Handling all the three clocks (hardclock, softclock, profclock) with the

LAPIC may lead to aliasing for softclock and profclock because frequencies
are sized in order to fit mainly hardclock.
atrtc used to take care of the softclock and profclock and it does still
do, if the LAPIC can't handle the clocks properly.

Revert the change when the LAPIC started taking charge of all three of
them and let atrtc handle softclock and profclock if not explicitly
requested. Such request can be made setting != 0 the new tunable
machdep.lapic_allclocks or if the new device ATPIC is not present
within the i386 kernel config (atrtc is linked to atpic presence).

Diagnosed by:	Sandvine Incorporated
Reviewed by:	jhb, emaste
Sponsored by:	Sandvine Incorporated
MFC:		3 weeks

1 files changed, 7 insertions, 1 deletions

diff --git a/sys/amd64/include/apicvar.h b/sys/amd64/include/apicvar.h
index 9d6d538..8f15d84 100644
--- a/sys/amd64/include/apicvar.h
+++ b/sys/amd64/include/apicvar.h
@@ -157,6 +157,12 @@
 #define	APIC_BUS_PCI		2
 #define	APIC_BUS_MAX		APIC_BUS_PCI
 
+enum lapic_clock {
+	LAPIC_CLOCK_NONE,
+	LAPIC_CLOCK_HARDCLOCK,
+	LAPIC_CLOCK_ALL
+};
+
 /*
  * An APIC enumerator is a psuedo bus driver that enumerates APIC's including
  * CPU's and I/O APIC's.
@@ -224,7 +230,7 @@ int	lapic_set_lvt_triggermode(u_int apic_id, u_int lvt,
 	    enum intr_trigger trigger);
 void	lapic_set_tpr(u_int vector);
 void	lapic_setup(int boot);
-int	lapic_setup_clock(void);
+enum lapic_clock	lapic_setup_clock(void);
 
 #endif /* !LOCORE */
 #endif /* _MACHINE_APICVAR_H_ */