1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright 2009 Freescale Semiconductor, Inc.
4 *
5 * provides masks and opcode images for use by code generation, emulation
6 * and for instructions that older assemblers might not know about
7 */
8#ifndef _ASM_POWERPC_DBELL_H
9#define _ASM_POWERPC_DBELL_H
10
11#include <linux/smp.h>
12#include <linux/threads.h>
13
14#include <asm/cputhreads.h>
15#include <asm/ppc-opcode.h>
16#include <asm/feature-fixups.h>
17#include <asm/kvm_ppc.h>
18
19#define PPC_DBELL_MSG_BRDCAST	(0x04000000)
20#define PPC_DBELL_TYPE(x)	(((x) & 0xf) << (63-36))
21#define PPC_DBELL_TYPE_MASK	PPC_DBELL_TYPE(0xf)
22#define PPC_DBELL_LPID(x)	((x) << (63 - 49))
23#define PPC_DBELL_PIR_MASK	0x3fff
24enum ppc_dbell {
25	PPC_DBELL = 0,		/* doorbell */
26	PPC_DBELL_CRIT = 1,	/* critical doorbell */
27	PPC_G_DBELL = 2,	/* guest doorbell */
28	PPC_G_DBELL_CRIT = 3,	/* guest critical doorbell */
29	PPC_G_DBELL_MC = 4,	/* guest mcheck doorbell */
30	PPC_DBELL_SERVER = 5,	/* doorbell on server */
31};
32
33#ifdef CONFIG_PPC_BOOK3S
34
35#define PPC_DBELL_MSGTYPE		PPC_DBELL_SERVER
36
37static inline void _ppc_msgsnd(u32 msg)
38{
39	__asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSND(%1), PPC_MSGSNDP(%1), %0)
40				: : "i" (CPU_FTR_HVMODE), "r" (msg));
41}
42
43/* sync before sending message */
44static inline void ppc_msgsnd_sync(void)
45{
46	__asm__ __volatile__ ("sync" : : : "memory");
47}
48
49/* sync after taking message interrupt */
50static inline void ppc_msgsync(void)
51{
52	/* sync is not required when taking messages from the same core */
53	__asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSYNC " ; lwsync", "", %0)
54				: : "i" (CPU_FTR_HVMODE|CPU_FTR_ARCH_300));
55}
56
57static inline void _ppc_msgclr(u32 msg)
58{
59	__asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGCLR(%1), PPC_MSGCLRP(%1), %0)
60				: : "i" (CPU_FTR_HVMODE), "r" (msg));
61}
62
63static inline void ppc_msgclr(enum ppc_dbell type)
64{
65	u32 msg = PPC_DBELL_TYPE(type);
66
67	_ppc_msgclr(msg);
68}
69
70#else /* CONFIG_PPC_BOOK3S */
71
72#define PPC_DBELL_MSGTYPE		PPC_DBELL
73
74static inline void _ppc_msgsnd(u32 msg)
75{
76	__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
77}
78
79/* sync before sending message */
80static inline void ppc_msgsnd_sync(void)
81{
82	__asm__ __volatile__ ("sync" : : : "memory");
83}
84
85/* sync after taking message interrupt */
86static inline void ppc_msgsync(void)
87{
88}
89
90#endif /* CONFIG_PPC_BOOK3S */
91
92extern void doorbell_exception(struct pt_regs *regs);
93
94static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
95{
96	u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
97			(tag & 0x07ffffff);
98
99	_ppc_msgsnd(msg);
100}
101
102#ifdef CONFIG_SMP
103
104/*
105 * Doorbells must only be used if CPU_FTR_DBELL is available.
106 * msgsnd is used in HV, and msgsndp is used in !HV.
107 *
108 * These should be used by platform code that is aware of restrictions.
109 * Other arch code should use ->cause_ipi.
110 *
111 * doorbell_global_ipi() sends a dbell to any target CPU.
112 * Must be used only by architectures that address msgsnd target
113 * by PIR/get_hard_smp_processor_id.
114 */
115static inline void doorbell_global_ipi(int cpu)
116{
117	u32 tag = get_hard_smp_processor_id(cpu);
118
119	kvmppc_set_host_ipi(cpu);
120	/* Order previous accesses vs. msgsnd, which is treated as a store */
121	ppc_msgsnd_sync();
122	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
123}
124
125/*
126 * doorbell_core_ipi() sends a dbell to a target CPU in the same core.
127 * Must be used only by architectures that address msgsnd target
128 * by TIR/cpu_thread_in_core.
129 */
130static inline void doorbell_core_ipi(int cpu)
131{
132	u32 tag = cpu_thread_in_core(cpu);
133
134	kvmppc_set_host_ipi(cpu);
135	/* Order previous accesses vs. msgsnd, which is treated as a store */
136	ppc_msgsnd_sync();
137	ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
138}
139
140/*
141 * Attempt to cause a core doorbell if destination is on the same core.
142 * Returns 1 on success, 0 on failure.
143 */
144static inline int doorbell_try_core_ipi(int cpu)
145{
146	int this_cpu = get_cpu();
147	int ret = 0;
148
149	if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) {
150		doorbell_core_ipi(cpu);
151		ret = 1;
152	}
153
154	put_cpu();
155
156	return ret;
157}
158
159#endif /* CONFIG_SMP */
160
161#endif /* _ASM_POWERPC_DBELL_H */
162