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 34 DECLARE_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 */ 48 extern u64 __cpu_logical_map[NR_CPUS]; 49 extern u64 cpu_logical_map(unsigned int cpu); 50 51 static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid) 52 { 53 __cpu_logical_map[cpu] = hwid; 54 } 55 56 struct seq_file; 57 58 /* 59 * Discover the set of possible CPUs and determine their 60 * SMP operations. 61 */ 62 extern void smp_init_cpus(void); 63 64 /* 65 * Register IPI interrupts with the arch SMP code 66 */ 67 extern 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 */ 72 asmlinkage void secondary_start_kernel(void); 73 74 /* 75 * Initial data for bringing up a secondary CPU. 76 * @stack - sp for the secondary CPU 77 * @status - Result passed back from the secondary CPU to 78 * indicate failure. 79 */ 80 struct secondary_data { 81 void *stack; 82 struct task_struct *task; 83 long status; 84 }; 85 86 extern struct secondary_data secondary_data; 87 extern long __early_cpu_boot_status; 88 extern void secondary_entry(void); 89 90 extern void arch_send_call_function_single_ipi(int cpu); 91 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); 92 93 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL 94 extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask); 95 #else 96 static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask) 97 { 98 BUILD_BUG(); 99 } 100 #endif 101 102 extern int __cpu_disable(void); 103 104 extern void __cpu_die(unsigned int cpu); 105 extern void cpu_die(void); 106 extern void cpu_die_early(void); 107 108 static inline void cpu_park_loop(void) 109 { 110 for (;;) { 111 wfe(); 112 wfi(); 113 } 114 } 115 116 static inline void update_cpu_boot_status(int val) 117 { 118 WRITE_ONCE(secondary_data.status, val); 119 /* Ensure the visibility of the status update */ 120 dsb(ishst); 121 } 122 123 /* 124 * The calling secondary CPU has detected serious configuration mismatch, 125 * which calls for a kernel panic. Update the boot status and park the calling 126 * CPU. 127 */ 128 static inline void cpu_panic_kernel(void) 129 { 130 update_cpu_boot_status(CPU_PANIC_KERNEL); 131 cpu_park_loop(); 132 } 133 134 /* 135 * If a secondary CPU enters the kernel but fails to come online, 136 * (e.g. due to mismatched features), and cannot exit the kernel, 137 * we increment cpus_stuck_in_kernel and leave the CPU in a 138 * quiesecent loop within the kernel text. The memory containing 139 * this loop must not be re-used for anything else as the 'stuck' 140 * core is executing it. 141 * 142 * This function is used to inhibit features like kexec and hibernate. 143 */ 144 bool cpus_are_stuck_in_kernel(void); 145 146 extern void crash_smp_send_stop(void); 147 extern bool smp_crash_stop_failed(void); 148 extern void panic_smp_self_stop(void); 149 150 #endif /* ifndef __ASSEMBLY__ */ 151 152 #endif /* ifndef __ASM_SMP_H */ 153