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),