Commit f8475a67 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_timers_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 RTC cleanups from Borislav Petkov:

 - Cleanup x86/rtc.c and delete duplicated functionality in favor of
   using the respective functionality from the RTC library

* tag 'x86_timers_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/rtc: Rename mach_set_rtc_mmss() to mach_set_cmos_time()
  x86/rtc: Rewrite & simplify mach_get_cmos_time() by deleting duplicated functionality
parents 3339914a e1a6bc7c

arch/x86/include/asm/mc146818rtc.h

+1 −1
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ static inline unsigned char current_lock_cmos_reg(void) 
unsigned char rtc_cmos_read(unsigned char addr);

void rtc_cmos_write(unsigned char val, unsigned char addr);



extern int mach_set_rtc_mmss(const struct timespec64 *now);

extern int mach_set_cmos_time(const struct timespec64 *now);

extern void mach_get_cmos_time(struct timespec64 *now);



#define RTC_IRQ 8

arch/x86/kernel/rtc.c

+9 −54
Original line number Diff line number Diff line
@@ -4,11 +4,8 @@ 
 */

#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>
@@ -20,26 +17,23 @@ 
/*

 * 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 timespec64 *now)

int mach_set_cmos_time(const struct timespec64 *now)

{

	unsigned long long nowtime = now->tv_sec;

	struct rtc_time tm;
@@ -62,8 +56,7 @@ int mach_set_rtc_mmss(const struct timespec64 *now) 


void mach_get_cmos_time(struct timespec64 *now)

{

	unsigned int status, year, mon, day, hour, min, sec, century = 0;

	unsigned long flags;

	struct rtc_time tm;



	/*

	 * If pm_trace abused the RTC as storage, set the timespec to 0,
@@ -74,51 +67,13 @@ void mach_get_cmos_time(struct timespec64 *now) 
		return;

	}



	spin_lock_irqsave(&rtc_lock, flags);



	/*

	 * 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.

	 */

	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 (mc146818_get_time(&tm)) {

		pr_err("Unable to read current time from RTC\n");

		now->tv_sec = now->tv_nsec = 0;

		return;

	}



	if (century) {

		century = bcd2bin(century);

		year += century * 100;

	} else

		year += CMOS_YEARS_OFFS;



	now->tv_sec = mktime64(year, mon, day, hour, min, sec);

	now->tv_sec = rtc_tm_to_time64(&tm);

	now->tv_nsec = 0;

}

arch/x86/kernel/x86_init.c

+1 −1
Original line number Diff line number Diff line
@@ -138,7 +138,7 @@ struct x86_platform_ops x86_platform __ro_after_init = { 
	.calibrate_cpu			= native_calibrate_cpu_early,

	.calibrate_tsc			= native_calibrate_tsc,

	.get_wallclock			= mach_get_cmos_time,

	.set_wallclock			= mach_set_rtc_mmss,

	.set_wallclock			= mach_set_cmos_time,

	.iommu_shutdown			= iommu_shutdown_noop,

	.is_untracked_pat_range		= is_ISA_range,

	.nmi_init			= default_nmi_init,