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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 after taking message interrupt */
44static inline void ppc_msgsync(void)
45{
46 /* sync is not required when taking messages from the same core */
47 __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSYNC " ; lwsync", "", %0)
48 : : "i" (CPU_FTR_HVMODE|CPU_FTR_ARCH_300));
49}
50
51static inline void _ppc_msgclr(u32 msg)
52{
53 __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGCLR(%1), PPC_MSGCLRP(%1), %0)
54 : : "i" (CPU_FTR_HVMODE), "r" (msg));
55}
56
57static inline void ppc_msgclr(enum ppc_dbell type)
58{
59 u32 msg = PPC_DBELL_TYPE(type);
60
61 _ppc_msgclr(msg);
62}
63
64#else /* CONFIG_PPC_BOOK3S */
65
66#define PPC_DBELL_MSGTYPE PPC_DBELL
67
68static inline void _ppc_msgsnd(u32 msg)
69{
70 __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
71}
72
73/* sync after taking message interrupt */
74static inline void ppc_msgsync(void)
75{
76}
77
78#endif /* CONFIG_PPC_BOOK3S */
79
80extern void doorbell_exception(struct pt_regs *regs);
81
82/* sync before sending message */
83static inline void ppc_msgsnd_sync(void)
84{
85 __asm__ __volatile__ ("sync" : : : "memory");
86}
87
88static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
89{
90 u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
91 (tag & 0x07ffffff);
92
93 _ppc_msgsnd(msg);
94}
95
96#ifdef CONFIG_SMP
97
98/*
99 * Doorbells must only be used if CPU_FTR_DBELL is available.
100 * msgsnd is used in HV, and msgsndp is used in !HV.
101 *
102 * These should be used by platform code that is aware of restrictions.
103 * Other arch code should use ->cause_ipi.
104 *
105 * doorbell_global_ipi() sends a dbell to any target CPU.
106 * Must be used only by architectures that address msgsnd target
107 * by PIR/get_hard_smp_processor_id.
108 */
109static inline void doorbell_global_ipi(int cpu)
110{
111 u32 tag = get_hard_smp_processor_id(cpu);
112
113 kvmppc_set_host_ipi(cpu);
114 /* Order previous accesses vs. msgsnd, which is treated as a store */
115 ppc_msgsnd_sync();
116 ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
117}
118
119/*
120 * doorbell_core_ipi() sends a dbell to a target CPU in the same core.
121 * Must be used only by architectures that address msgsnd target
122 * by TIR/cpu_thread_in_core.
123 */
124static inline void doorbell_core_ipi(int cpu)
125{
126 u32 tag = cpu_thread_in_core(cpu);
127
128 kvmppc_set_host_ipi(cpu);
129 /* Order previous accesses vs. msgsnd, which is treated as a store */
130 ppc_msgsnd_sync();
131 ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
132}
133
134/*
135 * Attempt to cause a core doorbell if destination is on the same core.
136 * Returns 1 on success, 0 on failure.
137 */
138static inline int doorbell_try_core_ipi(int cpu)
139{
140 int this_cpu = get_cpu();
141 int ret = 0;
142
143 if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) {
144 doorbell_core_ipi(cpu);
145 ret = 1;
146 }
147
148 put_cpu();
149
150 return ret;
151}
152
153#endif /* CONFIG_SMP */
154
155#endif /* _ASM_POWERPC_DBELL_H */