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
52 void clock_comparator_work(void);
53
54 void __init time_early_init(void);
55
56 extern 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 */
69 struct 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
ptff_query(unsigned int nr)76 static 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 */
85 struct 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
local_tick_disable(void)123 static 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
local_tick_enable(unsigned long long comp)133 static 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
142 typedef unsigned long long cycles_t;
143
get_tod_clock_ext(char * clk)144 static 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
get_tod_clock(void)151 static 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
get_tod_clock_fast(void)159 static 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
get_cycles(void)171 static inline cycles_t get_cycles(void)
172 {
173 return (cycles_t) get_tod_clock() >> 2;
174 }
175
176 int get_phys_clock(unsigned long *clock);
177 void init_cpu_timer(void);
178
179 extern unsigned char tod_clock_base[16] __aligned(8);
180
181 /**
182 * get_clock_monotonic - returns current time in clock rate units
183 *
184 * The clock and tod_clock_base get changed via stop_machine.
185 * Therefore preemption must be disabled, otherwise the returned
186 * value is not guaranteed to be monotonic.
187 */
get_tod_clock_monotonic(void)188 static inline unsigned long long get_tod_clock_monotonic(void)
189 {
190 unsigned long long tod;
191
192 preempt_disable_notrace();
193 tod = get_tod_clock() - *(unsigned long long *) &tod_clock_base[1];
194 preempt_enable_notrace();
195 return tod;
196 }
197
198 /**
199 * tod_to_ns - convert a TOD format value to nanoseconds
200 * @todval: to be converted TOD format value
201 * Returns: number of nanoseconds that correspond to the TOD format value
202 *
203 * Converting a 64 Bit TOD format value to nanoseconds means that the value
204 * must be divided by 4.096. In order to achieve that we multiply with 125
205 * and divide by 512:
206 *
207 * ns = (todval * 125) >> 9;
208 *
209 * In order to avoid an overflow with the multiplication we can rewrite this.
210 * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
211 * we end up with
212 *
213 * ns = ((2^9 * th + tl) * 125 ) >> 9;
214 * -> ns = (th * 125) + ((tl * 125) >> 9);
215 *
216 */
tod_to_ns(unsigned long long todval)217 static inline unsigned long long tod_to_ns(unsigned long long todval)
218 {
219 return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
220 }
221
222 /**
223 * tod_after - compare two 64 bit TOD values
224 * @a: first 64 bit TOD timestamp
225 * @b: second 64 bit TOD timestamp
226 *
227 * Returns: true if a is later than b
228 */
tod_after(unsigned long long a,unsigned long long b)229 static inline int tod_after(unsigned long long a, unsigned long long b)
230 {
231 if (MACHINE_HAS_SCC)
232 return (long long) a > (long long) b;
233 return a > b;
234 }
235
236 /**
237 * tod_after_eq - compare two 64 bit TOD values
238 * @a: first 64 bit TOD timestamp
239 * @b: second 64 bit TOD timestamp
240 *
241 * Returns: true if a is later than b
242 */
tod_after_eq(unsigned long long a,unsigned long long b)243 static inline int tod_after_eq(unsigned long long a, unsigned long long b)
244 {
245 if (MACHINE_HAS_SCC)
246 return (long long) a >= (long long) b;
247 return a >= b;
248 }
249
250 #endif
251