linux/drivers/xen/manage.c
Rafael J. Wysocki 2ed8d2b3a8 PM: Rework handling of interrupts during suspend-resume
Use the functions introduced in by the previous patch,
suspend_device_irqs(), resume_device_irqs() and check_wakeup_irqs(),
to rework the handling of interrupts during suspend (hibernation) and
resume.  Namely, interrupts will only be disabled on the CPU right
before suspending sysdevs, while device drivers will be prevented
from receiving interrupts, with the help of the new helper function,
before their "late" suspend callbacks run (and analogously during
resume).

In addition, since the device interrups are now disabled before the
CPU has turned all interrupts off and the CPU will ACK the interrupts
setting the IRQ_PENDING bit for them, check in sysdev_suspend() if
any wake-up interrupts are pending and abort suspend if that's the
case.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
2009-03-30 21:46:54 +02:00

263 lines
5.4 KiB
C

/*
* Handle extern requests for shutdown, reboot and sysrq
*/
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/reboot.h>
#include <linux/sysrq.h>
#include <linux/stop_machine.h>
#include <linux/freezer.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>
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;
#ifdef CONFIG_PM_SLEEP
static int xen_suspend(void *data)
{
int *cancelled = data;
int err;
BUG_ON(!irqs_disabled());
err = sysdev_suspend(PMSG_SUSPEND);
if (err) {
printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n",
err);
device_power_up(PMSG_RESUME);
return err;
}
xen_mm_pin_all();
gnttab_suspend();
xen_pre_suspend();
/*
* This hypercall returns 1 if suspend was cancelled
* or the domain was merely checkpointed, and 0 if it
* is resuming in a new domain.
*/
*cancelled = HYPERVISOR_suspend(virt_to_mfn(xen_start_info));
xen_post_suspend(*cancelled);
gnttab_resume();
xen_mm_unpin_all();
sysdev_resume();
if (!*cancelled) {
xen_irq_resume();
xen_console_resume();
xen_timer_resume();
}
return 0;
}
static void do_suspend(void)
{
int err;
int cancelled = 1;
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);
return;
}
#endif
err = device_suspend(PMSG_SUSPEND);
if (err) {
printk(KERN_ERR "xen suspend: device_suspend %d\n", err);
goto out;
}
printk("suspending xenbus...\n");
/* XXX use normal device tree? */
xenbus_suspend();
err = device_power_down(PMSG_SUSPEND);
if (err) {
printk(KERN_ERR "device_power_down failed: %d\n", err);
goto resume_devices;
}
err = stop_machine(xen_suspend, &cancelled, cpumask_of(0));
if (err) {
printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
goto out;
}
if (!cancelled) {
xen_arch_resume();
xenbus_resume();
} else
xenbus_suspend_cancel();
device_power_up(PMSG_RESUME);
resume_devices:
device_resume(PMSG_RESUME);
/* Make sure timer events get retriggered on all CPUs */
clock_was_set();
out:
#ifdef CONFIG_PREEMPT
thaw_processes();
#endif
shutting_down = SHUTDOWN_INVALID;
}
#endif /* CONFIG_PM_SLEEP */
static void shutdown_handler(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
char *str;
struct xenbus_transaction xbt;
int err;
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;
}
xenbus_write(xbt, "control", "shutdown", "");
err = xenbus_transaction_end(xbt, 0);
if (err == -EAGAIN) {
kfree(str);
goto again;
}
if (strcmp(str, "poweroff") == 0 ||
strcmp(str, "halt") == 0) {
shutting_down = SHUTDOWN_POWEROFF;
orderly_poweroff(false);
} else if (strcmp(str, "reboot") == 0) {
shutting_down = SHUTDOWN_POWEROFF; /* ? */
ctrl_alt_del();
#ifdef CONFIG_PM_SLEEP
} else if (strcmp(str, "suspend") == 0) {
do_suspend();
#endif
} else {
printk(KERN_INFO "Ignoring shutdown request: %s\n", str);
shutting_down = SHUTDOWN_INVALID;
}
kfree(str);
}
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, NULL);
}
static struct xenbus_watch shutdown_watch = {
.node = "control/shutdown",
.callback = shutdown_handler
};
static struct xenbus_watch sysrq_watch = {
.node = "control/sysrq",
.callback = sysrq_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;
}
err = register_xenbus_watch(&sysrq_watch);
if (err) {
printk(KERN_ERR "Failed to set sysrq watcher\n");
return err;
}
return 0;
}
static int shutdown_event(struct notifier_block *notifier,
unsigned long event,
void *data)
{
setup_shutdown_watcher();
return NOTIFY_DONE;
}
static int __init setup_shutdown_event(void)
{
static struct notifier_block xenstore_notifier = {
.notifier_call = shutdown_event
};
register_xenstore_notifier(&xenstore_notifier);
return 0;
}
subsys_initcall(setup_shutdown_event);