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 >
WARNING: multiple messages have this Message-ID (diff)
From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> To: Ulf Hansson <ulf.hansson@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com>, Geert Uytterhoeven <geert+renesas@glider.be>, Kevin Hilman <khilman@kernel.org>, Stephen Boyd <sboyd@kernel.org>, Viresh Kumar <viresh.kumar@linaro.org>, linux-pm@vger.kernel.org, Daniel Lezcano <daniel.lezcano@linaro.org>, "Rafael J . Wysocki" <rjw@rjwysocki.net>, linux-kernel@vger.kernel.org, Amit Kucheria <amit.kucheria@linaro.org>, Bjorn Andersson <bjorn.andersson@linaro.org>, Tony Lindgren <tony@atomide.com>, linux-arm-msm@vger.kernel.org, Lina Iyer <ilina@codeaurora.org>, Sudeep Holla <sudeep.holla@arm.com>, Niklas Cassel <niklas.cassel@linaro.org>, Souvik Chakravarty <souvik.chakravarty@arm.com>, "Raju P . L . S . S . S . N" <rplsssn@codeaurora.org>, linux-arm-kernel@lists.infradead.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 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-07-16 15:53 UTC|newest] Thread overview: 155+ 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 ` 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 2019-05-13 19:22 ` Ulf Hansson 2019-07-19 11:29 ` Lorenzo Pieralisi 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 ` 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:00 ` Sudeep Holla 2019-06-07 15:00 ` Sudeep Holla 2019-06-10 10:20 ` Ulf Hansson 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:01 ` Sudeep Holla 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:03 ` Sudeep Holla 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:17 ` Sudeep Holla 2019-06-07 15:17 ` Sudeep Holla 2019-06-10 10:21 ` Ulf Hansson 2019-06-10 10:21 ` Ulf Hansson 2019-06-10 10:42 ` Sudeep Holla 2019-06-10 10:42 ` Sudeep Holla 2019-07-16 14:53 ` 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:21 ` Sudeep Holla 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:27 ` Sudeep Holla 2019-06-07 15:27 ` Sudeep Holla 2019-06-10 10:21 ` Ulf Hansson 2019-06-10 10:21 ` Ulf Hansson 2019-06-10 10:59 ` Sudeep Holla 2019-06-10 10:59 ` Sudeep Holla 2019-07-16 15:05 ` Sudeep Holla 2019-07-16 15:05 ` Sudeep Holla 2019-07-18 11:04 ` Ulf Hansson 2019-07-18 11:04 ` Ulf Hansson 2019-07-18 13:19 ` Sudeep Holla 2019-07-18 13:19 ` Sudeep Holla 2019-07-18 17:57 ` Lina Iyer 2019-07-18 17:57 ` Lina Iyer 2019-07-19 9:45 ` Sudeep Holla 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 2019-05-13 19:22 ` Ulf Hansson 2019-07-09 15:31 ` Lorenzo Pieralisi 2019-07-09 15:31 ` Lorenzo Pieralisi 2019-07-16 8:45 ` Ulf Hansson 2019-07-16 8:45 ` Ulf Hansson 2019-07-16 14:51 ` Lorenzo Pieralisi 2019-07-16 14:51 ` Lorenzo Pieralisi 2019-07-18 11:43 ` Ulf Hansson 2019-07-18 11:43 ` Ulf Hansson 2019-07-18 13:36 ` Lorenzo Pieralisi 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 ` 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 ` 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 2019-05-13 19:22 ` Ulf Hansson 2019-07-16 15:53 ` Lorenzo Pieralisi [this message] 2019-07-16 15:53 ` Lorenzo Pieralisi 2019-07-18 10:35 ` Ulf Hansson 2019-07-18 10:35 ` Ulf Hansson 2019-07-18 13:30 ` Lorenzo Pieralisi 2019-07-18 13:30 ` Lorenzo Pieralisi 2019-07-18 16:54 ` Ulf Hansson 2019-07-18 16:54 ` Ulf Hansson 2019-07-18 17:41 ` Lina Iyer 2019-07-18 17:41 ` Lina Iyer 2019-07-18 21:49 ` Ulf Hansson 2019-07-18 21:49 ` Ulf Hansson 2019-07-19 10:02 ` Lorenzo Pieralisi 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 2019-05-13 19:22 ` Ulf Hansson 2019-06-07 15:31 ` Sudeep Holla 2019-06-07 15:31 ` Sudeep Holla 2019-06-10 10:21 ` Ulf Hansson 2019-06-10 10:21 ` Ulf Hansson 2019-06-10 11:02 ` Sudeep Holla 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 ` 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 2019-05-13 19:22 ` Ulf Hansson 2019-07-16 14:47 ` Sudeep Holla 2019-07-16 14:47 ` Sudeep Holla 2019-07-16 20:36 ` Lina Iyer 2019-07-16 20:36 ` Lina Iyer 2019-07-17 17:18 ` Sudeep Holla 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 2019-05-13 19:23 ` Ulf Hansson 2019-07-16 14:47 ` Sudeep Holla 2019-07-16 14:47 ` Sudeep Holla 2019-07-18 10:48 ` Ulf Hansson 2019-07-18 10:48 ` Ulf Hansson 2019-07-18 13:11 ` Sudeep Holla 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 8:08 ` Rafael J. Wysocki 2019-05-14 8:58 ` Ulf Hansson 2019-05-14 8:58 ` Ulf Hansson 2019-05-14 8:58 ` Ulf Hansson 2019-06-07 15:42 ` Sudeep Holla 2019-06-07 15:42 ` Sudeep Holla 2019-06-07 19:34 ` Bjorn Andersson 2019-06-07 19:34 ` Bjorn Andersson 2019-06-10 10:32 ` Sudeep Holla 2019-06-10 10:32 ` Sudeep Holla 2019-06-10 15:54 ` Ulf Hansson 2019-06-10 15:54 ` Ulf Hansson 2019-06-10 17:16 ` Lorenzo Pieralisi 2019-06-10 17:16 ` Lorenzo Pieralisi 2019-06-10 18:57 ` Ulf Hansson 2019-06-10 18:57 ` Ulf Hansson 2019-06-18 11:56 ` Ulf Hansson 2019-06-18 11:56 ` Ulf Hansson 2019-06-07 11:19 ` Ulf Hansson 2019-06-07 11:19 ` Ulf Hansson
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190716155317.GB32490@e121166-lin.cambridge.arm.com \ --to=lorenzo.pieralisi@arm.com \ --cc=amit.kucheria@linaro.org \ --cc=bjorn.andersson@linaro.org \ --cc=daniel.lezcano@linaro.org \ --cc=geert+renesas@glider.be \ --cc=ilina@codeaurora.org \ --cc=khilman@kernel.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-arm-msm@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pm@vger.kernel.org \ --cc=mark.rutland@arm.com \ --cc=niklas.cassel@linaro.org \ --cc=rjw@rjwysocki.net \ --cc=rplsssn@codeaurora.org \ --cc=sboyd@kernel.org \ --cc=souvik.chakravarty@arm.com \ --cc=sudeep.holla@arm.com \ --cc=tony@atomide.com \ --cc=ulf.hansson@linaro.org \ --cc=vincent.guittot@linaro.org \ --cc=viresh.kumar@linaro.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.