xref: /linux/arch/s390/include/asm/timex.h (revision 364eeb79a213fcf9164208b53764223ad522d6b3)
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_QUI	0x04	/* query UTC information */
100 #define PTFF_ATO	0x40	/* adjust tod offset */
101 #define PTFF_STO	0x41	/* set tod offset */
102 #define PTFF_SFS	0x42	/* set fine steering rate */
103 #define PTFF_SGS	0x43	/* set gross steering rate */
104 
105 /* Query TOD offset result */
106 struct ptff_qto {
107 	unsigned long physical_clock;
108 	unsigned long tod_offset;
109 	unsigned long logical_tod_offset;
110 	unsigned long tod_epoch_difference;
111 } __packed;
112 
113 static inline int ptff_query(unsigned int nr)
114 {
115 	unsigned char *ptr;
116 
117 	ptr = ptff_function_mask + (nr >> 3);
118 	return (*ptr & (0x80 >> (nr & 7))) != 0;
119 }
120 
121 /* Query UTC information result */
122 struct ptff_qui {
123 	unsigned int tm : 2;
124 	unsigned int ts : 2;
125 	unsigned int : 28;
126 	unsigned int pad_0x04;
127 	unsigned long leap_event;
128 	short old_leap;
129 	short new_leap;
130 	unsigned int pad_0x14;
131 	unsigned long prt[5];
132 	unsigned long cst[3];
133 	unsigned int skew;
134 	unsigned int pad_0x5c[41];
135 } __packed;
136 
137 /*
138  * ptff - Perform timing facility function
139  * @ptff_block: Pointer to ptff parameter block
140  * @len: Length of parameter block
141  * @func: Function code
142  * Returns: Condition code (0 on success)
143  */
144 #define ptff(ptff_block, len, func)					\
145 ({									\
146 	struct addrtype { char _[len]; };				\
147 	unsigned int reg0 = func;					\
148 	unsigned long reg1 = (unsigned long)(ptff_block);		\
149 	int rc;								\
150 									\
151 	asm volatile(							\
152 		"	lgr	0,%[reg0]\n"				\
153 		"	lgr	1,%[reg1]\n"				\
154 		"	ptff\n"						\
155 		CC_IPM(rc)						\
156 		: CC_OUT(rc, rc), "+m" (*(struct addrtype *)reg1)	\
157 		: [reg0] "d" (reg0), [reg1] "d" (reg1)			\
158 		: CC_CLOBBER_LIST("0", "1"));				\
159 	CC_TRANSFORM(rc);						\
160 })
161 
162 static inline unsigned long local_tick_disable(void)
163 {
164 	unsigned long old;
165 
166 	old = get_lowcore()->clock_comparator;
167 	get_lowcore()->clock_comparator = clock_comparator_max;
168 	set_clock_comparator(get_lowcore()->clock_comparator);
169 	return old;
170 }
171 
172 static inline void local_tick_enable(unsigned long comp)
173 {
174 	get_lowcore()->clock_comparator = comp;
175 	set_clock_comparator(get_lowcore()->clock_comparator);
176 }
177 
178 #define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
179 
180 typedef unsigned long cycles_t;
181 
182 static __always_inline unsigned long get_tod_clock(void)
183 {
184 	union tod_clock clk;
185 
186 	store_tod_clock_ext(&clk);
187 	return clk.tod;
188 }
189 
190 static inline unsigned long get_tod_clock_fast(void)
191 {
192 	unsigned long clk;
193 
194 	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
195 	return clk;
196 }
197 
198 static inline cycles_t get_cycles(void)
199 {
200 	return (cycles_t) get_tod_clock() >> 2;
201 }
202 #define get_cycles get_cycles
203 
204 int get_phys_clock(unsigned long *clock);
205 void init_cpu_timer(void);
206 
207 extern union tod_clock tod_clock_base;
208 
209 static __always_inline unsigned long __get_tod_clock_monotonic(void)
210 {
211 	return get_tod_clock() - tod_clock_base.tod;
212 }
213 
214 /**
215  * get_clock_monotonic - returns current time in clock rate units
216  *
217  * The clock and tod_clock_base get changed via stop_machine.
218  * Therefore preemption must be disabled, otherwise the returned
219  * value is not guaranteed to be monotonic.
220  */
221 static inline unsigned long get_tod_clock_monotonic(void)
222 {
223 	unsigned long tod;
224 
225 	preempt_disable_notrace();
226 	tod = __get_tod_clock_monotonic();
227 	preempt_enable_notrace();
228 	return tod;
229 }
230 
231 /**
232  * tod_to_ns - convert a TOD format value to nanoseconds
233  * @todval: to be converted TOD format value
234  * Returns: number of nanoseconds that correspond to the TOD format value
235  *
236  * Converting a 64 Bit TOD format value to nanoseconds means that the value
237  * must be divided by 4.096. In order to achieve that we multiply with 125
238  * and divide by 512:
239  *
240  *    ns = (todval * 125) >> 9;
241  *
242  * In order to avoid an overflow with the multiplication we can rewrite this.
243  * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
244  * we end up with
245  *
246  *    ns = ((2^9 * th + tl) * 125 ) >> 9;
247  * -> ns = (th * 125) + ((tl * 125) >> 9);
248  *
249  */
250 static __always_inline unsigned long tod_to_ns(unsigned long todval)
251 {
252 	return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
253 }
254 
255 /**
256  * tod_after - compare two 64 bit TOD values
257  * @a: first 64 bit TOD timestamp
258  * @b: second 64 bit TOD timestamp
259  *
260  * Returns: true if a is later than b
261  */
262 static inline int tod_after(unsigned long a, unsigned long b)
263 {
264 	if (MACHINE_HAS_SCC)
265 		return (long) a > (long) b;
266 	return a > b;
267 }
268 
269 /**
270  * tod_after_eq - compare two 64 bit TOD values
271  * @a: first 64 bit TOD timestamp
272  * @b: second 64 bit TOD timestamp
273  *
274  * Returns: true if a is later than b
275  */
276 static inline int tod_after_eq(unsigned long a, unsigned long b)
277 {
278 	if (MACHINE_HAS_SCC)
279 		return (long) a >= (long) b;
280 	return a >= b;
281 }
282 
283 #endif
284