From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-kernel@lists.infradead.org,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
"Raju P . L . S . S . S . N" <rplsssn@codeaurora.org>,
Amit Kucheria <amit.kucheria@linaro.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Stephen Boyd <sboyd@kernel.org>,
Niklas Cassel <niklas.cassel@linaro.org>,
Tony Lindgren <tony@atomide.com>,
Kevin Hilman <khilman@kernel.org>,
Lina Iyer <ilina@codeaurora.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Souvik Chakravarty <souvik.chakravarty@arm.com>,
linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 14/18] drivers: firmware: psci: Manage runtime PM in the idle path for CPUs
Date: Tue, 16 Jul 2019 16:53:17 +0100 [thread overview]
Message-ID: <20190716155317.GB32490@e121166-lin.cambridge.arm.com> (raw)
In-Reply-To: <20190513192300.653-15-ulf.hansson@linaro.org>
On Mon, May 13, 2019 at 09:22:56PM +0200, Ulf Hansson wrote:
> When the hierarchical CPU topology layout is used in DT, let's allow the
> CPU to be power managed through its PM domain, via deploying runtime PM
> support.
>
> To know for which idle states runtime PM reference counting is needed,
> let's store the index of deepest idle state for the CPU, in a per CPU
> variable. This allows psci_cpu_suspend_enter() to compare this index with
> the requested idle state index and then act accordingly.
I do not see why a system with two CPU CPUidle states, say CPU retention
and CPU shutdown, should not be calling runtime PM on CPU retention
entry.
The question then is what cluster/package/system states
are allowed for a given CPU idle state, to understand
what idle states can be actually entered at any hierarchy
level given the choice made for the CPU idle state.
In the case above, a CPU entering retention state should prevent
runtime PM selecting a cluster shutdown state; most likely firmware
would demote the request to cluster retention but still, we should
find a way to describe these dependencies.
Thanks,
Lorenzo
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>
> Changes:
> - Simplify the code by using the new per CPU struct, that stores the
> needed struct device*.
>
> ---
> drivers/firmware/psci/psci.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 54e23d4ed0ea..2c4157d3a616 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -20,6 +20,7 @@
> #include <linux/linkage.h>
> #include <linux/of.h>
> #include <linux/pm.h>
> +#include <linux/pm_runtime.h>
> #include <linux/printk.h>
> #include <linux/psci.h>
> #include <linux/reboot.h>
> @@ -298,6 +299,7 @@ static int __init psci_features(u32 psci_func_id)
>
> struct psci_cpuidle_data {
> u32 *psci_states;
> + u32 rpm_state_id;
> struct device *dev;
> };
>
> @@ -385,6 +387,7 @@ static int psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
> goto free_mem;
>
> data->dev = dev;
> + data->rpm_state_id = drv->state_count - 1;
> }
>
> /* Idle states parsed correctly, store them in the per-cpu struct. */
> @@ -481,8 +484,11 @@ static int psci_suspend_finisher(unsigned long index)
> int psci_cpu_suspend_enter(unsigned long index)
> {
> int ret;
> - u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
> - u32 composite_state = state[index - 1] | psci_get_domain_state();
> + struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data);
> + u32 *states = data->psci_states;
> + struct device *dev = data->dev;
> + bool runtime_pm = (dev && data->rpm_state_id == index);
> + u32 composite_state;
>
> /*
> * idle state index 0 corresponds to wfi, should never be called
> @@ -491,11 +497,23 @@ int psci_cpu_suspend_enter(unsigned long index)
> if (WARN_ON_ONCE(!index))
> return -EINVAL;
>
> + /*
> + * Do runtime PM if we are using the hierarchical CPU toplogy, but only
> + * when cpuidle have selected the deepest idle state for the CPU.
> + */
> + if (runtime_pm)
> + pm_runtime_put_sync_suspend(dev);
> +
> + composite_state = states[index - 1] | psci_get_domain_state();
> +
> if (!psci_power_state_loses_context(composite_state))
> ret = psci_ops.cpu_suspend(composite_state, 0);
> else
> ret = cpu_suspend(index, psci_suspend_finisher);
>
> + if (runtime_pm)
> + pm_runtime_get_sync(dev);
> +
> /* Clear the domain state to start fresh when back from idle. */
> psci_set_domain_state(0);
>
> --
> 2.17.1
>
next prev parent reply other threads:[~2019-07-16 15:53 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-13 19:22 [PATCH 00/18] ARM/ARM64: Support hierarchical CPU arrangement for PSCI Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 01/18] dt: psci: Update DT bindings to support hierarchical PSCI states Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-07-19 11:29 ` Lorenzo Pieralisi
2019-05-13 19:22 ` [PATCH 02/18] of: base: Add of_get_cpu_state_node() to get idle states for a CPU node Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 03/18] cpuidle: dt: Support hierarchical CPU idle states Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 04/18] ARM/ARM64: cpuidle: Let back-end init ops take the driver as input Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:00 ` Sudeep Holla
2019-06-10 10:20 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 05/18] drivers: firmware: psci: Simplify state node parsing Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:01 ` Sudeep Holla
2019-05-13 19:22 ` [PATCH 06/18] drivers: firmware: psci: Support hierarchical CPU idle states Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:03 ` Sudeep Holla
2019-05-13 19:22 ` [PATCH 07/18] drivers: firmware: psci: Prepare to use OS initiated suspend mode Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:17 ` Sudeep Holla
2019-06-10 10:21 ` Ulf Hansson
2019-06-10 10:42 ` Sudeep Holla
2019-07-16 14:53 ` Sudeep Holla
2019-05-13 19:22 ` [PATCH 08/18] drivers: firmware: psci: Prepare to support PM domains Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:21 ` Sudeep Holla
2019-05-13 19:22 ` [PATCH 09/18] drivers: firmware: psci: Add support for PM domains using genpd Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:27 ` Sudeep Holla
2019-06-10 10:21 ` Ulf Hansson
2019-06-10 10:59 ` Sudeep Holla
2019-07-16 15:05 ` Sudeep Holla
2019-07-18 11:04 ` Ulf Hansson
2019-07-18 13:19 ` Sudeep Holla
2019-07-18 17:57 ` Lina Iyer
2019-07-19 9:45 ` Sudeep Holla
2019-05-13 19:22 ` [PATCH 10/18] drivers: firmware: psci: Add hierarchical domain idle states converter Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-07-09 15:31 ` Lorenzo Pieralisi
2019-07-16 8:45 ` Ulf Hansson
2019-07-16 14:51 ` Lorenzo Pieralisi
2019-07-18 11:43 ` Ulf Hansson
2019-07-18 13:36 ` Lorenzo Pieralisi
2019-05-13 19:22 ` [PATCH 11/18] drivers: firmware: psci: Introduce psci_dt_topology_init() Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 12/18] drivers: firmware: psci: Add a helper to attach a CPU to its PM domain Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 13/18] drivers: firmware: psci: Attach the CPU's device " Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 14/18] drivers: firmware: psci: Manage runtime PM in the idle path for CPUs Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-07-16 15:53 ` Lorenzo Pieralisi [this message]
2019-07-18 10:35 ` Ulf Hansson
2019-07-18 13:30 ` Lorenzo Pieralisi
2019-07-18 16:54 ` Ulf Hansson
2019-07-18 17:41 ` Lina Iyer
2019-07-18 21:49 ` Ulf Hansson
2019-07-19 10:02 ` Lorenzo Pieralisi
2019-05-13 19:22 ` [PATCH 15/18] drivers: firmware: psci: Support CPU hotplug for the hierarchical model Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-06-07 15:31 ` Sudeep Holla
2019-06-10 10:21 ` Ulf Hansson
2019-06-10 11:02 ` Sudeep Holla
2019-05-13 19:22 ` [PATCH 16/18] arm64: kernel: Respect the hierarchical CPU topology in DT for PSCI Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-05-13 19:22 ` [PATCH 17/18] arm64: dts: Convert to the hierarchical CPU topology layout for MSM8916 Ulf Hansson
2019-05-13 19:22 ` Ulf Hansson
2019-07-16 14:47 ` Sudeep Holla
2019-07-16 20:36 ` Lina Iyer
2019-07-17 17:18 ` Sudeep Holla
2019-05-13 19:23 ` [PATCH 18/18] arm64: dts: hikey: Convert to the hierarchical CPU topology layout Ulf Hansson
2019-05-13 19:23 ` Ulf Hansson
2019-07-16 14:47 ` Sudeep Holla
2019-07-18 10:48 ` Ulf Hansson
2019-07-18 13:11 ` Sudeep Holla
2019-05-14 8:08 ` [PATCH 00/18] ARM/ARM64: Support hierarchical CPU arrangement for PSCI Rafael J. Wysocki
2019-05-14 8:08 ` Rafael J. Wysocki
2019-05-14 8:58 ` Ulf Hansson
2019-05-14 8:58 ` Ulf Hansson
2019-06-07 15:42 ` Sudeep Holla
2019-06-07 19:34 ` Bjorn Andersson
2019-06-10 10:32 ` Sudeep Holla
2019-06-10 15:54 ` Ulf Hansson
2019-06-10 17:16 ` Lorenzo Pieralisi
2019-06-10 18:57 ` Ulf Hansson
2019-06-18 11:56 ` Ulf Hansson
2019-06-07 11:19 ` Ulf Hansson
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