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
22/* Inline functions for clock register access. */
23static inline int set_tod_clock(__u64 time)
24{
25	int cc;
26
27	asm volatile(
28		"   sck   %1\n"
29		"   ipm   %0\n"
30		"   srl   %0,28\n"
31		: "=d" (cc) : "Q" (time) : "cc");
32	return cc;
33}
34
35static inline int store_tod_clock(__u64 *time)
36{
37	int cc;
38
39	asm volatile(
40		"   stck  %1\n"
41		"   ipm   %0\n"
42		"   srl   %0,28\n"
43		: "=d" (cc), "=Q" (*time) : : "cc");
44	return cc;
45}
46
47static inline void set_clock_comparator(__u64 time)
48{
49	asm volatile("sckc %0" : : "Q" (time));
50}
51
52void clock_comparator_work(void);
53
54void __init time_early_init(void);
55
56extern unsigned char ptff_function_mask[16];
57
58/* Function codes for the ptff instruction. */
59#define PTFF_QAF	0x00	/* query available functions */
60#define PTFF_QTO	0x01	/* query tod offset */
61#define PTFF_QSI	0x02	/* query steering information */
62#define PTFF_QUI	0x04	/* query UTC information */
63#define PTFF_ATO	0x40	/* adjust tod offset */
64#define PTFF_STO	0x41	/* set tod offset */
65#define PTFF_SFS	0x42	/* set fine steering rate */
66#define PTFF_SGS	0x43	/* set gross steering rate */
67
68/* Query TOD offset result */
69struct ptff_qto {
70	unsigned long long physical_clock;
71	unsigned long long tod_offset;
72	unsigned long long logical_tod_offset;
73	unsigned long long tod_epoch_difference;
74} __packed;
75
76static inline int ptff_query(unsigned int nr)
77{
78	unsigned char *ptr;
79
80	ptr = ptff_function_mask + (nr >> 3);
81	return (*ptr & (0x80 >> (nr & 7))) != 0;
82}
83
84/* Query UTC information result */
85struct ptff_qui {
86	unsigned int tm : 2;
87	unsigned int ts : 2;
88	unsigned int : 28;
89	unsigned int pad_0x04;
90	unsigned long leap_event;
91	short old_leap;
92	short new_leap;
93	unsigned int pad_0x14;
94	unsigned long prt[5];
95	unsigned long cst[3];
96	unsigned int skew;
97	unsigned int pad_0x5c[41];
98} __packed;
99
100/*
101 * ptff - Perform timing facility function
102 * @ptff_block: Pointer to ptff parameter block
103 * @len: Length of parameter block
104 * @func: Function code
105 * Returns: Condition code (0 on success)
106 */
107#define ptff(ptff_block, len, func)					\
108({									\
109	struct addrtype { char _[len]; };				\
110	register unsigned int reg0 asm("0") = func;			\
111	register unsigned long reg1 asm("1") = (unsigned long) (ptff_block);\
112	int rc;								\
113									\
114	asm volatile(							\
115		"	.word	0x0104\n"				\
116		"	ipm	%0\n"					\
117		"	srl	%0,28\n"				\
118		: "=d" (rc), "+m" (*(struct addrtype *) reg1)		\
119		: "d" (reg0), "d" (reg1) : "cc");			\
120	rc;								\
121})
122
123static inline unsigned long long local_tick_disable(void)
124{
125	unsigned long long old;
126
127	old = S390_lowcore.clock_comparator;
128	S390_lowcore.clock_comparator = clock_comparator_max;
129	set_clock_comparator(S390_lowcore.clock_comparator);
130	return old;
131}
132
133static inline void local_tick_enable(unsigned long long comp)
134{
135	S390_lowcore.clock_comparator = comp;
136	set_clock_comparator(S390_lowcore.clock_comparator);
137}
138
139#define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
140#define STORE_CLOCK_EXT_SIZE	16	/* stcke writes 16 bytes */
141
142typedef unsigned long long cycles_t;
143
144static inline void get_tod_clock_ext(char *clk)
145{
146	typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
147
148	asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
149}
150
151static inline unsigned long long get_tod_clock(void)
152{
153	char clk[STORE_CLOCK_EXT_SIZE];
154
155	get_tod_clock_ext(clk);
156	return *((unsigned long long *)&clk[1]);
157}
158
159static inline unsigned long long get_tod_clock_fast(void)
160{
161#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
162	unsigned long long clk;
163
164	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
165	return clk;
166#else
167	return get_tod_clock();
168#endif
169}
170
171static inline cycles_t get_cycles(void)
172{
173	return (cycles_t) get_tod_clock() >> 2;
174}
175#define get_cycles get_cycles
176
177int get_phys_clock(unsigned long *clock);
178void init_cpu_timer(void);
179
180extern unsigned char tod_clock_base[16] __aligned(8);
181
182/**
183 * get_clock_monotonic - returns current time in clock rate units
184 *
185 * The clock and tod_clock_base get changed via stop_machine.
186 * Therefore preemption must be disabled, otherwise the returned
187 * value is not guaranteed to be monotonic.
188 */
189static inline unsigned long long get_tod_clock_monotonic(void)
190{
191	unsigned long long tod;
192
193	preempt_disable_notrace();
194	tod = get_tod_clock() - *(unsigned long long *) &tod_clock_base[1];
195	preempt_enable_notrace();
196	return tod;
197}
198
199/**
200 * tod_to_ns - convert a TOD format value to nanoseconds
201 * @todval: to be converted TOD format value
202 * Returns: number of nanoseconds that correspond to the TOD format value
203 *
204 * Converting a 64 Bit TOD format value to nanoseconds means that the value
205 * must be divided by 4.096. In order to achieve that we multiply with 125
206 * and divide by 512:
207 *
208 *    ns = (todval * 125) >> 9;
209 *
210 * In order to avoid an overflow with the multiplication we can rewrite this.
211 * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
212 * we end up with
213 *
214 *    ns = ((2^9 * th + tl) * 125 ) >> 9;
215 * -> ns = (th * 125) + ((tl * 125) >> 9);
216 *
217 */
218static inline unsigned long long tod_to_ns(unsigned long long todval)
219{
220	return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
221}
222
223/**
224 * tod_after - compare two 64 bit TOD values
225 * @a: first 64 bit TOD timestamp
226 * @b: second 64 bit TOD timestamp
227 *
228 * Returns: true if a is later than b
229 */
230static inline int tod_after(unsigned long long a, unsigned long long b)
231{
232	if (MACHINE_HAS_SCC)
233		return (long long) a > (long long) b;
234	return a > b;
235}
236
237/**
238 * tod_after_eq - compare two 64 bit TOD values
239 * @a: first 64 bit TOD timestamp
240 * @b: second 64 bit TOD timestamp
241 *
242 * Returns: true if a is later than b
243 */
244static inline int tod_after_eq(unsigned long long a, unsigned long long b)
245{
246	if (MACHINE_HAS_SCC)
247		return (long long) a >= (long long) b;
248	return a >= b;
249}
250
251#endif
252