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From: Ulf Hansson <ulf.hansson@linaro.org>
To: "Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
	linux-pm@vger.kernel.org
Cc: Kevin Hilman <khilman@kernel.org>,
	Lina Iyer <ilina@codeaurora.org>,
	Lina Iyer <lina.iyer@linaro.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Stephen Boyd <sboyd@kernel.org>, Juri Lelli <juri.lelli@arm.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	linux-arm-kernel@lists.infradead.org,
	linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v6 08/25] PM / Domains: Extend genpd CPU governor to cope with QoS constraints
Date: Wed, 14 Mar 2018 17:58:18 +0100	[thread overview]
Message-ID: <1521046715-30683-9-git-send-email-ulf.hansson@linaro.org> (raw)
In-Reply-To: <1521046715-30683-1-git-send-email-ulf.hansson@linaro.org>

CPU devices and other regular devices may share the same PM domain and may
also be hierarchically related via subdomains. In either case, all devices
including CPUs, may be attached to a PM domain managed by genpd, that has
an idle state with an enter/exit latency.

Let's take these latencies into account in the state selection process by
genpd's governor for CPUs. This means the governor, pm_domain_cpu_gov,
becomes extended to satisfy both a state's residency and a potential dev PM
QoS constraint.

Cc: Lina Iyer <ilina@codeaurora.org>
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/power/domain_governor.c | 15 +++++++++++----
 include/linux/pm_domain.h            |  1 +
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c
index 70565a8..2f162bc 100644
--- a/drivers/base/power/domain_governor.c
+++ b/drivers/base/power/domain_governor.c
@@ -214,8 +214,10 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 	struct generic_pm_domain *genpd = pd_to_genpd(pd);
 	struct gpd_link *link;
 
-	if (!genpd->max_off_time_changed)
+	if (!genpd->max_off_time_changed) {
+		genpd->state_idx = genpd->cached_power_down_state_idx;
 		return genpd->cached_power_down_ok;
+	}
 
 	/*
 	 * We have to invalidate the cached results for the masters, so
@@ -240,6 +242,7 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 		genpd->state_idx--;
 	}
 
+	genpd->cached_power_down_state_idx = genpd->state_idx;
 	return genpd->cached_power_down_ok;
 }
 
@@ -255,6 +258,10 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd)
 	s64 idle_duration_ns;
 	int cpu, i;
 
+	/* Validate dev PM QoS constraints. */
+	if (!default_power_down_ok(pd))
+		return false;
+
 	if (!(genpd->flags & GENPD_FLAG_CPU_DOMAIN))
 		return true;
 
@@ -275,9 +282,9 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd)
 
 	/*
 	 * Find the deepest idle state, that has its residency value satisfied.
-	 * Start at the deepest supported state.
+	 * Start at the state picked by the dev PM QoS constraint validation.
 	 */
-	i = genpd->state_count - 1;
+	i = genpd->state_idx;
 	do {
 		if (!genpd->states[i].residency_ns)
 			break;
@@ -310,6 +317,6 @@ struct dev_power_governor pm_domain_always_on_gov = {
 };
 
 struct dev_power_governor pm_domain_cpu_gov = {
-	.suspend_ok = NULL,
+	.suspend_ok = default_suspend_ok,
 	.power_down_ok = cpu_power_down_ok,
 };
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 8f60181..e7910d2 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -77,6 +77,7 @@ struct generic_pm_domain {
 	s64 max_off_time_ns;	/* Maximum allowed "suspended" time. */
 	bool max_off_time_changed;
 	bool cached_power_down_ok;
+	bool cached_power_down_state_idx;
 	int (*attach_dev)(struct generic_pm_domain *domain,
 			  struct device *dev);
 	void (*detach_dev)(struct generic_pm_domain *domain,
-- 
2.7.4

  parent reply	other threads:[~2018-03-14 17:04 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-14 16:58 [PATCH v6 00/25] PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 01/25] PM / Domains: Don't treat zero found compatible idle states as an error Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 02/25] PM / Domains: Deal with multiple states but no governor in genpd Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 03/25] PM / Domains: Add generic data pointer to genpd_power_state struct Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 04/25] PM / Domains: Add support for CPU devices to genpd Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 05/25] PM / Domains: Add helper functions to attach/detach CPUs to/from genpd Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 06/25] timer: Export next wakeup time of a CPU Ulf Hansson
2018-03-14 17:19   ` Mark Rutland
2018-03-14 16:58 ` [PATCH v6 07/25] PM / Domains: Add genpd governor for CPUs Ulf Hansson
2018-03-14 16:58 ` Ulf Hansson [this message]
2018-03-14 16:58 ` [PATCH v6 09/25] kernel/cpu_pm: Manage runtime PM in the idle path " Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 10/25] dt: psci: Update DT bindings to support hierarchical PSCI states Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 11/25] of: base: Add of_get_cpu_state_node() to get idle states for a CPU node Ulf Hansson
2018-03-18 12:51   ` Rob Herring
2018-03-14 16:58 ` [PATCH v6 12/25] cpuidle: dt: Support hierarchical CPU idle states Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 13/25] drivers: firmware: psci: Split psci_dt_cpu_init_idle() Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 14/25] drivers: firmware: psci: Support hierarchical CPU idle states Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 15/25] drivers: firmware: psci: Simplify error path of psci_dt_init() Ulf Hansson
2018-03-14 17:25   ` Mark Rutland
2018-03-14 16:58 ` [PATCH v6 16/25] drivers: firmware: psci: Announce support for OS initiated suspend mode Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 17/25] drivers: firmware: psci: Prepare to use " Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 18/25] drivers: firmware: psci: Share a few internal PSCI functions Ulf Hansson
2018-03-14 17:30   ` Mark Rutland
2018-03-14 16:58 ` [PATCH v6 19/25] drivers: firmware: psci: Add support for PM domains using genpd Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 20/25] drivers: firmware: psci: Introduce psci_dt_topology_init() Ulf Hansson
2018-03-14 17:38   ` Mark Rutland
2018-04-10  7:19     ` Ulf Hansson
2018-04-10 11:10       ` Mark Rutland
2018-04-10 12:25         ` Ulf Hansson
2018-04-18 11:32           ` Mark Rutland
2018-03-14 16:58 ` [PATCH v6 21/25] drivers: firmware: psci: Try to attach CPU devices to their PM domains Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 22/25] drivers: firmware: psci: Deal with CPU hotplug when using OSI mode Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 23/25] MAINTAINERS: Update files for PSCI Ulf Hansson
2018-03-14 17:40   ` Mark Rutland
2018-03-14 16:58 ` [PATCH v6 24/25] arm64: kernel: Respect the hierarchical CPU topology in DT " Ulf Hansson
2018-03-14 16:58 ` [PATCH v6 25/25] arm64: dts: Convert to the hierarchical CPU topology layout for MSM8916 Ulf Hansson
2018-03-14 17:19 ` [PATCH v6 00/25] PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) Mark Rutland
2018-03-15 14:19   ` Ulf Hansson
2018-03-15 11:00 ` Geert Uytterhoeven
2018-03-15 13:14   ` Ulf Hansson

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