xref: /linux/arch/s390/include/asm/timex.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  S390 version
4  *    Copyright IBM Corp. 1999
5  *
6  *  Derived from "include/asm-i386/timex.h"
7  *    Copyright (C) 1992, Linus Torvalds
8  */
9 
10 #ifndef _ASM_S390_TIMEX_H
11 #define _ASM_S390_TIMEX_H
12 
13 #include <linux/preempt.h>
14 #include <linux/time64.h>
15 #include <asm/lowcore.h>
16 #include <asm/asm.h>
17 
18 /* The value of the TOD clock for 1.1.1970. */
19 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
20 
21 extern u64 clock_comparator_max;
22 
23 union tod_clock {
24 	__uint128_t val;
25 	struct {
26 		__uint128_t ei	:  8; /* epoch index */
27 		__uint128_t tod : 64; /* bits 0-63 of tod clock */
28 		__uint128_t	: 40;
29 		__uint128_t pf	: 16; /* programmable field */
30 	};
31 	struct {
32 		__uint128_t eitod : 72; /* epoch index + bits 0-63 tod clock */
33 		__uint128_t	  : 56;
34 	};
35 	struct {
36 		__uint128_t us	: 60; /* micro-seconds */
37 		__uint128_t sus	: 12; /* sub-microseconds */
38 		__uint128_t	: 56;
39 	};
40 } __packed;
41 
42 /* Inline functions for clock register access. */
43 static inline int set_tod_clock(__u64 time)
44 {
45 	int cc;
46 
47 	asm volatile(
48 		"	sck	%[time]\n"
49 		CC_IPM(cc)
50 		: CC_OUT(cc, cc)
51 		: [time] "Q" (time)
52 		: CC_CLOBBER);
53 	return CC_TRANSFORM(cc);
54 }
55 
56 static inline int store_tod_clock_ext_cc(union tod_clock *clk)
57 {
58 	int cc;
59 
60 	asm volatile(
61 		"	stcke	%[clk]\n"
62 		CC_IPM(cc)
63 		: CC_OUT(cc, cc), [clk] "=Q" (*clk)
64 		:
65 		: CC_CLOBBER);
66 	return CC_TRANSFORM(cc);
67 }
68 
69 static __always_inline void store_tod_clock_ext(union tod_clock *tod)
70 {
71 	asm volatile("stcke %0" : "=Q" (*tod) : : "cc");
72 }
73 
74 static inline void set_clock_comparator(__u64 time)
75 {
76 	asm volatile("sckc %0" : : "Q" (time));
77 }
78 
79 static inline void set_tod_programmable_field(u16 val)
80 {
81 	asm volatile(
82 		"	lgr	0,%[val]\n"
83 		"	sckpf\n"
84 		:
85 		: [val] "d" ((unsigned long)val)
86 		: "0");
87 }
88 
89 void clock_comparator_work(void);
90 
91 void __init time_early_init(void);
92 
93 extern unsigned char ptff_function_mask[16];
94 
95 /* Function codes for the ptff instruction. */
96 #define PTFF_QAF	0x00	/* query available functions */
97 #define PTFF_QTO	0x01	/* query tod offset */
98 #define PTFF_QSI	0x02	/* query steering information */
99 #define PTFF_QPT	0x03	/* query physical clock */
100 #define PTFF_QUI	0x04	/* query UTC information */
101 #define PTFF_ATO	0x40	/* adjust tod offset */
102 #define PTFF_STO	0x41	/* set tod offset */
103 #define PTFF_SFS	0x42	/* set fine steering rate */
104 #define PTFF_SGS	0x43	/* set gross steering rate */
105 
106 /* Query TOD offset result */
107 struct ptff_qto {
108 	unsigned long physical_clock;
109 	unsigned long tod_offset;
110 	unsigned long logical_tod_offset;
111 	unsigned long tod_epoch_difference;
112 } __packed;
113 
114 static inline int ptff_query(unsigned int nr)
115 {
116 	unsigned char *ptr;
117 
118 	ptr = ptff_function_mask + (nr >> 3);
119 	return (*ptr & (0x80 >> (nr & 7))) != 0;
120 }
121 
122 /* Query UTC information result */
123 struct ptff_qui {
124 	unsigned int tm : 2;
125 	unsigned int ts : 2;
126 	unsigned int : 28;
127 	unsigned int pad_0x04;
128 	unsigned long leap_event;
129 	short old_leap;
130 	short new_leap;
131 	unsigned int pad_0x14;
132 	unsigned long prt[5];
133 	unsigned long cst[3];
134 	unsigned int skew;
135 	unsigned int pad_0x5c[41];
136 } __packed;
137 
138 /*
139  * ptff - Perform timing facility function
140  * @ptff_block: Pointer to ptff parameter block
141  * @len: Length of parameter block
142  * @func: Function code
143  * Returns: Condition code (0 on success)
144  */
145 #define ptff(ptff_block, len, func)					\
146 ({									\
147 	struct addrtype { char _[len]; };				\
148 	unsigned int reg0 = func;					\
149 	unsigned long reg1 = (unsigned long)(ptff_block);		\
150 	int rc;								\
151 									\
152 	asm volatile(							\
153 		"	lgr	0,%[reg0]\n"				\
154 		"	lgr	1,%[reg1]\n"				\
155 		"	ptff\n"						\
156 		CC_IPM(rc)						\
157 		: CC_OUT(rc, rc), "+m" (*(struct addrtype *)reg1)	\
158 		: [reg0] "d" (reg0), [reg1] "d" (reg1)			\
159 		: CC_CLOBBER_LIST("0", "1"));				\
160 	CC_TRANSFORM(rc);						\
161 })
162 
163 static inline unsigned long local_tick_disable(void)
164 {
165 	unsigned long old;
166 
167 	old = get_lowcore()->clock_comparator;
168 	get_lowcore()->clock_comparator = clock_comparator_max;
169 	set_clock_comparator(get_lowcore()->clock_comparator);
170 	return old;
171 }
172 
173 static inline void local_tick_enable(unsigned long comp)
174 {
175 	get_lowcore()->clock_comparator = comp;
176 	set_clock_comparator(get_lowcore()->clock_comparator);
177 }
178 
179 #define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
180 
181 typedef unsigned long cycles_t;
182 
183 static __always_inline unsigned long get_tod_clock(void)
184 {
185 	union tod_clock clk;
186 
187 	store_tod_clock_ext(&clk);
188 	return clk.tod;
189 }
190 
191 static inline unsigned long get_tod_clock_fast(void)
192 {
193 	unsigned long clk;
194 
195 	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
196 	return clk;
197 }
198 
199 static inline cycles_t get_cycles(void)
200 {
201 	return (cycles_t) get_tod_clock() >> 2;
202 }
203 #define get_cycles get_cycles
204 
205 int get_phys_clock(unsigned long *clock);
206 void init_cpu_timer(void);
207 
208 extern union tod_clock tod_clock_base;
209 
210 static __always_inline unsigned long __get_tod_clock_monotonic(void)
211 {
212 	return get_tod_clock() - tod_clock_base.tod;
213 }
214 
215 /**
216  * get_clock_monotonic - returns current time in clock rate units
217  *
218  * The clock and tod_clock_base get changed via stop_machine.
219  * Therefore preemption must be disabled, otherwise the returned
220  * value is not guaranteed to be monotonic.
221  */
222 static inline unsigned long get_tod_clock_monotonic(void)
223 {
224 	unsigned long tod;
225 
226 	preempt_disable_notrace();
227 	tod = __get_tod_clock_monotonic();
228 	preempt_enable_notrace();
229 	return tod;
230 }
231 
232 /**
233  * tod_to_ns - convert a TOD format value to nanoseconds
234  * @todval: to be converted TOD format value
235  * Returns: number of nanoseconds that correspond to the TOD format value
236  *
237  * Converting a 64 Bit TOD format value to nanoseconds means that the value
238  * must be divided by 4.096. In order to achieve that we multiply with 125
239  * and divide by 512:
240  *
241  *    ns = (todval * 125) >> 9;
242  *
243  * In order to avoid an overflow with the multiplication we can rewrite this.
244  * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
245  * we end up with
246  *
247  *    ns = ((2^9 * th + tl) * 125 ) >> 9;
248  * -> ns = (th * 125) + ((tl * 125) >> 9);
249  *
250  */
251 static __always_inline unsigned long tod_to_ns(unsigned long todval)
252 {
253 	return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
254 }
255 
256 static __always_inline u128 eitod_to_ns(u128 todval)
257 {
258 	return (todval * 125) >> 9;
259 }
260 
261 /**
262  * tod_after - compare two 64 bit TOD values
263  * @a: first 64 bit TOD timestamp
264  * @b: second 64 bit TOD timestamp
265  *
266  * Returns: true if a is later than b
267  */
268 static inline int tod_after(unsigned long a, unsigned long b)
269 {
270 	if (MACHINE_HAS_SCC)
271 		return (long) a > (long) b;
272 	return a > b;
273 }
274 
275 /**
276  * tod_after_eq - compare two 64 bit TOD values
277  * @a: first 64 bit TOD timestamp
278  * @b: second 64 bit TOD timestamp
279  *
280  * Returns: true if a is later than b
281  */
282 static inline int tod_after_eq(unsigned long a, unsigned long b)
283 {
284 	if (MACHINE_HAS_SCC)
285 		return (long) a >= (long) b;
286 	return a >= b;
287 }
288 
289 #endif
290