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 * @status - Result passed back from the secondary CPU to 77 * indicate failure. 78 */ 79 struct secondary_data { 80 struct task_struct *task; 81 long status; 82 }; 83 84 extern struct secondary_data secondary_data; 85 extern long __early_cpu_boot_status; 86 extern void secondary_entry(void); 87 88 extern void arch_send_call_function_single_ipi(int cpu); 89 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); 90 91 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL 92 extern void arch_send_wakeup_ipi(unsigned int cpu); 93 #else 94 static inline void arch_send_wakeup_ipi(unsigned int cpu) 95 { 96 BUILD_BUG(); 97 } 98 #endif 99 100 extern int __cpu_disable(void); 101 102 static inline void __cpu_die(unsigned int cpu) { } 103 extern void __noreturn cpu_die(void); 104 extern void __noreturn cpu_die_early(void); 105 106 static inline void __noreturn cpu_park_loop(void) 107 { 108 for (;;) { 109 wfe(); 110 wfi(); 111 } 112 } 113 114 static 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 */ 126 static inline void __noreturn 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 */ 142 bool cpus_are_stuck_in_kernel(void); 143 144 extern void crash_smp_send_stop(void); 145 extern bool smp_crash_stop_failed(void); 146 147 #endif /* ifndef __ASSEMBLY__ */ 148 149 #endif /* ifndef __ASM_SMP_H */ 150