// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2017 Arm Ltd.
#define pr_fmt(fmt) "sdei: " fmt
#include <acpi/ghes.h>
#include <linux/acpi.h>
#include <linux/arm_sdei.h>
#include <linux/arm-smccc.h>
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/cpuhotplug.h>
#include <linux/cpu.h>
#include <linux/cpu_pm.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/kvm_host.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/percpu.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/ptrace.h>
#include <linux/preempt.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
/*
* The call to use to reach the firmware.
*/
static asmlinkage void (*sdei_firmware_call)(unsigned long function_id,
unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3,
unsigned long arg4, struct arm_smccc_res *res);
/* entry point from firmware to arch asm code */
static unsigned long sdei_entry_point;
static int sdei_hp_state;
struct sdei_event {
/* These three are protected by the sdei_list_lock */
struct list_head list;
bool reregister;
bool reenable;
u32 event_num;
u8 type;
u8 priority;
/* This pointer is handed to firmware as the event argument. */
union {
/* Shared events */
struct sdei_registered_event *registered;
/* CPU private events */
struct sdei_registered_event __percpu *private_registered;
};
};
/* Take the mutex for any API call or modification. Take the mutex first. */
static DEFINE_MUTEX(sdei_events_lock);
/* and then hold this when modifying the list */
static DEFINE_SPINLOCK(sdei_list_lock);
static LIST_HEAD(sdei_list);
/* Private events are registered/enabled via IPI passing one of these */
struct sdei_crosscall_args {
struct sdei_event *event;
atomic_t errors;
int first_error;
};
#define CROSSCALL_INIT(arg, event) \
do { \
arg.event = event; \
arg.first_error = 0; \
atomic_set(&arg.errors, 0); \
} while (0)
static inline int sdei_do_local_call(smp_call_func_t fn,
struct sdei_event *event)
{
struct sdei_crosscall_args arg;
CROSSCALL_INIT(arg, event);
fn(&arg);
return arg.first_error;
}
static inline int sdei_do_cross_call(smp_call_func_t fn,
struct sdei_event *event)
{
struct sdei_crosscall_args arg;
CROSSCALL_INIT(arg, event);
on_each_cpu(fn, &arg, true);
return arg.first_error;
}
static inline void
sdei_cross_call_return(struct sdei_crosscall_args *arg, int err)
{
if (err && (atomic_inc_return(&arg->errors) == 1))
arg->first_error = err;
}
static int sdei_to_linux_errno(unsigned long sdei_err)
{
switch (sdei_err) {
case SDEI_NOT_SUPPORTED:
return -EOPNOTSUPP;
case SDEI_INVALID_PARAMETERS:
return -EINVAL;
case SDEI_DENIED:
return -EPERM;
case SDEI_PENDING:
return -EINPROGRESS;
case SDEI_OUT_OF_RESOURCE:
return -ENOMEM;
}
return 0;
}
static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0,
unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4,
u64 *result)
{
int err;
struct arm_smccc_res res;
if (sdei_firmware_call) {
sdei_firmware_call(function_id, arg0, arg1, arg2, arg3, arg4,
&res);
err = sdei_to_linux_errno(res.a0);
} else {
/*
* !sdei_firmware_call means we failed to probe or called
* sdei_mark_interface_broken(). -EIO is not an error returned
* by sdei_to_linux_errno() and is used to suppress messages
* from this driver.
*/
err = -EIO;
res.a0 = SDEI_NOT_SUPPORTED;
}
if (result)
*result = res.a0;
return err;
}
NOKPROBE_SYMBOL(invoke_sdei_fn);
static struct sdei_event *sdei_event_find(u32 event_num)
{
struct sdei_event *e, *found = NULL;
lockdep_assert_held(&sdei_events_lock);
spin_lock(&sdei_list_lock);
list_for_each_entry(e, &sdei_list, list) {
if (e->event_num == event_num) {
found = e;
break;
}
}
spin_unlock(&sdei_list_lock);
return found;
}
int sdei_api_event_context(u32 query, u64 *result)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, query, 0, 0, 0, 0,
result);
}
NOKPROBE_SYMBOL(sdei_api_event_context);
static int sdei_api_event_get_info(u32 event, u32 info, u64 *result)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0,
0, 0, result);
}
static struct sdei_event *sdei_event_create(u32 event_num,
sdei_event_callback *cb,
void *cb_arg)
{
int err;
u64 result;
struct sdei_event *event;
struct sdei_registered_event *reg;
lockdep_assert_held(&sdei_events_lock);
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event) {
err = -ENOMEM;
goto fail;
}
INIT_LIST_HEAD(&event->list);
event->event_num = event_num;
err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
&result);
if (err)
goto fail;
event->priority = result;
err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_TYPE,
&result);
if (err)
goto fail;
event->type = result;
if (event->type == SDEI_EVENT_TYPE_SHARED) {
reg = kzalloc(sizeof(*reg), GFP_KERNEL);
if (!reg) {
err = -ENOMEM;
goto fail;
}
reg->event_num = event->event_num;
reg->priority = event->priority;
reg->callback = cb;
reg->callback_arg = cb_arg;
event->registered = reg;
} else {
int cpu;
struct sdei_registered_event __percpu *regs;
regs = alloc_percpu(struct sdei_registered_event);
if (!regs) {
err = -ENOMEM;
goto fail;
}
for_each_possible_cpu(cpu) {
reg = per_cpu_ptr(regs, cpu);
reg->event_num = event->event_num;
reg->priority = event->priority;
reg->callback = cb;
reg->callback_arg = cb_arg;
}
event->private_registered = regs;
}
spin_lock(&sdei_list_lock);
list_add(&event->list, &sdei_list);
spin_unlock(&sdei_list_lock);
return event;
fail:
kfree(event);
return ERR_PTR(err);
}
static void sdei_event_destroy_llocked(struct sdei_event *event)
{
lockdep_assert_held(&sdei_events_lock);
lockdep_assert_held(&sdei_list_lock);
list_del(&event->list);
if (event->type == SDEI_EVENT_TYPE_SHARED)
kfree(event->registered);
else
free_percpu(event->private_registered);
kfree(event);
}
static void sdei_event_destroy(struct sdei_event *event)
{
spin_lock(&sdei_list_lock);
sdei_event_destroy_llocked(event);
spin_unlock(&sdei_list_lock);
}
static int sdei_api_get_version(u64 *version)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version);
}
int sdei_mask_local_cpu(void)
{
int err;
err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_MASK, 0, 0, 0, 0, 0, NULL);
if (err && err != -EIO) {
pr_warn_once("failed to mask CPU[%u]: %d\n",
smp_processor_id(), err);
return err;
}
return 0;
}
static void _ipi_mask_cpu(void *ignored)
{
WARN_ON_ONCE(preemptible());
sdei_mask_local_cpu();
}
int sdei_unmask_local_cpu(void)
{
int err;
err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_UNMASK, 0, 0, 0, 0, 0, NULL);
if (err && err != -EIO) {
pr_warn_once("failed to unmask CPU[%u]: %d\n",
smp_processor_id(), err);
return err;
}
return 0;
}
static void _ipi_unmask_cpu(void *ignored)
{
WARN_ON_ONCE(preemptible());
sdei_unmask_local_cpu();
}
static void _ipi_private_reset(void *ignored)
{
int err;
WARN_ON_ONCE(preemptible());
err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PRIVATE_RESET, 0, 0, 0, 0, 0,
NULL);
if (err && err != -EIO)
pr_warn_once("failed to reset CPU[%u]: %d\n",
smp_processor_id(), err);
}
static int sdei_api_shared_reset(void)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_SHARED_RESET, 0, 0, 0, 0, 0,
NULL);
}
static void sdei_mark_interface_broken(void)
{
pr_err("disabling SDEI firmware interface\n");
on_each_cpu(&_ipi_mask_cpu, NULL, true);
sdei_firmware_call = NULL;
}
static int sdei_platform_reset(void)
{
int err;
on_each_cpu(&_ipi_private_reset, NULL, true);
err = sdei_api_shared_reset();
if (err) {
pr_err("Failed to reset platform: %d\n", err);
sdei_mark_interface_broken();
}
return err;
}
static int sdei_api_event_enable(u32 event_num)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_ENABLE, event_num, 0, 0, 0,
0, NULL);
}
/* Called directly by the hotplug callbacks */
static void _local_event_enable(void *data)
{
int err;
struct sdei_crosscall_args *arg = data;
err = sdei_api_event_enable(arg->event->event_num);
sdei_cross_call_return(arg, err);
}
int sdei_event_enable(u32 event_num)
{
int err = -EINVAL;
struct sdei_event *event;
mutex_lock(&sdei_events_lock);
event = sdei_event_find(event_num);
if (!event) {
mutex_unlock(&sdei_events_lock);
return -ENOENT;
}
cpus_read_lock();
if (event->type == SDEI_EVENT_TYPE_SHARED)
err = sdei_api_event_enable(event->event_num);
else
err = sdei_do_cross_call(_local_event_enable, event);
if (!err) {
spin_lock(&sdei_list_lock);
event->reenable = true;
spin_unlock(&sdei_list_lock);
}
cpus_read_unlock();
mutex_unlock(&sdei_events_lock);
return err;
}
static int sdei_api_event_disable(u32 event_num)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, event_num, 0, 0,
0, 0, NULL);
}
static void _ipi_event_disable(void *data)
{
int err;
struct sdei_crosscall_args *arg = data;
err = sdei_api_event_disable(arg->event->event_num);
sdei_cross_call_return(arg, err);
}
int sdei_event_disable(u32 event_num)
{
int err = -EINVAL;
struct sdei_event *event;
mutex_lock(&sdei_events_lock);
event = sdei_event_find(event_num);
if (!event) {
mutex_unlock(&sdei_events_lock);
return -ENOENT;
}
spin_lock(&sdei_list_lock);
event->reenable = false;
spin_unlock(&sdei_list_lock);
if (event->type == SDEI_EVENT_TYPE_SHARED)
err = sdei_api_event_disable(event->event_num);
else
err = sdei_do_cross_call(_ipi_event_disable, event);
mutex_unlock(&sdei_events_lock);
return err;
}
static int sdei_api_event_unregister(u32 event_num)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_UNREGISTER, event_num, 0,
0, 0, 0, NULL);
}
/* Called directly by the hotplug callbacks */
static void _local_event_unregister(void *data)
{
int err;
struct sdei_crosscall_args *arg = data;
err = sdei_api_event_unregister(arg->event->event_num);
sdei_cross_call_return(arg, err);
}
int sdei_event_unregister(u32 event_num)
{
int err;
struct sdei_event *event;
WARN_ON(in_nmi());
mutex_lock(&sdei_events_lock);
event = sdei_event_find(event_num);
if (!event) {
pr_warn("Event %u not registered\n", event_num);
err = -ENOENT;
goto unlock;
}
spin_lock(&sdei_list_lock);
event->reregister = false;
event->reenable = false;
spin_unlock(&sdei_list_lock);
if (event->type == SDEI_EVENT_TYPE_SHARED)
err = sdei_api_event_unregister(event->event_num);
else
err = sdei_do_cross_call(_local_event_unregister, event);
if (err)
goto unlock;
sdei_event_destroy(event);
unlock:
mutex_unlock(&sdei_events_lock);
return err;
}
/*
* unregister events, but don't destroy them as they are re-registered by
* sdei_reregister_shared().
*/
static int sdei_unregister_shared(void)
{
int err = 0;
struct sdei_event *event;
mutex_lock(&sdei_events_lock);
spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type != SDEI_EVENT_TYPE_SHARED)
continue;
err = sdei_api_event_unregister(event->event_num);
if (err)
break;
}
spin_unlock(&sdei_list_lock);
mutex_unlock(&sdei_events_lock);
return err;
}
static int sdei_api_event_register(u32 event_num, unsigned long entry_point,
void *arg, u64 flags, u64 affinity)
{
return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_REGISTER, event_num,
(unsigned long)entry_point, (unsigned long)arg,
flags, affinity, NULL);
}
/* Called directly by the hotplug callbacks */
static void _local_event_register(void *data)
{
int err;
struct sdei_registered_event *reg;
struct sdei_crosscall_args *arg = data;
reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id());
err = sdei_api_event_register(arg->event->event_num, sdei_entry_point,
reg, 0, 0);
sdei_cross_call_return(arg, err);
}
int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
{
int err;
struct sdei_event *event;
WARN_ON(in_nmi());
mutex_lock(&sdei_events_lock);
if (sdei_event_find(event_num)) {
pr_warn("Event %u already registered\n", event_num);
err = -EBUSY;
goto unlock;
}
event = sdei_event_create(event_num, cb, arg);
if (IS_ERR(event)) {
err = PTR_ERR(event);
pr_warn("Failed to create event %u: %d\n", event_num, err);
goto unlock;
}
cpus_read_lock();
if (event->type == SDEI_EVENT_TYPE_SHARED) {
err = sdei_api_event_register(event->event_num,
sdei_entry_point,
event->registered,
SDEI_EVENT_REGISTER_RM_ANY, 0);
} else {
err = sdei_do_cross_call(_local_event_register, event);
if (err)
sdei_do_cross_call(_local_event_unregister, event);
}
if (err) {
sdei_event_destroy(event);
pr_warn("Failed to register event %u: %d\n", event_num, err);
goto cpu_unlock;
}
spin_lock(&sdei_list_lock);
event->reregister = true;
spin_unlock(&sdei_list_lock);
cpu_unlock:
cpus_read_unlock();
unlock:
mutex_unlock(&sdei_events_lock);
return err;
}
static int sdei_reregister_shared(void)
{
int err = 0;
struct sdei_event *event;
mutex_lock(&sdei_events_lock);
spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type != SDEI_EVENT_TYPE_SHARED)
continue;
if (event->reregister) {
err = sdei_api_event_register(event->event_num,
sdei_entry_point, event->registered,
SDEI_EVENT_REGISTER_RM_ANY, 0);
if (err) {
pr_err("Failed to re-register event %u\n",
event->event_num);
sdei_event_destroy_llocked(event);
break;
}
}
if (event->reenable) {
err = sdei_api_event_enable(event->event_num);
if (err) {
pr_err("Failed to re-enable event %u\n",
event->event_num);
break;
}
}
}
spin_unlock(&sdei_list_lock);
mutex_unlock(&sdei_events_lock);
return err;
}
static int sdei_cpuhp_down(unsigned int cpu)
{
struct sdei_event *event;
int err;
/* un-register private events */
spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type == SDEI_EVENT_TYPE_SHARED)
continue;
err = sdei_do_local_call(_local_event_unregister, event);
if (err) {
pr_err("Failed to unregister event %u: %d\n",
event->event_num, err);
}
}
spin_unlock(&sdei_list_lock);
return sdei_mask_local_cpu();
}
static int sdei_cpuhp_up(unsigned int cpu)
{
struct sdei_event *event;
int err;
/* re-register/enable private events */
spin_lock(&sdei_list_lock);
list_for_each_entry(event, &sdei_list, list) {
if (event->type == SDEI_EVENT_TYPE_SHARED)
continue;
if (event->reregister) {
err = sdei_do_local_call(_local_event_register, event);
if (err) {
pr_err("Failed to re-register event %u: %d\n",
event->event_num, err);
}
}
if (event->reenable) {
err = sdei_do_local_call(_local_event_enable, event);
if (err) {
pr_err("Failed to re-enable event %u: %d\n",
event->event_num, err);
}
}
}
spin_unlock(&sdei_list_lock);
return sdei_unmask_local_cpu();
}
/* When entering idle, mask/unmask events for this cpu */
static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action,
void *data)
{
int rv;
WARN_ON_ONCE(preemptible());
switch (action) {
case CPU_PM_ENTER:
rv = sdei_mask_local_cpu();
break;
case CPU_PM_EXIT:
case CPU_PM_ENTER_FAILED:
rv = sdei_unmask_local_cpu();
break;
default:
return NOTIFY_DONE;
}
if (rv)
return notifier_from_errno(rv);
return NOTIFY_OK;
}
static struct notifier_block sdei_pm_nb = {
.notifier_call = sdei_pm_notifier,
};
static int sdei_device_suspend(struct device *dev)
{
on_each_cpu(_ipi_mask_cpu, NULL, true);
return 0;
}
static int sdei_device_resume(struct device *dev)
{
on_each_cpu(_ipi_unmask_cpu, NULL, true);
return 0;
}
/*
* We need all events to be reregistered when we resume from hibernate.
*
* The sequence is freeze->thaw. Reboot. freeze->restore. We unregister
* events during freeze, then re-register and re-enable them during thaw
* and restore.
*/
static int sdei_device_freeze(struct device *dev)
{
int err;
/* unregister private events */
cpuhp_remove_state(sdei_entry_point);
err = sdei_unregister_shared();
if (err)
return err;
return 0;
}
static int sdei_device_thaw(struct device *dev)
{
int err;
/* re-register shared events */
err = sdei_reregister_shared();
if (err) {
pr_warn("Failed to re-register shared events...\n");
sdei_mark_interface_broken();
return err;
}
err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SDEI",
&sdei_cpuhp_up, &sdei_cpuhp_down);
if (err < 0) {
pr_warn("Failed to re-register CPU hotplug notifier...\n");
return err;
}
sdei_hp_state = err;
return 0;
}
static int sdei_device_restore(struct device *dev)
{
int err;
err = sdei_platform_reset();
if (err)
return err;
return sdei_device_thaw(dev);
}
static const struct dev_pm_ops sdei_pm_ops = {
.suspend = sdei_device_suspend,
.resume = sdei_device_resume,
.freeze = sdei_device_freeze,
.thaw = sdei_device_thaw,
.restore = sdei_device_restore,
};
/*
* Mask all CPUs and unregister all events on panic, reboot or kexec.
*/
static int sdei_reboot_notifier(struct notifier_block *nb, unsigned long action,
void *data)
{
/*
* We are going to reset the interface, after this there is no point
* doing work when we take CPUs offline.
*/
cpuhp_remove_state(sdei_hp_state);
sdei_platform_reset();
return NOTIFY_OK;
}
static struct notifier_block sdei_reboot_nb = {
.notifier_call = sdei_reboot_notifier,
};
static void sdei_smccc_smc(unsigned long function_id,
unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3,
unsigned long arg4, struct arm_smccc_res *res)
{
arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
}
NOKPROBE_SYMBOL(sdei_smccc_smc);
static void sdei_smccc_hvc(unsigned long function_id,
unsigned long arg0, unsigned long arg1,
unsigned long arg2, unsigned long arg3,
unsigned long arg4, struct arm_smccc_res *res)
{
arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
}
NOKPROBE_SYMBOL(sdei_smccc_hvc);
int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
sdei_event_callback *critical_cb)
{
int err;
u64 result;
u32 event_num;
sdei_event_callback *cb;
if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
return -EOPNOTSUPP;
event_num = ghes->generic->notify.vector;
if (event_num == 0) {
/*
* Event 0 is reserved by the specification for
* SDEI_EVENT_SIGNAL.
*/
return -EINVAL;
}
err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
&result);
if (err)
return err;
if (result == SDEI_EVENT_PRIORITY_CRITICAL)
cb = critical_cb;
else
cb = normal_cb;
err = sdei_event_register(event_num, cb, ghes);
if (!err)
err = sdei_event_enable(event_num);
return err;
}
int sdei_unregister_ghes(struct ghes *ghes)
{
int i;
int err;
u32 event_num = ghes->generic->notify.vector;
might_sleep();
if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
return -EOPNOTSUPP;
/*
* The event may be running on another CPU. Disable it
* to stop new events, then try to unregister a few times.
*/
err = sdei_event_disable(event_num);
if (err)
return err;
for (i = 0; i < 3; i++) {
err = sdei_event_unregister(event_num);
if (err != -EINPROGRESS)
break;
schedule();
}
return err;
}
static int sdei_get_conduit(struct platform_device *pdev)
{
const char *method;
struct device_node *np = pdev->dev.of_node;
sdei_firmware_call = NULL;
if (np) {
if (of_property_read_string(np, "method", &method)) {
pr_warn("missing \"method\" property\n");
return SMCCC_CONDUIT_NONE;
}
if (!strcmp("hvc", method)) {
sdei_firmware_call = &sdei_smccc_hvc;
return SMCCC_CONDUIT_HVC;
} else if (!strcmp("smc", method)) {
sdei_firmware_call = &sdei_smccc_smc;
return SMCCC_CONDUIT_SMC;
}
pr_warn("invalid \"method\" property: %s\n", method);
} else if (!acpi_disabled) {
if (acpi_psci_use_hvc()) {
sdei_firmware_call = &sdei_smccc_hvc;
return SMCCC_CONDUIT_HVC;
} else {
sdei_firmware_call = &sdei_smccc_smc;
return SMCCC_CONDUIT_SMC;
}
}
return SMCCC_CONDUIT_NONE;
}
static int sdei_probe(struct platform_device *pdev)
{
int err;
u64 ver = 0;
int conduit;
conduit = sdei_get_conduit(pdev);
if (!sdei_firmware_call)
return 0;
err = sdei_api_get_version(&ver);
if (err) {
pr_err("Failed to get SDEI version: %d\n", err);
sdei_mark_interface_broken();
return err;
}
pr_info("SDEIv%d.%d (0x%x) detected in firmware.\n",
(int)SDEI_VERSION_MAJOR(ver), (int)SDEI_VERSION_MINOR(ver),
(int)SDEI_VERSION_VENDOR(ver));
if (SDEI_VERSION_MAJOR(ver) != 1) {
pr_warn("Conflicting SDEI version detected.\n");
sdei_mark_interface_broken();
return -EINVAL;
}
err = sdei_platform_reset();
if (err)
return err;
sdei_entry_point = sdei_arch_get_entry_point(conduit);
if (!sdei_entry_point) {
/* Not supported due to hardware or boot configuration */
sdei_mark_interface_broken();
return 0;
}
err = cpu_pm_register_notifier(&sdei_pm_nb);
if (err) {
pr_warn("Failed to register CPU PM notifier...\n");
goto error;
}
err = register_reboot_notifier(&sdei_reboot_nb);
if (err) {
pr_warn("Failed to register reboot notifier...\n");
goto remove_cpupm;
}
err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SDEI",
&sdei_cpuhp_up, &sdei_cpuhp_down);
if (err < 0) {
pr_warn("Failed to register CPU hotplug notifier...\n");
goto remove_reboot;
}
sdei_hp_state = err;
return 0;
remove_reboot:
unregister_reboot_notifier(&sdei_reboot_nb);
remove_cpupm:
cpu_pm_unregister_notifier(&sdei_pm_nb);
error:
sdei_mark_interface_broken();
return err;
}
static const struct of_device_id sdei_of_match[] = {
{ .compatible = "arm,sdei-1.0" },
{}
};
static struct platform_driver sdei_driver = {
.driver = {
.name = "sdei",
.pm = &sdei_pm_ops,
.of_match_table = sdei_of_match,
},
.probe = sdei_probe,
};
static bool __init sdei_present_acpi(void)
{
acpi_status status;
struct acpi_table_header *sdei_table_header;
if (acpi_disabled)
return false;
status = acpi_get_table(ACPI_SIG_SDEI, 0, &sdei_table_header);
if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
const char *msg = acpi_format_exception(status);
pr_info("Failed to get ACPI:SDEI table, %s\n", msg);
}
if (ACPI_FAILURE(status))
return false;
acpi_put_table(sdei_table_header);
return true;
}
void __init sdei_init(void)
{
struct platform_device *pdev;
int ret;
ret = platform_driver_register(&sdei_driver);
if (ret || !sdei_present_acpi())
return;
pdev = platform_device_register_simple(sdei_driver.driver.name,
0, NULL, 0);
if (IS_ERR(pdev)) {
ret = PTR_ERR(pdev);
platform_driver_unregister(&sdei_driver);
pr_info("Failed to register ACPI:SDEI platform device %d\n",
ret);
}
}
int sdei_event_handler(struct pt_regs *regs,
struct sdei_registered_event *arg)
{
int err;
u32 event_num = arg->event_num;
err = arg->callback(event_num, regs, arg->callback_arg);
if (err)
pr_err_ratelimited("event %u on CPU %u failed with error: %d\n",
event_num, smp_processor_id(), err);
return err;
}
NOKPROBE_SYMBOL(sdei_event_handler);
void sdei_handler_abort(void)
{
/*
* If the crash happened in an SDEI event handler then we need to
* finish the handler with the firmware so that we can have working
* interrupts in the crash kernel.
*/
if (__this_cpu_read(sdei_active_critical_event)) {
pr_warn("still in SDEI critical event context, attempting to finish handler.\n");
__sdei_handler_abort();
__this_cpu_write(sdei_active_critical_event, NULL);
}
if (__this_cpu_read(sdei_active_normal_event)) {
pr_warn("still in SDEI normal event context, attempting to finish handler.\n");
__sdei_handler_abort();
__this_cpu_write(sdei_active_normal_event, NULL);
}
}
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