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
24 enum 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
37 static 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 */
44 static inline void ppc_msgsnd_sync(void)
45 {
46 __asm__ __volatile__ ("sync" : : : "memory");
47 }
48
49 /* sync after taking message interrupt */
50 static 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
57 static 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
63 static 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
74 static inline void _ppc_msgsnd(u32 msg)
75 {
76 __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
77 }
78
79 /* sync before sending message */
80 static inline void ppc_msgsnd_sync(void)
81 {
82 __asm__ __volatile__ ("sync" : : : "memory");
83 }
84
85 /* sync after taking message interrupt */
86 static inline void ppc_msgsync(void)
87 {
88 }
89
90 #endif /* CONFIG_PPC_BOOK3S */
91
92 extern void doorbell_exception(struct pt_regs *regs);
93
94 static 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 */
115 static 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 */
130 static 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 */
144 static 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
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