[v10,18/27] drivers: firmware: psci: Add support for PM domains using genpd
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Message ID 20181129174700.16585-19-ulf.hansson@linaro.org
State Deferred
Headers show
Series
  • PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM)
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Commit Message

Ulf Hansson Nov. 29, 2018, 5:46 p.m. UTC
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.

To try to initiate the PM domain data structures, the PSCI driver shall
call the new function, psci_dt_init_pm_domains(). However, this is done
from following changes.

Cc: Lina Iyer <ilina@codeaurora.org>
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---

Changes in V10:
	- Enable the PM domains to be used for both PC and OSI mode.
	- Fixup error paths.
	- Move the management of kexec started kernels into this patch.
	- Rewrite changelog.

---
 drivers/firmware/psci/Makefile         |   2 +-
 drivers/firmware/psci/psci.c           |   7 +-
 drivers/firmware/psci/psci.h           |   6 +
 drivers/firmware/psci/psci_pm_domain.c | 262 +++++++++++++++++++++++++
 4 files changed, 275 insertions(+), 2 deletions(-)
 create mode 100644 drivers/firmware/psci/psci_pm_domain.c

Comments

Lina Iyer Dec. 3, 2018, 4:37 p.m. UTC | #1
On Thu, Nov 29 2018 at 10:49 -0700, 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.
>
>To try to initiate the PM domain data structures, the PSCI driver shall
>call the new function, psci_dt_init_pm_domains(). However, this is done
>from following changes.
>
>Cc: Lina Iyer <ilina@codeaurora.org>
>Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
>Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>---
>
>Changes in V10:
>	- Enable the PM domains to be used for both PC and OSI mode.
>	- Fixup error paths.
>	- Move the management of kexec started kernels into this patch.
>	- Rewrite changelog.
>
>---
> drivers/firmware/psci/Makefile         |   2 +-
> drivers/firmware/psci/psci.c           |   7 +-
> drivers/firmware/psci/psci.h           |   6 +
> drivers/firmware/psci/psci_pm_domain.c | 262 +++++++++++++++++++++++++
> 4 files changed, 275 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 623591b541a4..19af2093151b 100644
>--- a/drivers/firmware/psci/psci.c
>+++ b/drivers/firmware/psci/psci.c
>@@ -704,9 +704,14 @@ 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);
>+	}
>+
> 	return 0;
> }
>
>diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h
>index 7d9d38fd57e1..8cf6d7206fab 100644
>--- a/drivers/firmware/psci/psci.h
>+++ b/drivers/firmware/psci/psci.h
>@@ -11,4 +11,10 @@ void psci_set_domain_state(u32 state);
> bool psci_has_osi_support(void);
> int psci_dt_parse_state_node(struct device_node *np, u32 *state);
>
>+#ifdef CONFIG_CPU_IDLE
>+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 /* __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..d0dc38e96f85
>--- /dev/null
>+++ b/drivers/firmware/psci/psci_pm_domain.c
>@@ -0,0 +1,262 @@
>+// SPDX-License-Identifier: GPL-2.0
>+/*
>+ * PM domains for CPUs via genpd - managed by PSCI.
>+ *
>+ * Copyright (C) 2018 Linaro Ltd.
>+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
>+ *
>+ */
>+
>+#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"
>+
>+#ifdef CONFIG_CPU_IDLE
>+
>+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;
>+	u32 composite_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;
>+	composite_pd_state = *pd_state | psci_get_domain_state();
This should not be needed. The domain_state should be 0x0 being set
after coming out of idle.
>+	psci_set_domain_state(composite_pd_state);
The three lines can be summarized as:
	psci_set_domain_state(*state->data);

Thanks,
Lina
Ulf Hansson Dec. 3, 2018, 8:03 p.m. UTC | #2
On Mon, 3 Dec 2018 at 17:37, Lina Iyer <ilina@codeaurora.org> wrote:
>
> On Thu, Nov 29 2018 at 10:49 -0700, 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.
> >
> >To try to initiate the PM domain data structures, the PSCI driver shall
> >call the new function, psci_dt_init_pm_domains(). However, this is done
> >from following changes.
> >
> >Cc: Lina Iyer <ilina@codeaurora.org>
> >Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
> >Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> >---
> >
> >Changes in V10:
> >       - Enable the PM domains to be used for both PC and OSI mode.
> >       - Fixup error paths.
> >       - Move the management of kexec started kernels into this patch.
> >       - Rewrite changelog.
> >
> >---
> > drivers/firmware/psci/Makefile         |   2 +-
> > drivers/firmware/psci/psci.c           |   7 +-
> > drivers/firmware/psci/psci.h           |   6 +
> > drivers/firmware/psci/psci_pm_domain.c | 262 +++++++++++++++++++++++++
> > 4 files changed, 275 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 623591b541a4..19af2093151b 100644
> >--- a/drivers/firmware/psci/psci.c
> >+++ b/drivers/firmware/psci/psci.c
> >@@ -704,9 +704,14 @@ 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);
> >+      }
> >+
> >       return 0;
> > }
> >
> >diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h
> >index 7d9d38fd57e1..8cf6d7206fab 100644
> >--- a/drivers/firmware/psci/psci.h
> >+++ b/drivers/firmware/psci/psci.h
> >@@ -11,4 +11,10 @@ void psci_set_domain_state(u32 state);
> > bool psci_has_osi_support(void);
> > int psci_dt_parse_state_node(struct device_node *np, u32 *state);
> >
> >+#ifdef CONFIG_CPU_IDLE
> >+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 /* __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..d0dc38e96f85
> >--- /dev/null
> >+++ b/drivers/firmware/psci/psci_pm_domain.c
> >@@ -0,0 +1,262 @@
> >+// SPDX-License-Identifier: GPL-2.0
> >+/*
> >+ * PM domains for CPUs via genpd - managed by PSCI.
> >+ *
> >+ * Copyright (C) 2018 Linaro Ltd.
> >+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
> >+ *
> >+ */
> >+
> >+#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"
> >+
> >+#ifdef CONFIG_CPU_IDLE
> >+
> >+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;
> >+      u32 composite_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;
> >+      composite_pd_state = *pd_state | psci_get_domain_state();
> This should not be needed. The domain_state should be 0x0 being set
> after coming out of idle.
> >+      psci_set_domain_state(composite_pd_state);
> The three lines can be summarized as:
>         psci_set_domain_state(*state->data);

Sure, let me change accordingly and thanks for spotting this!

Kind regards
Uffe
Daniel Lezcano Dec. 20, 2018, 2:35 p.m. UTC | #3
On 29/11/2018 18:46, 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.
> 
> To try to initiate the PM domain data structures, the PSCI driver shall
> call the new function, psci_dt_init_pm_domains(). However, this is done
> from following changes.
> 
> Cc: Lina Iyer <ilina@codeaurora.org>
> Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
> 
> Changes in V10:
> 	- Enable the PM domains to be used for both PC and OSI mode.
> 	- Fixup error paths.
> 	- Move the management of kexec started kernels into this patch.
> 	- Rewrite changelog.
> 
> ---
>  drivers/firmware/psci/Makefile         |   2 +-
>  drivers/firmware/psci/psci.c           |   7 +-
>  drivers/firmware/psci/psci.h           |   6 +
>  drivers/firmware/psci/psci_pm_domain.c | 262 +++++++++++++++++++++++++
>  4 files changed, 275 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

Same comment as 17/27.

+obj-$(CONFIG_PSCI_IDLE) += 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 623591b541a4..19af2093151b 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -704,9 +704,14 @@ 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);
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h
> index 7d9d38fd57e1..8cf6d7206fab 100644
> --- a/drivers/firmware/psci/psci.h
> +++ b/drivers/firmware/psci/psci.h
> @@ -11,4 +11,10 @@ void psci_set_domain_state(u32 state);
>  bool psci_has_osi_support(void);
>  int psci_dt_parse_state_node(struct device_node *np, u32 *state);
>  
> +#ifdef CONFIG_CPU_IDLE

Same comment as 17/27 for the config option.

> +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 /* __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..d0dc38e96f85
> --- /dev/null
> +++ b/drivers/firmware/psci/psci_pm_domain.c
> @@ -0,0 +1,262 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PM domains for CPUs via genpd - managed by PSCI.
> + *
> + * Copyright (C) 2018 Linaro Ltd.
> + * Author: Ulf Hansson <ulf.hansson@linaro.org>
> + *
> + */
> +
> +#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"
> +
> +#ifdef CONFIG_CPU_IDLE

Same comment as 17/27 for the config option. This condition should go away.

> +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;
> +	u32 composite_pd_state;
> +
> +	/* If we have failed to enable OSI mode, then abort power off. */
> +	if (psci_has_osi_support() && !osi_mode_enabled)
> +		return -EBUSY;

I'm not sure EBUSY is the best error code to describe this situation.
May be ENOTSUP ?

However, how possible is it to pass in this function if the OSI mode was
not enabled ?

> +	if (!state->data)
> +		return 0;
> +
> +	/* When OSI mode is enabled, set the corresponding domain state. */
> +	pd_state = state->data;
> +	composite_pd_state = *pd_state | psci_get_domain_state();
> +	psci_set_domain_state(composite_pd_state);
> +
> +	return 0;
> +}
> +
> +static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> +				int state_count)

__init ?

> +{
> +	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:
> +	while (i >= 0) {
> +		kfree(states[i].data);
> +		i--;
> +	}

for (; i >= 0; i--)

> +	return ret;
> +}
> +
> +static int psci_pd_parse_states(struct device_node *np,
> +			struct genpd_power_state **states, int *state_count)

__init ?

> +{
> +	int ret;
> +
> +	/* Parse the domain idle states. */
> +	ret = of_genpd_parse_idle_states(np, states, state_count);
> +	if (ret)
> +		return ret;
> +
> +	/* Fill out the PSCI specifics for each found state. */
> +	ret = psci_pd_parse_state_nodes(*states, *state_count);
> +	if (ret)
> +		kfree(*states);
> +
> +	return ret;
> +}
> +
> +static int psci_pd_init(struct device_node *np)

__init ?

> +{
> +	struct generic_pm_domain *pd;
> +	struct psci_pd_provider *pd_provider;
> +	struct dev_power_governor *pd_gov;
> +	struct genpd_power_state *states = NULL;
> +	int i, ret = -ENOMEM, state_count = 0;
> +
> +	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
> +	if (!pd)
> +		goto out;
> +
> +	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
> +	if (!pd_provider)
> +		goto free_pd;
> +
> +	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
> +	if (!pd->name)
> +		goto free_pd_prov;
> +
> +	/*
> +	 * For OSI mode, parse the domain idle states and let genpd manage the
> +	 * state selection for those being compatible with "domain-idle-state".
> +	 */
> +	if (psci_has_osi_support()) {
> +		ret = psci_pd_parse_states(np, &states, &state_count);
> +		if (ret)
> +			goto free_name;
> +	}
> +
> +	pd->name = kbasename(pd->name);
> +	pd->power_off = psci_pd_power_off;
> +	pd->states = states;
> +	pd->state_count = state_count;
> +	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
> +
> +	/* Use governor for CPU PM domains if it has some states to manage. */
> +	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
> +
> +	ret = pm_genpd_init(pd, pd_gov, false);
> +	if (ret)
> +		goto free_state;
> +
> +	ret = of_genpd_add_provider_simple(np, pd);
> +	if (ret)
> +		goto remove_pd;
> +
> +	pd_provider->node = of_node_get(np);
> +	list_add(&pd_provider->link, &psci_pd_providers);
> +
> +	pr_debug("init PM domain %s\n", pd->name);
> +	return 0;
> +
> +remove_pd:
> +	pm_genpd_remove(pd);
> +free_state:
> +	for (i = 0; i < state_count; i++)
> +		kfree(states[i].data);
> +	kfree(states);
> +free_name:
> +	kfree(pd->name);
> +free_pd_prov:
> +	kfree(pd_provider);
> +free_pd:
> +	kfree(pd);
> +out:
> +	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
> +	return ret;
> +}
> +
> +static void psci_pd_remove(void)
> +{
> +	struct psci_pd_provider *pd_provider, *it;
> +	struct generic_pm_domain *genpd;
> +	int i;
> +
> +	list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
> +		of_genpd_del_provider(pd_provider->node);
> +
> +		genpd = of_genpd_remove_last(pd_provider->node);
> +		if (!IS_ERR(genpd)) {
> +			for (i = 0; i < genpd->state_count; i++)
> +				kfree(genpd->states[i].data);
> +			kfree(genpd->states);
> +			kfree(genpd);
> +		}
> +
> +		of_node_put(pd_provider->node);
> +		list_del(&pd_provider->link);
> +		kfree(pd_provider);
> +	}
> +}
> +
> +static int psci_pd_init_topology(struct device_node *np)

__init ?

> +{
> +	struct device_node *node;
> +	struct of_phandle_args child, parent;
> +	int ret;
> +
> +	for_each_child_of_node(np, node) {
> +		if (of_parse_phandle_with_args(node, "power-domains",
> +					"#power-domain-cells", 0, &parent))
> +			continue;
> +
> +		child.np = node;
> +		child.args_count = 0;
> +
> +		ret = of_genpd_add_subdomain(&parent, &child);
> +		of_node_put(parent.np);
> +		if (ret) {
> +			of_node_put(node);
> +			return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +int psci_dt_init_pm_domains(struct device_node *np)

__init ?

> +{
> +	struct device_node *node;
> +	int ret, pd_count = 0;
> +
> +	/*
> +	 * Parse child nodes for the "#power-domain-cells" property and
> +	 * initialize a genpd/genpd-of-provider pair when it's found.
> +	 */
> +	for_each_child_of_node(np, node) {
> +		if (!of_find_property(node, "#power-domain-cells", NULL))
> +			continue;
> +
> +		ret = psci_pd_init(node);
> +		if (ret)
> +			goto put_node;
> +
> +		pd_count++;
> +	}
> +
> +	/* Bail out if not using the hierarchical CPU topology. */
> +	if (!pd_count)
> +		return 0;
> +
> +	/* Link genpd masters/subdomains to model the CPU topology. */
> +	ret = psci_pd_init_topology(np);
> +	if (ret)
> +		goto remove_pd;
> +
> +	/* Try to enable OSI mode if supported. */
> +	if (psci_has_osi_support())
> +		osi_mode_enabled = psci_set_osi_mode();
> +
> +	pr_info("Initialized CPU PM domain topology\n");
> +	return pd_count;
> +
> +put_node:
> +	of_node_put(node);
> +remove_pd:
> +	if (pd_count)
> +		psci_pd_remove();
> +	pr_err("failed to create CPU PM domains ret=%d\n", ret);
> +	return ret;
> +}
> +#endif
>
Ulf Hansson Dec. 20, 2018, 9:09 p.m. UTC | #4
[...]

> > -obj-$(CONFIG_ARM_PSCI_FW)    += psci.o
> > +obj-$(CONFIG_ARM_PSCI_FW)    += psci.o psci_pm_domain.o
>
> Same comment as 17/27.
>
> +obj-$(CONFIG_PSCI_IDLE) += psci_pm_domain.o

Let's discuss that in patch 17 to agree on the way forward.

[...]

> > +static int psci_pd_power_off(struct generic_pm_domain *pd)
> > +{
> > +     struct genpd_power_state *state = &pd->states[pd->state_idx];
> > +     u32 *pd_state;
> > +     u32 composite_pd_state;
> > +
> > +     /* If we have failed to enable OSI mode, then abort power off. */
> > +     if (psci_has_osi_support() && !osi_mode_enabled)
> > +             return -EBUSY;
>
> I'm not sure EBUSY is the best error code to describe this situation.
> May be ENOTSUP ?

I see your point. However, -EBUSY is the correct code for this case as
it tells genpd that the PM domain could not power off, but needs to
stay powered on.

To be clear, genpd treat -EBUSY, in a bit special way.

>
> However, how possible is it to pass in this function if the OSI mode was
> not enabled ?

If we fail to enable OSI mode, we keep having the CPUs attached to
PSCI PM PM domains. Although, as we are then running in platform
coordinated mode, there is no point allowing a cluster idle state.

The option would be to convert to the flattened model in case we fail
to enable OSI mode, but that error path is going to be rather
complicated (we need to detach CPUs, unregister domains and providers,
etc). Instead the assumption is that it simply shouldn't fail when we
decide to try. If it does, it's likely something need to be fixed
anyways.

>
> > +     if (!state->data)
> > +             return 0;
> > +
> > +     /* When OSI mode is enabled, set the corresponding domain state. */
> > +     pd_state = state->data;
> > +     composite_pd_state = *pd_state | psci_get_domain_state();
> > +     psci_set_domain_state(composite_pd_state);
> > +
> > +     return 0;
> > +}
> > +
> > +static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> > +                             int state_count)
>
> __init ?

Yes, probably. I will check and see if/where it could makes sense.
Thanks for pointing it out!

[...]

Kind regards
Uffe

Patch
diff mbox series

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 623591b541a4..19af2093151b 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -704,9 +704,14 @@  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);
+	}
+
 	return 0;
 }
 
diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h
index 7d9d38fd57e1..8cf6d7206fab 100644
--- a/drivers/firmware/psci/psci.h
+++ b/drivers/firmware/psci/psci.h
@@ -11,4 +11,10 @@  void psci_set_domain_state(u32 state);
 bool psci_has_osi_support(void);
 int psci_dt_parse_state_node(struct device_node *np, u32 *state);
 
+#ifdef CONFIG_CPU_IDLE
+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 /* __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..d0dc38e96f85
--- /dev/null
+++ b/drivers/firmware/psci/psci_pm_domain.c
@@ -0,0 +1,262 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PM domains for CPUs via genpd - managed by PSCI.
+ *
+ * Copyright (C) 2018 Linaro Ltd.
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ */
+
+#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"
+
+#ifdef CONFIG_CPU_IDLE
+
+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;
+	u32 composite_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;
+	composite_pd_state = *pd_state | psci_get_domain_state();
+	psci_set_domain_state(composite_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:
+	while (i >= 0) {
+		kfree(states[i].data);
+		i--;
+	}
+	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;
+
+	/* Fill out the PSCI specifics for each found state. */
+	ret = psci_pd_parse_state_nodes(*states, *state_count);
+	if (ret)
+		kfree(*states);
+
+	return ret;
+}
+
+static int psci_pd_init(struct device_node *np)
+{
+	struct generic_pm_domain *pd;
+	struct psci_pd_provider *pd_provider;
+	struct dev_power_governor *pd_gov;
+	struct genpd_power_state *states = NULL;
+	int i, ret = -ENOMEM, state_count = 0;
+
+	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		goto out;
+
+	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
+	if (!pd_provider)
+		goto free_pd;
+
+	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
+	if (!pd->name)
+		goto free_pd_prov;
+
+	/*
+	 * For OSI mode, parse the domain idle states and let genpd manage the
+	 * state selection for those being compatible with "domain-idle-state".
+	 */
+	if (psci_has_osi_support()) {
+		ret = psci_pd_parse_states(np, &states, &state_count);
+		if (ret)
+			goto free_name;
+	}
+
+	pd->name = kbasename(pd->name);
+	pd->power_off = psci_pd_power_off;
+	pd->states = states;
+	pd->state_count = state_count;
+	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
+
+	/* Use governor for CPU PM domains if it has some states to manage. */
+	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
+
+	ret = pm_genpd_init(pd, pd_gov, false);
+	if (ret)
+		goto free_state;
+
+	ret = of_genpd_add_provider_simple(np, pd);
+	if (ret)
+		goto remove_pd;
+
+	pd_provider->node = of_node_get(np);
+	list_add(&pd_provider->link, &psci_pd_providers);
+
+	pr_debug("init PM domain %s\n", pd->name);
+	return 0;
+
+remove_pd:
+	pm_genpd_remove(pd);
+free_state:
+	for (i = 0; i < state_count; i++)
+		kfree(states[i].data);
+	kfree(states);
+free_name:
+	kfree(pd->name);
+free_pd_prov:
+	kfree(pd_provider);
+free_pd:
+	kfree(pd);
+out:
+	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
+	return ret;
+}
+
+static void psci_pd_remove(void)
+{
+	struct psci_pd_provider *pd_provider, *it;
+	struct generic_pm_domain *genpd;
+	int i;
+
+	list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
+		of_genpd_del_provider(pd_provider->node);
+
+		genpd = of_genpd_remove_last(pd_provider->node);
+		if (!IS_ERR(genpd)) {
+			for (i = 0; i < genpd->state_count; i++)
+				kfree(genpd->states[i].data);
+			kfree(genpd->states);
+			kfree(genpd);
+		}
+
+		of_node_put(pd_provider->node);
+		list_del(&pd_provider->link);
+		kfree(pd_provider);
+	}
+}
+
+static int psci_pd_init_topology(struct device_node *np)
+{
+	struct device_node *node;
+	struct of_phandle_args child, parent;
+	int ret;
+
+	for_each_child_of_node(np, node) {
+		if (of_parse_phandle_with_args(node, "power-domains",
+					"#power-domain-cells", 0, &parent))
+			continue;
+
+		child.np = node;
+		child.args_count = 0;
+
+		ret = of_genpd_add_subdomain(&parent, &child);
+		of_node_put(parent.np);
+		if (ret) {
+			of_node_put(node);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+int psci_dt_init_pm_domains(struct device_node *np)
+{
+	struct device_node *node;
+	int ret, pd_count = 0;
+
+	/*
+	 * Parse child nodes for the "#power-domain-cells" property and
+	 * initialize a genpd/genpd-of-provider pair when it's found.
+	 */
+	for_each_child_of_node(np, node) {
+		if (!of_find_property(node, "#power-domain-cells", NULL))
+			continue;
+
+		ret = psci_pd_init(node);
+		if (ret)
+			goto put_node;
+
+		pd_count++;
+	}
+
+	/* Bail out if not using the hierarchical CPU topology. */
+	if (!pd_count)
+		return 0;
+
+	/* Link genpd masters/subdomains to model the CPU topology. */
+	ret = psci_pd_init_topology(np);
+	if (ret)
+		goto remove_pd;
+
+	/* Try to enable OSI mode if supported. */
+	if (psci_has_osi_support())
+		osi_mode_enabled = psci_set_osi_mode();
+
+	pr_info("Initialized CPU PM domain topology\n");
+	return pd_count;
+
+put_node:
+	of_node_put(node);
+remove_pd:
+	if (pd_count)
+		psci_pd_remove();
+	pr_err("failed to create CPU PM domains ret=%d\n", ret);
+	return ret;
+}
+#endif