| Message ID | 20191230144402.30195-11-ulf.hansson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | cpuidle: psci: Support hierarchical CPU arrangement | expand |
On Mon, Dec 30, 2019 at 03:43:57PM +0100, Ulf Hansson wrote: > The per CPU variable psci_power_state, contains an array of fixed values, > which reflects the corresponding arm,psci-suspend-param parsed from DT, for > each of the available CPU idle states. > > This isn't sufficient when using the hierarchical CPU topology in DT, in > combination with having PSCI OS initiated (OSI) mode enabled. More > precisely, in OSI mode, Linux is responsible of telling the PSCI FW what > idle state the cluster (a group of CPUs) should enter, while in PSCI > Platform Coordinated (PC) mode, each CPU independently votes for an idle > state of the cluster. > > For this reason, introduce a per CPU variable called domain_state and > implement two helper functions to read/write its value. Then let the > domain_state take precedence over the regular selected state, when entering > and idle state. > > To avoid executing the above OSI specific code in the ->enter() callback, > while operating in the default PSCI Platform Coordinated mode, let's also > add a new enter-function and use it for OSI. > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Changes in v5: > - None. > > --- > drivers/cpuidle/cpuidle-psci.c | 56 ++++++++++++++++++++++++++++++---- > 1 file changed, 50 insertions(+), 6 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > index 6a87848be3c3..9600fe674a89 100644 > --- a/drivers/cpuidle/cpuidle-psci.c > +++ b/drivers/cpuidle/cpuidle-psci.c > @@ -29,14 +29,47 @@ struct psci_cpuidle_data { > }; > > static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data); > +static DEFINE_PER_CPU(u32, domain_state); > + > +static inline void psci_set_domain_state(u32 state) > +{ > + __this_cpu_write(domain_state, state); > +} > + > +static inline u32 psci_get_domain_state(void) > +{ > + return __this_cpu_read(domain_state); > +} > + > +static inline int psci_enter_state(int idx, u32 state) > +{ > + return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); > +} > + > +static int psci_enter_domain_idle_state(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int idx) > +{ > + struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data); > + u32 *states = data->psci_states; > + u32 state = psci_get_domain_state(); > + int ret; > + > + if (!state) > + state = states[idx]; > + > + ret = psci_enter_state(idx, state); > + > + /* Clear the domain state to start fresh when back from idle. */ > + psci_set_domain_state(0); > + return ret; > +} > > static int psci_enter_idle_state(struct cpuidle_device *dev, > struct cpuidle_driver *drv, int idx) > { > u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states); > > - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, > - idx, state[idx]); > + return psci_enter_state(idx, state[idx]); > } > > static struct cpuidle_driver psci_idle_driver __initdata = { > @@ -79,7 +112,8 @@ static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) > return 0; > } > > -static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, > +static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv, > + struct device_node *cpu_node, > unsigned int state_count, int cpu) > { > int i, ret = 0; > @@ -118,6 +152,15 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, > ret = PTR_ERR(data->dev); > goto free_mem; > } > + > + /* > + * Using the deepest state for the CPU to trigger a potential > + * selection of a shared state for the domain, assumes the > + * domain states are all deeper states. > + */ > + if (data->dev) Do we still need this check ? I thought we won't attach genpd if OSI is not enabled. If possible, please drop the check. Other than that, looks good to me. Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> -- Regards, Sudeep
On Mon, 30 Dec 2019 at 17:35, Sudeep Holla <sudeep.holla@arm.com> wrote: > > On Mon, Dec 30, 2019 at 03:43:57PM +0100, Ulf Hansson wrote: > > The per CPU variable psci_power_state, contains an array of fixed values, > > which reflects the corresponding arm,psci-suspend-param parsed from DT, for > > each of the available CPU idle states. > > > > This isn't sufficient when using the hierarchical CPU topology in DT, in > > combination with having PSCI OS initiated (OSI) mode enabled. More > > precisely, in OSI mode, Linux is responsible of telling the PSCI FW what > > idle state the cluster (a group of CPUs) should enter, while in PSCI > > Platform Coordinated (PC) mode, each CPU independently votes for an idle > > state of the cluster. > > > > For this reason, introduce a per CPU variable called domain_state and > > implement two helper functions to read/write its value. Then let the > > domain_state take precedence over the regular selected state, when entering > > and idle state. > > > > To avoid executing the above OSI specific code in the ->enter() callback, > > while operating in the default PSCI Platform Coordinated mode, let's also > > add a new enter-function and use it for OSI. > > > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > > --- > > > > Changes in v5: > > - None. > > > > --- > > drivers/cpuidle/cpuidle-psci.c | 56 ++++++++++++++++++++++++++++++---- > > 1 file changed, 50 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > > index 6a87848be3c3..9600fe674a89 100644 > > --- a/drivers/cpuidle/cpuidle-psci.c > > +++ b/drivers/cpuidle/cpuidle-psci.c > > @@ -29,14 +29,47 @@ struct psci_cpuidle_data { > > }; > > > > static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data); > > +static DEFINE_PER_CPU(u32, domain_state); > > + > > +static inline void psci_set_domain_state(u32 state) > > +{ > > + __this_cpu_write(domain_state, state); > > +} > > + > > +static inline u32 psci_get_domain_state(void) > > +{ > > + return __this_cpu_read(domain_state); > > +} > > + > > +static inline int psci_enter_state(int idx, u32 state) > > +{ > > + return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); > > +} > > + > > +static int psci_enter_domain_idle_state(struct cpuidle_device *dev, > > + struct cpuidle_driver *drv, int idx) > > +{ > > + struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data); > > + u32 *states = data->psci_states; > > + u32 state = psci_get_domain_state(); > > + int ret; > > + > > + if (!state) > > + state = states[idx]; > > + > > + ret = psci_enter_state(idx, state); > > + > > + /* Clear the domain state to start fresh when back from idle. */ > > + psci_set_domain_state(0); > > + return ret; > > +} > > > > static int psci_enter_idle_state(struct cpuidle_device *dev, > > struct cpuidle_driver *drv, int idx) > > { > > u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states); > > > > - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, > > - idx, state[idx]); > > + return psci_enter_state(idx, state[idx]); > > } > > > > static struct cpuidle_driver psci_idle_driver __initdata = { > > @@ -79,7 +112,8 @@ static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) > > return 0; > > } > > > > -static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, > > +static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv, > > + struct device_node *cpu_node, > > unsigned int state_count, int cpu) > > { > > int i, ret = 0; > > @@ -118,6 +152,15 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, > > ret = PTR_ERR(data->dev); > > goto free_mem; > > } > > + > > + /* > > + * Using the deepest state for the CPU to trigger a potential > > + * selection of a shared state for the domain, assumes the > > + * domain states are all deeper states. > > + */ > > + if (data->dev) > > Do we still need this check ? I thought we won't attach genpd if OSI is > not enabled. If possible, please drop the check. This check is still needed. psci_dt_attach_cpu() now returns NULL when OSI has not been enabled (see patch 14), as we agreed on during the discussions around the previous version. > > Other than that, looks good to me. > > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Thanks! Kind regards Uffe
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 6a87848be3c3..9600fe674a89 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -29,14 +29,47 @@ struct psci_cpuidle_data { }; static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data); +static DEFINE_PER_CPU(u32, domain_state); + +static inline void psci_set_domain_state(u32 state) +{ + __this_cpu_write(domain_state, state); +} + +static inline u32 psci_get_domain_state(void) +{ + return __this_cpu_read(domain_state); +} + +static inline int psci_enter_state(int idx, u32 state) +{ + return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); +} + +static int psci_enter_domain_idle_state(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int idx) +{ + struct psci_cpuidle_data *data = this_cpu_ptr(&psci_cpuidle_data); + u32 *states = data->psci_states; + u32 state = psci_get_domain_state(); + int ret; + + if (!state) + state = states[idx]; + + ret = psci_enter_state(idx, state); + + /* Clear the domain state to start fresh when back from idle. */ + psci_set_domain_state(0); + return ret; +} static int psci_enter_idle_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int idx) { u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states); - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, - idx, state[idx]); + return psci_enter_state(idx, state[idx]); } static struct cpuidle_driver psci_idle_driver __initdata = { @@ -79,7 +112,8 @@ static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) return 0; } -static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, +static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv, + struct device_node *cpu_node, unsigned int state_count, int cpu) { int i, ret = 0; @@ -118,6 +152,15 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, ret = PTR_ERR(data->dev); goto free_mem; } + + /* + * Using the deepest state for the CPU to trigger a potential + * selection of a shared state for the domain, assumes the + * domain states are all deeper states. + */ + if (data->dev) + drv->states[state_count - 1].enter = + psci_enter_domain_idle_state; } /* Idle states parsed correctly, store them in the per-cpu struct. */ @@ -129,7 +172,8 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, return ret; } -static __init int psci_cpu_init_idle(unsigned int cpu, unsigned int state_count) +static __init int psci_cpu_init_idle(struct cpuidle_driver *drv, + unsigned int cpu, unsigned int state_count) { struct device_node *cpu_node; int ret; @@ -145,7 +189,7 @@ static __init int psci_cpu_init_idle(unsigned int cpu, unsigned int state_count) if (!cpu_node) return -ENODEV; - ret = psci_dt_cpu_init_idle(cpu_node, state_count, cpu); + ret = psci_dt_cpu_init_idle(drv, cpu_node, state_count, cpu); of_node_put(cpu_node); @@ -201,7 +245,7 @@ static int __init psci_idle_init_cpu(int cpu) /* * Initialize PSCI idle states. */ - ret = psci_cpu_init_idle(cpu, ret); + ret = psci_cpu_init_idle(drv, cpu, ret); if (ret) { pr_err("CPU %d failed to PSCI idle\n", cpu); goto out_kfree_drv;