xref: /openbmc/linux/arch/sparc/include/asm/timer_64.h (revision 2cf1c348)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* timer.h: System timer definitions for sun5.
3  *
4  * Copyright (C) 1997, 2008 David S. Miller (davem@davemloft.net)
5  */
6 
7 #ifndef _SPARC64_TIMER_H
8 #define _SPARC64_TIMER_H
9 
10 #include <uapi/asm/asi.h>
11 #include <linux/types.h>
12 #include <linux/init.h>
13 
14 /* The most frequently accessed fields should be first,
15  * to fit into the same cacheline.
16  */
17 struct sparc64_tick_ops {
18 	unsigned long ticks_per_nsec_quotient;
19 	unsigned long offset;
20 	unsigned long long (*get_tick)(void);
21 	int (*add_compare)(unsigned long);
22 	unsigned long softint_mask;
23 	void (*disable_irq)(void);
24 
25 	void (*init_tick)(void);
26 	unsigned long (*add_tick)(unsigned long);
27 	unsigned long (*get_frequency)(void);
28 	unsigned long frequency;
29 
30 	char *name;
31 };
32 
33 extern struct sparc64_tick_ops *tick_ops;
34 
35 unsigned long sparc64_get_clock_tick(unsigned int cpu);
36 void setup_sparc64_timer(void);
37 void __init time_init(void);
38 
39 #define TICK_PRIV_BIT		BIT(63)
40 #define TICKCMP_IRQ_BIT		BIT(63)
41 
42 #define HBIRD_STICKCMP_ADDR	0x1fe0000f060UL
43 #define HBIRD_STICK_ADDR	0x1fe0000f070UL
44 
45 #define GET_TICK_NINSTR		13
46 struct get_tick_patch {
47 	unsigned int	addr;
48 	unsigned int	tick[GET_TICK_NINSTR];
49 	unsigned int	stick[GET_TICK_NINSTR];
50 };
51 
52 extern struct get_tick_patch __get_tick_patch;
53 extern struct get_tick_patch __get_tick_patch_end;
54 
55 static inline unsigned long get_tick(void)
56 {
57 	unsigned long tick, tmp1, tmp2;
58 
59 	__asm__ __volatile__(
60 	/* read hbtick 13 instructions */
61 	"661:\n"
62 	"	mov	0x1fe, %1\n"
63 	"	sllx	%1, 0x20, %1\n"
64 	"	sethi	%%hi(0xf000), %2\n"
65 	"	or	%2, 0x70, %2\n"
66 	"	or	%1, %2, %1\n"	/* %1 = HBIRD_STICK_ADDR */
67 	"	add	%1, 8, %2\n"
68 	"	ldxa	[%2]%3, %0\n"
69 	"	ldxa	[%1]%3, %1\n"
70 	"	ldxa	[%2]%3, %2\n"
71 	"	sub	%2, %0, %0\n"	/* don't modify %xcc */
72 	"	brnz,pn	%0, 661b\n"	/* restart to save one register */
73 	"	 sllx	%2, 32, %2\n"
74 	"	or	%2, %1, %0\n"
75 	/* Common/not patched code */
76 	"	sllx	%0, 1, %0\n"
77 	"	srlx	%0, 1, %0\n"	/* Clear TICK_PRIV_BIT */
78 	/* Beginning of patch section */
79 	"	.section .get_tick_patch, \"ax\"\n"
80 	"	.word	661b\n"
81 	/* read tick 2 instructions and 11 skipped */
82 	"	ba	1f\n"
83 	"	 rd	%%tick, %0\n"
84 	"	.skip	4 * (%4 - 2)\n"
85 	"1:\n"
86 	/* read stick 2 instructions and 11 skipped */
87 	"	ba	1f\n"
88 	"	 rd	%%asr24, %0\n"
89 	"	.skip	4 * (%4 - 2)\n"
90 	"1:\n"
91 	/* End of patch section */
92 	"	.previous\n"
93 	: "=&r" (tick), "=&r" (tmp1), "=&r" (tmp2)
94 	: "i" (ASI_PHYS_BYPASS_EC_E), "i" (GET_TICK_NINSTR));
95 
96 	return tick;
97 }
98 
99 #endif /* _SPARC64_TIMER_H */
100