xref: /openbmc/linux/arch/s390/include/asm/timex.h (revision 4f6cce39)
1 /*
2  *  S390 version
3  *    Copyright IBM Corp. 1999
4  *
5  *  Derived from "include/asm-i386/timex.h"
6  *    Copyright (C) 1992, Linus Torvalds
7  */
8 
9 #ifndef _ASM_S390_TIMEX_H
10 #define _ASM_S390_TIMEX_H
11 
12 #include <asm/lowcore.h>
13 #include <linux/time64.h>
14 
15 /* The value of the TOD clock for 1.1.1970. */
16 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
17 
18 /* Inline functions for clock register access. */
19 static inline int set_tod_clock(__u64 time)
20 {
21 	int cc;
22 
23 	asm volatile(
24 		"   sck   %1\n"
25 		"   ipm   %0\n"
26 		"   srl   %0,28\n"
27 		: "=d" (cc) : "Q" (time) : "cc");
28 	return cc;
29 }
30 
31 static inline int store_tod_clock(__u64 *time)
32 {
33 	int cc;
34 
35 	asm volatile(
36 		"   stck  %1\n"
37 		"   ipm   %0\n"
38 		"   srl   %0,28\n"
39 		: "=d" (cc), "=Q" (*time) : : "cc");
40 	return cc;
41 }
42 
43 static inline void set_clock_comparator(__u64 time)
44 {
45 	asm volatile("sckc %0" : : "Q" (time));
46 }
47 
48 static inline void store_clock_comparator(__u64 *time)
49 {
50 	asm volatile("stckc %0" : "=Q" (*time));
51 }
52 
53 void clock_comparator_work(void);
54 
55 void __init time_early_init(void);
56 
57 extern unsigned char ptff_function_mask[16];
58 
59 /* Function codes for the ptff instruction. */
60 #define PTFF_QAF	0x00	/* query available functions */
61 #define PTFF_QTO	0x01	/* query tod offset */
62 #define PTFF_QSI	0x02	/* query steering information */
63 #define PTFF_QUI	0x04	/* query UTC information */
64 #define PTFF_ATO	0x40	/* adjust tod offset */
65 #define PTFF_STO	0x41	/* set tod offset */
66 #define PTFF_SFS	0x42	/* set fine steering rate */
67 #define PTFF_SGS	0x43	/* set gross steering rate */
68 
69 /* Query TOD offset result */
70 struct ptff_qto {
71 	unsigned long long physical_clock;
72 	unsigned long long tod_offset;
73 	unsigned long long logical_tod_offset;
74 	unsigned long long tod_epoch_difference;
75 } __packed;
76 
77 static inline int ptff_query(unsigned int nr)
78 {
79 	unsigned char *ptr;
80 
81 	ptr = ptff_function_mask + (nr >> 3);
82 	return (*ptr & (0x80 >> (nr & 7))) != 0;
83 }
84 
85 /* Query UTC information result */
86 struct ptff_qui {
87 	unsigned int tm : 2;
88 	unsigned int ts : 2;
89 	unsigned int : 28;
90 	unsigned int pad_0x04;
91 	unsigned long leap_event;
92 	short old_leap;
93 	short new_leap;
94 	unsigned int pad_0x14;
95 	unsigned long prt[5];
96 	unsigned long cst[3];
97 	unsigned int skew;
98 	unsigned int pad_0x5c[41];
99 } __packed;
100 
101 /*
102  * ptff - Perform timing facility function
103  * @ptff_block: Pointer to ptff parameter block
104  * @len: Length of parameter block
105  * @func: Function code
106  * Returns: Condition code (0 on success)
107  */
108 #define ptff(ptff_block, len, func)					\
109 ({									\
110 	struct addrtype { char _[len]; };				\
111 	register unsigned int reg0 asm("0") = func;			\
112 	register unsigned long reg1 asm("1") = (unsigned long) (ptff_block);\
113 	int rc;								\
114 									\
115 	asm volatile(							\
116 		"	.word	0x0104\n"				\
117 		"	ipm	%0\n"					\
118 		"	srl	%0,28\n"				\
119 		: "=d" (rc), "+m" (*(struct addrtype *) reg1)		\
120 		: "d" (reg0), "d" (reg1) : "cc");			\
121 	rc;								\
122 })
123 
124 static inline unsigned long long local_tick_disable(void)
125 {
126 	unsigned long long old;
127 
128 	old = S390_lowcore.clock_comparator;
129 	S390_lowcore.clock_comparator = -1ULL;
130 	set_clock_comparator(S390_lowcore.clock_comparator);
131 	return old;
132 }
133 
134 static inline void local_tick_enable(unsigned long long comp)
135 {
136 	S390_lowcore.clock_comparator = comp;
137 	set_clock_comparator(S390_lowcore.clock_comparator);
138 }
139 
140 #define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
141 #define STORE_CLOCK_EXT_SIZE	16	/* stcke writes 16 bytes */
142 
143 typedef unsigned long long cycles_t;
144 
145 static inline void get_tod_clock_ext(char *clk)
146 {
147 	typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
148 
149 	asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
150 }
151 
152 static inline unsigned long long get_tod_clock(void)
153 {
154 	unsigned char clk[STORE_CLOCK_EXT_SIZE];
155 
156 	get_tod_clock_ext(clk);
157 	return *((unsigned long long *)&clk[1]);
158 }
159 
160 static inline unsigned long long get_tod_clock_fast(void)
161 {
162 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
163 	unsigned long long clk;
164 
165 	asm volatile("stckf %0" : "=Q" (clk) : : "cc");
166 	return clk;
167 #else
168 	return get_tod_clock();
169 #endif
170 }
171 
172 static inline cycles_t get_cycles(void)
173 {
174 	return (cycles_t) get_tod_clock() >> 2;
175 }
176 
177 int get_phys_clock(unsigned long long *clock);
178 void init_cpu_timer(void);
179 unsigned long long monotonic_clock(void);
180 
181 extern u64 sched_clock_base_cc;
182 
183 /**
184  * get_clock_monotonic - returns current time in clock rate units
185  *
186  * The caller must ensure that preemption is disabled.
187  * The clock and sched_clock_base get changed via stop_machine.
188  * Therefore preemption must be disabled when calling this
189  * function, otherwise the returned value is not guaranteed to
190  * be monotonic.
191  */
192 static inline unsigned long long get_tod_clock_monotonic(void)
193 {
194 	return get_tod_clock() - sched_clock_base_cc;
195 }
196 
197 /**
198  * tod_to_ns - convert a TOD format value to nanoseconds
199  * @todval: to be converted TOD format value
200  * Returns: number of nanoseconds that correspond to the TOD format value
201  *
202  * Converting a 64 Bit TOD format value to nanoseconds means that the value
203  * must be divided by 4.096. In order to achieve that we multiply with 125
204  * and divide by 512:
205  *
206  *    ns = (todval * 125) >> 9;
207  *
208  * In order to avoid an overflow with the multiplication we can rewrite this.
209  * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
210  * we end up with
211  *
212  *    ns = ((2^9 * th + tl) * 125 ) >> 9;
213  * -> ns = (th * 125) + ((tl * 125) >> 9);
214  *
215  */
216 static inline unsigned long long tod_to_ns(unsigned long long todval)
217 {
218 	return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
219 }
220 
221 #endif
222