338 lines
6.8 KiB
C
338 lines
6.8 KiB
C
/*
|
|
* Handle extern requests for shutdown, reboot and sysrq
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/err.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/sysrq.h>
|
|
#include <linux/stop_machine.h>
|
|
#include <linux/freezer.h>
|
|
#include <linux/syscore_ops.h>
|
|
|
|
#include <xen/xen.h>
|
|
#include <xen/xenbus.h>
|
|
#include <xen/grant_table.h>
|
|
#include <xen/events.h>
|
|
#include <xen/hvc-console.h>
|
|
#include <xen/xen-ops.h>
|
|
|
|
#include <asm/xen/hypercall.h>
|
|
#include <asm/xen/page.h>
|
|
#include <asm/xen/hypervisor.h>
|
|
|
|
enum shutdown_state {
|
|
SHUTDOWN_INVALID = -1,
|
|
SHUTDOWN_POWEROFF = 0,
|
|
SHUTDOWN_SUSPEND = 2,
|
|
/* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only
|
|
report a crash, not be instructed to crash!
|
|
HALT is the same as POWEROFF, as far as we're concerned. The tools use
|
|
the distinction when we return the reason code to them. */
|
|
SHUTDOWN_HALT = 4,
|
|
};
|
|
|
|
/* Ignore multiple shutdown requests. */
|
|
static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
|
|
|
|
struct suspend_info {
|
|
int cancelled;
|
|
unsigned long arg; /* extra hypercall argument */
|
|
void (*pre)(void);
|
|
void (*post)(int cancelled);
|
|
};
|
|
|
|
static void xen_hvm_post_suspend(int cancelled)
|
|
{
|
|
xen_arch_hvm_post_suspend(cancelled);
|
|
gnttab_resume();
|
|
}
|
|
|
|
static void xen_pre_suspend(void)
|
|
{
|
|
xen_mm_pin_all();
|
|
gnttab_suspend();
|
|
xen_arch_pre_suspend();
|
|
}
|
|
|
|
static void xen_post_suspend(int cancelled)
|
|
{
|
|
xen_arch_post_suspend(cancelled);
|
|
gnttab_resume();
|
|
xen_mm_unpin_all();
|
|
}
|
|
|
|
#ifdef CONFIG_HIBERNATE_CALLBACKS
|
|
static int xen_suspend(void *data)
|
|
{
|
|
struct suspend_info *si = data;
|
|
int err;
|
|
|
|
BUG_ON(!irqs_disabled());
|
|
|
|
err = syscore_suspend();
|
|
if (err) {
|
|
printk(KERN_ERR "xen_suspend: system core suspend failed: %d\n",
|
|
err);
|
|
return err;
|
|
}
|
|
|
|
if (si->pre)
|
|
si->pre();
|
|
|
|
/*
|
|
* This hypercall returns 1 if suspend was cancelled
|
|
* or the domain was merely checkpointed, and 0 if it
|
|
* is resuming in a new domain.
|
|
*/
|
|
si->cancelled = HYPERVISOR_suspend(si->arg);
|
|
|
|
if (si->post)
|
|
si->post(si->cancelled);
|
|
|
|
if (!si->cancelled) {
|
|
xen_irq_resume();
|
|
xen_console_resume();
|
|
xen_timer_resume();
|
|
}
|
|
|
|
syscore_resume();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void do_suspend(void)
|
|
{
|
|
int err;
|
|
struct suspend_info si;
|
|
|
|
shutting_down = SHUTDOWN_SUSPEND;
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
/* If the kernel is preemptible, we need to freeze all the processes
|
|
to prevent them from being in the middle of a pagetable update
|
|
during suspend. */
|
|
err = freeze_processes();
|
|
if (err) {
|
|
printk(KERN_ERR "xen suspend: freeze failed %d\n", err);
|
|
goto out;
|
|
}
|
|
#endif
|
|
|
|
err = dpm_suspend_start(PMSG_FREEZE);
|
|
if (err) {
|
|
printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err);
|
|
goto out_thaw;
|
|
}
|
|
|
|
printk(KERN_DEBUG "suspending xenstore...\n");
|
|
xs_suspend();
|
|
|
|
err = dpm_suspend_noirq(PMSG_FREEZE);
|
|
if (err) {
|
|
printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err);
|
|
goto out_resume;
|
|
}
|
|
|
|
si.cancelled = 1;
|
|
|
|
if (xen_hvm_domain()) {
|
|
si.arg = 0UL;
|
|
si.pre = NULL;
|
|
si.post = &xen_hvm_post_suspend;
|
|
} else {
|
|
si.arg = virt_to_mfn(xen_start_info);
|
|
si.pre = &xen_pre_suspend;
|
|
si.post = &xen_post_suspend;
|
|
}
|
|
|
|
err = stop_machine(xen_suspend, &si, cpumask_of(0));
|
|
|
|
dpm_resume_noirq(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
|
|
|
|
if (err) {
|
|
printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
|
|
si.cancelled = 1;
|
|
}
|
|
|
|
out_resume:
|
|
if (!si.cancelled) {
|
|
xen_arch_resume();
|
|
xs_resume();
|
|
} else
|
|
xs_suspend_cancel();
|
|
|
|
dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
|
|
|
|
/* Make sure timer events get retriggered on all CPUs */
|
|
clock_was_set();
|
|
|
|
out_thaw:
|
|
#ifdef CONFIG_PREEMPT
|
|
thaw_processes();
|
|
out:
|
|
#endif
|
|
shutting_down = SHUTDOWN_INVALID;
|
|
}
|
|
#endif /* CONFIG_HIBERNATE_CALLBACKS */
|
|
|
|
struct shutdown_handler {
|
|
const char *command;
|
|
void (*cb)(void);
|
|
};
|
|
|
|
static void do_poweroff(void)
|
|
{
|
|
shutting_down = SHUTDOWN_POWEROFF;
|
|
orderly_poweroff(false);
|
|
}
|
|
|
|
static void do_reboot(void)
|
|
{
|
|
shutting_down = SHUTDOWN_POWEROFF; /* ? */
|
|
ctrl_alt_del();
|
|
}
|
|
|
|
static void shutdown_handler(struct xenbus_watch *watch,
|
|
const char **vec, unsigned int len)
|
|
{
|
|
char *str;
|
|
struct xenbus_transaction xbt;
|
|
int err;
|
|
static struct shutdown_handler handlers[] = {
|
|
{ "poweroff", do_poweroff },
|
|
{ "halt", do_poweroff },
|
|
{ "reboot", do_reboot },
|
|
#ifdef CONFIG_HIBERNATE_CALLBACKS
|
|
{ "suspend", do_suspend },
|
|
#endif
|
|
{NULL, NULL},
|
|
};
|
|
static struct shutdown_handler *handler;
|
|
|
|
if (shutting_down != SHUTDOWN_INVALID)
|
|
return;
|
|
|
|
again:
|
|
err = xenbus_transaction_start(&xbt);
|
|
if (err)
|
|
return;
|
|
|
|
str = (char *)xenbus_read(xbt, "control", "shutdown", NULL);
|
|
/* Ignore read errors and empty reads. */
|
|
if (XENBUS_IS_ERR_READ(str)) {
|
|
xenbus_transaction_end(xbt, 1);
|
|
return;
|
|
}
|
|
|
|
for (handler = &handlers[0]; handler->command; handler++) {
|
|
if (strcmp(str, handler->command) == 0)
|
|
break;
|
|
}
|
|
|
|
/* Only acknowledge commands which we are prepared to handle. */
|
|
if (handler->cb)
|
|
xenbus_write(xbt, "control", "shutdown", "");
|
|
|
|
err = xenbus_transaction_end(xbt, 0);
|
|
if (err == -EAGAIN) {
|
|
kfree(str);
|
|
goto again;
|
|
}
|
|
|
|
if (handler->cb) {
|
|
handler->cb();
|
|
} else {
|
|
printk(KERN_INFO "Ignoring shutdown request: %s\n", str);
|
|
shutting_down = SHUTDOWN_INVALID;
|
|
}
|
|
|
|
kfree(str);
|
|
}
|
|
|
|
#ifdef CONFIG_MAGIC_SYSRQ
|
|
static void sysrq_handler(struct xenbus_watch *watch, const char **vec,
|
|
unsigned int len)
|
|
{
|
|
char sysrq_key = '\0';
|
|
struct xenbus_transaction xbt;
|
|
int err;
|
|
|
|
again:
|
|
err = xenbus_transaction_start(&xbt);
|
|
if (err)
|
|
return;
|
|
if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) {
|
|
printk(KERN_ERR "Unable to read sysrq code in "
|
|
"control/sysrq\n");
|
|
xenbus_transaction_end(xbt, 1);
|
|
return;
|
|
}
|
|
|
|
if (sysrq_key != '\0')
|
|
xenbus_printf(xbt, "control", "sysrq", "%c", '\0');
|
|
|
|
err = xenbus_transaction_end(xbt, 0);
|
|
if (err == -EAGAIN)
|
|
goto again;
|
|
|
|
if (sysrq_key != '\0')
|
|
handle_sysrq(sysrq_key);
|
|
}
|
|
|
|
static struct xenbus_watch sysrq_watch = {
|
|
.node = "control/sysrq",
|
|
.callback = sysrq_handler
|
|
};
|
|
#endif
|
|
|
|
static struct xenbus_watch shutdown_watch = {
|
|
.node = "control/shutdown",
|
|
.callback = shutdown_handler
|
|
};
|
|
|
|
static int setup_shutdown_watcher(void)
|
|
{
|
|
int err;
|
|
|
|
err = register_xenbus_watch(&shutdown_watch);
|
|
if (err) {
|
|
printk(KERN_ERR "Failed to set shutdown watcher\n");
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_MAGIC_SYSRQ
|
|
err = register_xenbus_watch(&sysrq_watch);
|
|
if (err) {
|
|
printk(KERN_ERR "Failed to set sysrq watcher\n");
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int shutdown_event(struct notifier_block *notifier,
|
|
unsigned long event,
|
|
void *data)
|
|
{
|
|
setup_shutdown_watcher();
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
int xen_setup_shutdown_event(void)
|
|
{
|
|
static struct notifier_block xenstore_notifier = {
|
|
.notifier_call = shutdown_event
|
|
};
|
|
|
|
if (!xen_domain())
|
|
return -ENODEV;
|
|
register_xenstore_notifier(&xenstore_notifier);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xen_setup_shutdown_event);
|
|
|
|
subsys_initcall(xen_setup_shutdown_event);
|