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 #include <asm/pointer_auth.h> 34 35 DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number); 36 37 /* 38 * We don't use this_cpu_read(cpu_number) as that has implicit writes to 39 * preempt_count, and associated (compiler) barriers, that we'd like to avoid 40 * the expense of. If we're preemptible, the value can be stale at use anyway. 41 * And we can't use this_cpu_ptr() either, as that winds up recursing back 42 * here under CONFIG_DEBUG_PREEMPT=y. 43 */ 44 #define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number)) 45 46 /* 47 * Logical CPU mapping. 48 */ 49 extern u64 __cpu_logical_map[NR_CPUS]; 50 #define cpu_logical_map(cpu) __cpu_logical_map[cpu] 51 52 struct seq_file; 53 54 /* 55 * generate IPI list text 56 */ 57 extern void show_ipi_list(struct seq_file *p, int prec); 58 59 /* 60 * Called from C code, this handles an IPI. 61 */ 62 extern void handle_IPI(int ipinr, struct pt_regs *regs); 63 64 /* 65 * Discover the set of possible CPUs and determine their 66 * SMP operations. 67 */ 68 extern void smp_init_cpus(void); 69 70 /* 71 * Provide a function to raise an IPI cross call on CPUs in callmap. 72 */ 73 extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int)); 74 75 extern void (*__smp_cross_call)(const struct cpumask *, unsigned int); 76 77 /* 78 * Called from the secondary holding pen, this is the secondary CPU entry point. 79 */ 80 asmlinkage void secondary_start_kernel(void); 81 82 /* 83 * Initial data for bringing up a secondary CPU. 84 * @stack - sp for the secondary CPU 85 * @status - Result passed back from the secondary CPU to 86 * indicate failure. 87 */ 88 struct secondary_data { 89 void *stack; 90 struct task_struct *task; 91 long status; 92 }; 93 94 extern struct secondary_data secondary_data; 95 extern long __early_cpu_boot_status; 96 extern void secondary_entry(void); 97 98 extern void arch_send_call_function_single_ipi(int cpu); 99 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); 100 101 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL 102 extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask); 103 #else 104 static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask) 105 { 106 BUILD_BUG(); 107 } 108 #endif 109 110 extern int __cpu_disable(void); 111 112 extern void __cpu_die(unsigned int cpu); 113 extern void cpu_die(void); 114 extern void cpu_die_early(void); 115 116 static inline void cpu_park_loop(void) 117 { 118 for (;;) { 119 wfe(); 120 wfi(); 121 } 122 } 123 124 static inline void update_cpu_boot_status(int val) 125 { 126 WRITE_ONCE(secondary_data.status, val); 127 /* Ensure the visibility of the status update */ 128 dsb(ishst); 129 } 130 131 /* 132 * The calling secondary CPU has detected serious configuration mismatch, 133 * which calls for a kernel panic. Update the boot status and park the calling 134 * CPU. 135 */ 136 static inline void cpu_panic_kernel(void) 137 { 138 update_cpu_boot_status(CPU_PANIC_KERNEL); 139 cpu_park_loop(); 140 } 141 142 /* 143 * If a secondary CPU enters the kernel but fails to come online, 144 * (e.g. due to mismatched features), and cannot exit the kernel, 145 * we increment cpus_stuck_in_kernel and leave the CPU in a 146 * quiesecent loop within the kernel text. The memory containing 147 * this loop must not be re-used for anything else as the 'stuck' 148 * core is executing it. 149 * 150 * This function is used to inhibit features like kexec and hibernate. 151 */ 152 bool cpus_are_stuck_in_kernel(void); 153 154 extern void crash_smp_send_stop(void); 155 extern bool smp_crash_stop_failed(void); 156 157 #endif /* ifndef __ASSEMBLY__ */ 158 159 #endif /* ifndef __ASM_SMP_H */ 160