diff options
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/psci.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c index f25cd79c8a79..11bfee8b79a9 100644 --- a/drivers/firmware/psci.c +++ b/drivers/firmware/psci.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) "psci: " fmt #include <linux/arm-smccc.h> +#include <linux/cpuidle.h> #include <linux/errno.h> #include <linux/linkage.h> #include <linux/of.h> @@ -21,10 +22,12 @@ #include <linux/printk.h> #include <linux/psci.h> #include <linux/reboot.h> +#include <linux/slab.h> #include <linux/suspend.h> #include <uapi/linux/psci.h> +#include <asm/cpuidle.h> #include <asm/cputype.h> #include <asm/system_misc.h> #include <asm/smp_plat.h> @@ -244,6 +247,123 @@ static int __init psci_features(u32 psci_func_id) psci_func_id, 0, 0); } +#ifdef CONFIG_CPU_IDLE +static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state); + +static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu) +{ + int i, ret, count = 0; + u32 *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++; + of_node_put(state_node); + } + + if (!count) + return -ENODEV; + + psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL); + if (!psci_states) + return -ENOMEM; + + for (i = 0; i < count; i++) { + u32 state; + + state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i); + + ret = of_property_read_u32(state_node, + "arm,psci-suspend-param", + &state); + if (ret) { + pr_warn(" * %s missing arm,psci-suspend-param property\n", + state_node->full_name); + of_node_put(state_node); + goto free_mem; + } + + of_node_put(state_node); + pr_debug("psci-power-state %#x index %d\n", state, i); + if (!psci_power_state_is_valid(state)) { + pr_warn("Invalid PSCI power state %#x\n", state); + ret = -EINVAL; + goto free_mem; + } + psci_states[i] = state; + } + /* 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; +} + +int psci_cpu_init_idle(unsigned int cpu) +{ + struct device_node *cpu_node; + int ret; + + cpu_node = of_get_cpu_node(cpu, NULL); + if (!cpu_node) + return -ENODEV; + + ret = psci_dt_cpu_init_idle(cpu_node, cpu); + + of_node_put(cpu_node); + + return ret; +} + +static int psci_suspend_finisher(unsigned long index) +{ + u32 *state = __this_cpu_read(psci_power_state); + + return psci_ops.cpu_suspend(state[index - 1], + virt_to_phys(cpu_resume)); +} + +int psci_cpu_suspend_enter(unsigned long index) +{ + int ret; + u32 *state = __this_cpu_read(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; + + if (!psci_power_state_loses_context(state[index - 1])) + ret = psci_ops.cpu_suspend(state[index - 1], 0); + else + ret = cpu_suspend(index, psci_suspend_finisher); + + return ret; +} + +/* ARM specific CPU idle operations */ +#ifdef CONFIG_ARM +static struct cpuidle_ops psci_cpuidle_ops __initdata = { + .suspend = psci_cpu_suspend_enter, + .init = psci_dt_cpu_init_idle, +}; + +CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops); +#endif +#endif + static int psci_system_suspend(unsigned long unused) { return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND), |