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
17/* The value of the TOD clock for 1.1.1970. */
18#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
19
20extern u64 clock_comparator_max;
21
22union tod_clock {
23	__uint128_t val;
24	struct {
25		__uint128_t ei	:  8; /* epoch index */
26		__uint128_t tod : 64; /* bits 0-63 of tod clock */
27		__uint128_t	: 40;
28		__uint128_t pf	: 16; /* programmable field */
29	};
30	struct {
31		__uint128_t eitod : 72; /* epoch index + bits 0-63 tod clock */
32		__uint128_t	  : 56;
33	};
34	struct {
35		__uint128_t us	: 60; /* micro-seconds */
36		__uint128_t sus	: 12; /* sub-microseconds */
37		__uint128_t	: 56;
38	};
39} __packed;
40
41/* Inline functions for clock register access. */
42static inline int set_tod_clock(__u64 time)
43{
44	int cc;
45
46	asm volatile(
47		"   sck   %1\n"
48		"   ipm   %0\n"
49		"   srl   %0,28\n"
50		: "=d" (cc) : "Q" (time) : "cc");
51	return cc;
52}
53
54static inline int store_tod_clock_ext_cc(union tod_clock *clk)
55{
56	int cc;
57
58	asm volatile(
59		"   stcke  %1\n"
60		"   ipm   %0\n"
61		"   srl   %0,28\n"
62		: "=d" (cc), "=Q" (*clk) : : "cc");
63	return cc;
64}
65
66static __always_inline void store_tod_clock_ext(union tod_clock *tod)
67{
68	asm volatile("stcke %0" : "=Q" (*tod) : : "cc");
69}
70
71static inline void set_clock_comparator(__u64 time)
72{
73	asm volatile("sckc %0" : : "Q" (time));
74}
75
76static inline void set_tod_programmable_field(u16 val)
77{
78	asm volatile(
79		"	lgr	0,%[val]\n"
80		"	sckpf\n"
81		:
82		: [val] "d" ((unsigned long)val)
83		: "0");
84}
85
86void clock_comparator_work(void);
87
88void __init time_early_init(void);
89
90extern unsigned char ptff_function_mask[16];
91
92/* Function codes for the ptff instruction. */
93#define PTFF_QAF	0x00	/* query available functions */
94#define PTFF_QTO	0x01	/* query tod offset */
95#define PTFF_QSI	0x02	/* query steering information */
96#define PTFF_QUI	0x04	/* query UTC information */
97#define PTFF_ATO	0x40	/* adjust tod offset */
98#define PTFF_STO	0x41	/* set tod offset */
99#define PTFF_SFS	0x42	/* set fine steering rate */
100#define PTFF_SGS	0x43	/* set gross steering rate */
101
102/* Query TOD offset result */
103struct ptff_qto {
104	unsigned long physical_clock;
105	unsigned long tod_offset;
106	unsigned long logical_tod_offset;
107	unsigned long tod_epoch_difference;
108} __packed;
109
110static inline int ptff_query(unsigned int nr)
111{
112	unsigned char *ptr;
113
114	ptr = ptff_function_mask + (nr >> 3);
115	return (*ptr & (0x80 >> (nr & 7))) != 0;
116}
117
118/* Query UTC information result */
119struct ptff_qui {
120	unsigned int tm : 2;
121	unsigned int ts : 2;
122	unsigned int : 28;
123	unsigned int pad_0x04;
124	unsigned long leap_event;
125	short old_leap;
126	short new_leap;
127	unsigned int pad_0x14;
128	unsigned long prt[5];
129	unsigned long cst[3];
130	unsigned int skew;
131	unsigned int pad_0x5c[41];
132} __packed;
133
134/*
135 * ptff - Perform timing facility function
136 * @ptff_block: Pointer to ptff parameter block
137 * @len: Length of parameter block
138 * @func: Function code
139 * Returns: Condition code (0 on success)
140 */
141#define ptff(ptff_block, len, func)					\
142({									\
143	struct addrtype { char _[len]; };				\
144	unsigned int reg0 = func;					\
145	unsigned long reg1 = (unsigned long)(ptff_block);		\
146	int rc;								\
147									\
148	asm volatile(							\
149		"	lgr	0,%[reg0]\n"				\
150		"	lgr	1,%[reg1]\n"				\
151		"	ptff\n"						\
152		"	ipm	%[rc]\n"				\
153		"	srl	%[rc],28\n"				\
154		: [rc] "=&d" (rc), "+m" (*(struct addrtype *)reg1)	\
155		: [reg0] "d" (reg0), [reg1] "d" (reg1)			\
156		: "cc", "0", "1");					\
157	rc;								\
158})
159
160static inline unsigned long local_tick_disable(void)
161{
162	unsigned long old;
163
164	old = S390_lowcore.clock_comparator;
165	S390_lowcore.clock_comparator = clock_comparator_max;
166	set_clock_comparator(S390_lowcore.clock_comparator);
167	return old;
168}
169
170static inline void local_tick_enable(unsigned long comp)
171{
172	S390_lowcore.clock_comparator = comp;
173	set_clock_comparator(S390_lowcore.clock_comparator);
174}
175
176#define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
177
178typedef unsigned long cycles_t;
179
180static __always_inline unsigned long get_tod_clock(void)
181{
182	union tod_clock clk;
183
184	store_tod_clock_ext(&clk);
185	return clk.tod;
186}
187
188static inline unsigned long get_tod_clock_fast(void)
189{
190	unsigned long clk;
191
192	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
193	return clk;
194}
195
196static inline cycles_t get_cycles(void)
197{
198	return (cycles_t) get_tod_clock() >> 2;
199}
200#define get_cycles get_cycles
201
202int get_phys_clock(unsigned long *clock);
203void init_cpu_timer(void);
204
205extern union tod_clock tod_clock_base;
206
207static __always_inline unsigned long __get_tod_clock_monotonic(void)
208{
209	return get_tod_clock() - tod_clock_base.tod;
210}
211
212/**
213 * get_clock_monotonic - returns current time in clock rate units
214 *
215 * The clock and tod_clock_base get changed via stop_machine.
216 * Therefore preemption must be disabled, otherwise the returned
217 * value is not guaranteed to be monotonic.
218 */
219static inline unsigned long get_tod_clock_monotonic(void)
220{
221	unsigned long tod;
222
223	preempt_disable_notrace();
224	tod = __get_tod_clock_monotonic();
225	preempt_enable_notrace();
226	return tod;
227}
228
229/**
230 * tod_to_ns - convert a TOD format value to nanoseconds
231 * @todval: to be converted TOD format value
232 * Returns: number of nanoseconds that correspond to the TOD format value
233 *
234 * Converting a 64 Bit TOD format value to nanoseconds means that the value
235 * must be divided by 4.096. In order to achieve that we multiply with 125
236 * and divide by 512:
237 *
238 *    ns = (todval * 125) >> 9;
239 *
240 * In order to avoid an overflow with the multiplication we can rewrite this.
241 * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
242 * we end up with
243 *
244 *    ns = ((2^9 * th + tl) * 125 ) >> 9;
245 * -> ns = (th * 125) + ((tl * 125) >> 9);
246 *
247 */
248static __always_inline unsigned long tod_to_ns(unsigned long todval)
249{
250	return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
251}
252
253/**
254 * tod_after - compare two 64 bit TOD values
255 * @a: first 64 bit TOD timestamp
256 * @b: second 64 bit TOD timestamp
257 *
258 * Returns: true if a is later than b
259 */
260static inline int tod_after(unsigned long a, unsigned long b)
261{
262	if (MACHINE_HAS_SCC)
263		return (long) a > (long) b;
264	return a > b;
265}
266
267/**
268 * tod_after_eq - compare two 64 bit TOD values
269 * @a: first 64 bit TOD timestamp
270 * @b: second 64 bit TOD timestamp
271 *
272 * Returns: true if a is later than b
273 */
274static inline int tod_after_eq(unsigned long a, unsigned long b)
275{
276	if (MACHINE_HAS_SCC)
277		return (long) a >= (long) b;
278	return a >= b;
279}
280
281#endif
282