x86: Convert x86_platform_ops to timespec64

The x86 platform operations are fairly isolated, so it's easy to change
them from using timespec to timespec64. It has been checked that all the
users and callers are safe, and there is only one critical function that is
broken beyond 2106:

  pvclock_read_wallclock() uses a 32-bit number of seconds since the epoch
  to communicate the boot time between host and guest in a virtual
  environment. This will work until 2106, but fixing this is outside the
  scope of this change, Add a comment at least.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: jailhouse-dev@googlegroups.com
Cc: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Cc: y2038@lists.linaro.org
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: xen-devel@lists.xenproject.org
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Link: https://lkml.kernel.org/r/20180427201435.3194219-1-arnd@arndb.de

4 files changed, 19 insertions, 12 deletions

diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index a15fe0e92cf9..108c48d0d40e 100644
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -37,7 +37,7 @@ static uint32_t __init jailhouse_detect(void)
 	return jailhouse_cpuid_base();
 }
 
-static void jailhouse_get_wallclock(struct timespec *now)
+static void jailhouse_get_wallclock(struct timespec64 *now)
 {
 	memset(now, 0, sizeof(*now));
 }
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 8b26c9e01cc4..bf8d1eb7fca3 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -53,7 +53,7 @@ static struct pvclock_wall_clock *wall_clock;
  * have elapsed since the hypervisor wrote the data. So we try to account for
  * that with system time
  */
-static void kvm_get_wallclock(struct timespec *now)
+static void kvm_get_wallclock(struct timespec64 *now)
 {
 	struct pvclock_vcpu_time_info *vcpu_time;
 	int low, high;
@@ -72,7 +72,7 @@ static void kvm_get_wallclock(struct timespec *now)
 	put_cpu();
 }
 
-static int kvm_set_wallclock(const struct timespec *now)
+static int kvm_set_wallclock(const struct timespec64 *now)
 {
 	return -ENODEV;
 }
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 761f6af6efa5..637982efecd8 100644
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -123,28 +123,35 @@ u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
 
 void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
 			    struct pvclock_vcpu_time_info *vcpu_time,
-			    struct timespec *ts)
+			    struct timespec64 *ts)
 {
 	u32 version;
 	u64 delta;
-	struct timespec now;
+	struct timespec64 now;
 
 	/* get wallclock at system boot */
 	do {
 		version = wall_clock->version;
 		rmb();		/* fetch version before time */
+		/*
+		 * Note: wall_clock->sec is a u32 value, so it can
+		 * only store dates between 1970 and 2106. To allow
+		 * times beyond that, we need to create a new hypercall
+		 * interface with an extended pvclock_wall_clock structure
+		 * like ARM has.
+		 */
 		now.tv_sec  = wall_clock->sec;
 		now.tv_nsec = wall_clock->nsec;
 		rmb();		/* fetch time before checking version */
 	} while ((wall_clock->version & 1) || (version != wall_clock->version));
 
 	delta = pvclock_clocksource_read(vcpu_time);	/* time since system boot */
-	delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;
+	delta += now.tv_sec * NSEC_PER_SEC + now.tv_nsec;
 
 	now.tv_nsec = do_div(delta, NSEC_PER_SEC);
 	now.tv_sec = delta;
 
-	set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
+	set_normalized_timespec64(ts, now.tv_sec, now.tv_nsec);
 }
 
 void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index f7b82ed7b5b5..586f718b8e95 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -39,7 +39,7 @@ EXPORT_SYMBOL(rtc_lock);
  * 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_rtc_mmss(const struct timespec64 *now)
 {
 	unsigned long long nowtime = now->tv_sec;
 	struct rtc_time tm;
@@ -60,7 +60,7 @@ int mach_set_rtc_mmss(const struct timespec *now)
 	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;
@@ -118,7 +118,7 @@ void mach_get_cmos_time(struct timespec *now)
 	} else
 		year += CMOS_YEARS_OFFS;
 
-	now->tv_sec = mktime(year, mon, day, hour, min, sec);
+	now->tv_sec = mktime64(year, mon, day, hour, min, sec);
 	now->tv_nsec = 0;
 }
 
@@ -145,13 +145,13 @@ 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);
 }