Thread (6 messages) 6 messages, 5 authors, 2021-05-15

[PATCH v2] clocksource/drivers/hyper-v: Re-enable VDSO_CLOCKMODE_HVCLOCK on X86

From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: 2021-05-13 07:33:26
Also in: linux-hyperv
Subsystem: clocksource, clockevent drivers, hyper-v/azure core and drivers, the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Daniel Lezcano, Thomas Gleixner, "K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds, Ingo Molnar, Borislav Petkov, Dave Hansen

Mohammed reports (https://bugzilla.kernel.org/show_bug.cgi?id=213029)
the commit e4ab4658f1cf ("clocksource/drivers/hyper-v: Handle vDSO
differences inline") broke vDSO on x86. The problem appears to be that
VDSO_CLOCKMODE_HVCLOCK is an enum value in 'enum vdso_clock_mode' and
'#ifdef VDSO_CLOCKMODE_HVCLOCK' branch evaluates to false (it is not
a define). Use a dedicated HAVE_VDSO_CLOCKMODE_HVCLOCK define instead.

Suggested-by: Thomas Gleixner <redacted>
Reported-by: Mohammed Gamal <redacted>
Fixes: e4ab4658f1cf ("clocksource/drivers/hyper-v: Handle vDSO differences inline")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/vdso/clocksource.h | 2 ++
 drivers/clocksource/hyperv_timer.c      | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/vdso/clocksource.h b/arch/x86/include/asm/vdso/clocksource.h
index 119ac8612d89..136e5e57cfe1 100644
--- a/arch/x86/include/asm/vdso/clocksource.h
+++ b/arch/x86/include/asm/vdso/clocksource.h
@@ -7,4 +7,6 @@
 	VDSO_CLOCKMODE_PVCLOCK,	\
 	VDSO_CLOCKMODE_HVCLOCK
 
+#define HAVE_VDSO_CLOCKMODE_HVCLOCK
+
 #endif /* __ASM_VDSO_CLOCKSOURCE_H */
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 977fd05ac35f..d6ece7bbce89 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -419,7 +419,7 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
 	hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
 }
 
-#ifdef VDSO_CLOCKMODE_HVCLOCK
+#ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK
 static int hv_cs_enable(struct clocksource *cs)
 {
 	vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
@@ -435,7 +435,7 @@ static struct clocksource hyperv_cs_tsc = {
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
 	.suspend= suspend_hv_clock_tsc,
 	.resume	= resume_hv_clock_tsc,
-#ifdef VDSO_CLOCKMODE_HVCLOCK
+#ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK
 	.enable = hv_cs_enable,
 	.vdso_clock_mode = VDSO_CLOCKMODE_HVCLOCK,
 #else
-- 
2.31.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help