, mon, day, hour, min, sec, century = 0;
-	unsigned long flags;
-
-	spin_lock_irqsave(&rtc_lock, flags);
+	struct rtc_time tm;
 
 	/*
-	 * If UIP is clear, then we have >= 244 microseconds before
-	 * RTC registers will be updated.  Spec sheet says that this
-	 * is the reliable way to read RTC - registers. If UIP is set
-	 * then the register access might be invalid.
+	 * If pm_trace abused the RTC as storage, set the timespec to 0,
+	 * which tells the caller that this RTC value is unusable.
 	 */
-	while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
-		cpu_relax();
-
-	sec = CMOS_READ(RTC_SECONDS);
-	min = CMOS_READ(RTC_MINUTES);
-	hour = CMOS_READ(RTC_HOURS);
-	day = CMOS_READ(RTC_DAY_OF_MONTH);
-	mon = CMOS_READ(RTC_MONTH);
-	year = CMOS_READ(RTC_YEAR);
-
-#ifdef CONFIG_ACPI
-	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
-	    acpi_gbl_FADT.century)
-		century = CMOS_READ(acpi_gbl_FADT.century);
-#endif
-
-	status = CMOS_READ(RTC_CONTROL);
-	WARN_ON_ONCE(RTC_ALWAYS_BCD && (status & RTC_DM_BINARY));
-
-	spin_unlock_irqrestore(&rtc_lock, flags);
-
-	if (RTC_ALWAYS_BCD || !(status & RTC_DM_BINARY)) {
-		sec = bcd2bin(sec);
-		min = bcd2bin(min);
-		hour = bcd2bin(hour);
-		day = bcd2bin(day);
-		mon = bcd2bin(mon);
-		year = bcd2bin(year);
+	if (!pm_trace_rtc_valid()) {
+		now->tv_sec = now->tv_nsec = 0;
+		return;
 	}
 
-	if (century) {
-		century = bcd2bin(century);
-		year += century * 100;
-	} else
-		year += CMOS_YEARS_OFFS;
+	if (mc146818_get_time(&tm, 1000)) {
+		pr_err("Unable to read current time from RTC\n");
+		now->tv_sec = now->tv_nsec = 0;
+		return;
+	}
 
-	now->tv_sec = mktime(year, mon, day, hour, min, sec);
+	now->tv_sec = rtc_tm_to_time64(&tm);
 	now->tv_nsec = 0;
 }
 
@@ -135,13 +99,13 @@ void rtc_cmos_write(unsigned char val, unsigned char addr)
 }
 EXPORT_SYMBOL(rtc_cmos_write);
 
-int update_persistent_clock(struct timespec now)
+int update_persistent_clock64(struct timespec64 now)
 {
 	return x86_platform.set_wallclock(&now);
 }
 
 /* not static: needed by APM */
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	x86_platform.get_wallclock(ts);
 }
@@ -170,26 +134,19 @@ static struct platform_device rtc_device = {
 static __init int add_rtc_cmos(void)
 {
 #ifdef CONFIG_PNP
-	static const char * const  const ids[] __initconst =
+	static const char * const ids[] __initconst =
 	    { "PNP0b00", "PNP0b01", "PNP0b02", };
 	struct pnp_dev *dev;
-	struct pnp_id *id;
 	int i;
 
 	pnp_for_each_dev(dev) {
-		for (id = dev->id; id; id = id->next) {
-			for (i = 0; i < ARRAY_SIZE(ids); i++) {
-				if (compare_pnp_id(id, ids[i]) != 0)
-					return 0;
-			}
+		for (i = 0; i < ARRAY_SIZE(ids); i++) {
+			if (compare_pnp_id(dev->id, ids[i]) != 0)
+				return 0;
 		}
 	}
 #endif
-	if (of_have_populated_dt())
-		return 0;
-
-	/* Intel MID platforms don't have ioport rtc */
-	if (mrst_identify_cpu())
+	if (!x86_platform.legacy.rtc)
 		return -ENODEV;
 
 	platform_device_register(&rtc_device);