linux-kernel - [PATCH v8 04/11] cpuidle-haltpoll: define arch_haltpoll

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Message-Id: <20240925232425.2763385-5-ankur.a.arora@oracle.com>
Date: Wed, 25 Sep 2024 16:24:18 -0700
From: Ankur Arora <ankur.a.arora@...cle.com>
To: linux-pm@...r.kernel.org, kvm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: catalin.marinas@....com, will@...nel.org, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        x86@...nel.org, hpa@...or.com, pbonzini@...hat.com,
        wanpengli@...cent.com, vkuznets@...hat.com, rafael@...nel.org,
        daniel.lezcano@...aro.org, peterz@...radead.org, arnd@...db.de,
        lenb@...nel.org, mark.rutland@....com, harisokn@...zon.com,
        mtosatti@...hat.com, sudeep.holla@....com, cl@...two.org,
        misono.tomohiro@...itsu.com, maobibo@...ngson.cn,
        joao.m.martins@...cle.com, boris.ostrovsky@...cle.com,
        konrad.wilk@...cle.com
Subject: [PATCH v8 04/11] cpuidle-haltpoll: define arch_haltpoll_want()

From: Joao Martins <joao.m.martins@...cle.com>

While initializing haltpoll we check if KVM supports the
realtime hint and if idle is overridden at boot.

Both of these checks are x86 specific. So, in pursuit of
making cpuidle-haltpoll architecture independent, move these
checks out of common code.

Signed-off-by: Joao Martins <joao.m.martins@...cle.com>
Signed-off-by: Mihai Carabas <mihai.carabas@...cle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@...cle.com>
---
 arch/x86/include/asm/cpuidle_haltpoll.h |  1 +
 arch/x86/kernel/kvm.c                   | 13 +++++++++++++
 drivers/cpuidle/cpuidle-haltpoll.c      | 12 +-----------
 include/linux/cpuidle_haltpoll.h        |  5 +++++
 4 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/cpuidle_haltpoll.h b/arch/x86/include/asm/cpuidle_haltpoll.h
index c8b39c6716ff..8a0a12769c2e 100644
--- a/arch/x86/include/asm/cpuidle_haltpoll.h
+++ b/arch/x86/include/asm/cpuidle_haltpoll.h
@@ -4,5 +4,6 @@
 
 void arch_haltpoll_enable(unsigned int cpu);
 void arch_haltpoll_disable(unsigned int cpu);
+bool arch_haltpoll_want(bool force);
 
 #endif
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 263f8aed4e2c..63710cb1aa63 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -1151,4 +1151,17 @@ void arch_haltpoll_disable(unsigned int cpu)
 	smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1);
 }
 EXPORT_SYMBOL_GPL(arch_haltpoll_disable);
+
+bool arch_haltpoll_want(bool force)
+{
+	/* Do not load haltpoll if idle= is passed */
+	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
+		return false;
+
+	if (!kvm_para_available())
+		return false;
+
+	return kvm_para_has_hint(KVM_HINTS_REALTIME) || force;
+}
+EXPORT_SYMBOL_GPL(arch_haltpoll_want);
 #endif
diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c
index bcd03e893a0a..e532aa2bf608 100644
--- a/drivers/cpuidle/cpuidle-haltpoll.c
+++ b/drivers/cpuidle/cpuidle-haltpoll.c
@@ -15,7 +15,6 @@
 #include <linux/cpuidle.h>
 #include <linux/module.h>
 #include <linux/sched/idle.h>
-#include <linux/kvm_para.h>
 #include <linux/cpuidle_haltpoll.h>
 
 static bool force __read_mostly;
@@ -93,21 +92,12 @@ static void haltpoll_uninit(void)
 	haltpoll_cpuidle_devices = NULL;
 }
 
-static bool haltpoll_want(void)
-{
-	return kvm_para_has_hint(KVM_HINTS_REALTIME) || force;
-}
-
 static int __init haltpoll_init(void)
 {
 	int ret;
 	struct cpuidle_driver *drv = &haltpoll_driver;
 
-	/* Do not load haltpoll if idle= is passed */
-	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
-		return -ENODEV;
-
-	if (!kvm_para_available() || !haltpoll_want())
+	if (!arch_haltpoll_want(force))
 		return -ENODEV;
 
 	cpuidle_poll_state_init(drv);
diff --git a/include/linux/cpuidle_haltpoll.h b/include/linux/cpuidle_haltpoll.h
index d50c1e0411a2..68eb7a757120 100644
--- a/include/linux/cpuidle_haltpoll.h
+++ b/include/linux/cpuidle_haltpoll.h
@@ -12,5 +12,10 @@ static inline void arch_haltpoll_enable(unsigned int cpu)
 static inline void arch_haltpoll_disable(unsigned int cpu)
 {
 }
+
+static inline bool arch_haltpoll_want(bool force)
+{
+	return false;
+}
 #endif
 #endif
-- 
2.43.5