x86/tsc: Fix UV TSC initialization

The recent rework of the TSC calibration code introduced a regression on UV
systems as it added a call to tsc_early_init() which initializes the TSC
ADJUST values before acpi_boot_table_init().  In the case of UV systems,
that is a necessary step that calls uv_system_init().  This informs
tsc_sanitize_first_cpu() that the kernel runs on a platform with async TSC
resets as documented in commit 341102c3ef29 ("x86/tsc: Add option that TSC
on Socket 0 being non-zero is valid")

Fix it by skipping the early tsc initialization on UV systems and let TSC
init tests take place later in tsc_init().

Fixes: cf7a63ef4e02 ("x86/tsc: Calibrate tsc only once")
Suggested-by: Hedi Berriche <[email protected]>
Signed-off-by: Mike Travis <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Russ Anderson <[email protected]>
Reviewed-by: Dimitri Sivanich <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Russ Anderson <[email protected]>
Cc: Dimitri Sivanich <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Dou Liyang <[email protected]>
Cc: Xiaoming Gao <[email protected]>
Cc: Rajvi Jingar <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 6490f618e096..b52bd2b6cdb4 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -26,6 +26,7 @@
 #include <asm/apic.h>
 #include <asm/intel-family.h>
 #include <asm/i8259.h>
+#include <asm/uv/uv.h>
 
 unsigned int __read_mostly cpu_khz;	/* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
@@ -1433,6 +1434,9 @@ void __init tsc_early_init(void)
 {
 	if (!boot_cpu_has(X86_FEATURE_TSC))
 		return;
+	/* Don't change UV TSC multi-chassis synchronization */
+	if (is_early_uv_system())
+		return;
 	if (!determine_cpu_tsc_frequencies(true))
 		return;
 	loops_per_jiffy = get_loops_per_jiffy();