diff mbox

[v6,4/7] arm64: add PSCI CPU_SUSPEND based cpu_suspend support

Message ID 1405958786-17243-5-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Lorenzo Pieralisi July 21, 2014, 4:06 p.m. UTC
This patch implements the cpu_suspend cpu operations method through
the PSCI CPU SUSPEND API. The PSCI implementation translates the idle state
index passed by the cpu_suspend core call into a valid PSCI state according to
the PSCI states initialized at boot through the cpu_init_idle() CPU
operations hook.

Entry point is set to cpu_resume physical address, that represents the
default kernel execution address following a CPU reset; for standby
states the entry point address is useless and will therefore be ignored
by the PSCI implementation.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

Comments

Ashwin Chaugule July 23, 2014, 4:15 p.m. UTC | #1
On 21 July 2014 12:06, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote:
> This patch implements the cpu_suspend cpu operations method through
> the PSCI CPU SUSPEND API. The PSCI implementation translates the idle state
> index passed by the cpu_suspend core call into a valid PSCI state according to
> the PSCI states initialized at boot through the cpu_init_idle() CPU
> operations hook.
>
> Entry point is set to cpu_resume physical address, that represents the
> default kernel execution address following a CPU reset; for standby
> states the entry point address is useless and will therefore be ignored
> by the PSCI implementation.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> ---
>  arch/arm64/kernel/psci.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 89 insertions(+)
>
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index a623c44..bbdf41d 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -21,6 +21,7 @@
>  #include <linux/reboot.h>
>  #include <linux/pm.h>
>  #include <linux/delay.h>
> +#include <linux/slab.h>
>  #include <uapi/linux/psci.h>
>
>  #include <asm/compiler.h>
> @@ -28,6 +29,7 @@
>  #include <asm/errno.h>
>  #include <asm/psci.h>
>  #include <asm/smp_plat.h>
> +#include <asm/suspend.h>
>  #include <asm/system_misc.h>
>
>  #define PSCI_POWER_STATE_TYPE_STANDBY          0
> @@ -65,6 +67,8 @@ enum psci_function {
>         PSCI_FN_MAX,
>  };
>
> +static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
> +
>  static u32 psci_function_id[PSCI_FN_MAX];
>
>  static int psci_to_linux_errno(int errno)
> @@ -93,6 +97,18 @@ static u32 psci_power_state_pack(struct psci_power_state state)
>                  & PSCI_0_2_POWER_STATE_AFFL_MASK);
>  }
>
> +static void psci_power_state_unpack(u32 power_state,
> +                                   struct psci_power_state *state)
> +{
> +       state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
> +                       PSCI_0_2_POWER_STATE_ID_SHIFT;
> +       state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
> +                       PSCI_0_2_POWER_STATE_TYPE_SHIFT;
> +       state->affinity_level =
> +                       (power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
> +                       PSCI_0_2_POWER_STATE_AFFL_SHIFT;
> +}
> +
>  /*
>   * The following two functions are invoked via the invoke_psci_fn pointer
>   * and will not be inlined, allowing us to piggyback on the AAPCS.
> @@ -199,6 +215,61 @@ static int psci_migrate_info_type(void)
>         return err;
>  }
>
> +static int cpu_psci_cpu_init_idle(struct device_node *cpu_node,
> +                                 unsigned int cpu)
> +{
> +       int i, ret, count = 0;
> +       struct psci_power_state *psci_states;
> +       struct device_node *state_node;
> +
> +       /*
> +        * If the PSCI cpu_suspend function hook has not been initialized
> +        * idle states must not be enabled, so bail out
> +        */
> +       if (!psci_ops.cpu_suspend)
> +               return -EOPNOTSUPP;
> +
> +       /* Count idle states */
> +       while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
> +                                             count)))
> +               count++;
> +
> +       if (!count)
> +               return -ENODEV;
> +
> +       psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
> +       if (!psci_states) {
> +               pr_warn("idle state psci_state allocation failed\n");
> +               return -ENOMEM;
> +       }
> +
> +       for (i = 0; i < count; i++) {
> +               u32 psci_power_state;
> +
> +               state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
> +
> +               ret = of_property_read_u32(state_node,
> +                                          "arm,psci-suspend-param",
> +                                          &psci_power_state);
> +               if (ret) {
> +                       pr_warn(" * %s missing arm,psci-suspend-param property\n",
> +                               state_node->full_name);
> +                       goto free_mem;
> +               }
> +
> +               pr_debug("psci-power-state %#x index %d\n", psci_power_state,
> +                                                           i);
> +               psci_power_state_unpack(psci_power_state, &psci_states[i]);
> +       }
> +       /* Idle states parsed correctly, initialize per-cpu pointer */
> +       per_cpu(psci_power_state, cpu) = psci_states;
> +       return 0;
> +
> +free_mem:
> +       kfree(psci_states);
> +       return ret;
> +}
> +
>  static int get_set_conduit_method(struct device_node *np)
>  {
>         const char *method;
> @@ -436,8 +507,23 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
>  #endif
>  #endif
>
> +static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
> +{
> +       struct psci_power_state *state = __get_cpu_var(psci_power_state);
> +       /*
> +        * idle state index 0 corresponds to wfi, should never be called
> +        * from the cpu_suspend operations
> +        */
> +       if (WARN_ON_ONCE(!index))
> +               return -EINVAL;
> +
> +       return psci_ops.cpu_suspend(state[index - 1],
> +                                   virt_to_phys(cpu_resume));
> +}
> +
>  const struct cpu_operations cpu_psci_ops = {
>         .name           = "psci",
> +       .cpu_init_idle  = cpu_psci_cpu_init_idle,
>  #ifdef CONFIG_SMP
>         .cpu_init       = cpu_psci_cpu_init,
>         .cpu_prepare    = cpu_psci_cpu_prepare,
> @@ -448,5 +534,8 @@ const struct cpu_operations cpu_psci_ops = {
>         .cpu_kill       = cpu_psci_cpu_kill,
>  #endif
>  #endif
> +#ifdef CONFIG_ARM64_CPU_SUSPEND
> +       .cpu_suspend    = cpu_psci_cpu_suspend,
> +#endif
>  };
>
> --
> 1.9.1

Reviewed-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>

>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox

Patch

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index a623c44..bbdf41d 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -21,6 +21,7 @@ 
 #include <linux/reboot.h>
 #include <linux/pm.h>
 #include <linux/delay.h>
+#include <linux/slab.h>
 #include <uapi/linux/psci.h>
 
 #include <asm/compiler.h>
@@ -28,6 +29,7 @@ 
 #include <asm/errno.h>
 #include <asm/psci.h>
 #include <asm/smp_plat.h>
+#include <asm/suspend.h>
 #include <asm/system_misc.h>
 
 #define PSCI_POWER_STATE_TYPE_STANDBY		0
@@ -65,6 +67,8 @@  enum psci_function {
 	PSCI_FN_MAX,
 };
 
+static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
+
 static u32 psci_function_id[PSCI_FN_MAX];
 
 static int psci_to_linux_errno(int errno)
@@ -93,6 +97,18 @@  static u32 psci_power_state_pack(struct psci_power_state state)
 		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
 }
 
+static void psci_power_state_unpack(u32 power_state,
+				    struct psci_power_state *state)
+{
+	state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
+			PSCI_0_2_POWER_STATE_ID_SHIFT;
+	state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
+			PSCI_0_2_POWER_STATE_TYPE_SHIFT;
+	state->affinity_level =
+			(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
+			PSCI_0_2_POWER_STATE_AFFL_SHIFT;
+}
+
 /*
  * The following two functions are invoked via the invoke_psci_fn pointer
  * and will not be inlined, allowing us to piggyback on the AAPCS.
@@ -199,6 +215,61 @@  static int psci_migrate_info_type(void)
 	return err;
 }
 
+static int cpu_psci_cpu_init_idle(struct device_node *cpu_node,
+				  unsigned int cpu)
+{
+	int i, ret, count = 0;
+	struct psci_power_state *psci_states;
+	struct device_node *state_node;
+
+	/*
+	 * If the PSCI cpu_suspend function hook has not been initialized
+	 * idle states must not be enabled, so bail out
+	 */
+	if (!psci_ops.cpu_suspend)
+		return -EOPNOTSUPP;
+
+	/* Count idle states */
+	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
+					      count)))
+		count++;
+
+	if (!count)
+		return -ENODEV;
+
+	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
+	if (!psci_states) {
+		pr_warn("idle state psci_state allocation failed\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < count; i++) {
+		u32 psci_power_state;
+
+		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+
+		ret = of_property_read_u32(state_node,
+					   "arm,psci-suspend-param",
+					   &psci_power_state);
+		if (ret) {
+			pr_warn(" * %s missing arm,psci-suspend-param property\n",
+				state_node->full_name);
+			goto free_mem;
+		}
+
+		pr_debug("psci-power-state %#x index %d\n", psci_power_state,
+							    i);
+		psci_power_state_unpack(psci_power_state, &psci_states[i]);
+	}
+	/* Idle states parsed correctly, initialize per-cpu pointer */
+	per_cpu(psci_power_state, cpu) = psci_states;
+	return 0;
+
+free_mem:
+	kfree(psci_states);
+	return ret;
+}
+
 static int get_set_conduit_method(struct device_node *np)
 {
 	const char *method;
@@ -436,8 +507,23 @@  static int cpu_psci_cpu_kill(unsigned int cpu)
 #endif
 #endif
 
+static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
+{
+	struct psci_power_state *state = __get_cpu_var(psci_power_state);
+	/*
+	 * idle state index 0 corresponds to wfi, should never be called
+	 * from the cpu_suspend operations
+	 */
+	if (WARN_ON_ONCE(!index))
+		return -EINVAL;
+
+	return psci_ops.cpu_suspend(state[index - 1],
+				    virt_to_phys(cpu_resume));
+}
+
 const struct cpu_operations cpu_psci_ops = {
 	.name		= "psci",
+	.cpu_init_idle	= cpu_psci_cpu_init_idle,
 #ifdef CONFIG_SMP
 	.cpu_init	= cpu_psci_cpu_init,
 	.cpu_prepare	= cpu_psci_cpu_prepare,
@@ -448,5 +534,8 @@  const struct cpu_operations cpu_psci_ops = {
 	.cpu_kill	= cpu_psci_cpu_kill,
 #endif
 #endif
+#ifdef CONFIG_ARM64_CPU_SUSPEND
+	.cpu_suspend	= cpu_psci_cpu_suspend,
+#endif
 };