xref: /linux/arch/powerpc/include/asm/time.h (revision fbf46565c67c626849c7ce2a326972d3008d2a91)
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 extern u64 decrementer_max;
28 
29 
30 extern void generic_calibrate_decr(void);
31 
32 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
33 extern unsigned long ppc_proc_freq;
34 #define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
35 extern unsigned long ppc_tb_freq;
36 #define DEFAULT_TB_FREQ		125000000UL
37 
38 extern bool tb_invalid;
39 
40 struct div_result {
41 	u64 result_high;
42 	u64 result_low;
43 };
44 
45 static inline u64 get_vtb(void)
46 {
47 	if (cpu_has_feature(CPU_FTR_ARCH_207S))
48 		return mfspr(SPRN_VTB);
49 
50 	return 0;
51 }
52 
53 /* Accessor functions for the decrementer register.
54  * The 4xx doesn't even have a decrementer.  I tried to use the
55  * generic timer interrupt code, which seems OK, with the 4xx PIT
56  * in auto-reload mode.  The problem is PIT stops counting when it
57  * hits zero.  If it would wrap, we could use it just like a decrementer.
58  */
59 static inline u64 get_dec(void)
60 {
61 	if (IS_ENABLED(CONFIG_40x))
62 		return mfspr(SPRN_PIT);
63 
64 	return mfspr(SPRN_DEC);
65 }
66 
67 /*
68  * Note: Book E and 4xx processors differ from other PowerPC processors
69  * in when the decrementer generates its interrupt: on the 1 to 0
70  * transition for Book E/4xx, but on the 0 to -1 transition for others.
71  */
72 static inline void set_dec(u64 val)
73 {
74 	if (IS_ENABLED(CONFIG_40x))
75 		mtspr(SPRN_PIT, (u32)val);
76 	else if (IS_ENABLED(CONFIG_BOOKE))
77 		mtspr(SPRN_DEC, val);
78 	else
79 		mtspr(SPRN_DEC, val - 1);
80 }
81 
82 static inline unsigned long tb_ticks_since(unsigned long tstamp)
83 {
84 	return mftb() - tstamp;
85 }
86 
87 #define mulhwu(x,y) \
88 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
89 
90 #ifdef CONFIG_PPC64
91 #define mulhdu(x,y) \
92 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
93 #else
94 extern u64 mulhdu(u64, u64);
95 #endif
96 
97 extern void div128_by_32(u64 dividend_high, u64 dividend_low,
98 			 unsigned divisor, struct div_result *dr);
99 
100 extern void secondary_cpu_time_init(void);
101 extern void __init time_init(void);
102 
103 DECLARE_PER_CPU(u64, decrementers_next_tb);
104 
105 static inline u64 timer_get_next_tb(void)
106 {
107 	return __this_cpu_read(decrementers_next_tb);
108 }
109 
110 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
111 void timer_rearm_host_dec(u64 now);
112 #endif
113 
114 /* Convert timebase ticks to nanoseconds */
115 unsigned long long tb_to_ns(unsigned long long tb_ticks);
116 
117 void timer_broadcast_interrupt(void);
118 
119 /* SPLPAR and VIRT_CPU_ACCOUNTING_NATIVE */
120 void pseries_accumulate_stolen_time(void);
121 u64 pseries_calculate_stolen_time(u64 stop_tb);
122 
123 #endif /* __KERNEL__ */
124 #endif /* __POWERPC_TIME_H */
125