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
20 extern u64 clock_comparator_max;
21
22 /* Inline functions for clock register access. */
set_tod_clock(__u64 time)23 static 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
store_tod_clock(__u64 * time)35 static 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
set_clock_comparator(__u64 time)47 static inline void set_clock_comparator(__u64 time)
48 {
49 asm volatile("sckc %0" : : "Q" (time));
50 }
51
store_clock_comparator(__u64 * time)52 static inline void store_clock_comparator(__u64 *time)
53 {
54 asm volatile("stckc %0" : "=Q" (*time));
55 }
56
57 void clock_comparator_work(void);
58
59 void __init time_early_init(void);
60
61 extern unsigned char ptff_function_mask[16];
62
63 /* Function codes for the ptff instruction. */
64 #define PTFF_QAF 0x00 /* query available functions */
65 #define PTFF_QTO 0x01 /* query tod offset */
66 #define PTFF_QSI 0x02 /* query steering information */
67 #define PTFF_QUI 0x04 /* query UTC information */
68 #define PTFF_ATO 0x40 /* adjust tod offset */
69 #define PTFF_STO 0x41 /* set tod offset */
70 #define PTFF_SFS 0x42 /* set fine steering rate */
71 #define PTFF_SGS 0x43 /* set gross steering rate */
72
73 /* Query TOD offset result */
74 struct ptff_qto {
75 unsigned long long physical_clock;
76 unsigned long long tod_offset;
77 unsigned long long logical_tod_offset;
78 unsigned long long tod_epoch_difference;
79 } __packed;
80
ptff_query(unsigned int nr)81 static inline int ptff_query(unsigned int nr)
82 {
83 unsigned char *ptr;
84
85 ptr = ptff_function_mask + (nr >> 3);
86 return (*ptr & (0x80 >> (nr & 7))) != 0;
87 }
88
89 /* Query UTC information result */
90 struct ptff_qui {
91 unsigned int tm : 2;
92 unsigned int ts : 2;
93 unsigned int : 28;
94 unsigned int pad_0x04;
95 unsigned long leap_event;
96 short old_leap;
97 short new_leap;
98 unsigned int pad_0x14;
99 unsigned long prt[5];
100 unsigned long cst[3];
101 unsigned int skew;
102 unsigned int pad_0x5c[41];
103 } __packed;
104
105 /*
106 * ptff - Perform timing facility function
107 * @ptff_block: Pointer to ptff parameter block
108 * @len: Length of parameter block
109 * @func: Function code
110 * Returns: Condition code (0 on success)
111 */
112 #define ptff(ptff_block, len, func) \
113 ({ \
114 struct addrtype { char _[len]; }; \
115 register unsigned int reg0 asm("0") = func; \
116 register unsigned long reg1 asm("1") = (unsigned long) (ptff_block);\
117 int rc; \
118 \
119 asm volatile( \
120 " .word 0x0104\n" \
121 " ipm %0\n" \
122 " srl %0,28\n" \
123 : "=d" (rc), "+m" (*(struct addrtype *) reg1) \
124 : "d" (reg0), "d" (reg1) : "cc"); \
125 rc; \
126 })
127
local_tick_disable(void)128 static inline unsigned long long local_tick_disable(void)
129 {
130 unsigned long long old;
131
132 old = S390_lowcore.clock_comparator;
133 S390_lowcore.clock_comparator = clock_comparator_max;
134 set_clock_comparator(S390_lowcore.clock_comparator);
135 return old;
136 }
137
local_tick_enable(unsigned long long comp)138 static inline void local_tick_enable(unsigned long long comp)
139 {
140 S390_lowcore.clock_comparator = comp;
141 set_clock_comparator(S390_lowcore.clock_comparator);
142 }
143
144 #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
145 #define STORE_CLOCK_EXT_SIZE 16 /* stcke writes 16 bytes */
146
147 typedef unsigned long long cycles_t;
148
get_tod_clock_ext(char * clk)149 static inline void get_tod_clock_ext(char *clk)
150 {
151 typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
152
153 asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
154 }
155
get_tod_clock(void)156 static inline unsigned long long get_tod_clock(void)
157 {
158 char clk[STORE_CLOCK_EXT_SIZE];
159
160 get_tod_clock_ext(clk);
161 return *((unsigned long long *)&clk[1]);
162 }
163
get_tod_clock_fast(void)164 static inline unsigned long long get_tod_clock_fast(void)
165 {
166 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
167 unsigned long long clk;
168
169 asm volatile("stckf %0" : "=Q" (clk) : : "cc");
170 return clk;
171 #else
172 return get_tod_clock();
173 #endif
174 }
175
get_cycles(void)176 static inline cycles_t get_cycles(void)
177 {
178 return (cycles_t) get_tod_clock() >> 2;
179 }
180
181 int get_phys_clock(unsigned long *clock);
182 void init_cpu_timer(void);
183 unsigned long long monotonic_clock(void);
184
185 extern unsigned char tod_clock_base[16] __aligned(8);
186
187 /**
188 * get_clock_monotonic - returns current time in clock rate units
189 *
190 * The clock and tod_clock_base get changed via stop_machine.
191 * Therefore preemption must be disabled, otherwise the returned
192 * value is not guaranteed to be monotonic.
193 */
get_tod_clock_monotonic(void)194 static inline unsigned long long get_tod_clock_monotonic(void)
195 {
196 unsigned long long tod;
197
198 preempt_disable_notrace();
199 tod = get_tod_clock() - *(unsigned long long *) &tod_clock_base[1];
200 preempt_enable_notrace();
201 return tod;
202 }
203
204 /**
205 * tod_to_ns - convert a TOD format value to nanoseconds
206 * @todval: to be converted TOD format value
207 * Returns: number of nanoseconds that correspond to the TOD format value
208 *
209 * Converting a 64 Bit TOD format value to nanoseconds means that the value
210 * must be divided by 4.096. In order to achieve that we multiply with 125
211 * and divide by 512:
212 *
213 * ns = (todval * 125) >> 9;
214 *
215 * In order to avoid an overflow with the multiplication we can rewrite this.
216 * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
217 * we end up with
218 *
219 * ns = ((2^9 * th + tl) * 125 ) >> 9;
220 * -> ns = (th * 125) + ((tl * 125) >> 9);
221 *
222 */
tod_to_ns(unsigned long long todval)223 static inline unsigned long long tod_to_ns(unsigned long long todval)
224 {
225 return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
226 }
227
228 /**
229 * tod_after - compare two 64 bit TOD values
230 * @a: first 64 bit TOD timestamp
231 * @b: second 64 bit TOD timestamp
232 *
233 * Returns: true if a is later than b
234 */
tod_after(unsigned long long a,unsigned long long b)235 static inline int tod_after(unsigned long long a, unsigned long long b)
236 {
237 if (MACHINE_HAS_SCC)
238 return (long long) a > (long long) b;
239 return a > b;
240 }
241
242 /**
243 * tod_after_eq - compare two 64 bit TOD values
244 * @a: first 64 bit TOD timestamp
245 * @b: second 64 bit TOD timestamp
246 *
247 * Returns: true if a is later than b
248 */
tod_after_eq(unsigned long long a,unsigned long long b)249 static inline int tod_after_eq(unsigned long long a, unsigned long long b)
250 {
251 if (MACHINE_HAS_SCC)
252 return (long long) a >= (long long) b;
253 return a >= b;
254 }
255
256 #endif
257