summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/psci/psci.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/firmware/psci/psci.c')
-rw-r--r--drivers/firmware/psci/psci.c791
1 files changed, 791 insertions, 0 deletions
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
new file mode 100644
index 0000000000..d9629ff878
--- /dev/null
+++ b/drivers/firmware/psci/psci.c
@@ -0,0 +1,791 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2015 ARM Limited
+ */
+
+#define pr_fmt(fmt) "psci: " fmt
+
+#include <linux/acpi.h>
+#include <linux/arm-smccc.h>
+#include <linux/cpuidle.h>
+#include <linux/debugfs.h>
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#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/hypervisor.h>
+#include <asm/system_misc.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+
+/*
+ * While a 64-bit OS can make calls with SMC32 calling conventions, for some
+ * calls it is necessary to use SMC64 to pass or return 64-bit values.
+ * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
+ * (native-width) function ID.
+ */
+#ifdef CONFIG_64BIT
+#define PSCI_FN_NATIVE(version, name) PSCI_##version##_FN64_##name
+#else
+#define PSCI_FN_NATIVE(version, name) PSCI_##version##_FN_##name
+#endif
+
+/*
+ * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
+ * calls to its resident CPU, so we must avoid issuing those. We never migrate
+ * a Trusted OS even if it claims to be capable of migration -- doing so will
+ * require cooperation with a Trusted OS driver.
+ */
+static int resident_cpu = -1;
+struct psci_operations psci_ops;
+static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
+
+bool psci_tos_resident_on(int cpu)
+{
+ return cpu == resident_cpu;
+}
+
+typedef unsigned long (psci_fn)(unsigned long, unsigned long,
+ unsigned long, unsigned long);
+static psci_fn *invoke_psci_fn;
+
+static struct psci_0_1_function_ids psci_0_1_function_ids;
+
+struct psci_0_1_function_ids get_psci_0_1_function_ids(void)
+{
+ return psci_0_1_function_ids;
+}
+
+#define PSCI_0_2_POWER_STATE_MASK \
+ (PSCI_0_2_POWER_STATE_ID_MASK | \
+ PSCI_0_2_POWER_STATE_TYPE_MASK | \
+ PSCI_0_2_POWER_STATE_AFFL_MASK)
+
+#define PSCI_1_0_EXT_POWER_STATE_MASK \
+ (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
+ PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
+
+static u32 psci_cpu_suspend_feature;
+static bool psci_system_reset2_supported;
+
+static inline bool psci_has_ext_power_state(void)
+{
+ return psci_cpu_suspend_feature &
+ PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
+}
+
+bool psci_has_osi_support(void)
+{
+ return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
+}
+
+static inline bool psci_power_state_loses_context(u32 state)
+{
+ const u32 mask = psci_has_ext_power_state() ?
+ PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
+ PSCI_0_2_POWER_STATE_TYPE_MASK;
+
+ return state & mask;
+}
+
+bool psci_power_state_is_valid(u32 state)
+{
+ const u32 valid_mask = psci_has_ext_power_state() ?
+ PSCI_1_0_EXT_POWER_STATE_MASK :
+ PSCI_0_2_POWER_STATE_MASK;
+
+ return !(state & ~valid_mask);
+}
+
+static __always_inline unsigned long
+__invoke_psci_fn_hvc(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
+ return res.a0;
+}
+
+static __always_inline unsigned long
+__invoke_psci_fn_smc(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
+ return res.a0;
+}
+
+static __always_inline int psci_to_linux_errno(int errno)
+{
+ switch (errno) {
+ case PSCI_RET_SUCCESS:
+ return 0;
+ case PSCI_RET_NOT_SUPPORTED:
+ return -EOPNOTSUPP;
+ case PSCI_RET_INVALID_PARAMS:
+ case PSCI_RET_INVALID_ADDRESS:
+ return -EINVAL;
+ case PSCI_RET_DENIED:
+ return -EPERM;
+ }
+
+ return -EINVAL;
+}
+
+static u32 psci_0_1_get_version(void)
+{
+ return PSCI_VERSION(0, 1);
+}
+
+static u32 psci_0_2_get_version(void)
+{
+ return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+}
+
+int psci_set_osi_mode(bool enable)
+{
+ unsigned long suspend_mode;
+ int err;
+
+ suspend_mode = enable ? PSCI_1_0_SUSPEND_MODE_OSI :
+ PSCI_1_0_SUSPEND_MODE_PC;
+
+ err = invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, suspend_mode, 0, 0);
+ if (err < 0)
+ pr_info(FW_BUG "failed to set %s mode: %d\n",
+ enable ? "OSI" : "PC", err);
+ return psci_to_linux_errno(err);
+}
+
+static __always_inline int
+__psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point)
+{
+ int err;
+
+ err = invoke_psci_fn(fn, state, entry_point, 0);
+ return psci_to_linux_errno(err);
+}
+
+static __always_inline int
+psci_0_1_cpu_suspend(u32 state, unsigned long entry_point)
+{
+ return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend,
+ state, entry_point);
+}
+
+static __always_inline int
+psci_0_2_cpu_suspend(u32 state, unsigned long entry_point)
+{
+ return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND),
+ state, entry_point);
+}
+
+static int __psci_cpu_off(u32 fn, u32 state)
+{
+ int err;
+
+ err = invoke_psci_fn(fn, state, 0, 0);
+ return psci_to_linux_errno(err);
+}
+
+static int psci_0_1_cpu_off(u32 state)
+{
+ return __psci_cpu_off(psci_0_1_function_ids.cpu_off, state);
+}
+
+static int psci_0_2_cpu_off(u32 state)
+{
+ return __psci_cpu_off(PSCI_0_2_FN_CPU_OFF, state);
+}
+
+static int __psci_cpu_on(u32 fn, unsigned long cpuid, unsigned long entry_point)
+{
+ int err;
+
+ err = invoke_psci_fn(fn, cpuid, entry_point, 0);
+ return psci_to_linux_errno(err);
+}
+
+static int psci_0_1_cpu_on(unsigned long cpuid, unsigned long entry_point)
+{
+ return __psci_cpu_on(psci_0_1_function_ids.cpu_on, cpuid, entry_point);
+}
+
+static int psci_0_2_cpu_on(unsigned long cpuid, unsigned long entry_point)
+{
+ return __psci_cpu_on(PSCI_FN_NATIVE(0_2, CPU_ON), cpuid, entry_point);
+}
+
+static int __psci_migrate(u32 fn, unsigned long cpuid)
+{
+ int err;
+
+ err = invoke_psci_fn(fn, cpuid, 0, 0);
+ return psci_to_linux_errno(err);
+}
+
+static int psci_0_1_migrate(unsigned long cpuid)
+{
+ return __psci_migrate(psci_0_1_function_ids.migrate, cpuid);
+}
+
+static int psci_0_2_migrate(unsigned long cpuid)
+{
+ return __psci_migrate(PSCI_FN_NATIVE(0_2, MIGRATE), cpuid);
+}
+
+static int psci_affinity_info(unsigned long target_affinity,
+ unsigned long lowest_affinity_level)
+{
+ return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
+ target_affinity, lowest_affinity_level, 0);
+}
+
+static int psci_migrate_info_type(void)
+{
+ return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
+}
+
+static unsigned long psci_migrate_info_up_cpu(void)
+{
+ return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
+ 0, 0, 0);
+}
+
+static void set_conduit(enum arm_smccc_conduit conduit)
+{
+ switch (conduit) {
+ case SMCCC_CONDUIT_HVC:
+ invoke_psci_fn = __invoke_psci_fn_hvc;
+ break;
+ case SMCCC_CONDUIT_SMC:
+ invoke_psci_fn = __invoke_psci_fn_smc;
+ break;
+ default:
+ WARN(1, "Unexpected PSCI conduit %d\n", conduit);
+ }
+
+ psci_conduit = conduit;
+}
+
+static int get_set_conduit_method(const struct device_node *np)
+{
+ const char *method;
+
+ pr_info("probing for conduit method from DT.\n");
+
+ if (of_property_read_string(np, "method", &method)) {
+ pr_warn("missing \"method\" property\n");
+ return -ENXIO;
+ }
+
+ if (!strcmp("hvc", method)) {
+ set_conduit(SMCCC_CONDUIT_HVC);
+ } else if (!strcmp("smc", method)) {
+ set_conduit(SMCCC_CONDUIT_SMC);
+ } else {
+ pr_warn("invalid \"method\" property: %s\n", method);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
+ psci_system_reset2_supported) {
+ /*
+ * reset_type[31] = 0 (architectural)
+ * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
+ * cookie = 0 (ignored by the implementation)
+ */
+ invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
+ } else {
+ invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block psci_sys_reset_nb = {
+ .notifier_call = psci_sys_reset,
+ .priority = 129,
+};
+
+static void psci_sys_poweroff(void)
+{
+ invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+}
+
+static int psci_features(u32 psci_func_id)
+{
+ return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
+ psci_func_id, 0, 0);
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#define PSCI_ID(ver, _name) \
+ { .fn = PSCI_##ver##_FN_##_name, .name = #_name, }
+#define PSCI_ID_NATIVE(ver, _name) \
+ { .fn = PSCI_FN_NATIVE(ver, _name), .name = #_name, }
+
+/* A table of all optional functions */
+static const struct {
+ u32 fn;
+ const char *name;
+} psci_fn_ids[] = {
+ PSCI_ID_NATIVE(0_2, MIGRATE),
+ PSCI_ID(0_2, MIGRATE_INFO_TYPE),
+ PSCI_ID_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
+ PSCI_ID(1_0, CPU_FREEZE),
+ PSCI_ID_NATIVE(1_0, CPU_DEFAULT_SUSPEND),
+ PSCI_ID_NATIVE(1_0, NODE_HW_STATE),
+ PSCI_ID_NATIVE(1_0, SYSTEM_SUSPEND),
+ PSCI_ID(1_0, SET_SUSPEND_MODE),
+ PSCI_ID_NATIVE(1_0, STAT_RESIDENCY),
+ PSCI_ID_NATIVE(1_0, STAT_COUNT),
+ PSCI_ID_NATIVE(1_1, SYSTEM_RESET2),
+ PSCI_ID(1_1, MEM_PROTECT),
+ PSCI_ID_NATIVE(1_1, MEM_PROTECT_CHECK_RANGE),
+};
+
+static int psci_debugfs_read(struct seq_file *s, void *data)
+{
+ int feature, type, i;
+ u32 ver;
+
+ ver = psci_ops.get_version();
+ seq_printf(s, "PSCIv%d.%d\n",
+ PSCI_VERSION_MAJOR(ver),
+ PSCI_VERSION_MINOR(ver));
+
+ /* PSCI_FEATURES is available only starting from 1.0 */
+ if (PSCI_VERSION_MAJOR(ver) < 1)
+ return 0;
+
+ feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
+ if (feature != PSCI_RET_NOT_SUPPORTED) {
+ ver = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
+ seq_printf(s, "SMC Calling Convention v%d.%d\n",
+ PSCI_VERSION_MAJOR(ver),
+ PSCI_VERSION_MINOR(ver));
+ } else {
+ seq_puts(s, "SMC Calling Convention v1.0 is assumed\n");
+ }
+
+ feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
+ if (feature < 0) {
+ seq_printf(s, "PSCI_FEATURES(CPU_SUSPEND) error (%d)\n", feature);
+ } else {
+ seq_printf(s, "OSI is %ssupported\n",
+ (feature & BIT(0)) ? "" : "not ");
+ seq_printf(s, "%s StateID format is used\n",
+ (feature & BIT(1)) ? "Extended" : "Original");
+ }
+
+ type = psci_ops.migrate_info_type();
+ if (type == PSCI_0_2_TOS_UP_MIGRATE ||
+ type == PSCI_0_2_TOS_UP_NO_MIGRATE) {
+ unsigned long cpuid;
+
+ seq_printf(s, "Trusted OS %smigrate capable\n",
+ type == PSCI_0_2_TOS_UP_NO_MIGRATE ? "not " : "");
+ cpuid = psci_migrate_info_up_cpu();
+ seq_printf(s, "Trusted OS resident on physical CPU 0x%lx (#%d)\n",
+ cpuid, resident_cpu);
+ } else if (type == PSCI_0_2_TOS_MP) {
+ seq_puts(s, "Trusted OS migration not required\n");
+ } else {
+ if (type != PSCI_RET_NOT_SUPPORTED)
+ seq_printf(s, "MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(psci_fn_ids); i++) {
+ feature = psci_features(psci_fn_ids[i].fn);
+ if (feature == PSCI_RET_NOT_SUPPORTED)
+ continue;
+ if (feature < 0)
+ seq_printf(s, "PSCI_FEATURES(%s) error (%d)\n",
+ psci_fn_ids[i].name, feature);
+ else
+ seq_printf(s, "%s is supported\n", psci_fn_ids[i].name);
+ }
+
+ return 0;
+}
+
+static int psci_debugfs_open(struct inode *inode, struct file *f)
+{
+ return single_open(f, psci_debugfs_read, NULL);
+}
+
+static const struct file_operations psci_debugfs_ops = {
+ .owner = THIS_MODULE,
+ .open = psci_debugfs_open,
+ .release = single_release,
+ .read = seq_read,
+ .llseek = seq_lseek
+};
+
+static int __init psci_debugfs_init(void)
+{
+ if (!invoke_psci_fn || !psci_ops.get_version)
+ return 0;
+
+ return PTR_ERR_OR_ZERO(debugfs_create_file("psci", 0444, NULL, NULL,
+ &psci_debugfs_ops));
+}
+late_initcall(psci_debugfs_init)
+#endif
+
+#ifdef CONFIG_CPU_IDLE
+static noinstr int psci_suspend_finisher(unsigned long state)
+{
+ u32 power_state = state;
+ phys_addr_t pa_cpu_resume;
+
+ pa_cpu_resume = __pa_symbol_nodebug((unsigned long)cpu_resume);
+
+ return psci_ops.cpu_suspend(power_state, pa_cpu_resume);
+}
+
+int psci_cpu_suspend_enter(u32 state)
+{
+ int ret;
+
+ if (!psci_power_state_loses_context(state)) {
+ struct arm_cpuidle_irq_context context;
+
+ ct_cpuidle_enter();
+ arm_cpuidle_save_irq_context(&context);
+ ret = psci_ops.cpu_suspend(state, 0);
+ arm_cpuidle_restore_irq_context(&context);
+ ct_cpuidle_exit();
+ } else {
+ /*
+ * ARM64 cpu_suspend() wants to do ct_cpuidle_*() itself.
+ */
+ if (!IS_ENABLED(CONFIG_ARM64))
+ ct_cpuidle_enter();
+
+ ret = cpu_suspend(state, psci_suspend_finisher);
+
+ if (!IS_ENABLED(CONFIG_ARM64))
+ ct_cpuidle_exit();
+ }
+
+ return ret;
+}
+#endif
+
+static int psci_system_suspend(unsigned long unused)
+{
+ phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume);
+
+ return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
+ pa_cpu_resume, 0, 0);
+}
+
+static int psci_system_suspend_enter(suspend_state_t state)
+{
+ return cpu_suspend(0, psci_system_suspend);
+}
+
+static const struct platform_suspend_ops psci_suspend_ops = {
+ .valid = suspend_valid_only_mem,
+ .enter = psci_system_suspend_enter,
+};
+
+static void __init psci_init_system_reset2(void)
+{
+ int ret;
+
+ ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
+
+ if (ret != PSCI_RET_NOT_SUPPORTED)
+ psci_system_reset2_supported = true;
+}
+
+static void __init psci_init_system_suspend(void)
+{
+ int ret;
+
+ if (!IS_ENABLED(CONFIG_SUSPEND))
+ return;
+
+ ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
+
+ if (ret != PSCI_RET_NOT_SUPPORTED)
+ suspend_set_ops(&psci_suspend_ops);
+}
+
+static void __init psci_init_cpu_suspend(void)
+{
+ int feature = psci_features(PSCI_FN_NATIVE(0_2, CPU_SUSPEND));
+
+ if (feature != PSCI_RET_NOT_SUPPORTED)
+ psci_cpu_suspend_feature = feature;
+}
+
+/*
+ * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
+ * return DENIED (which would be fatal).
+ */
+static void __init psci_init_migrate(void)
+{
+ unsigned long cpuid;
+ int type, cpu = -1;
+
+ type = psci_ops.migrate_info_type();
+
+ if (type == PSCI_0_2_TOS_MP) {
+ pr_info("Trusted OS migration not required\n");
+ return;
+ }
+
+ if (type == PSCI_RET_NOT_SUPPORTED) {
+ pr_info("MIGRATE_INFO_TYPE not supported.\n");
+ return;
+ }
+
+ if (type != PSCI_0_2_TOS_UP_MIGRATE &&
+ type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
+ pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
+ return;
+ }
+
+ cpuid = psci_migrate_info_up_cpu();
+ if (cpuid & ~MPIDR_HWID_BITMASK) {
+ pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
+ cpuid);
+ return;
+ }
+
+ cpu = get_logical_index(cpuid);
+ resident_cpu = cpu >= 0 ? cpu : -1;
+
+ pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
+}
+
+static void __init psci_init_smccc(void)
+{
+ u32 ver = ARM_SMCCC_VERSION_1_0;
+ int feature;
+
+ feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID);
+
+ if (feature != PSCI_RET_NOT_SUPPORTED) {
+ u32 ret;
+ ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0);
+ if (ret >= ARM_SMCCC_VERSION_1_1) {
+ arm_smccc_version_init(ret, psci_conduit);
+ ver = ret;
+ }
+ }
+
+ /*
+ * Conveniently, the SMCCC and PSCI versions are encoded the
+ * same way. No, this isn't accidental.
+ */
+ pr_info("SMC Calling Convention v%d.%d\n",
+ PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
+
+}
+
+static void __init psci_0_2_set_functions(void)
+{
+ pr_info("Using standard PSCI v0.2 function IDs\n");
+
+ psci_ops = (struct psci_operations){
+ .get_version = psci_0_2_get_version,
+ .cpu_suspend = psci_0_2_cpu_suspend,
+ .cpu_off = psci_0_2_cpu_off,
+ .cpu_on = psci_0_2_cpu_on,
+ .migrate = psci_0_2_migrate,
+ .affinity_info = psci_affinity_info,
+ .migrate_info_type = psci_migrate_info_type,
+ };
+
+ register_restart_handler(&psci_sys_reset_nb);
+
+ pm_power_off = psci_sys_poweroff;
+}
+
+/*
+ * Probe function for PSCI firmware versions >= 0.2
+ */
+static int __init psci_probe(void)
+{
+ u32 ver = psci_0_2_get_version();
+
+ pr_info("PSCIv%d.%d detected in firmware.\n",
+ PSCI_VERSION_MAJOR(ver),
+ PSCI_VERSION_MINOR(ver));
+
+ if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
+ pr_err("Conflicting PSCI version detected.\n");
+ return -EINVAL;
+ }
+
+ psci_0_2_set_functions();
+
+ psci_init_migrate();
+
+ if (PSCI_VERSION_MAJOR(ver) >= 1) {
+ psci_init_smccc();
+ psci_init_cpu_suspend();
+ psci_init_system_suspend();
+ psci_init_system_reset2();
+ kvm_init_hyp_services();
+ }
+
+ return 0;
+}
+
+typedef int (*psci_initcall_t)(const struct device_node *);
+
+/*
+ * PSCI init function for PSCI versions >=0.2
+ *
+ * Probe based on PSCI PSCI_VERSION function
+ */
+static int __init psci_0_2_init(const struct device_node *np)
+{
+ int err;
+
+ err = get_set_conduit_method(np);
+ if (err)
+ return err;
+
+ /*
+ * Starting with v0.2, the PSCI specification introduced a call
+ * (PSCI_VERSION) that allows probing the firmware version, so
+ * that PSCI function IDs and version specific initialization
+ * can be carried out according to the specific version reported
+ * by firmware
+ */
+ return psci_probe();
+}
+
+/*
+ * PSCI < v0.2 get PSCI Function IDs via DT.
+ */
+static int __init psci_0_1_init(const struct device_node *np)
+{
+ u32 id;
+ int err;
+
+ err = get_set_conduit_method(np);
+ if (err)
+ return err;
+
+ pr_info("Using PSCI v0.1 Function IDs from DT\n");
+
+ psci_ops.get_version = psci_0_1_get_version;
+
+ if (!of_property_read_u32(np, "cpu_suspend", &id)) {
+ psci_0_1_function_ids.cpu_suspend = id;
+ psci_ops.cpu_suspend = psci_0_1_cpu_suspend;
+ }
+
+ if (!of_property_read_u32(np, "cpu_off", &id)) {
+ psci_0_1_function_ids.cpu_off = id;
+ psci_ops.cpu_off = psci_0_1_cpu_off;
+ }
+
+ if (!of_property_read_u32(np, "cpu_on", &id)) {
+ psci_0_1_function_ids.cpu_on = id;
+ psci_ops.cpu_on = psci_0_1_cpu_on;
+ }
+
+ if (!of_property_read_u32(np, "migrate", &id)) {
+ psci_0_1_function_ids.migrate = id;
+ psci_ops.migrate = psci_0_1_migrate;
+ }
+
+ return 0;
+}
+
+static int __init psci_1_0_init(const struct device_node *np)
+{
+ int err;
+
+ err = psci_0_2_init(np);
+ if (err)
+ return err;
+
+ if (psci_has_osi_support()) {
+ pr_info("OSI mode supported.\n");
+
+ /* Default to PC mode. */
+ psci_set_osi_mode(false);
+ }
+
+ return 0;
+}
+
+static const struct of_device_id psci_of_match[] __initconst = {
+ { .compatible = "arm,psci", .data = psci_0_1_init},
+ { .compatible = "arm,psci-0.2", .data = psci_0_2_init},
+ { .compatible = "arm,psci-1.0", .data = psci_1_0_init},
+ {},
+};
+
+int __init psci_dt_init(void)
+{
+ struct device_node *np;
+ const struct of_device_id *matched_np;
+ psci_initcall_t init_fn;
+ int ret;
+
+ np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
+
+ if (!np || !of_device_is_available(np))
+ return -ENODEV;
+
+ init_fn = (psci_initcall_t)matched_np->data;
+ ret = init_fn(np);
+
+ of_node_put(np);
+ return ret;
+}
+
+#ifdef CONFIG_ACPI
+/*
+ * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
+ * explicitly clarified in SBBR
+ */
+int __init psci_acpi_init(void)
+{
+ if (!acpi_psci_present()) {
+ pr_info("is not implemented in ACPI.\n");
+ return -EOPNOTSUPP;
+ }
+
+ pr_info("probing for conduit method from ACPI.\n");
+
+ if (acpi_psci_use_hvc())
+ set_conduit(SMCCC_CONDUIT_HVC);
+ else
+ set_conduit(SMCCC_CONDUIT_SMC);
+
+ return psci_probe();
+}
+#endif