| Message ID | 20191029164438.17012-9-ulf.hansson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | cpuidle: psci: Support hierarchical CPU arrangement | expand |
On Tue, Oct 29, 2019 at 05:44:33PM +0100, Ulf Hansson wrote: > Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a > CPU number as an in-parameter and tries to attach the CPU's struct device > to its corresponding PM domain. > > Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to > specify "psci" as the "name" of the PM domain to attach to. Additionally, > let's also prepare the attached device to be power managed via runtime PM. > > Note that, the implementation of the new helper function is in a new > separate c-file, which may seems a bit too much at this point. However, > subsequent changes that implements the remaining part of the PM domain > support for cpuidle-psci, helps to justify this split. > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Changes in v2: > - Reorder patch to be the first one that starts adding the PM domain > support. > - Rebased. > > --- > drivers/cpuidle/Makefile | 4 ++- > drivers/cpuidle/cpuidle-psci-domain.c | 36 +++++++++++++++++++++++++++ > drivers/cpuidle/cpuidle-psci.h | 12 +++++++++ > 3 files changed, 51 insertions(+), 1 deletion(-) > create mode 100644 drivers/cpuidle/cpuidle-psci-domain.c > create mode 100644 drivers/cpuidle/cpuidle-psci.h > > diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile > index ee70d5cc5b99..cc8c769d7fa9 100644 > --- a/drivers/cpuidle/Makefile > +++ b/drivers/cpuidle/Makefile > @@ -21,7 +21,9 @@ obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o > obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o > obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o > obj-$(CONFIG_ARM_CPUIDLE) += cpuidle-arm.o > -obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle-psci.o > +obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle_psci.o > +cpuidle_psci-y := cpuidle-psci.o > +cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o > > ############################################################################### > # MIPS drivers > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c > new file mode 100644 > index 000000000000..bc7df4dc0686 > --- /dev/null > +++ b/drivers/cpuidle/cpuidle-psci-domain.c > @@ -0,0 +1,36 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * PM domains for CPUs via genpd - managed by cpuidle-psci. > + * > + * Copyright (C) 2019 Linaro Ltd. > + * Author: Ulf Hansson <ulf.hansson@linaro.org> > + * > + */ > + > +#include <linux/cpu.h> > +#include <linux/device.h> > +#include <linux/kernel.h> > +#include <linux/pm_domain.h> > +#include <linux/pm_runtime.h> > +#include <linux/psci.h> > + > +#include "cpuidle-psci.h" > + > +struct device *psci_dt_attach_cpu(int cpu) > +{ > + struct device *dev; > + > + /* Currently limit the hierarchical topology to be used in OSI mode. */ > + if (!psci_has_osi_support()) > + return NULL; > + > + dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); Hello Ulf, here you use dev_pm_domain_attach_by_name(), which will call genpd_dev_pm_attach_by_name(), which will call genpd_dev_pm_attach_by_id(), which will call __genpd_dev_pm_attach(virt_dev, dev, index, false); the last argument is power_on, which here is always set to false. In older versions of your patch series, psci_dt_attach_cpu() called dev_pm_domain_attach(dev, true), where the last argument is power_on. Interestingly enough (for the non-ACPI case), dev_pm_domain_attach() ignores the power_on parameter, and simply calls genpd_dev_pm_attach(dev); which will call __genpd_dev_pm_attach(dev, dev, 0, true); the last argument is power_on, which here is always set to true. In other words, your previous patch series always powered on the power domain, while the newer versions do not. Is this change intentional? Perhaps psci_dt_attach_cpu() should call dev_to_genpd(dev)->power_on() after attaching the power domain? (In order to be consistent with the previous behavior of this patch series.) Kind regards, Niklas > + if (IS_ERR_OR_NULL(dev)) > + return dev; > + > + pm_runtime_irq_safe(dev); > + if (cpu_online(cpu)) > + pm_runtime_get_sync(dev); > + > + return dev; > +} > diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h > new file mode 100644 > index 000000000000..0cadbb71dc55 > --- /dev/null > +++ b/drivers/cpuidle/cpuidle-psci.h > @@ -0,0 +1,12 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef __CPUIDLE_PSCI_H > +#define __CPUIDLE_PSCI_H > + > +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF > +struct device *psci_dt_attach_cpu(int cpu); > +#else > +static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; } > +#endif > + > +#endif /* __CPUIDLE_PSCI_H */ > -- > 2.17.1 >
On Tue, Oct 29, 2019 at 05:44:33PM +0100, Ulf Hansson wrote: > Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a > CPU number as an in-parameter and tries to attach the CPU's struct device > to its corresponding PM domain. > > Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to > specify "psci" as the "name" of the PM domain to attach to. Additionally, > let's also prepare the attached device to be power managed via runtime PM. > > Note that, the implementation of the new helper function is in a new > separate c-file, which may seems a bit too much at this point. However, > subsequent changes that implements the remaining part of the PM domain > support for cpuidle-psci, helps to justify this split. > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Changes in v2: > - Reorder patch to be the first one that starts adding the PM domain > support. > - Rebased. > > --- > drivers/cpuidle/Makefile | 4 ++- > drivers/cpuidle/cpuidle-psci-domain.c | 36 +++++++++++++++++++++++++++ > drivers/cpuidle/cpuidle-psci.h | 12 +++++++++ > 3 files changed, 51 insertions(+), 1 deletion(-) > create mode 100644 drivers/cpuidle/cpuidle-psci-domain.c > create mode 100644 drivers/cpuidle/cpuidle-psci.h > > diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile > index ee70d5cc5b99..cc8c769d7fa9 100644 > --- a/drivers/cpuidle/Makefile > +++ b/drivers/cpuidle/Makefile > @@ -21,7 +21,9 @@ obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o > obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o > obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o > obj-$(CONFIG_ARM_CPUIDLE) += cpuidle-arm.o > -obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle-psci.o > +obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle_psci.o > +cpuidle_psci-y := cpuidle-psci.o > +cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o This was super confusing for a minute until I noticed the difference between _ and - used here. I know such pattern is used in the kernel, just that it's difficult to notice on first go :) > > ############################################################################### > # MIPS drivers > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c > new file mode 100644 > index 000000000000..bc7df4dc0686 > --- /dev/null > +++ b/drivers/cpuidle/cpuidle-psci-domain.c > @@ -0,0 +1,36 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * PM domains for CPUs via genpd - managed by cpuidle-psci. > + * > + * Copyright (C) 2019 Linaro Ltd. > + * Author: Ulf Hansson <ulf.hansson@linaro.org> > + * > + */ > + > +#include <linux/cpu.h> > +#include <linux/device.h> > +#include <linux/kernel.h> > +#include <linux/pm_domain.h> > +#include <linux/pm_runtime.h> > +#include <linux/psci.h> > + > +#include "cpuidle-psci.h" > + > +struct device *psci_dt_attach_cpu(int cpu) > +{ > + struct device *dev; > + > + /* Currently limit the hierarchical topology to be used in OSI mode. */ > + if (!psci_has_osi_support()) > + return NULL; > + > + dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); > + if (IS_ERR_OR_NULL(dev)) > + return dev; > + > + pm_runtime_irq_safe(dev); > + if (cpu_online(cpu)) > + pm_runtime_get_sync(dev); I probably have to wait till I see the user of this, but until then I assume we have some way to deal with CPU HP machinery for this. Other than that, it looks fine. I will get back to this to ack or with more questions as I review further. -- Regards, Sudeep
On Fri, 15 Nov 2019 at 18:13, Sudeep Holla <sudeep.holla@arm.com> wrote: > > On Tue, Oct 29, 2019 at 05:44:33PM +0100, Ulf Hansson wrote: > > Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a > > CPU number as an in-parameter and tries to attach the CPU's struct device > > to its corresponding PM domain. > > > > Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to > > specify "psci" as the "name" of the PM domain to attach to. Additionally, > > let's also prepare the attached device to be power managed via runtime PM. > > > > Note that, the implementation of the new helper function is in a new > > separate c-file, which may seems a bit too much at this point. However, > > subsequent changes that implements the remaining part of the PM domain > > support for cpuidle-psci, helps to justify this split. > > > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > > --- > > > > Changes in v2: > > - Reorder patch to be the first one that starts adding the PM domain > > support. > > - Rebased. > > > > --- > > drivers/cpuidle/Makefile | 4 ++- > > drivers/cpuidle/cpuidle-psci-domain.c | 36 +++++++++++++++++++++++++++ > > drivers/cpuidle/cpuidle-psci.h | 12 +++++++++ > > 3 files changed, 51 insertions(+), 1 deletion(-) > > create mode 100644 drivers/cpuidle/cpuidle-psci-domain.c > > create mode 100644 drivers/cpuidle/cpuidle-psci.h > > > > diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile > > index ee70d5cc5b99..cc8c769d7fa9 100644 > > --- a/drivers/cpuidle/Makefile > > +++ b/drivers/cpuidle/Makefile > > @@ -21,7 +21,9 @@ obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o > > obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o > > obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o > > obj-$(CONFIG_ARM_CPUIDLE) += cpuidle-arm.o > > -obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle-psci.o > > +obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle_psci.o > > +cpuidle_psci-y := cpuidle-psci.o > > +cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o > > This was super confusing for a minute until I noticed the difference > between _ and - used here. I know such pattern is used in the kernel, > just that it's difficult to notice on first go :) > > > > > ############################################################################### > > # MIPS drivers > > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c > > new file mode 100644 > > index 000000000000..bc7df4dc0686 > > --- /dev/null > > +++ b/drivers/cpuidle/cpuidle-psci-domain.c > > @@ -0,0 +1,36 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * PM domains for CPUs via genpd - managed by cpuidle-psci. > > + * > > + * Copyright (C) 2019 Linaro Ltd. > > + * Author: Ulf Hansson <ulf.hansson@linaro.org> > > + * > > + */ > > + > > +#include <linux/cpu.h> > > +#include <linux/device.h> > > +#include <linux/kernel.h> > > +#include <linux/pm_domain.h> > > +#include <linux/pm_runtime.h> > > +#include <linux/psci.h> > > + > > +#include "cpuidle-psci.h" > > + > > +struct device *psci_dt_attach_cpu(int cpu) > > +{ > > + struct device *dev; > > + > > + /* Currently limit the hierarchical topology to be used in OSI mode. */ > > + if (!psci_has_osi_support()) > > + return NULL; > > + > > + dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); > > + if (IS_ERR_OR_NULL(dev)) > > + return dev; > > + > > + pm_runtime_irq_safe(dev); > > + if (cpu_online(cpu)) > > + pm_runtime_get_sync(dev); > > I probably have to wait till I see the user of this, but until then I > assume we have some way to deal with CPU HP machinery for this. Yes, I discussed this with Lorenzo at LPC as well. I did not include a patch in the series using a CPU HP, simply because I am targeting to land the basic support first. For now, this means that the "cluster" will remain on even if there are CPUs being put offline. > > Other than that, it looks fine. I will get back to this to ack or with > more questions as I review further. Great, thanks! Kind regards Uffe
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index ee70d5cc5b99..cc8c769d7fa9 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -21,7 +21,9 @@ obj-$(CONFIG_ARM_U8500_CPUIDLE) += cpuidle-ux500.o obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o obj-$(CONFIG_ARM_CPUIDLE) += cpuidle-arm.o -obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle-psci.o +obj-$(CONFIG_ARM_PSCI_CPUIDLE) += cpuidle_psci.o +cpuidle_psci-y := cpuidle-psci.o +cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o ############################################################################### # MIPS drivers diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c new file mode 100644 index 000000000000..bc7df4dc0686 --- /dev/null +++ b/drivers/cpuidle/cpuidle-psci-domain.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PM domains for CPUs via genpd - managed by cpuidle-psci. + * + * Copyright (C) 2019 Linaro Ltd. + * Author: Ulf Hansson <ulf.hansson@linaro.org> + * + */ + +#include <linux/cpu.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/pm_domain.h> +#include <linux/pm_runtime.h> +#include <linux/psci.h> + +#include "cpuidle-psci.h" + +struct device *psci_dt_attach_cpu(int cpu) +{ + struct device *dev; + + /* Currently limit the hierarchical topology to be used in OSI mode. */ + if (!psci_has_osi_support()) + return NULL; + + dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci"); + if (IS_ERR_OR_NULL(dev)) + return dev; + + pm_runtime_irq_safe(dev); + if (cpu_online(cpu)) + pm_runtime_get_sync(dev); + + return dev; +} diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h new file mode 100644 index 000000000000..0cadbb71dc55 --- /dev/null +++ b/drivers/cpuidle/cpuidle-psci.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __CPUIDLE_PSCI_H +#define __CPUIDLE_PSCI_H + +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF +struct device *psci_dt_attach_cpu(int cpu); +#else +static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; } +#endif + +#endif /* __CPUIDLE_PSCI_H */
Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a CPU number as an in-parameter and tries to attach the CPU's struct device to its corresponding PM domain. Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to specify "psci" as the "name" of the PM domain to attach to. Additionally, let's also prepare the attached device to be power managed via runtime PM. Note that, the implementation of the new helper function is in a new separate c-file, which may seems a bit too much at this point. However, subsequent changes that implements the remaining part of the PM domain support for cpuidle-psci, helps to justify this split. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- Changes in v2: - Reorder patch to be the first one that starts adding the PM domain support. - Rebased. --- drivers/cpuidle/Makefile | 4 ++- drivers/cpuidle/cpuidle-psci-domain.c | 36 +++++++++++++++++++++++++++ drivers/cpuidle/cpuidle-psci.h | 12 +++++++++ 3 files changed, 51 insertions(+), 1 deletion(-) create mode 100644 drivers/cpuidle/cpuidle-psci-domain.c create mode 100644 drivers/cpuidle/cpuidle-psci.h -- 2.17.1