xref: /openbmc/linux/arch/powerpc/include/asm/time.h (revision 5d331b7f)
1 /*
2  * Common time prototypes and such for all ppc machines.
3  *
4  * Written by Cort Dougan (cort@cs.nmt.edu) to merge
5  * Paul Mackerras' version and mine for PReP and Pmac.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12 
13 #ifndef __POWERPC_TIME_H
14 #define __POWERPC_TIME_H
15 
16 #ifdef __KERNEL__
17 #include <linux/types.h>
18 #include <linux/percpu.h>
19 
20 #include <asm/processor.h>
21 #include <asm/cpu_has_feature.h>
22 
23 /* time.c */
24 extern unsigned long tb_ticks_per_jiffy;
25 extern unsigned long tb_ticks_per_usec;
26 extern unsigned long tb_ticks_per_sec;
27 extern struct clock_event_device decrementer_clockevent;
28 
29 
30 extern void generic_calibrate_decr(void);
31 extern void hdec_interrupt(struct pt_regs *regs);
32 
33 /* Some sane defaults: 125 MHz timebase, 1GHz processor */
34 extern unsigned long ppc_proc_freq;
35 #define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
36 extern unsigned long ppc_tb_freq;
37 #define DEFAULT_TB_FREQ		125000000UL
38 
39 struct div_result {
40 	u64 result_high;
41 	u64 result_low;
42 };
43 
44 /* Accessor functions for the timebase (RTC on 601) registers. */
45 /* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
46 #ifdef CONFIG_6xx
47 #define __USE_RTC()	(cpu_has_feature(CPU_FTR_USE_RTC))
48 #else
49 #define __USE_RTC()	0
50 #endif
51 
52 #ifdef CONFIG_PPC64
53 
54 /* For compatibility, get_tbl() is defined as get_tb() on ppc64 */
55 #define get_tbl		get_tb
56 
57 #else
58 
59 static inline unsigned long get_tbl(void)
60 {
61 #if defined(CONFIG_403GCX)
62 	unsigned long tbl;
63 	asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
64 	return tbl;
65 #else
66 	return mftbl();
67 #endif
68 }
69 
70 static inline unsigned int get_tbu(void)
71 {
72 #ifdef CONFIG_403GCX
73 	unsigned int tbu;
74 	asm volatile("mfspr %0, 0x3dc" : "=r" (tbu));
75 	return tbu;
76 #else
77 	return mftbu();
78 #endif
79 }
80 #endif /* !CONFIG_PPC64 */
81 
82 static inline unsigned int get_rtcl(void)
83 {
84 	unsigned int rtcl;
85 
86 	asm volatile("mfrtcl %0" : "=r" (rtcl));
87 	return rtcl;
88 }
89 
90 static inline u64 get_rtc(void)
91 {
92 	unsigned int hi, lo, hi2;
93 
94 	do {
95 		asm volatile("mfrtcu %0; mfrtcl %1; mfrtcu %2"
96 			     : "=r" (hi), "=r" (lo), "=r" (hi2));
97 	} while (hi2 != hi);
98 	return (u64)hi * 1000000000 + lo;
99 }
100 
101 static inline u64 get_vtb(void)
102 {
103 #ifdef CONFIG_PPC_BOOK3S_64
104 	if (cpu_has_feature(CPU_FTR_ARCH_207S))
105 		return mfspr(SPRN_VTB);
106 #endif
107 	return 0;
108 }
109 
110 #ifdef CONFIG_PPC64
111 static inline u64 get_tb(void)
112 {
113 	return mftb();
114 }
115 #else /* CONFIG_PPC64 */
116 static inline u64 get_tb(void)
117 {
118 	unsigned int tbhi, tblo, tbhi2;
119 
120 	do {
121 		tbhi = get_tbu();
122 		tblo = get_tbl();
123 		tbhi2 = get_tbu();
124 	} while (tbhi != tbhi2);
125 
126 	return ((u64)tbhi << 32) | tblo;
127 }
128 #endif /* !CONFIG_PPC64 */
129 
130 static inline u64 get_tb_or_rtc(void)
131 {
132 	return __USE_RTC() ? get_rtc() : get_tb();
133 }
134 
135 static inline void set_tb(unsigned int upper, unsigned int lower)
136 {
137 	mtspr(SPRN_TBWL, 0);
138 	mtspr(SPRN_TBWU, upper);
139 	mtspr(SPRN_TBWL, lower);
140 }
141 
142 /* Accessor functions for the decrementer register.
143  * The 4xx doesn't even have a decrementer.  I tried to use the
144  * generic timer interrupt code, which seems OK, with the 4xx PIT
145  * in auto-reload mode.  The problem is PIT stops counting when it
146  * hits zero.  If it would wrap, we could use it just like a decrementer.
147  */
148 static inline u64 get_dec(void)
149 {
150 #if defined(CONFIG_40x)
151 	return (mfspr(SPRN_PIT));
152 #else
153 	return (mfspr(SPRN_DEC));
154 #endif
155 }
156 
157 /*
158  * Note: Book E and 4xx processors differ from other PowerPC processors
159  * in when the decrementer generates its interrupt: on the 1 to 0
160  * transition for Book E/4xx, but on the 0 to -1 transition for others.
161  */
162 static inline void set_dec(u64 val)
163 {
164 #if defined(CONFIG_40x)
165 	mtspr(SPRN_PIT, (u32) val);
166 #else
167 #ifndef CONFIG_BOOKE
168 	--val;
169 #endif
170 	mtspr(SPRN_DEC, val);
171 #endif /* not 40x */
172 }
173 
174 static inline unsigned long tb_ticks_since(unsigned long tstamp)
175 {
176 	if (__USE_RTC()) {
177 		int delta = get_rtcl() - (unsigned int) tstamp;
178 		return delta < 0 ? delta + 1000000000 : delta;
179 	}
180 	return get_tbl() - tstamp;
181 }
182 
183 #define mulhwu(x,y) \
184 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
185 
186 #ifdef CONFIG_PPC64
187 #define mulhdu(x,y) \
188 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
189 #else
190 extern u64 mulhdu(u64, u64);
191 #endif
192 
193 extern void div128_by_32(u64 dividend_high, u64 dividend_low,
194 			 unsigned divisor, struct div_result *dr);
195 
196 extern void secondary_cpu_time_init(void);
197 extern void __init time_init(void);
198 
199 DECLARE_PER_CPU(u64, decrementers_next_tb);
200 
201 /* Convert timebase ticks to nanoseconds */
202 unsigned long long tb_to_ns(unsigned long long tb_ticks);
203 
204 #endif /* __KERNEL__ */
205 #endif /* __POWERPC_TIME_H */
206