On Mon, May 13, 2019 at 09:22:51PM +0200, Ulf Hansson wrote: > When the hierarchical CPU topology layout is used in DT, we need to setup > the corresponding PM domain data structures, as to allow a CPU and a group > of CPUs to be power managed accordingly. Let's enable this by deploying > support through the genpd interface. > > Additionally, when the OS initiated mode is supported by the PSCI FW, let's > also parse the domain idle states DT bindings as to make genpd responsible > for the state selection, when the states are compatible with > "domain-idle-state". Otherwise, when only Platform Coordinated mode is > supported, we rely solely on the state selection to be managed through the > regular cpuidle framework. > > If the initialization of the PM domain data structures succeeds and the OS > initiated mode is supported, we try to switch to it. In case it fails, > let's fall back into a degraded mode, rather than bailing out and returning > an error code. > > Due to that the OS initiated mode may become enabled, we need to adjust to > maintain backwards compatibility for a kernel started through a kexec call. > Do this by explicitly switch to Platform Coordinated mode during boot. > > Finally, the actual initialization of the PM domain data structures, is > done via calling the new shared function, psci_dt_init_pm_domains(). > However, this is implemented by subsequent changes. > > Co-developed-by: Lina Iyer <lina.iyer@xxxxxxxxxx> > Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx> > Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > --- > > Changes: > - Simplify code setting domain_state at power off. > - Use the genpd ->free_state() callback to manage freeing of states. > - Fixup a bogus while loop. > > --- > drivers/firmware/psci/Makefile | 2 +- > drivers/firmware/psci/psci.c | 7 +- > drivers/firmware/psci/psci.h | 5 + > drivers/firmware/psci/psci_pm_domain.c | 268 +++++++++++++++++++++++++ > 4 files changed, 280 insertions(+), 2 deletions(-) > create mode 100644 drivers/firmware/psci/psci_pm_domain.c > > diff --git a/drivers/firmware/psci/Makefile b/drivers/firmware/psci/Makefile > index 1956b882470f..ff300f1fec86 100644 > --- a/drivers/firmware/psci/Makefile > +++ b/drivers/firmware/psci/Makefile > @@ -1,4 +1,4 @@ > # SPDX-License-Identifier: GPL-2.0 > # > -obj-$(CONFIG_ARM_PSCI_FW) += psci.o > +obj-$(CONFIG_ARM_PSCI_FW) += psci.o psci_pm_domain.o > obj-$(CONFIG_ARM_PSCI_CHECKER) += psci_checker.o > diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c > index 0e91d864e346..bfef300b7ebe 100644 > --- a/drivers/firmware/psci/psci.c > +++ b/drivers/firmware/psci/psci.c > @@ -721,9 +721,14 @@ static int __init psci_1_0_init(struct device_node *np) > if (err) > return err; > > - if (psci_has_osi_support()) > + if (psci_has_osi_support()) { > pr_info("OSI mode supported.\n"); > > + /* Make sure we default to PC mode. */ > + invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, > + PSCI_1_0_SUSPEND_MODE_PC, 0, 0); > + } > + This can go on it's own, any issues with that ? > return 0; > } > > diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h > index f2277c3ad405..00d2e3dcef49 100644 > --- a/drivers/firmware/psci/psci.h > +++ b/drivers/firmware/psci/psci.h > @@ -11,6 +11,11 @@ bool psci_has_osi_support(void); > #ifdef CONFIG_CPU_IDLE > void psci_set_domain_state(u32 state); > int psci_dt_parse_state_node(struct device_node *np, u32 *state); > +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF > +int psci_dt_init_pm_domains(struct device_node *np); > +#else > +static inline int psci_dt_init_pm_domains(struct device_node *np) { return 0; } > +#endif > #endif > > #endif /* __PSCI_H */ > diff --git a/drivers/firmware/psci/psci_pm_domain.c b/drivers/firmware/psci/psci_pm_domain.c > new file mode 100644 > index 000000000000..3c6ca846caf4 > --- /dev/null > +++ b/drivers/firmware/psci/psci_pm_domain.c > @@ -0,0 +1,268 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * PM domains for CPUs via genpd - managed by PSCI. > + * > + * Copyright (C) 2019 Linaro Ltd. > + * Author: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > + * > + */ > + > +#define pr_fmt(fmt) "psci: " fmt > + > +#include <linux/device.h> > +#include <linux/kernel.h> > +#include <linux/pm_domain.h> > +#include <linux/slab.h> > +#include <linux/string.h> > + > +#include "psci.h" > + > +#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_PM_GENERIC_DOMAINS_OF) > + > +struct psci_pd_provider { > + struct list_head link; > + struct device_node *node; > +}; > + > +static LIST_HEAD(psci_pd_providers); > +static bool osi_mode_enabled; > + > +static int psci_pd_power_off(struct generic_pm_domain *pd) > +{ > + struct genpd_power_state *state = &pd->states[pd->state_idx]; > + u32 *pd_state; > + > + /* If we have failed to enable OSI mode, then abort power off. */ > + if (psci_has_osi_support() && !osi_mode_enabled) > + return -EBUSY; > + > + if (!state->data) > + return 0; > + > + /* When OSI mode is enabled, set the corresponding domain state. */ > + pd_state = state->data; > + psci_set_domain_state(*pd_state); > + > + return 0; > +} > + > +static int psci_pd_parse_state_nodes(struct genpd_power_state *states, > + int state_count) > +{ > + int i, ret; > + u32 psci_state, *psci_state_buf; > + > + for (i = 0; i < state_count; i++) { > + ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode), > + &psci_state); > + if (ret) > + goto free_state; > + > + psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL); > + if (!psci_state_buf) { > + ret = -ENOMEM; > + goto free_state; > + } > + *psci_state_buf = psci_state; > + states[i].data = psci_state_buf; > + } > + > + return 0; > + > +free_state: > + i--; > + for (; i >= 0; i--) > + kfree(states[i].data); > + return ret; > +} > + > +static int psci_pd_parse_states(struct device_node *np, > + struct genpd_power_state **states, int *state_count) > +{ > + int ret; > + > + /* Parse the domain idle states. */ > + ret = of_genpd_parse_idle_states(np, states, state_count); > + if (ret) > + return ret; > + Lots of things here in this file are not psci specific. They can be moved as generic CPU PM domain support. > + /* Fill out the PSCI specifics for each found state. */ > + ret = psci_pd_parse_state_nodes(*states, *state_count); > + if (ret) > + kfree(*states); > + Things like above are PSCI. I am trying to see if we can do something to achieve partitions like we have today: psci.c just has PSCI specific stuff and dt_idle_states.c deals with generic idle stuff. -- Regards, Sudeep