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 /* Possible options for __cpu_setup */ 27 /* Option to setup primary cpu */ 28 #define ARM64_CPU_BOOT_PRIMARY (1) 29 /* Option to setup secondary cpus */ 30 #define ARM64_CPU_BOOT_SECONDARY (2) 31 /* Option to setup cpus for different cpu run time services */ 32 #define ARM64_CPU_RUNTIME (3) 33 34 #ifndef __ASSEMBLY__ 35 36 #include <asm/percpu.h> 37 38 #include <linux/threads.h> 39 #include <linux/cpumask.h> 40 #include <linux/thread_info.h> 41 #include <asm/pointer_auth.h> 42 43 DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number); 44 45 /* 46 * We don't use this_cpu_read(cpu_number) as that has implicit writes to 47 * preempt_count, and associated (compiler) barriers, that we'd like to avoid 48 * the expense of. If we're preemptible, the value can be stale at use anyway. 49 * And we can't use this_cpu_ptr() either, as that winds up recursing back 50 * here under CONFIG_DEBUG_PREEMPT=y. 51 */ 52 #define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number)) 53 54 /* 55 * Logical CPU mapping. 56 */ 57 extern u64 __cpu_logical_map[NR_CPUS]; 58 #define cpu_logical_map(cpu) __cpu_logical_map[cpu] 59 60 struct seq_file; 61 62 /* 63 * generate IPI list text 64 */ 65 extern void show_ipi_list(struct seq_file *p, int prec); 66 67 /* 68 * Called from C code, this handles an IPI. 69 */ 70 extern void handle_IPI(int ipinr, struct pt_regs *regs); 71 72 /* 73 * Discover the set of possible CPUs and determine their 74 * SMP operations. 75 */ 76 extern void smp_init_cpus(void); 77 78 /* 79 * Provide a function to raise an IPI cross call on CPUs in callmap. 80 */ 81 extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int)); 82 83 extern void (*__smp_cross_call)(const struct cpumask *, unsigned int); 84 85 /* 86 * Called from the secondary holding pen, this is the secondary CPU entry point. 87 */ 88 asmlinkage void secondary_start_kernel(void); 89 90 /* 91 * Initial data for bringing up a secondary CPU. 92 * @stack - sp for the secondary CPU 93 * @status - Result passed back from the secondary CPU to 94 * indicate failure. 95 */ 96 struct secondary_data { 97 void *stack; 98 struct task_struct *task; 99 #ifdef CONFIG_ARM64_PTR_AUTH 100 struct ptrauth_keys_kernel ptrauth_key; 101 #endif 102 long status; 103 }; 104 105 extern struct secondary_data secondary_data; 106 extern long __early_cpu_boot_status; 107 extern void secondary_entry(void); 108 109 extern void arch_send_call_function_single_ipi(int cpu); 110 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); 111 112 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL 113 extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask); 114 #else 115 static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask) 116 { 117 BUILD_BUG(); 118 } 119 #endif 120 121 extern int __cpu_disable(void); 122 123 extern void __cpu_die(unsigned int cpu); 124 extern void cpu_die(void); 125 extern void cpu_die_early(void); 126 127 static inline void cpu_park_loop(void) 128 { 129 for (;;) { 130 wfe(); 131 wfi(); 132 } 133 } 134 135 static inline void update_cpu_boot_status(int val) 136 { 137 WRITE_ONCE(secondary_data.status, val); 138 /* Ensure the visibility of the status update */ 139 dsb(ishst); 140 } 141 142 /* 143 * The calling secondary CPU has detected serious configuration mismatch, 144 * which calls for a kernel panic. Update the boot status and park the calling 145 * CPU. 146 */ 147 static inline void cpu_panic_kernel(void) 148 { 149 update_cpu_boot_status(CPU_PANIC_KERNEL); 150 cpu_park_loop(); 151 } 152 153 /* 154 * If a secondary CPU enters the kernel but fails to come online, 155 * (e.g. due to mismatched features), and cannot exit the kernel, 156 * we increment cpus_stuck_in_kernel and leave the CPU in a 157 * quiesecent loop within the kernel text. The memory containing 158 * this loop must not be re-used for anything else as the 'stuck' 159 * core is executing it. 160 * 161 * This function is used to inhibit features like kexec and hibernate. 162 */ 163 bool cpus_are_stuck_in_kernel(void); 164 165 extern void crash_smp_send_stop(void); 166 extern bool smp_crash_stop_failed(void); 167 168 #endif /* ifndef __ASSEMBLY__ */ 169 170 #endif /* ifndef __ASM_SMP_H */ 171