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/machine.h>
17 #include <asm/asm.h>
18 
19 /* The value of the TOD clock for 1.1.1970. */
20 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
21 
22 extern u64 clock_comparator_max;
23 
24 union tod_clock {
25 	__uint128_t val;
26 	struct {
27 		__uint128_t ei	:  8; /* epoch index */
28 		__uint128_t tod : 64; /* bits 0-63 of tod clock */
29 		__uint128_t	: 40;
30 		__uint128_t pf	: 16; /* programmable field */
31 	};
32 	struct {
33 		__uint128_t eitod : 72; /* epoch index + bits 0-63 tod clock */
34 		__uint128_t	  : 56;
35 	};
36 	struct {
37 		__uint128_t us	: 60; /* micro-seconds */
38 		__uint128_t sus	: 12; /* sub-microseconds */
39 		__uint128_t	: 56;
40 	};
41 } __packed;
42 
43 /* Inline functions for clock register access. */
44 static inline int set_tod_clock(__u64 time)
45 {
46 	int cc;
47 
48 	asm volatile(
49 		"	sck	%[time]\n"
50 		CC_IPM(cc)
51 		: CC_OUT(cc, cc)
52 		: [time] "Q" (time)
53 		: CC_CLOBBER);
54 	return CC_TRANSFORM(cc);
55 }
56 
57 static inline int store_tod_clock_ext_cc(union tod_clock *clk)
58 {
59 	int cc;
60 
61 	asm volatile(
62 		"	stcke	%[clk]\n"
63 		CC_IPM(cc)
64 		: CC_OUT(cc, cc), [clk] "=Q" (*clk)
65 		:
66 		: CC_CLOBBER);
67 	return CC_TRANSFORM(cc);
68 }
69 
70 static __always_inline void store_tod_clock_ext(union tod_clock *tod)
71 {
72 	asm volatile("stcke %0" : "=Q" (*tod) : : "cc");
73 }
74 
75 static inline void set_clock_comparator(__u64 time)
76 {
77 	asm volatile("sckc %0" : : "Q" (time));
78 }
79 
80 static inline void set_tod_programmable_field(u16 val)
81 {
82 	asm volatile(
83 		"	lgr	0,%[val]\n"
84 		"	sckpf\n"
85 		:
86 		: [val] "d" ((unsigned long)val)
87 		: "0");
88 }
89 
90 void clock_comparator_work(void);
91 
92 void __init time_early_init(void);
93 
94 extern unsigned char ptff_function_mask[16];
95 
96 /* Function codes for the ptff instruction. */
97 #define PTFF_QAF	0x00	/* query available functions */
98 #define PTFF_QTO	0x01	/* query tod offset */
99 #define PTFF_QSI	0x02	/* query steering information */
100 #define PTFF_QPT	0x03	/* query physical clock */
101 #define PTFF_QUI	0x04	/* query UTC information */
102 #define PTFF_ATO	0x40	/* adjust tod offset */
103 #define PTFF_STO	0x41	/* set tod offset */
104 #define PTFF_SFS	0x42	/* set fine steering rate */
105 #define PTFF_SGS	0x43	/* set gross steering rate */
106 
107 /* Query TOD offset result */
108 struct ptff_qto {
109 	unsigned long physical_clock;
110 	unsigned long tod_offset;
111 	unsigned long logical_tod_offset;
112 	unsigned long tod_epoch_difference;
113 } __packed;
114 
115 static inline int ptff_query(unsigned int nr)
116 {
117 	unsigned char *ptr;
118 
119 	ptr = ptff_function_mask + (nr >> 3);
120 	return (*ptr & (0x80 >> (nr & 7))) != 0;
121 }
122 
123 /* Query UTC information result */
124 struct ptff_qui {
125 	unsigned int tm : 2;
126 	unsigned int ts : 2;
127 	unsigned int : 28;
128 	unsigned int pad_0x04;
129 	unsigned long leap_event;
130 	short old_leap;
131 	short new_leap;
132 	unsigned int pad_0x14;
133 	unsigned long prt[5];
134 	unsigned long cst[3];
135 	unsigned int skew;
136 	unsigned int pad_0x5c[41];
137 } __packed;
138 
139 /*
140  * ptff - Perform timing facility function
141  * @ptff_block: Pointer to ptff parameter block
142  * @len: Length of parameter block
143  * @func: Function code
144  * Returns: Condition code (0 on success)
145  */
146 #define ptff(ptff_block, len, func)					\
147 ({									\
148 	struct addrtype { char _[len]; };				\
149 	unsigned int reg0 = func;					\
150 	unsigned long reg1 = (unsigned long)(ptff_block);		\
151 	int rc;								\
152 									\
153 	asm volatile(							\
154 		"	lgr	0,%[reg0]\n"				\
155 		"	lgr	1,%[reg1]\n"				\
156 		"	ptff\n"						\
157 		CC_IPM(rc)						\
158 		: CC_OUT(rc, rc), "+m" (*(struct addrtype *)reg1)	\
159 		: [reg0] "d" (reg0), [reg1] "d" (reg1)			\
160 		: CC_CLOBBER_LIST("0", "1"));				\
161 	CC_TRANSFORM(rc);						\
162 })
163 
164 static inline unsigned long local_tick_disable(void)
165 {
166 	unsigned long old;
167 
168 	old = get_lowcore()->clock_comparator;
169 	get_lowcore()->clock_comparator = clock_comparator_max;
170 	set_clock_comparator(get_lowcore()->clock_comparator);
171 	return old;
172 }
173 
174 static inline void local_tick_enable(unsigned long comp)
175 {
176 	get_lowcore()->clock_comparator = comp;
177 	set_clock_comparator(get_lowcore()->clock_comparator);
178 }
179 
180 #define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
181 
182 typedef unsigned long cycles_t;
183 
184 static __always_inline unsigned long get_tod_clock(void)
185 {
186 	union tod_clock clk;
187 
188 	store_tod_clock_ext(&clk);
189 	return clk.tod;
190 }
191 
192 static inline unsigned long get_tod_clock_fast(void)
193 {
194 	unsigned long clk;
195 
196 	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
197 	return clk;
198 }
199 
200 static inline cycles_t get_cycles(void)
201 {
202 	return (cycles_t) get_tod_clock() >> 2;
203 }
204 #define get_cycles get_cycles
205 
206 int get_phys_clock(unsigned long *clock);
207 void init_cpu_timer(void);
208 
209 extern union tod_clock tod_clock_base;
210 
211 static __always_inline unsigned long __get_tod_clock_monotonic(void)
212 {
213 	return get_tod_clock() - tod_clock_base.tod;
214 }
215 
216 /**
217  * get_clock_monotonic - returns current time in clock rate units
218  *
219  * The clock and tod_clock_base get changed via stop_machine.
220  * Therefore preemption must be disabled, otherwise the returned
221  * value is not guaranteed to be monotonic.
222  */
223 static inline unsigned long get_tod_clock_monotonic(void)
224 {
225 	unsigned long tod;
226 
227 	preempt_disable_notrace();
228 	tod = __get_tod_clock_monotonic();
229 	preempt_enable_notrace();
230 	return tod;
231 }
232 
233 /**
234  * tod_to_ns - convert a TOD format value to nanoseconds
235  * @todval: to be converted TOD format value
236  * Returns: number of nanoseconds that correspond to the TOD format value
237  *
238  * Converting a 64 Bit TOD format value to nanoseconds means that the value
239  * must be divided by 4.096. In order to achieve that we multiply with 125
240  * and divide by 512:
241  *
242  *    ns = (todval * 125) >> 9;
243  *
244  * In order to avoid an overflow with the multiplication we can rewrite this.
245  * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
246  * we end up with
247  *
248  *    ns = ((2^9 * th + tl) * 125 ) >> 9;
249  * -> ns = (th * 125) + ((tl * 125) >> 9);
250  *
251  */
252 static __always_inline unsigned long tod_to_ns(unsigned long todval)
253 {
254 	return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
255 }
256 
257 static __always_inline u128 eitod_to_ns(u128 todval)
258 {
259 	return (todval * 125) >> 9;
260 }
261 
262 /**
263  * tod_after - compare two 64 bit TOD values
264  * @a: first 64 bit TOD timestamp
265  * @b: second 64 bit TOD timestamp
266  *
267  * Returns: true if a is later than b
268  */
269 static inline int tod_after(unsigned long a, unsigned long b)
270 {
271 	if (machine_has_scc())
272 		return (long) a > (long) b;
273 	return a > b;
274 }
275 
276 /**
277  * tod_after_eq - compare two 64 bit TOD values
278  * @a: first 64 bit TOD timestamp
279  * @b: second 64 bit TOD timestamp
280  *
281  * Returns: true if a is later than b
282  */
283 static inline int tod_after_eq(unsigned long a, unsigned long b)
284 {
285 	if (machine_has_scc())
286 		return (long) a >= (long) b;
287 	return a >= b;
288 }
289 
290 #endif
291