xref: /linux/arch/powerpc/include/asm/time.h (revision c5d3cdad688ed75fb311a3a671eb30ba7106d7d3)
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 
19 /* time.c */
20 extern unsigned long tb_ticks_per_jiffy;
21 extern unsigned long tb_ticks_per_usec;
22 extern unsigned long tb_ticks_per_sec;
23 extern struct clock_event_device decrementer_clockevent;
24 
25 
26 extern void generic_calibrate_decr(void);
27 
28 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
29 extern unsigned long ppc_proc_freq;
30 #define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
31 extern unsigned long ppc_tb_freq;
32 #define DEFAULT_TB_FREQ		125000000UL
33 
34 extern bool tb_invalid;
35 
36 struct div_result {
37 	u64 result_high;
38 	u64 result_low;
39 };
40 
41 /* Accessor functions for the timebase (RTC on 601) registers. */
42 /* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
43 #define __USE_RTC()	(IS_ENABLED(CONFIG_PPC_BOOK3S_601))
44 
45 #ifdef CONFIG_PPC64
46 
47 /* For compatibility, get_tbl() is defined as get_tb() on ppc64 */
48 #define get_tbl		get_tb
49 
50 #else
51 
52 static inline unsigned long get_tbl(void)
53 {
54 #if defined(CONFIG_403GCX)
55 	unsigned long tbl;
56 	asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
57 	return tbl;
58 #else
59 	return mftbl();
60 #endif
61 }
62 
63 static inline unsigned int get_tbu(void)
64 {
65 #ifdef CONFIG_403GCX
66 	unsigned int tbu;
67 	asm volatile("mfspr %0, 0x3dc" : "=r" (tbu));
68 	return tbu;
69 #else
70 	return mftbu();
71 #endif
72 }
73 #endif /* !CONFIG_PPC64 */
74 
75 static inline unsigned int get_rtcl(void)
76 {
77 	unsigned int rtcl;
78 
79 	asm volatile("mfrtcl %0" : "=r" (rtcl));
80 	return rtcl;
81 }
82 
83 static inline u64 get_rtc(void)
84 {
85 	unsigned int hi, lo, hi2;
86 
87 	do {
88 		asm volatile("mfrtcu %0; mfrtcl %1; mfrtcu %2"
89 			     : "=r" (hi), "=r" (lo), "=r" (hi2));
90 	} while (hi2 != hi);
91 	return (u64)hi * 1000000000 + lo;
92 }
93 
94 static inline u64 get_vtb(void)
95 {
96 #ifdef CONFIG_PPC_BOOK3S_64
97 	if (cpu_has_feature(CPU_FTR_ARCH_207S))
98 		return mfspr(SPRN_VTB);
99 #endif
100 	return 0;
101 }
102 
103 #ifdef CONFIG_PPC64
104 static inline u64 get_tb(void)
105 {
106 	return mftb();
107 }
108 #else /* CONFIG_PPC64 */
109 static inline u64 get_tb(void)
110 {
111 	unsigned int tbhi, tblo, tbhi2;
112 
113 	do {
114 		tbhi = get_tbu();
115 		tblo = get_tbl();
116 		tbhi2 = get_tbu();
117 	} while (tbhi != tbhi2);
118 
119 	return ((u64)tbhi << 32) | tblo;
120 }
121 #endif /* !CONFIG_PPC64 */
122 
123 static inline u64 get_tb_or_rtc(void)
124 {
125 	return __USE_RTC() ? get_rtc() : get_tb();
126 }
127 
128 static inline void set_tb(unsigned int upper, unsigned int lower)
129 {
130 	mtspr(SPRN_TBWL, 0);
131 	mtspr(SPRN_TBWU, upper);
132 	mtspr(SPRN_TBWL, lower);
133 }
134 
135 /* Accessor functions for the decrementer register.
136  * The 4xx doesn't even have a decrementer.  I tried to use the
137  * generic timer interrupt code, which seems OK, with the 4xx PIT
138  * in auto-reload mode.  The problem is PIT stops counting when it
139  * hits zero.  If it would wrap, we could use it just like a decrementer.
140  */
141 static inline u64 get_dec(void)
142 {
143 #if defined(CONFIG_40x)
144 	return (mfspr(SPRN_PIT));
145 #else
146 	return (mfspr(SPRN_DEC));
147 #endif
148 }
149 
150 /*
151  * Note: Book E and 4xx processors differ from other PowerPC processors
152  * in when the decrementer generates its interrupt: on the 1 to 0
153  * transition for Book E/4xx, but on the 0 to -1 transition for others.
154  */
155 static inline void set_dec(u64 val)
156 {
157 #if defined(CONFIG_40x)
158 	mtspr(SPRN_PIT, (u32) val);
159 #else
160 #ifndef CONFIG_BOOKE
161 	--val;
162 #endif
163 	mtspr(SPRN_DEC, val);
164 #endif /* not 40x */
165 }
166 
167 static inline unsigned long tb_ticks_since(unsigned long tstamp)
168 {
169 	if (__USE_RTC()) {
170 		int delta = get_rtcl() - (unsigned int) tstamp;
171 		return delta < 0 ? delta + 1000000000 : delta;
172 	}
173 	return get_tbl() - tstamp;
174 }
175 
176 #define mulhwu(x,y) \
177 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
178 
179 #ifdef CONFIG_PPC64
180 #define mulhdu(x,y) \
181 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
182 #else
183 extern u64 mulhdu(u64, u64);
184 #endif
185 
186 extern void div128_by_32(u64 dividend_high, u64 dividend_low,
187 			 unsigned divisor, struct div_result *dr);
188 
189 extern void secondary_cpu_time_init(void);
190 extern void __init time_init(void);
191 
192 DECLARE_PER_CPU(u64, decrementers_next_tb);
193 
194 /* Convert timebase ticks to nanoseconds */
195 unsigned long long tb_to_ns(unsigned long long tb_ticks);
196 
197 /* SPLPAR */
198 void accumulate_stolen_time(void);
199 
200 #endif /* __KERNEL__ */
201 #endif /* __POWERPC_TIME_H */
202