On Wed, Jan 21, 2015 at 11:35:55AM +0000, Sudeep Holla wrote:
> PSCI specifications upto v0.2 and the related kernel back-end
> implementation lack a method to enter system wide suspend state.
>
> This patch implements suspend to RAM support for all ARM64 systems
> with PSCIv0.2 support using CPU SUSPEND and the new system state DT
> bindings.
>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> ---
> arch/arm64/kernel/psci.c | 83 ++++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 74 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
> index f1dbca7d5c96..8be464747dd6 100644
> --- a/arch/arm64/kernel/psci.c
> +++ b/arch/arm64/kernel/psci.c
> @@ -22,6 +22,7 @@
> #include <linux/pm.h>
> #include <linux/delay.h>
> #include <linux/slab.h>
> +#include <linux/suspend.h>
> #include <uapi/linux/psci.h>
>
> #include <asm/compiler.h>
> @@ -304,6 +305,75 @@ static void psci_sys_poweroff(void)
> invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
> }
>
> +static int psci_suspend_finisher(unsigned long arg)
> +{
> + return psci_ops.cpu_suspend(*(struct psci_power_state *)arg,
> + virt_to_phys(cpu_resume));
> +}
> +
> +#ifdef CONFIG_SUSPEND
> +static struct psci_power_state psci_system_suspend_state;
> +
> +static int psci_system_suspend_enter(suspend_state_t state)
> +{
> + if (state != PM_SUSPEND_MEM)
> + return 0;
> +
> + /*
> + * TODO remove pack/unpacking of power_state to do away with
> + * these ugly type conversions
> + */
> + return __cpu_suspend((unsigned long)&psci_system_suspend_state,
> + psci_suspend_finisher);
> +}
> +
> +static const struct platform_suspend_ops psci_suspend_ops = {
> + .valid = suspend_valid_only_mem,
> + .enter = psci_system_suspend_enter,
> +};
> +
> +static void __init psci_0_2_system_suspend_init(void)
> +{
> + int ret;
> + u32 psci_power_state;
> + const char *entry_method;
> + struct device_node *node;
> +
> + if (!psci_ops.cpu_suspend)
> + return; /* -EOPNOTSUPP */
> +
> + node = of_find_compatible_node(NULL, NULL, "arm,system-suspend");
> + if (!node || !of_device_is_available(node))
> + return; /* -EOPNOTSUPP */
> +
> + if (of_property_read_string(node, "entry-method", &entry_method)) {
> + pr_warn(" * %s missing entry-method property\n", node->full_name);
> + goto exit;
> + }
> +
> + if (strcmp(entry_method, "arm,psci"))
> + goto exit; /* out of PSCI scope ignore */
> +
> + ret = of_property_read_u32(node, "arm,psci-suspend-param",
> + &psci_power_state);
> + if (ret) {
> + pr_warn(" * %s missing arm,psci-suspend-param property\n",
> + node->full_name);
> + goto exit;
> + }
> +
> + pr_debug("psci-power-state for system suspend %#x\n", psci_power_state);
> +
> + psci_power_state_unpack(psci_power_state, &psci_system_suspend_state);
> +
How about unify the power states passing for cpu idle and suspend?
below is a example for dts which place all power state into psci
entry, so that idle-states and system suspend both can reference
the power state.
psci {
compatible = "arm,psci-0.2";
method = "smc";
power_state {
CPU_POWER_OFF: cpu_power_off {
state = <0x00010000>;
};
CLUSTER_POWER_OFF: cluster_power_off {
state = <0x01010000>;
};
SOC_SUSPEND: soc_suspend {
state = <0x01010001>;
};
};
};
> + suspend_set_ops(&psci_suspend_ops);
> +exit:
> + of_node_put(node);
> +}
> +#else
> +static void __init psci_0_2_system_suspend_init(void) { }
> +#endif
> +
> /*
> * PSCI Function IDs for v0.2+ are well defined so use
> * standard values.
> @@ -361,6 +431,8 @@ static int __init psci_0_2_init(struct device_node *np)
>
> pm_power_off = psci_sys_poweroff;
>
> + psci_0_2_system_suspend_init();
> +
> out_put_node:
> of_node_put(np);
> return err;
> @@ -509,14 +581,6 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
> #endif
> #endif
>
> -static int psci_suspend_finisher(unsigned long index)
> -{
> - struct psci_power_state *state = __this_cpu_read(psci_power_state);
> -
> - return psci_ops.cpu_suspend(state[index - 1],
> - virt_to_phys(cpu_resume));
> -}
> -
> static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
> {
> int ret;
> @@ -531,7 +595,8 @@ static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
> if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
> ret = psci_ops.cpu_suspend(state[index - 1], 0);
> else
> - ret = __cpu_suspend(index, psci_suspend_finisher);
> + ret = __cpu_suspend((unsigned long)&state[index - 1],
> + psci_suspend_finisher);
>
> return ret;
> }
> --
> 1.9.1
>
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