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authorLinus Torvalds <torvalds@linux-foundation.org>2022-10-04 19:13:21 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-10-04 19:13:21 +0300
commitf8475a6749ae9727878c189bbff073a257e43cba (patch)
tree6735a68a7d3019fb6d2ec6f0b43fab64e4d7b544 /arch/x86/kernel
parent3339914a5832cffdecd578931b3db20d3deba5f6 (diff)
parente1a6bc7c6969527dbe0afa4801a0237e41e26b1b (diff)
downloadlinux-f8475a6749ae9727878c189bbff073a257e43cba.tar.xz
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
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/rtc.c63
-rw-r--r--arch/x86/kernel/x86_init.c2
2 files changed, 10 insertions, 55 deletions
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 586f718b8e95..349046434513 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -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;
}
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index e84ee5cdbd8c..57353519bc11 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -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,