Revision 8aef33a7cf40ca9da188e8578b2abe7267a38c52 authored by Daniel Lezcano on 15 January 2013, 13:18:04 UTC, committed by Rafael J. Wysocki on 15 January 2013, 13:18:04 UTC
We realized that the power usage field is never filled and when it is filled for tegra, the power_specified flag is not set causing all of these values to be reset when the driver is initialized with set_power_state(). However, the power_specified flag can be simply removed under the assumption that the states are always backward sorted, which is the case with the current code. This change allows the menu governor select function and the cpuidle_play_dead() to be simplified. Moreover, the set_power_states() function can removed as it does not make sense any more. Drop the power_specified flag from struct cpuidle_driver and make the related changes as described above. As a consequence, this also fixes the bug where on the dynamic C-states system, the power fields are not initialized. [rjw: Changelog] References: https://bugzilla.kernel.org/show_bug.cgi?id=42870 References: https://bugzilla.kernel.org/show_bug.cgi?id=43349 References: https://lkml.org/lkml/2012/10/16/518 Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 parent a412a11
manage.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 <linux/export.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_end(PMSG_FREEZE);
if (err) {
printk(KERN_ERR "dpm_suspend_end failed: %d\n", err);
si.cancelled = 0;
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_start(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);
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