xref: /openbmc/linux/arch/powerpc/include/asm/time.h (revision f68f2ff9)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Common time prototypes and such for all ppc machines.
4  *
5  * Written by Cort Dougan (cort@cs.nmt.edu) to merge
6  * Paul Mackerras' version and mine for PReP and Pmac.
7  */
8 
9 #ifndef __POWERPC_TIME_H
10 #define __POWERPC_TIME_H
11 
12 #ifdef __KERNEL__
13 #include <linux/types.h>
14 #include <linux/percpu.h>
15 
16 #include <asm/processor.h>
17 #include <asm/cpu_has_feature.h>
18 #include <asm/vdso/timebase.h>
19 
20 /* time.c */
21 extern u64 decrementer_max;
22 
23 extern unsigned long tb_ticks_per_jiffy;
24 extern unsigned long tb_ticks_per_usec;
25 extern unsigned long tb_ticks_per_sec;
26 extern struct clock_event_device decrementer_clockevent;
27 
28 
29 extern void generic_calibrate_decr(void);
30 
31 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
32 extern unsigned long ppc_proc_freq;
33 #define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
34 extern unsigned long ppc_tb_freq;
35 #define DEFAULT_TB_FREQ		125000000UL
36 
37 extern bool tb_invalid;
38 
39 struct div_result {
40 	u64 result_high;
41 	u64 result_low;
42 };
43 
44 static inline u64 get_vtb(void)
45 {
46 	if (cpu_has_feature(CPU_FTR_ARCH_207S))
47 		return mfspr(SPRN_VTB);
48 
49 	return 0;
50 }
51 
52 /* Accessor functions for the decrementer register.
53  * The 4xx doesn't even have a decrementer.  I tried to use the
54  * generic timer interrupt code, which seems OK, with the 4xx PIT
55  * in auto-reload mode.  The problem is PIT stops counting when it
56  * hits zero.  If it would wrap, we could use it just like a decrementer.
57  */
58 static inline u64 get_dec(void)
59 {
60 	if (IS_ENABLED(CONFIG_40x))
61 		return mfspr(SPRN_PIT);
62 
63 	return mfspr(SPRN_DEC);
64 }
65 
66 /*
67  * Note: Book E and 4xx processors differ from other PowerPC processors
68  * in when the decrementer generates its interrupt: on the 1 to 0
69  * transition for Book E/4xx, but on the 0 to -1 transition for others.
70  */
71 static inline void set_dec(u64 val)
72 {
73 	if (IS_ENABLED(CONFIG_40x))
74 		mtspr(SPRN_PIT, (u32)val);
75 	else if (IS_ENABLED(CONFIG_BOOKE))
76 		mtspr(SPRN_DEC, val);
77 	else
78 		mtspr(SPRN_DEC, val - 1);
79 }
80 
81 static inline unsigned long tb_ticks_since(unsigned long tstamp)
82 {
83 	return mftb() - tstamp;
84 }
85 
86 #define mulhwu(x,y) \
87 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
88 
89 #ifdef CONFIG_PPC64
90 #define mulhdu(x,y) \
91 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
92 #else
93 extern u64 mulhdu(u64, u64);
94 #endif
95 
96 extern void div128_by_32(u64 dividend_high, u64 dividend_low,
97 			 unsigned divisor, struct div_result *dr);
98 
99 extern void secondary_cpu_time_init(void);
100 extern void __init time_init(void);
101 
102 DECLARE_PER_CPU(u64, decrementers_next_tb);
103 
104 static inline u64 timer_get_next_tb(void)
105 {
106 	return __this_cpu_read(decrementers_next_tb);
107 }
108 
109 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
110 void timer_rearm_host_dec(u64 now);
111 #endif
112 
113 /* Convert timebase ticks to nanoseconds */
114 unsigned long long tb_to_ns(unsigned long long tb_ticks);
115 
116 void timer_broadcast_interrupt(void);
117 
118 /* SPLPAR */
119 void accumulate_stolen_time(void);
120 
121 #endif /* __KERNEL__ */
122 #endif /* __POWERPC_TIME_H */
123