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 __ASSEMBLER__
 27
 28#include <linux/threads.h>
 29#include <linux/cpumask.h>
 30#include <linux/thread_info.h>
 31
 32#define raw_smp_processor_id() (current_thread_info()->cpu)
 33
 34/*
 35 * Logical CPU mapping.
 36 */
 37extern u64 __cpu_logical_map[NR_CPUS];
 38extern u64 cpu_logical_map(unsigned int cpu);
 39
 40static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid)
 41{
 42	__cpu_logical_map[cpu] = hwid;
 43}
 44
 45struct seq_file;
 46
 47/*
 48 * Discover the set of possible CPUs and determine their
 49 * SMP operations.
 50 */
 51extern void smp_init_cpus(void);
 52
 53enum ipi_msg_type {
 54	IPI_RESCHEDULE,
 55	IPI_CALL_FUNC,
 56	IPI_CPU_STOP,
 57	IPI_CPU_STOP_NMI,
 58	IPI_TIMER,
 59	IPI_IRQ_WORK,
 60	NR_IPI,
 61	/*
 62	 * Any enum >= NR_IPI and < MAX_IPI is special and not tracable
 63	 * with trace_ipi_*
 64	 */
 65	IPI_CPU_BACKTRACE = NR_IPI,
 66	IPI_KGDB_ROUNDUP,
 67	MAX_IPI
 68};
 69
 70/*
 71 * Register IPI interrupts with the arch SMP code
 72 */
 73extern void set_smp_ipi_range_percpu(int ipi_base, int nr_ipi, int ncpus);
 74
 75static inline void set_smp_ipi_range(int ipi_base, int n)
 76{
 77	set_smp_ipi_range_percpu(ipi_base, n, 0);
 78}
 79
 80/*
 81 * Called from the secondary holding pen, this is the secondary CPU entry point.
 82 */
 83asmlinkage void secondary_start_kernel(void);
 84
 85/*
 86 * Initial data for bringing up a secondary CPU.
 87 * @status - Result passed back from the secondary CPU to
 88 *           indicate failure.
 89 */
 90struct secondary_data {
 91	struct task_struct *task;
 92	long status;
 93};
 94
 95extern struct secondary_data secondary_data;
 96extern long __early_cpu_boot_status;
 97extern void secondary_entry(void);
 98
 99extern void arch_send_call_function_single_ipi(int cpu);
100extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
101
102#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
103extern void arch_send_wakeup_ipi(unsigned int cpu);
104#else
105static inline void arch_send_wakeup_ipi(unsigned int cpu)
106{
107	BUILD_BUG();
108}
109#endif
110
111extern int __cpu_disable(void);
112
113static inline void __cpu_die(unsigned int cpu) { }
114extern void __noreturn cpu_die(void);
115extern void __noreturn cpu_die_early(void);
116
117static inline void __noreturn cpu_park_loop(void)
118{
119	for (;;) {
120		wfe();
121		wfi();
122	}
123}
124
125static inline void update_cpu_boot_status(int val)
126{
127	WRITE_ONCE(secondary_data.status, val);
128	/* Ensure the visibility of the status update */
129	dsb(ishst);
130}
131
132/*
133 * The calling secondary CPU has detected serious configuration mismatch,
134 * which calls for a kernel panic. Update the boot status and park the calling
135 * CPU.
136 */
137static inline void __noreturn cpu_panic_kernel(void)
138{
139	update_cpu_boot_status(CPU_PANIC_KERNEL);
140	cpu_park_loop();
141}
142
143/*
144 * If a secondary CPU enters the kernel but fails to come online,
145 * (e.g. due to mismatched features), and cannot exit the kernel,
146 * we increment cpus_stuck_in_kernel and leave the CPU in a
147 * quiesecent loop within the kernel text. The memory containing
148 * this loop must not be re-used for anything else as the 'stuck'
149 * core is executing it.
150 *
151 * This function is used to inhibit features like kexec and hibernate.
152 */
153bool cpus_are_stuck_in_kernel(void);
154
155extern void crash_smp_send_stop(void);
156extern bool smp_crash_stop_failed(void);
157
158#endif /* ifndef __ASSEMBLER__ */
159
160#endif /* ifndef __ASM_SMP_H */