dbell.h

  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 */