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Merge branch 'pm-sysoff'

Browse Source 
Merge system power off handling rework from Dmitry Osipenko for
5.19-rc1.

This introduces a mechanism allowing power sequences to be used for
powering off the system and makes related changes in platform-specific
code for multiple platforms.

* pm-sysoff: (29 commits)
  kernel/reboot: Change registration order of legacy power-off handler
  m68k: virt: Switch to new sys-off handler API
  kernel/reboot: Add devm_register_restart_handler()
  kernel/reboot: Add devm_register_power_off_handler()
  soc/tegra: pmc: Use sys-off handler API to power off Nexus 7 properly
  reboot: Remove pm_power_off_prepare()
  regulator: pfuze100: Use devm_register_sys_off_handler()
  ACPI: power: Switch to sys-off handler API
  memory: emif: Use kernel_can_power_off()
  mips: Use do_kernel_power_off()
  ia64: Use do_kernel_power_off()
  x86: Use do_kernel_power_off()
  sh: Use do_kernel_power_off()
  m68k: Switch to new sys-off handler API
  powerpc: Use do_kernel_power_off()
  xen/x86: Use do_kernel_power_off()
  parisc: Use do_kernel_power_off()
  arm64: Use do_kernel_power_off()
  riscv: Use do_kernel_power_off()
  csky: Use do_kernel_power_off()
  ...
This commit is contained in:
Rafael J. Wysocki 2022-05-30 15:41:11 +02:00
commit 9f9c1f6844
28 changed files with 644 additions and 126 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/arm/kernel/reboot.c
View File

@ -116,9 +116,7 @@ void machine_power_off(void)
{
local_irq_disable();
smp_send_stop();
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
}
/*

3
arch/arm64/kernel/process.c
View File

@ -111,8 +111,7 @@ void machine_power_off(void)
{
local_irq_disable();
smp_send_stop();
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
}
/*

6
arch/csky/kernel/power.c
View File

@ -9,16 +9,14 @@ EXPORT_SYMBOL(pm_power_off);
void machine_power_off(void)
{
local_irq_disable();
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
asm volatile ("bkpt");
}
void machine_halt(void)
{
local_irq_disable();
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
asm volatile ("bkpt");
}

4
arch/ia64/kernel/process.c
View File

@ -19,6 +19,7 @@
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/personality.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/hotplug.h>
@ -599,8 +600,7 @@ machine_halt (void)
void
machine_power_off (void)
{
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
machine_halt();
}

3
arch/m68k/emu/natfeat.c
View File

@ -15,6 +15,7 @@
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/io.h>
#include <asm/machdep.h>
#include <asm/natfeat.h>
@ -90,5 +91,5 @@ void __init nf_init(void)
pr_info("NatFeats found (%s, %lu.%lu)\n", buf, version >> 16,
version & 0xffff);
mach_power_off = nf_poweroff;
register_platform_power_off(nf_poweroff);
}

1
arch/m68k/include/asm/machdep.h
View File

@ -24,7 +24,6 @@ extern int (*mach_get_rtc_pll)(struct rtc_pll_info *);
extern int (*mach_set_rtc_pll)(struct rtc_pll_info *);
extern void (*mach_reset)( void );
extern void (*mach_halt)( void );
extern void (*mach_power_off)( void );
extern unsigned long (*mach_hd_init) (unsigned long, unsigned long);
extern void (*mach_hd_setup)(char *, int *);
extern void (*mach_heartbeat) (int);

5
arch/m68k/kernel/process.c
View File

@ -67,12 +67,11 @@ void machine_halt(void)
void machine_power_off(void)
{
if (mach_power_off)
mach_power_off();
do_kernel_power_off();
for (;;);
}
void (*pm_power_off)(void) = machine_power_off;
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
void show_regs(struct pt_regs * regs)

1
arch/m68k/kernel/setup_mm.c
View File

@ -98,7 +98,6 @@ EXPORT_SYMBOL(mach_get_rtc_pll);
EXPORT_SYMBOL(mach_set_rtc_pll);
void (*mach_reset)( void );
void (*mach_halt)( void );
void (*mach_power_off)( void );
#ifdef CONFIG_HEARTBEAT
void (*mach_heartbeat) (int);
EXPORT_SYMBOL(mach_heartbeat);

1
arch/m68k/kernel/setup_no.c
View File

@ -55,7 +55,6 @@ int (*mach_hwclk) (int, struct rtc_time*);
/* machine dependent reboot functions */
void (*mach_reset)(void);
void (*mach_halt)(void);
void (*mach_power_off)(void);
#ifdef CONFIG_M68000
#if defined(CONFIG_M68328)

4
arch/m68k/mac/config.c
View File

@ -12,6 +12,7 @@
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/tty.h>
@ -140,7 +141,6 @@ void __init config_mac(void)
mach_hwclk = mac_hwclk;
mach_reset = mac_reset;
mach_halt = mac_poweroff;
mach_power_off = mac_poweroff;
#if IS_ENABLED(CONFIG_INPUT_M68K_BEEP)
mach_beep = mac_mksound;
#endif
@ -160,6 +160,8 @@ void __init config_mac(void)
if (macintosh_config->ident == MAC_MODEL_IICI)
mach_l2_flush = via_l2_flush;
register_platform_power_off(mac_poweroff);
}

4
arch/m68k/virt/config.c
View File

@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/reboot.h>
#include <linux/serial_core.h>
#include <clocksource/timer-goldfish.h>
@ -126,5 +127,6 @@ void __init config_virt(void)
mach_get_model = virt_get_model;
mach_reset = virt_reset;
mach_halt = virt_halt;
mach_power_off = virt_halt;
register_platform_power_off(virt_halt);
}

3
arch/mips/kernel/reset.c
View File

@ -114,8 +114,7 @@ void machine_halt(void)
void machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
#ifdef CONFIG_SMP
preempt_disable();

4
arch/parisc/kernel/process.c
View File

@ -26,6 +26,7 @@
#include <linux/module.h>
#include <linux/personality.h>
#include <linux/ptrace.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
@ -116,8 +117,7 @@ void machine_power_off(void)
pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN);
/* ipmi_poweroff may have been installed. */
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
/* It seems we have no way to power the system off via
* software. The user has to press the button himself. */

4
arch/powerpc/kernel/setup-common.c
View File

@ -161,9 +161,7 @@ void machine_restart(char *cmd)
void machine_power_off(void)
{
machine_shutdown();
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
smp_send_stop();
machine_hang();
}

3
arch/powerpc/xmon/xmon.c
View File

@ -1243,8 +1243,7 @@ static void bootcmds(void)
} else if (cmd == 'h') {
ppc_md.halt();
} else if (cmd == 'p') {
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
}
}

12
arch/riscv/kernel/reset.c
View File

@ -23,16 +23,12 @@ void machine_restart(char *cmd)
void machine_halt(void)
{
if (pm_power_off != NULL)
pm_power_off();
else
default_power_off();
do_kernel_power_off();
default_power_off();
}
void machine_power_off(void)
{
if (pm_power_off != NULL)
pm_power_off();
else
default_power_off();
do_kernel_power_off();
default_power_off();
}

3
arch/sh/kernel/reboot.c
View File

@ -46,8 +46,7 @@ static void native_machine_shutdown(void)
static void native_machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
}
static void native_machine_halt(void)

4
arch/x86/kernel/reboot.c
View File

@ -739,10 +739,10 @@ static void native_machine_halt(void)
static void native_machine_power_off(void)
{
if (pm_power_off) {
if (kernel_can_power_off()) {
if (!reboot_force)
machine_shutdown();
pm_power_off();
do_kernel_power_off();
}
/* A fallback in case there is no PM info available */
tboot_shutdown(TB_SHUTDOWN_HALT);

4
arch/x86/xen/enlighten_pv.c
View File

@ -30,6 +30,7 @@
#include <linux/pci.h>
#include <linux/gfp.h>
#include <linux/edd.h>
#include <linux/reboot.h>
#include <xen/xen.h>
#include <xen/events.h>
@ -1069,8 +1070,7 @@ static void xen_machine_halt(void)
static void xen_machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
do_kernel_power_off();
xen_reboot(SHUTDOWN_poweroff);
}

16
drivers/acpi/sleep.c
View File

@ -1035,20 +1035,22 @@ static void acpi_sleep_hibernate_setup(void)
static inline void acpi_sleep_hibernate_setup(void) {}
#endif /* !CONFIG_HIBERNATION */
static void acpi_power_off_prepare(void)
static int acpi_power_off_prepare(struct sys_off_data *data)
{
/* Prepare to power off the system */
acpi_sleep_prepare(ACPI_STATE_S5);
acpi_disable_all_gpes();
acpi_os_wait_events_complete();
return NOTIFY_DONE;
}
static void acpi_power_off(void)
static int acpi_power_off(struct sys_off_data *data)
{
/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
pr_debug("%s called\n", __func__);
local_irq_disable();
acpi_enter_sleep_state(ACPI_STATE_S5);
return NOTIFY_DONE;
}
int __init acpi_sleep_init(void)
@ -1067,8 +1069,14 @@ int __init acpi_sleep_init(void)
if (acpi_sleep_state_supported(ACPI_STATE_S5)) {
sleep_states[ACPI_STATE_S5] = 1;
pm_power_off_prepare = acpi_power_off_prepare;
pm_power_off = acpi_power_off;
register_sys_off_handler(SYS_OFF_MODE_POWER_OFF_PREPARE,
SYS_OFF_PRIO_FIRMWARE,
acpi_power_off_prepare, NULL);
register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
SYS_OFF_PRIO_FIRMWARE,
acpi_power_off, NULL);
} else {
acpi_no_s5 = true;
}

2
drivers/memory/emif.c
View File

@ -630,7 +630,7 @@ static irqreturn_t emif_threaded_isr(int irq, void *dev_id)
dev_emerg(emif->dev, "SDRAM temperature exceeds operating limit.. Needs shut down!!!\n");
/* If we have Power OFF ability, use it, else try restarting */
if (pm_power_off) {
if (kernel_can_power_off()) {
kernel_power_off();
} else {
WARN(1, "FIXME: NO pm_power_off!!! trying restart\n");

42
drivers/regulator/pfuze100-regulator.c
View File

@ -10,6 +10,7 @@
#include <linux/of_device.h>
#include <linux/regulator/of_regulator.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/pfuze100.h>
@ -571,10 +572,10 @@ static inline struct device_node *match_of_node(int index)
return pfuze_matches[index].of_node;
}
static struct pfuze_chip *syspm_pfuze_chip;
static void pfuze_power_off_prepare(void)
static int pfuze_power_off_prepare(struct sys_off_data *data)
{
struct pfuze_chip *syspm_pfuze_chip = data->cb_data;
dev_info(syspm_pfuze_chip->dev, "Configure standby mode for power off");
/* Switch from default mode: APS/APS to APS/Off */
@ -609,28 +610,30 @@ static void pfuze_power_off_prepare(void)
regmap_update_bits(syspm_pfuze_chip->regmap, PFUZE100_VGEN6VOL,
PFUZE100_VGENxLPWR | PFUZE100_VGENxSTBY,
PFUZE100_VGENxSTBY);
return NOTIFY_DONE;
}
static int pfuze_power_off_prepare_init(struct pfuze_chip *pfuze_chip)
{
int err;
if (pfuze_chip->chip_id != PFUZE100) {
dev_warn(pfuze_chip->dev, "Requested pm_power_off_prepare handler for not supported chip\n");
return -ENODEV;
}
if (pm_power_off_prepare) {
dev_warn(pfuze_chip->dev, "pm_power_off_prepare is already registered.\n");
return -EBUSY;
err = devm_register_sys_off_handler(pfuze_chip->dev,
SYS_OFF_MODE_POWER_OFF_PREPARE,
SYS_OFF_PRIO_DEFAULT,
pfuze_power_off_prepare,
pfuze_chip);
if (err) {
dev_err(pfuze_chip->dev, "failed to register sys-off handler: %d\n",
err);
return err;
}
if (syspm_pfuze_chip) {
dev_warn(pfuze_chip->dev, "syspm_pfuze_chip is already set.\n");
return -EBUSY;
}
syspm_pfuze_chip = pfuze_chip;
pm_power_off_prepare = pfuze_power_off_prepare;
return 0;
}
@ -839,23 +842,12 @@ static int pfuze100_regulator_probe(struct i2c_client *client,
return 0;
}
static int pfuze100_regulator_remove(struct i2c_client *client)
{
if (syspm_pfuze_chip) {
syspm_pfuze_chip = NULL;
pm_power_off_prepare = NULL;
}
return 0;
}
static struct i2c_driver pfuze_driver = {
.driver = {
.name = "pfuze100-regulator",
.of_match_table = pfuze_dt_ids,
},
.probe = pfuze100_regulator_probe,
.remove = pfuze100_regulator_remove,
};
module_i2c_driver(pfuze_driver);

87
drivers/soc/tegra/pmc.c
View File

@ -39,6 +39,7 @@
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_opp.h>
#include <linux/power_supply.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/reset.h>
@ -108,6 +109,7 @@
#define PMC_USB_DEBOUNCE_DEL 0xec
#define PMC_USB_AO 0xf0
#define PMC_SCRATCH37 0x130
#define PMC_SCRATCH41 0x140
#define PMC_WAKE2_MASK 0x160
@ -1099,8 +1101,7 @@ static struct notifier_block tegra_pmc_reboot_notifier = {
.notifier_call = tegra_pmc_reboot_notify,
};
static int tegra_pmc_restart_notify(struct notifier_block *this,
unsigned long action, void *data)
static void tegra_pmc_restart(void)
{
u32 value;
@ -1108,14 +1109,31 @@ static int tegra_pmc_restart_notify(struct notifier_block *this,
value = tegra_pmc_readl(pmc, PMC_CNTRL);
value |= PMC_CNTRL_MAIN_RST;
tegra_pmc_writel(pmc, value, PMC_CNTRL);
}
static int tegra_pmc_restart_handler(struct sys_off_data *data)
{
tegra_pmc_restart();
return NOTIFY_DONE;
}
static struct notifier_block tegra_pmc_restart_handler = {
.notifier_call = tegra_pmc_restart_notify,
.priority = 128,
};
static int tegra_pmc_power_off_handler(struct sys_off_data *data)
{
/*
* Reboot Nexus 7 into special bootloader mode if USB cable is
* connected in order to display battery status and power off.
*/
if (of_machine_is_compatible("asus,grouper") &&
power_supply_is_system_supplied()) {
const u32 go_to_charger_mode = 0xa5a55a5a;
tegra_pmc_writel(pmc, go_to_charger_mode, PMC_SCRATCH37);
tegra_pmc_restart();
}
return NOTIFY_DONE;
}
static int powergate_show(struct seq_file *s, void *data)
{
@ -2877,6 +2895,42 @@ static int tegra_pmc_probe(struct platform_device *pdev)
pmc->clk = NULL;
}
/*
* PMC should be last resort for restarting since it soft-resets
* CPU without resetting everything else.
*/
err = devm_register_reboot_notifier(&pdev->dev,
&tegra_pmc_reboot_notifier);
if (err) {
dev_err(&pdev->dev, "unable to register reboot notifier, %d\n",
err);
return err;
}
err = devm_register_sys_off_handler(&pdev->dev,
SYS_OFF_MODE_RESTART,
SYS_OFF_PRIO_LOW,
tegra_pmc_restart_handler, NULL);
if (err) {
dev_err(&pdev->dev, "failed to register sys-off handler: %d\n",
err);
return err;
}
/*
* PMC should be primary power-off method if it soft-resets CPU,
* asking bootloader to shutdown hardware.
*/
err = devm_register_sys_off_handler(&pdev->dev,
SYS_OFF_MODE_POWER_OFF,
SYS_OFF_PRIO_FIRMWARE,
tegra_pmc_power_off_handler, NULL);
if (err) {
dev_err(&pdev->dev, "failed to register sys-off handler: %d\n",
err);
return err;
}
/*
* PCLK clock rate can't be retrieved using CLK API because it
* causes lockup if CPU enters LP2 idle state from some other
@ -2908,28 +2962,13 @@ static int tegra_pmc_probe(struct platform_device *pdev)
goto cleanup_sysfs;
}
err = devm_register_reboot_notifier(&pdev->dev,
&tegra_pmc_reboot_notifier);
if (err) {
dev_err(&pdev->dev, "unable to register reboot notifier, %d\n",
err);
goto cleanup_debugfs;
}
err = register_restart_handler(&tegra_pmc_restart_handler);
if (err) {
dev_err(&pdev->dev, "unable to register restart handler, %d\n",
err);
goto cleanup_debugfs;
}
err = tegra_pmc_pinctrl_init(pmc);
if (err)
goto cleanup_restart_handler;
goto cleanup_debugfs;
err = tegra_pmc_regmap_init(pmc);
if (err < 0)
goto cleanup_restart_handler;
goto cleanup_debugfs;
err = tegra_powergate_init(pmc, pdev->dev.of_node);
if (err < 0)
@ -2952,8 +2991,6 @@ static int tegra_pmc_probe(struct platform_device *pdev)
cleanup_powergates:
tegra_powergate_remove_all(pdev->dev.of_node);
cleanup_restart_handler:
unregister_restart_handler(&tegra_pmc_restart_handler);
cleanup_debugfs:
debugfs_remove(pmc->debugfs);
cleanup_sysfs:

7
include/linux/notifier.h
View File

@ -150,6 +150,11 @@ extern int raw_notifier_chain_register(struct raw_notifier_head *nh,
extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
struct notifier_block *nb);
extern int atomic_notifier_chain_register_unique_prio(
struct atomic_notifier_head *nh, struct notifier_block *nb);
extern int blocking_notifier_chain_register_unique_prio(
struct blocking_notifier_head *nh, struct notifier_block *nb);
extern int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
struct notifier_block *nb);
extern int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
@ -173,6 +178,8 @@ extern int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh
extern int raw_notifier_call_chain_robust(struct raw_notifier_head *nh,
unsigned long val_up, unsigned long val_down, void *v);
extern bool atomic_notifier_call_chain_is_empty(struct atomic_notifier_head *nh);
#define NOTIFY_DONE 0x0000 /* Don't care */
#define NOTIFY_OK 0x0001 /* Suits me */
#define NOTIFY_STOP_MASK 0x8000 /* Don't call further */

1
include/linux/pm.h
View File

@ -21,7 +21,6 @@
* Callbacks for platform drivers to implement.
*/
extern void (*pm_power_off)(void);
extern void (*pm_power_off_prepare)(void);
struct device; /* we have a circular dep with device.h */
#ifdef CONFIG_VT_CONSOLE_SLEEP

91
include/linux/reboot.h
View File

@ -7,6 +7,7 @@
#include <uapi/linux/reboot.h>
struct device;
struct sys_off_handler;
#define SYS_DOWN 0x0001 /* Notify of system down */
#define SYS_RESTART SYS_DOWN
@ -62,6 +63,95 @@ extern void machine_shutdown(void);
struct pt_regs;
extern void machine_crash_shutdown(struct pt_regs *);
void do_kernel_power_off(void);
/*
* sys-off handler API.
*/
/*
* Standard sys-off priority levels. Users are expected to set priorities
* relative to the standard levels.
*
* SYS_OFF_PRIO_PLATFORM: Use this for platform-level handlers.
*
* SYS_OFF_PRIO_LOW: Use this for handler of last resort.
*
* SYS_OFF_PRIO_DEFAULT: Use this for normal handlers.
*
* SYS_OFF_PRIO_HIGH: Use this for higher priority handlers.
*
* SYS_OFF_PRIO_FIRMWARE: Use this if handler uses firmware call.
*/
#define SYS_OFF_PRIO_PLATFORM -256
#define SYS_OFF_PRIO_LOW -128
#define SYS_OFF_PRIO_DEFAULT 0
#define SYS_OFF_PRIO_HIGH 192
#define SYS_OFF_PRIO_FIRMWARE 224
enum sys_off_mode {
/**
* @SYS_OFF_MODE_POWER_OFF_PREPARE:
*
* Handlers prepare system to be powered off. Handlers are
* allowed to sleep.
*/
SYS_OFF_MODE_POWER_OFF_PREPARE,
/**
* @SYS_OFF_MODE_POWER_OFF:
*
* Handlers power-off system. Handlers are disallowed to sleep.
*/
SYS_OFF_MODE_POWER_OFF,
/**
* @SYS_OFF_MODE_RESTART:
*
* Handlers restart system. Handlers are disallowed to sleep.
*/
SYS_OFF_MODE_RESTART,
};
/**
* struct sys_off_data - sys-off callback argument
*
* @mode: Mode ID. Currently used only by the sys-off restart mode,
* see enum reboot_mode for the available modes.
* @cb_data: User's callback data.
* @cmd: Command string. Currently used only by the sys-off restart mode,
* NULL otherwise.
*/
struct sys_off_data {
int mode;
void *cb_data;
const char *cmd;
};
struct sys_off_handler *
register_sys_off_handler(enum sys_off_mode mode,
int priority,
int (*callback)(struct sys_off_data *data),
void *cb_data);
void unregister_sys_off_handler(struct sys_off_handler *handler);
int devm_register_sys_off_handler(struct device *dev,
enum sys_off_mode mode,
int priority,
int (*callback)(struct sys_off_data *data),
void *cb_data);
int devm_register_power_off_handler(struct device *dev,
int (*callback)(struct sys_off_data *data),
void *cb_data);
int devm_register_restart_handler(struct device *dev,
int (*callback)(struct sys_off_data *data),
void *cb_data);
int register_platform_power_off(void (*power_off)(void));
void unregister_platform_power_off(void (*power_off)(void));
/*
* Architecture independent implemenations of sys_reboot commands.
*/
@ -70,6 +160,7 @@ extern void kernel_restart_prepare(char *cmd);
extern void kernel_restart(char *cmd);
extern void kernel_halt(void);
extern void kernel_power_off(void);
extern bool kernel_can_power_off(void);
extern int C_A_D; /* for sysctl */
void ctrl_alt_del(void);

101
kernel/notifier.c
View File

@ -20,7 +20,8 @@ BLOCKING_NOTIFIER_HEAD(reboot_notifier_list);
*/
static int notifier_chain_register(struct notifier_block **nl,
struct notifier_block *n)
struct notifier_block *n,
bool unique_priority)
{
while ((*nl) != NULL) {
if (unlikely((*nl) == n)) {
@ -30,6 +31,8 @@ static int notifier_chain_register(struct notifier_block **nl,
}
if (n->priority > (*nl)->priority)
break;
if (n->priority == (*nl)->priority && unique_priority)
return -EBUSY;
nl = &((*nl)->next);
}
n->next = *nl;
@ -144,12 +147,35 @@ int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
int ret;
spin_lock_irqsave(&nh->lock, flags);
ret = notifier_chain_register(&nh->head, n);
ret = notifier_chain_register(&nh->head, n, false);
spin_unlock_irqrestore(&nh->lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(atomic_notifier_chain_register);
/**
* atomic_notifier_chain_register_unique_prio - Add notifier to an atomic notifier chain
* @nh: Pointer to head of the atomic notifier chain
* @n: New entry in notifier chain
*
* Adds a notifier to an atomic notifier chain if there is no other
* notifier registered using the same priority.
*
* Returns 0 on success, %-EEXIST or %-EBUSY on error.
*/
int atomic_notifier_chain_register_unique_prio(struct atomic_notifier_head *nh,
struct notifier_block *n)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&nh->lock, flags);
ret = notifier_chain_register(&nh->head, n, true);
spin_unlock_irqrestore(&nh->lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(atomic_notifier_chain_register_unique_prio);
/**
* atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain
* @nh: Pointer to head of the atomic notifier chain
@ -204,11 +230,44 @@ int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
NOKPROBE_SYMBOL(atomic_notifier_call_chain);
/**
* atomic_notifier_call_chain_is_empty - Check whether notifier chain is empty
* @nh: Pointer to head of the atomic notifier chain
*
* Checks whether notifier chain is empty.
*
* Returns true is notifier chain is empty, false otherwise.
*/
bool atomic_notifier_call_chain_is_empty(struct atomic_notifier_head *nh)
{
return !rcu_access_pointer(nh->head);
}
/*
* Blocking notifier chain routines. All access to the chain is
* synchronized by an rwsem.
*/
static int __blocking_notifier_chain_register(struct blocking_notifier_head *nh,
struct notifier_block *n,
bool unique_priority)
{
int ret;
/*
* This code gets used during boot-up, when task switching is
* not yet working and interrupts must remain disabled. At
* such times we must not call down_write().
*/
if (unlikely(system_state == SYSTEM_BOOTING))
return notifier_chain_register(&nh->head, n, unique_priority);
down_write(&nh->rwsem);
ret = notifier_chain_register(&nh->head, n, unique_priority);
up_write(&nh->rwsem);
return ret;
}
/**
* blocking_notifier_chain_register - Add notifier to a blocking notifier chain
* @nh: Pointer to head of the blocking notifier chain
@ -222,23 +281,27 @@ NOKPROBE_SYMBOL(atomic_notifier_call_chain);
int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
struct notifier_block *n)
{
int ret;
/*
* This code gets used during boot-up, when task switching is
* not yet working and interrupts must remain disabled. At
* such times we must not call down_write().
*/
if (unlikely(system_state == SYSTEM_BOOTING))
return notifier_chain_register(&nh->head, n);
down_write(&nh->rwsem);
ret = notifier_chain_register(&nh->head, n);
up_write(&nh->rwsem);
return ret;
return __blocking_notifier_chain_register(nh, n, false);
}
EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);
/**
* blocking_notifier_chain_register_unique_prio - Add notifier to a blocking notifier chain
* @nh: Pointer to head of the blocking notifier chain
* @n: New entry in notifier chain
*
* Adds a notifier to an blocking notifier chain if there is no other
* notifier registered using the same priority.
*
* Returns 0 on success, %-EEXIST or %-EBUSY on error.
*/
int blocking_notifier_chain_register_unique_prio(struct blocking_notifier_head *nh,
struct notifier_block *n)
{
return __blocking_notifier_chain_register(nh, n, true);
}
EXPORT_SYMBOL_GPL(blocking_notifier_chain_register_unique_prio);
/**
* blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain
* @nh: Pointer to head of the blocking notifier chain
@ -341,7 +404,7 @@ EXPORT_SYMBOL_GPL(blocking_notifier_call_chain);
int raw_notifier_chain_register(struct raw_notifier_head *nh,
struct notifier_block *n)
{
return notifier_chain_register(&nh->head, n);
return notifier_chain_register(&nh->head, n, false);
}
EXPORT_SYMBOL_GPL(raw_notifier_chain_register);
@ -420,10 +483,10 @@ int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
* such times we must not call mutex_lock().
*/
if (unlikely(system_state == SYSTEM_BOOTING))
return notifier_chain_register(&nh->head, n);
return notifier_chain_register(&nh->head, n, false);
mutex_lock(&nh->mutex);
ret = notifier_chain_register(&nh->head, n);
ret = notifier_chain_register(&nh->head, n, false);
mutex_unlock(&nh->mutex);
return ret;
}

350
kernel/reboot.c
View File

@ -48,12 +48,20 @@ int reboot_cpu;
enum reboot_type reboot_type = BOOT_ACPI;
int reboot_force;
/*
* If set, this is used for preparing the system to power off.
*/
struct sys_off_handler {
struct notifier_block nb;
int (*sys_off_cb)(struct sys_off_data *data);
void *cb_data;
enum sys_off_mode mode;
bool blocking;
void *list;
};
void (*pm_power_off_prepare)(void);
EXPORT_SYMBOL_GPL(pm_power_off_prepare);
/*
* Temporary stub that prevents linkage failure while we're in process
* of removing all uses of legacy pm_power_off() around the kernel.
*/
void __weak (*pm_power_off)(void);
/**
* emergency_restart - reboot the system
@ -281,6 +289,316 @@ void kernel_halt(void)
}
EXPORT_SYMBOL_GPL(kernel_halt);
/*
* Notifier list for kernel code which wants to be called
* to prepare system for power off.
*/
static BLOCKING_NOTIFIER_HEAD(power_off_prep_handler_list);
/*
* Notifier list for kernel code which wants to be called
* to power off system.
*/
static ATOMIC_NOTIFIER_HEAD(power_off_handler_list);
static int sys_off_notify(struct notifier_block *nb,
unsigned long mode, void *cmd)
{
struct sys_off_handler *handler;
struct sys_off_data data = {};
handler = container_of(nb, struct sys_off_handler, nb);
data.cb_data = handler->cb_data;
data.mode = mode;
data.cmd = cmd;
return handler->sys_off_cb(&data);
}
/**
* register_sys_off_handler - Register sys-off handler
* @mode: Sys-off mode
* @priority: Handler priority
* @callback: Callback function
* @cb_data: Callback argument
*
* Registers system power-off or restart handler that will be invoked
* at the step corresponding to the given sys-off mode. Handler's callback
* should return NOTIFY_DONE to permit execution of the next handler in
* the call chain or NOTIFY_STOP to break the chain (in error case for
* example).
*
* Multiple handlers can be registered at the default priority level.
*
* Only one handler can be registered at the non-default priority level,
* otherwise ERR_PTR(-EBUSY) is returned.
*
* Returns a new instance of struct sys_off_handler on success, or
* an ERR_PTR()-encoded error code otherwise.
*/
struct sys_off_handler *
register_sys_off_handler(enum sys_off_mode mode,
int priority,
int (*callback)(struct sys_off_data *data),
void *cb_data)
{
struct sys_off_handler *handler;
int err;
handler = kzalloc(sizeof(*handler), GFP_KERNEL);
if (!handler)
return ERR_PTR(-ENOMEM);
switch (mode) {
case SYS_OFF_MODE_POWER_OFF_PREPARE:
handler->list = &power_off_prep_handler_list;
handler->blocking = true;
break;
case SYS_OFF_MODE_POWER_OFF:
handler->list = &power_off_handler_list;
break;
case SYS_OFF_MODE_RESTART:
handler->list = &restart_handler_list;
break;
default:
kfree(handler);
return ERR_PTR(-EINVAL);
}
handler->nb.notifier_call = sys_off_notify;
handler->nb.priority = priority;
handler->sys_off_cb = callback;
handler->cb_data = cb_data;
handler->mode = mode;
if (handler->blocking) {
if (priority == SYS_OFF_PRIO_DEFAULT)
err = blocking_notifier_chain_register(handler->list,
&handler->nb);
else
err = blocking_notifier_chain_register_unique_prio(handler->list,
&handler->nb);
} else {
if (priority == SYS_OFF_PRIO_DEFAULT)
err = atomic_notifier_chain_register(handler->list,
&handler->nb);
else
err = atomic_notifier_chain_register_unique_prio(handler->list,
&handler->nb);
}
if (err) {
kfree(handler);
return ERR_PTR(err);
}
return handler;
}
EXPORT_SYMBOL_GPL(register_sys_off_handler);
/**
* unregister_sys_off_handler - Unregister sys-off handler
* @handler: Sys-off handler
*
* Unregisters given sys-off handler.
*/
void unregister_sys_off_handler(struct sys_off_handler *handler)
{
int err;
if (!handler)
return;
if (handler->blocking)
err = blocking_notifier_chain_unregister(handler->list,
&handler->nb);
else
err = atomic_notifier_chain_unregister(handler->list,
&handler->nb);
/* sanity check, shall never happen */
WARN_ON(err);
kfree(handler);
}
EXPORT_SYMBOL_GPL(unregister_sys_off_handler);
static void devm_unregister_sys_off_handler(void *data)
{
struct sys_off_handler *handler = data;
unregister_sys_off_handler(handler);
}
/**
* devm_register_sys_off_handler - Register sys-off handler
* @dev: Device that registers handler
* @mode: Sys-off mode
* @priority: Handler priority
* @callback: Callback function
* @cb_data: Callback argument
*
* Registers resource-managed sys-off handler.
*
* Returns zero on success, or error code on failure.
*/
int devm_register_sys_off_handler(struct device *dev,
enum sys_off_mode mode,
int priority,
int (*callback)(struct sys_off_data *data),
void *cb_data)
{
struct sys_off_handler *handler;
handler = register_sys_off_handler(mode, priority, callback, cb_data);
if (IS_ERR(handler))
return PTR_ERR(handler);
return devm_add_action_or_reset(dev, devm_unregister_sys_off_handler,
handler);
}
EXPORT_SYMBOL_GPL(devm_register_sys_off_handler);
/**
* devm_register_power_off_handler - Register power-off handler
* @dev: Device that registers callback
* @callback: Callback function
* @cb_data: Callback's argument
*
* Registers resource-managed sys-off handler with a default priority
* and using power-off mode.
*
* Returns zero on success, or error code on failure.
*/
int devm_register_power_off_handler(struct device *dev,
int (*callback)(struct sys_off_data *data),
void *cb_data)
{
return devm_register_sys_off_handler(dev,
SYS_OFF_MODE_POWER_OFF,
SYS_OFF_PRIO_DEFAULT,
callback, cb_data);
}
EXPORT_SYMBOL_GPL(devm_register_power_off_handler);
/**
* devm_register_restart_handler - Register restart handler
* @dev: Device that registers callback
* @callback: Callback function
* @cb_data: Callback's argument
*
* Registers resource-managed sys-off handler with a default priority
* and using restart mode.
*
* Returns zero on success, or error code on failure.
*/
int devm_register_restart_handler(struct device *dev,
int (*callback)(struct sys_off_data *data),
void *cb_data)
{
return devm_register_sys_off_handler(dev,
SYS_OFF_MODE_RESTART,
SYS_OFF_PRIO_DEFAULT,
callback, cb_data);
}
EXPORT_SYMBOL_GPL(devm_register_restart_handler);
static struct sys_off_handler *platform_power_off_handler;
static int platform_power_off_notify(struct sys_off_data *data)
{
void (*platform_power_power_off_cb)(void) = data->cb_data;
platform_power_power_off_cb();
return NOTIFY_DONE;
}
/**
* register_platform_power_off - Register platform-level power-off callback
* @power_off: Power-off callback
*
* Registers power-off callback that will be called as last step
* of the power-off sequence. This callback is expected to be invoked
* for the last resort. Only one platform power-off callback is allowed
* to be registered at a time.
*
* Returns zero on success, or error code on failure.
*/
int register_platform_power_off(void (*power_off)(void))
{
struct sys_off_handler *handler;
handler = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
SYS_OFF_PRIO_PLATFORM,
platform_power_off_notify,
power_off);
if (IS_ERR(handler))
return PTR_ERR(handler);
platform_power_off_handler = handler;
return 0;
}
EXPORT_SYMBOL_GPL(register_platform_power_off);
/**
* unregister_platform_power_off - Unregister platform-level power-off callback
* @power_off: Power-off callback
*
* Unregisters previously registered platform power-off callback.
*/
void unregister_platform_power_off(void (*power_off)(void))
{
if (platform_power_off_handler &&
platform_power_off_handler->cb_data == power_off) {
unregister_sys_off_handler(platform_power_off_handler);
platform_power_off_handler = NULL;
}
}
EXPORT_SYMBOL_GPL(unregister_platform_power_off);
static int legacy_pm_power_off(struct sys_off_data *data)
{
if (pm_power_off)
pm_power_off();
return NOTIFY_DONE;
}
static void do_kernel_power_off_prepare(void)
{
blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL);
}
/**
* do_kernel_power_off - Execute kernel power-off handler call chain
*
* Expected to be called as last step of the power-off sequence.
*
* Powers off the system immediately if a power-off handler function has
* been registered. Otherwise does nothing.
*/
void do_kernel_power_off(void)
{
atomic_notifier_call_chain(&power_off_handler_list, 0, NULL);
}
/**
* kernel_can_power_off - check whether system can be powered off
*
* Returns true if power-off handler is registered and system can be
* powered off, false otherwise.
*/
bool kernel_can_power_off(void)
{
return !atomic_notifier_call_chain_is_empty(&power_off_handler_list);
}
EXPORT_SYMBOL_GPL(kernel_can_power_off);
/**
* kernel_power_off - power_off the system
*
@ -289,8 +607,7 @@ EXPORT_SYMBOL_GPL(kernel_halt);
void kernel_power_off(void)
{
kernel_shutdown_prepare(SYSTEM_POWER_OFF);
if (pm_power_off_prepare)
pm_power_off_prepare();
do_kernel_power_off_prepare();
migrate_to_reboot_cpu();
syscore_shutdown();
pr_emerg("Power down\n");
@ -313,6 +630,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
void __user *, arg)
{
struct pid_namespace *pid_ns = task_active_pid_ns(current);
struct sys_off_handler *sys_off = NULL;
char buffer[256];
int ret = 0;
@ -337,10 +655,25 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
if (ret)
return ret;
/*
* Register sys-off handlers for legacy PM callback. This allows
* legacy PM callbacks temporary co-exist with the new sys-off API.
*
* TODO: Remove legacy handlers once all legacy PM users will be
* switched to the sys-off based APIs.
*/
if (pm_power_off) {
sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
SYS_OFF_PRIO_DEFAULT,
legacy_pm_power_off, NULL);
if (IS_ERR(sys_off))
return PTR_ERR(sys_off);
}
/* Instead of trying to make the power_off code look like
* halt when pm_power_off is not set do it the easy way.
*/
if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off())
cmd = LINUX_REBOOT_CMD_HALT;
mutex_lock(&system_transition_mutex);
@ -394,6 +727,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
break;
}
mutex_unlock(&system_transition_mutex);
unregister_sys_off_handler(sys_off);
return ret;
}