include/asm/dbell.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  * Copyright 2009 Freescale Semiconductor, Inc.
0004  *
0005  * provides masks and opcode images for use by code generation, emulation
0006  * and for instructions that older assemblers might not know about
0007  */
0008 #ifndef _ASM_POWERPC_DBELL_H
0009 #define _ASM_POWERPC_DBELL_H
0010
0011 #include <linux/smp.h>
0012 #include <linux/threads.h>
0013
0014 #include <asm/cputhreads.h>
0015 #include <asm/ppc-opcode.h>
0016 #include <asm/feature-fixups.h>
0017 #include <asm/kvm_ppc.h>
0018
0019 #define PPC_DBELL_MSG_BRDCAST   (0x04000000)
0020 #define PPC_DBELL_TYPE(x)   (((x) & 0xf) << (63-36))
0021 #define PPC_DBELL_TYPE_MASK PPC_DBELL_TYPE(0xf)
0022 #define PPC_DBELL_LPID(x)   ((x) << (63 - 49))
0023 #define PPC_DBELL_PIR_MASK  0x3fff
0024 enum ppc_dbell {
0025     PPC_DBELL = 0,      /* doorbell */
0026     PPC_DBELL_CRIT = 1, /* critical doorbell */
0027     PPC_G_DBELL = 2,    /* guest doorbell */
0028     PPC_G_DBELL_CRIT = 3,   /* guest critical doorbell */
0029     PPC_G_DBELL_MC = 4, /* guest mcheck doorbell */
0030     PPC_DBELL_SERVER = 5,   /* doorbell on server */
0031 };
0032
0033 #ifdef CONFIG_PPC_BOOK3S
0034
0035 #define PPC_DBELL_MSGTYPE       PPC_DBELL_SERVER
0036
0037 static inline void _ppc_msgsnd(u32 msg)
0038 {
0039     __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSND(%1), PPC_MSGSNDP(%1), %0)
0040                 : : "i" (CPU_FTR_HVMODE), "r" (msg));
0041 }
0042
0043 /* sync before sending message */
0044 static inline void ppc_msgsnd_sync(void)
0045 {
0046     __asm__ __volatile__ ("sync" : : : "memory");
0047 }
0048
0049 /* sync after taking message interrupt */
0050 static inline void ppc_msgsync(void)
0051 {
0052     /* sync is not required when taking messages from the same core */
0053     __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGSYNC " ; lwsync", "", %0)
0054                 : : "i" (CPU_FTR_HVMODE|CPU_FTR_ARCH_300));
0055 }
0056
0057 static inline void _ppc_msgclr(u32 msg)
0058 {
0059     __asm__ __volatile__ (ASM_FTR_IFSET(PPC_MSGCLR(%1), PPC_MSGCLRP(%1), %0)
0060                 : : "i" (CPU_FTR_HVMODE), "r" (msg));
0061 }
0062
0063 static inline void ppc_msgclr(enum ppc_dbell type)
0064 {
0065     u32 msg = PPC_DBELL_TYPE(type);
0066
0067     _ppc_msgclr(msg);
0068 }
0069
0070 #else /* CONFIG_PPC_BOOK3S */
0071
0072 #define PPC_DBELL_MSGTYPE       PPC_DBELL
0073
0074 static inline void _ppc_msgsnd(u32 msg)
0075 {
0076     __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
0077 }
0078
0079 /* sync before sending message */
0080 static inline void ppc_msgsnd_sync(void)
0081 {
0082     __asm__ __volatile__ ("sync" : : : "memory");
0083 }
0084
0085 /* sync after taking message interrupt */
0086 static inline void ppc_msgsync(void)
0087 {
0088 }
0089
0090 #endif /* CONFIG_PPC_BOOK3S */
0091
0092 extern void doorbell_exception(struct pt_regs *regs);
0093
0094 static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
0095 {
0096     u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
0097             (tag & 0x07ffffff);
0098
0099     _ppc_msgsnd(msg);
0100 }
0101
0102 #ifdef CONFIG_SMP
0103
0104 /*
0105  * Doorbells must only be used if CPU_FTR_DBELL is available.
0106  * msgsnd is used in HV, and msgsndp is used in !HV.
0107  *
0108  * These should be used by platform code that is aware of restrictions.
0109  * Other arch code should use ->cause_ipi.
0110  *
0111  * doorbell_global_ipi() sends a dbell to any target CPU.
0112  * Must be used only by architectures that address msgsnd target
0113  * by PIR/get_hard_smp_processor_id.
0114  */
0115 static inline void doorbell_global_ipi(int cpu)
0116 {
0117     u32 tag = get_hard_smp_processor_id(cpu);
0118
0119     kvmppc_set_host_ipi(cpu);
0120     /* Order previous accesses vs. msgsnd, which is treated as a store */
0121     ppc_msgsnd_sync();
0122     ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
0123 }
0124
0125 /*
0126  * doorbell_core_ipi() sends a dbell to a target CPU in the same core.
0127  * Must be used only by architectures that address msgsnd target
0128  * by TIR/cpu_thread_in_core.
0129  */
0130 static inline void doorbell_core_ipi(int cpu)
0131 {
0132     u32 tag = cpu_thread_in_core(cpu);
0133
0134     kvmppc_set_host_ipi(cpu);
0135     /* Order previous accesses vs. msgsnd, which is treated as a store */
0136     ppc_msgsnd_sync();
0137     ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag);
0138 }
0139
0140 /*
0141  * Attempt to cause a core doorbell if destination is on the same core.
0142  * Returns 1 on success, 0 on failure.
0143  */
0144 static inline int doorbell_try_core_ipi(int cpu)
0145 {
0146     int this_cpu = get_cpu();
0147     int ret = 0;
0148
0149     if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) {
0150         doorbell_core_ipi(cpu);
0151         ret = 1;
0152     }
0153
0154     put_cpu();
0155
0156     return ret;
0157 }
0158
0159 #endif /* CONFIG_SMP */
0160
0161 #endif /* _ASM_POWERPC_DBELL_H */