arch/powerpc/include/asm/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
  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 */