mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
80a05b9ffa
The current logic which handles clock events programming failures can increase min_delta_ns unlimited and even can cause overflows. Sanitize it by: - prevent zero increase when min_delta_ns == 1 - limiting min_delta_ns to a jiffie - bail out if the jiffie limit is hit - add retries stats for /proc/timer_list so we can gather data Reported-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
155 lines
4.5 KiB
C
155 lines
4.5 KiB
C
/* linux/include/linux/clockchips.h
|
|
*
|
|
* This file contains the structure definitions for clockchips.
|
|
*
|
|
* If you are not a clockchip, or the time of day code, you should
|
|
* not be including this file!
|
|
*/
|
|
#ifndef _LINUX_CLOCKCHIPS_H
|
|
#define _LINUX_CLOCKCHIPS_H
|
|
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BUILD
|
|
|
|
#include <linux/clocksource.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/ktime.h>
|
|
#include <linux/notifier.h>
|
|
|
|
struct clock_event_device;
|
|
|
|
/* Clock event mode commands */
|
|
enum clock_event_mode {
|
|
CLOCK_EVT_MODE_UNUSED = 0,
|
|
CLOCK_EVT_MODE_SHUTDOWN,
|
|
CLOCK_EVT_MODE_PERIODIC,
|
|
CLOCK_EVT_MODE_ONESHOT,
|
|
CLOCK_EVT_MODE_RESUME,
|
|
};
|
|
|
|
/* Clock event notification values */
|
|
enum clock_event_nofitiers {
|
|
CLOCK_EVT_NOTIFY_ADD,
|
|
CLOCK_EVT_NOTIFY_BROADCAST_ON,
|
|
CLOCK_EVT_NOTIFY_BROADCAST_OFF,
|
|
CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
|
|
CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
|
|
CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
|
|
CLOCK_EVT_NOTIFY_SUSPEND,
|
|
CLOCK_EVT_NOTIFY_RESUME,
|
|
CLOCK_EVT_NOTIFY_CPU_DYING,
|
|
CLOCK_EVT_NOTIFY_CPU_DEAD,
|
|
};
|
|
|
|
/*
|
|
* Clock event features
|
|
*/
|
|
#define CLOCK_EVT_FEAT_PERIODIC 0x000001
|
|
#define CLOCK_EVT_FEAT_ONESHOT 0x000002
|
|
/*
|
|
* x86(64) specific misfeatures:
|
|
*
|
|
* - Clockevent source stops in C3 State and needs broadcast support.
|
|
* - Local APIC timer is used as a dummy device.
|
|
*/
|
|
#define CLOCK_EVT_FEAT_C3STOP 0x000004
|
|
#define CLOCK_EVT_FEAT_DUMMY 0x000008
|
|
|
|
/**
|
|
* struct clock_event_device - clock event device descriptor
|
|
* @name: ptr to clock event name
|
|
* @features: features
|
|
* @max_delta_ns: maximum delta value in ns
|
|
* @min_delta_ns: minimum delta value in ns
|
|
* @mult: nanosecond to cycles multiplier
|
|
* @shift: nanoseconds to cycles divisor (power of two)
|
|
* @rating: variable to rate clock event devices
|
|
* @irq: IRQ number (only for non CPU local devices)
|
|
* @cpumask: cpumask to indicate for which CPUs this device works
|
|
* @set_next_event: set next event function
|
|
* @set_mode: set mode function
|
|
* @event_handler: Assigned by the framework to be called by the low
|
|
* level handler of the event source
|
|
* @broadcast: function to broadcast events
|
|
* @list: list head for the management code
|
|
* @mode: operating mode assigned by the management code
|
|
* @next_event: local storage for the next event in oneshot mode
|
|
* @retries: number of forced programming retries
|
|
*/
|
|
struct clock_event_device {
|
|
const char *name;
|
|
unsigned int features;
|
|
u64 max_delta_ns;
|
|
u64 min_delta_ns;
|
|
u32 mult;
|
|
u32 shift;
|
|
int rating;
|
|
int irq;
|
|
const struct cpumask *cpumask;
|
|
int (*set_next_event)(unsigned long evt,
|
|
struct clock_event_device *);
|
|
void (*set_mode)(enum clock_event_mode mode,
|
|
struct clock_event_device *);
|
|
void (*event_handler)(struct clock_event_device *);
|
|
void (*broadcast)(const struct cpumask *mask);
|
|
struct list_head list;
|
|
enum clock_event_mode mode;
|
|
ktime_t next_event;
|
|
unsigned long retries;
|
|
};
|
|
|
|
/*
|
|
* Calculate a multiplication factor for scaled math, which is used to convert
|
|
* nanoseconds based values to clock ticks:
|
|
*
|
|
* clock_ticks = (nanoseconds * factor) >> shift.
|
|
*
|
|
* div_sc is the rearranged equation to calculate a factor from a given clock
|
|
* ticks / nanoseconds ratio:
|
|
*
|
|
* factor = (clock_ticks << shift) / nanoseconds
|
|
*/
|
|
static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
|
|
int shift)
|
|
{
|
|
uint64_t tmp = ((uint64_t)ticks) << shift;
|
|
|
|
do_div(tmp, nsec);
|
|
return (unsigned long) tmp;
|
|
}
|
|
|
|
/* Clock event layer functions */
|
|
extern u64 clockevent_delta2ns(unsigned long latch,
|
|
struct clock_event_device *evt);
|
|
extern void clockevents_register_device(struct clock_event_device *dev);
|
|
|
|
extern void clockevents_exchange_device(struct clock_event_device *old,
|
|
struct clock_event_device *new);
|
|
extern void clockevents_set_mode(struct clock_event_device *dev,
|
|
enum clock_event_mode mode);
|
|
extern int clockevents_register_notifier(struct notifier_block *nb);
|
|
extern int clockevents_program_event(struct clock_event_device *dev,
|
|
ktime_t expires, ktime_t now);
|
|
|
|
extern void clockevents_handle_noop(struct clock_event_device *dev);
|
|
|
|
static inline void
|
|
clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
|
|
{
|
|
return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
|
|
freq, minsec);
|
|
}
|
|
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS
|
|
extern void clockevents_notify(unsigned long reason, void *arg);
|
|
#else
|
|
# define clockevents_notify(reason, arg) do { } while (0)
|
|
#endif
|
|
|
|
#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */
|
|
|
|
#define clockevents_notify(reason, arg) do { } while (0)
|
|
|
|
#endif
|
|
|
|
#endif
|