1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
/* 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
/* 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_CPU_DYING,
CLOCK_EVT_NOTIFY_CPU_DEAD,
};
#ifdef CONFIG_GENERIC_CLOCKEVENTS
#include <linux/clocksource.h>
#include <linux/cpumask.h>
#include <linux/ktime.h>
#include <linux/notifier.h>
struct clock_event_device;
struct module;
/* Clock event mode commands for legacy ->set_mode(): OBSOLETE */
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,
};
/*
* Possible states of a clock event device.
*
* DETACHED: Device is not used by clockevents core. Initial state or can be
* reached from SHUTDOWN.
* SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT.
* PERIODIC: Device is programmed to generate events periodically. Can be
* reached from DETACHED or SHUTDOWN.
* ONESHOT: Device is programmed to generate event only once. Can be reached
* from DETACHED or SHUTDOWN.
*/
enum clock_event_state {
CLOCK_EVT_STATE_DETACHED = 0,
CLOCK_EVT_STATE_SHUTDOWN,
CLOCK_EVT_STATE_PERIODIC,
CLOCK_EVT_STATE_ONESHOT,
};
/*
* Clock event features
*/
#define CLOCK_EVT_FEAT_PERIODIC 0x000001
#define CLOCK_EVT_FEAT_ONESHOT 0x000002
#define CLOCK_EVT_FEAT_KTIME 0x000004
/*
* 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 0x000008
#define CLOCK_EVT_FEAT_DUMMY 0x000010
/*
* Core shall set the interrupt affinity dynamically in broadcast mode
*/
#define CLOCK_EVT_FEAT_DYNIRQ 0x000020
#define CLOCK_EVT_FEAT_PERCPU 0x000040
/*
* Clockevent device is based on a hrtimer for broadcast
*/
#define CLOCK_EVT_FEAT_HRTIMER 0x000080
/**
* struct clock_event_device - clock event device descriptor
* @event_handler: Assigned by the framework to be called by the low
* level handler of the event source
* @set_next_event: set next event function using a clocksource delta
* @set_next_ktime: set next event function using a direct ktime value
* @next_event: local storage for the next event in oneshot mode
* @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)
* @mode: operating mode, relevant only to ->set_mode(), OBSOLETE
* @state: current state of the device, assigned by the core code
* @features: features
* @retries: number of forced programming retries
* @set_mode: legacy set mode function, only for modes <= CLOCK_EVT_MODE_RESUME.
* @set_state_periodic: switch state to periodic, if !set_mode
* @set_state_oneshot: switch state to oneshot, if !set_mode
* @set_state_shutdown: switch state to shutdown, if !set_mode
* @tick_resume: resume clkevt device, if !set_mode
* @broadcast: function to broadcast events
* @min_delta_ticks: minimum delta value in ticks stored for reconfiguration
* @max_delta_ticks: maximum delta value in ticks stored for reconfiguration
* @name: ptr to clock event name
* @rating: variable to rate clock event devices
* @irq: IRQ number (only for non CPU local devices)
* @bound_on: Bound on CPU
* @cpumask: cpumask to indicate for which CPUs this device works
* @list: list head for the management code
* @owner: module reference
*/
struct clock_event_device {
void (*event_handler)(struct clock_event_device *);
int (*set_next_event)(unsigned long evt,
struct clock_event_device *);
int (*set_next_ktime)(ktime_t expires,
struct clock_event_device *);
ktime_t next_event;
u64 max_delta_ns;
u64 min_delta_ns;
u32 mult;
u32 shift;
enum clock_event_mode mode;
enum clock_event_state state;
unsigned int features;
unsigned long retries;
/*
* State transition callback(s): Only one of the two groups should be
* defined:
* - set_mode(), only for modes <= CLOCK_EVT_MODE_RESUME.
* - set_state_{shutdown|periodic|oneshot}(), tick_resume().
*/
void (*set_mode)(enum clock_event_mode mode,
struct clock_event_device *);
int (*set_state_periodic)(struct clock_event_device *);
int (*set_state_oneshot)(struct clock_event_device *);
int (*set_state_shutdown)(struct clock_event_device *);
int (*tick_resume)(struct clock_event_device *);
void (*broadcast)(const struct cpumask *mask);
void (*suspend)(struct clock_event_device *);
void (*resume)(struct clock_event_device *);
unsigned long min_delta_ticks;
unsigned long max_delta_ticks;
const char *name;
int rating;
int irq;
int bound_on;
const struct cpumask *cpumask;
struct list_head list;
struct module *owner;
} ____cacheline_aligned;
/*
* 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 int clockevents_unbind_device(struct clock_event_device *ced, int cpu);
extern void clockevents_config(struct clock_event_device *dev, u32 freq);
extern void clockevents_config_and_register(struct clock_event_device *dev,
u32 freq, unsigned long min_delta,
unsigned long max_delta);
extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);
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);
}
/* Should be core only, but is abused by arm bl_switcher */
extern void clockevents_set_state(struct clock_event_device *dev,
enum clock_event_state state);
extern int clockevents_program_event(struct clock_event_device *dev,
ktime_t expires, bool force);
extern void clockevents_suspend(void);
extern void clockevents_resume(void);
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
#ifdef CONFIG_ARCH_HAS_TICK_BROADCAST
extern void tick_broadcast(const struct cpumask *mask);
#else
#define tick_broadcast NULL
#endif
extern int tick_receive_broadcast(void);
#endif
#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
extern void tick_setup_hrtimer_broadcast(void);
extern int tick_check_broadcast_expired(void);
#else
static inline int tick_check_broadcast_expired(void) { return 0; }
static inline void tick_setup_hrtimer_broadcast(void) {};
#endif
extern int clockevents_notify(unsigned long reason, void *arg);
#else /* CONFIG_GENERIC_CLOCKEVENTS */
static inline void clockevents_suspend(void) {}
static inline void clockevents_resume(void) {}
static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
static inline int tick_check_broadcast_expired(void) { return 0; }
static inline void tick_setup_hrtimer_broadcast(void) {};
static inline int clockevents_notify(unsigned long reason, void *arg) { return 0; }
#endif
#endif
|
