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From: Boqun Feng <boqun.feng@gmail.com>
To: linux-hyperv@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Michael Kelley <mikelley@microsoft.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Sasha Levin <sashal@kernel.org>,
	xen-devel@lists.xenproject.org,
	Stefano Stabellini <sstabellini@kernel.org>,
	Boqun Feng <boqun.feng@gmail.com>
Subject: [RFC 6/6] arm64: hyperv: Enable vDSO
Date: Mon, 16 Dec 2019 08:19:22 +0800	[thread overview]
Message-ID: <20191216001922.23008-7-boqun.feng@gmail.com> (raw)
In-Reply-To: <20191216001922.23008-1-boqun.feng@gmail.com>

Similar to x86, add a new vclock_mode VCLOCK_HVCLOCK, and reuse the
hv_read_tsc_page() for userspace to read tsc page clocksource.

Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com>
---
 arch/arm64/include/asm/clocksource.h       |  3 ++-
 arch/arm64/include/asm/mshyperv.h          |  2 +-
 arch/arm64/include/asm/vdso/gettimeofday.h | 19 +++++++++++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h
index fbe80057468c..c6acd45fe748 100644
--- a/arch/arm64/include/asm/clocksource.h
+++ b/arch/arm64/include/asm/clocksource.h
@@ -4,7 +4,8 @@
 
 #define VCLOCK_NONE	0	/* No vDSO clock available.		*/
 #define VCLOCK_CNTVCT	1	/* vDSO should use cntvcnt		*/
-#define VCLOCK_MAX	1
+#define VCLOCK_HVCLOCK	2	/* vDSO should use vread_hvclock()	*/
+#define VCLOCK_MAX	2
 
 struct arch_clocksource_data {
 	int vclock_mode;
diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h
index 0afb00e3501d..7c85dd816dca 100644
--- a/arch/arm64/include/asm/mshyperv.h
+++ b/arch/arm64/include/asm/mshyperv.h
@@ -90,7 +90,7 @@ extern void hv_get_vpreg_128(u32 reg, struct hv_get_vp_register_output *result);
 #define hv_set_reference_tsc(val) \
 		hv_set_vpreg(HV_REGISTER_REFERENCE_TSC, val)
 #define hv_set_clocksource_vdso(val) \
-		((val).archdata.vclock_mode = VCLOCK_NONE)
+		((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
 
 #if IS_ENABLED(CONFIG_HYPERV)
 #define hv_enable_stimer0_percpu_irq(irq)	enable_percpu_irq(irq, 0)
diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h
index e6e3fe0488c7..7e689b903f4d 100644
--- a/arch/arm64/include/asm/vdso/gettimeofday.h
+++ b/arch/arm64/include/asm/vdso/gettimeofday.h
@@ -67,6 +67,20 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
 	return ret;
 }
 
+#ifdef CONFIG_HYPERV_TIMER
+/* This will override the default hv_get_raw_timer() */
+#define hv_get_raw_timer() __arch_counter_get_cntvct()
+#include <clocksource/hyperv_timer.h>
+
+extern struct ms_hyperv_tsc_page
+_hvclock_page __attribute__((visibility("hidden")));
+
+static u64 vread_hvclock(void)
+{
+	return hv_read_tsc_page(&_hvclock_page);
+}
+#endif
+
 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
 	u64 res;
@@ -78,6 +92,11 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	if (clock_mode == VCLOCK_NONE)
 		return __VDSO_USE_SYSCALL;
 
+#ifdef CONFIG_HYPERV_TIMER
+	if (likely(clock_mode == VCLOCK_HVCLOCK))
+		return vread_hvclock();
+#endif
+
 	/*
 	 * This isb() is required to prevent that the counter value
 	 * is speculated.
-- 
2.24.0


  parent reply	other threads:[~2019-12-16  0:20 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-16  0:19 [RFC 0/6] vDSO support for Hyper-V guest on ARM64 Boqun Feng
2019-12-16  0:19 ` [RFC 1/6] arm64: hyperv: Allow hv_get_raw_timer() definition to be overridden Boqun Feng
2019-12-16  0:19 ` [RFC 2/6] arm64: vdso: Add support for multiple vDSO data pages Boqun Feng
2019-12-16  0:19 ` [RFC 3/6] arm/arm64: clocksource: Introduce vclock_mode Boqun Feng
2019-12-16  0:19 ` [RFC 4/6] arm64: vdso: hyperv: Map tsc page into vDSO if enabled Boqun Feng
2019-12-16  0:19 ` [RFC 5/6] arm64: hyperv: Enable userspace to read cntvct Boqun Feng
2019-12-16  0:19 ` Boqun Feng [this message]
2019-12-17 14:10   ` [RFC 6/6] arm64: hyperv: Enable vDSO Vitaly Kuznetsov
2019-12-18  5:47     ` Boqun Feng
2020-01-23 10:48 ` [RFC 0/6] vDSO support for Hyper-V guest on ARM64 Vincenzo Frascino
2020-01-24  6:32   ` Boqun Feng
2020-01-24 10:24     ` Vincenzo Frascino
2020-01-28  5:58       ` Boqun Feng
2020-01-28 11:48         ` Marc Zyngier

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