LXR linux/arch/arm64/include/asm/smp.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright (C) 2012 ARM Ltd.
   4 */
   5#ifndef __ASM_SMP_H
   6#define __ASM_SMP_H
   7
   8#include <linux/const.h>
   9
  10/* Values for secondary_data.status */
  11#define CPU_STUCK_REASON_SHIFT          (8)
  12#define CPU_BOOT_STATUS_MASK            ((UL(1) << CPU_STUCK_REASON_SHIFT) - 1)
  13
  14#define CPU_MMU_OFF                     (-1)
  15#define CPU_BOOT_SUCCESS                (0)
  16/* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */
  17#define CPU_KILL_ME                     (1)
  18/* The cpu couldn't die gracefully and is looping in the kernel */
  19#define CPU_STUCK_IN_KERNEL             (2)
  20/* Fatal system error detected by secondary CPU, crash the system */
  21#define CPU_PANIC_KERNEL                (3)
  22
  23#define CPU_STUCK_REASON_52_BIT_VA      (UL(1) << CPU_STUCK_REASON_SHIFT)
  24#define CPU_STUCK_REASON_NO_GRAN        (UL(2) << CPU_STUCK_REASON_SHIFT)
  25
  26#ifndef __ASSEMBLY__
  27
  28#include <asm/percpu.h>
  29
  30#include <linux/threads.h>
  31#include <linux/cpumask.h>
  32#include <linux/thread_info.h>
  33
  34DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
  35
  36/*
  37 * We don't use this_cpu_read(cpu_number) as that has implicit writes to
  38 * preempt_count, and associated (compiler) barriers, that we'd like to avoid
  39 * the expense of. If we're preemptible, the value can be stale at use anyway.
  40 * And we can't use this_cpu_ptr() either, as that winds up recursing back
  41 * here under CONFIG_DEBUG_PREEMPT=y.
  42 */
  43#define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number))
  44
  45/*
  46 * Logical CPU mapping.
  47 */
  48extern u64 __cpu_logical_map[NR_CPUS];
  49extern u64 cpu_logical_map(unsigned int cpu);
  50
  51static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid)
  52{
  53        __cpu_logical_map[cpu] = hwid;
  54}
  55
  56struct seq_file;
  57
  58/*
  59 * Discover the set of possible CPUs and determine their
  60 * SMP operations.
  61 */
  62extern void smp_init_cpus(void);
  63
  64/*
  65 * Register IPI interrupts with the arch SMP code
  66 */
  67extern void set_smp_ipi_range(int ipi_base, int nr_ipi);
  68
  69/*
  70 * Called from the secondary holding pen, this is the secondary CPU entry point.
  71 */
  72asmlinkage void secondary_start_kernel(void);
  73
  74/*
  75 * Initial data for bringing up a secondary CPU.
  76 * @status - Result passed back from the secondary CPU to
  77 *           indicate failure.
  78 */
  79struct secondary_data {
  80        struct task_struct *task;
  81        long status;
  82};
  83
  84extern struct secondary_data secondary_data;
  85extern long __early_cpu_boot_status;
  86extern void secondary_entry(void);
  87
  88extern void arch_send_call_function_single_ipi(int cpu);
  89extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
  90
  91#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
  92extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
  93#else
  94static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
  95{
  96        BUILD_BUG();
  97}
  98#endif
  99
 100extern int __cpu_disable(void);
 101
 102extern void __cpu_die(unsigned int cpu);
 103extern void cpu_die(void);
 104extern void cpu_die_early(void);
 105
 106static inline void cpu_park_loop(void)
 107{
 108        for (;;) {
 109                wfe();
 110                wfi();
 111        }
 112}
 113
 114static inline void update_cpu_boot_status(int val)
 115{
 116        WRITE_ONCE(secondary_data.status, val);
 117        /* Ensure the visibility of the status update */
 118        dsb(ishst);
 119}
 120
 121/*
 122 * The calling secondary CPU has detected serious configuration mismatch,
 123 * which calls for a kernel panic. Update the boot status and park the calling
 124 * CPU.
 125 */
 126static inline void cpu_panic_kernel(void)
 127{
 128        update_cpu_boot_status(CPU_PANIC_KERNEL);
 129        cpu_park_loop();
 130}
 131
 132/*
 133 * If a secondary CPU enters the kernel but fails to come online,
 134 * (e.g. due to mismatched features), and cannot exit the kernel,
 135 * we increment cpus_stuck_in_kernel and leave the CPU in a
 136 * quiesecent loop within the kernel text. The memory containing
 137 * this loop must not be re-used for anything else as the 'stuck'
 138 * core is executing it.
 139 *
 140 * This function is used to inhibit features like kexec and hibernate.
 141 */
 142bool cpus_are_stuck_in_kernel(void);
 143
 144extern void crash_smp_send_stop(void);
 145extern bool smp_crash_stop_failed(void);
 146extern void panic_smp_self_stop(void);
 147
 148#endif /* ifndef __ASSEMBLY__ */
 149
 150#endif /* ifndef __ASM_SMP_H */
 151