From 8b6f2499ac45d5a0ab2e4b6f9613ab3f60416be1 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 1 Feb 2016 18:01:30 +0100 Subject: ARM: 8511/1: ARM64: kernel: PSCI: move PSCI idle management code to drivers/firmware ARM64 PSCI kernel interfaces that initialize idle states and implement the suspend API to enter them are generic and can be shared with the ARM architecture. To achieve that goal, this patch moves ARM64 PSCI idle management code to drivers/firmware, so that the interface to initialize and enter idle states can actually be shared by ARM and ARM64 arches back-ends. The ARM generic CPUidle implementation also requires the definition of a cpuidle_ops section entry for the kernel to initialize the CPUidle operations at boot based on the enable-method (ie ARM64 has the statically initialized cpu_ops counterparts for that purpose); therefore this patch also adds the required section entry on CONFIG_ARM for PSCI so that the kernel can initialize the PSCI CPUidle back-end when PSCI is the probed enable-method. On ARM64 this patch provides no functional change. Signed-off-by: Lorenzo Pieralisi Acked-by: Daniel Lezcano Acked-by: Catalin Marinas [arch/arm64] Acked-by: Mark Rutland Tested-by: Jisheng Zhang Cc: Will Deacon Cc: Sudeep Holla Cc: Daniel Lezcano Cc: Catalin Marinas Cc: Mark Rutland Cc: Jisheng Zhang Signed-off-by: Russell King --- drivers/firmware/psci.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) (limited to 'drivers/firmware') 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 +#include #include #include #include @@ -21,10 +22,12 @@ #include #include #include +#include #include #include +#include #include #include #include @@ -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), -- cgit v1.2.1