xref: /openbmc/linux/arch/s390/include/asm/timex.h (revision 80483c3a)
1 /*
2  *  S390 version
3  *    Copyright IBM Corp. 1999
4  *
5  *  Derived from "include/asm-i386/timex.h"
6  *    Copyright (C) 1992, Linus Torvalds
7  */
8 
9 #ifndef _ASM_S390_TIMEX_H
10 #define _ASM_S390_TIMEX_H
11 
12 #include <asm/lowcore.h>
13 #include <linux/time64.h>
14 
15 /* The value of the TOD clock for 1.1.1970. */
16 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
17 
18 /* Inline functions for clock register access. */
19 static inline int set_tod_clock(__u64 time)
20 {
21 	int cc;
22 
23 	asm volatile(
24 		"   sck   %1\n"
25 		"   ipm   %0\n"
26 		"   srl   %0,28\n"
27 		: "=d" (cc) : "Q" (time) : "cc");
28 	return cc;
29 }
30 
31 static inline int store_tod_clock(__u64 *time)
32 {
33 	int cc;
34 
35 	asm volatile(
36 		"   stck  %1\n"
37 		"   ipm   %0\n"
38 		"   srl   %0,28\n"
39 		: "=d" (cc), "=Q" (*time) : : "cc");
40 	return cc;
41 }
42 
43 static inline void set_clock_comparator(__u64 time)
44 {
45 	asm volatile("sckc %0" : : "Q" (time));
46 }
47 
48 static inline void store_clock_comparator(__u64 *time)
49 {
50 	asm volatile("stckc %0" : "=Q" (*time));
51 }
52 
53 void clock_comparator_work(void);
54 
55 void __init ptff_init(void);
56 
57 extern unsigned char ptff_function_mask[16];
58 extern unsigned long lpar_offset;
59 extern unsigned long initial_leap_seconds;
60 
61 /* Function codes for the ptff instruction. */
62 #define PTFF_QAF	0x00	/* query available functions */
63 #define PTFF_QTO	0x01	/* query tod offset */
64 #define PTFF_QSI	0x02	/* query steering information */
65 #define PTFF_QUI	0x04	/* query UTC information */
66 #define PTFF_ATO	0x40	/* adjust tod offset */
67 #define PTFF_STO	0x41	/* set tod offset */
68 #define PTFF_SFS	0x42	/* set fine steering rate */
69 #define PTFF_SGS	0x43	/* set gross steering rate */
70 
71 /* Query TOD offset result */
72 struct ptff_qto {
73 	unsigned long long physical_clock;
74 	unsigned long long tod_offset;
75 	unsigned long long logical_tod_offset;
76 	unsigned long long tod_epoch_difference;
77 } __packed;
78 
79 static inline int ptff_query(unsigned int nr)
80 {
81 	unsigned char *ptr;
82 
83 	ptr = ptff_function_mask + (nr >> 3);
84 	return (*ptr & (0x80 >> (nr & 7))) != 0;
85 }
86 
87 /* Query UTC information result */
88 struct ptff_qui {
89 	unsigned int tm : 2;
90 	unsigned int ts : 2;
91 	unsigned int : 28;
92 	unsigned int pad_0x04;
93 	unsigned long leap_event;
94 	short old_leap;
95 	short new_leap;
96 	unsigned int pad_0x14;
97 	unsigned long prt[5];
98 	unsigned long cst[3];
99 	unsigned int skew;
100 	unsigned int pad_0x5c[41];
101 } __packed;
102 
103 static inline int ptff(void *ptff_block, size_t len, unsigned int func)
104 {
105 	typedef struct { char _[len]; } addrtype;
106 	register unsigned int reg0 asm("0") = func;
107 	register unsigned long reg1 asm("1") = (unsigned long) ptff_block;
108 	int rc;
109 
110 	asm volatile(
111 		"	.word	0x0104\n"
112 		"	ipm	%0\n"
113 		"	srl	%0,28\n"
114 		: "=d" (rc), "+m" (*(addrtype *) ptff_block)
115 		: "d" (reg0), "d" (reg1) : "cc");
116 	return rc;
117 }
118 
119 static inline unsigned long long local_tick_disable(void)
120 {
121 	unsigned long long old;
122 
123 	old = S390_lowcore.clock_comparator;
124 	S390_lowcore.clock_comparator = -1ULL;
125 	set_clock_comparator(S390_lowcore.clock_comparator);
126 	return old;
127 }
128 
129 static inline void local_tick_enable(unsigned long long comp)
130 {
131 	S390_lowcore.clock_comparator = comp;
132 	set_clock_comparator(S390_lowcore.clock_comparator);
133 }
134 
135 #define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
136 #define STORE_CLOCK_EXT_SIZE	16	/* stcke writes 16 bytes */
137 
138 typedef unsigned long long cycles_t;
139 
140 static inline void get_tod_clock_ext(char *clk)
141 {
142 	typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
143 
144 	asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
145 }
146 
147 static inline unsigned long long get_tod_clock(void)
148 {
149 	unsigned char clk[STORE_CLOCK_EXT_SIZE];
150 
151 	get_tod_clock_ext(clk);
152 	return *((unsigned long long *)&clk[1]);
153 }
154 
155 static inline unsigned long long get_tod_clock_fast(void)
156 {
157 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
158 	unsigned long long clk;
159 
160 	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
161 	return clk;
162 #else
163 	return get_tod_clock();
164 #endif
165 }
166 
167 static inline cycles_t get_cycles(void)
168 {
169 	return (cycles_t) get_tod_clock() >> 2;
170 }
171 
172 int get_phys_clock(unsigned long long *clock);
173 void init_cpu_timer(void);
174 unsigned long long monotonic_clock(void);
175 
176 void tod_to_timeval(__u64 todval, struct timespec64 *xt);
177 
178 static inline
179 void stck_to_timespec64(unsigned long long stck, struct timespec64 *ts)
180 {
181 	tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
182 }
183 
184 extern u64 sched_clock_base_cc;
185 
186 /**
187  * get_clock_monotonic - returns current time in clock rate units
188  *
189  * The caller must ensure that preemption is disabled.
190  * The clock and sched_clock_base get changed via stop_machine.
191  * Therefore preemption must be disabled when calling this
192  * function, otherwise the returned value is not guaranteed to
193  * be monotonic.
194  */
195 static inline unsigned long long get_tod_clock_monotonic(void)
196 {
197 	return get_tod_clock() - sched_clock_base_cc;
198 }
199 
200 /**
201  * tod_to_ns - convert a TOD format value to nanoseconds
202  * @todval: to be converted TOD format value
203  * Returns: number of nanoseconds that correspond to the TOD format value
204  *
205  * Converting a 64 Bit TOD format value to nanoseconds means that the value
206  * must be divided by 4.096. In order to achieve that we multiply with 125
207  * and divide by 512:
208  *
209  *    ns = (todval * 125) >> 9;
210  *
211  * In order to avoid an overflow with the multiplication we can rewrite this.
212  * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits)
213  * we end up with
214  *
215  *    ns = ((2^32 * th + tl) * 125 ) >> 9;
216  * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9);
217  *
218  */
219 static inline unsigned long long tod_to_ns(unsigned long long todval)
220 {
221 	unsigned long long ns;
222 
223 	ns = ((todval >> 32) << 23) * 125;
224 	ns += ((todval & 0xffffffff) * 125) >> 9;
225 	return ns;
226 }
227 
228 #endif
229