1 /* 2 * Copyright (C) 2012 ARM Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program. If not, see <http://www.gnu.org/licenses/>. 15 */ 16 #ifndef __ASM_SMP_H 17 #define __ASM_SMP_H 18 19 /* Values for secondary_data.status */ 20 21 #define CPU_MMU_OFF (-1) 22 #define CPU_BOOT_SUCCESS (0) 23 /* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */ 24 #define CPU_KILL_ME (1) 25 /* The cpu couldn't die gracefully and is looping in the kernel */ 26 #define CPU_STUCK_IN_KERNEL (2) 27 /* Fatal system error detected by secondary CPU, crash the system */ 28 #define CPU_PANIC_KERNEL (3) 29 30 #ifndef __ASSEMBLY__ 31 32 #include <linux/threads.h> 33 #include <linux/cpumask.h> 34 #include <linux/thread_info.h> 35 36 #define raw_smp_processor_id() (current_thread_info()->cpu) 37 38 struct seq_file; 39 40 /* 41 * generate IPI list text 42 */ 43 extern void show_ipi_list(struct seq_file *p, int prec); 44 45 /* 46 * Called from C code, this handles an IPI. 47 */ 48 extern void handle_IPI(int ipinr, struct pt_regs *regs); 49 50 /* 51 * Discover the set of possible CPUs and determine their 52 * SMP operations. 53 */ 54 extern void smp_init_cpus(void); 55 56 /* 57 * Provide a function to raise an IPI cross call on CPUs in callmap. 58 */ 59 extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int)); 60 61 extern void (*__smp_cross_call)(const struct cpumask *, unsigned int); 62 63 /* 64 * Called from the secondary holding pen, this is the secondary CPU entry point. 65 */ 66 asmlinkage void secondary_start_kernel(void); 67 68 /* 69 * Initial data for bringing up a secondary CPU. 70 * @stack - sp for the secondary CPU 71 * @status - Result passed back from the secondary CPU to 72 * indicate failure. 73 */ 74 struct secondary_data { 75 void *stack; 76 long status; 77 }; 78 79 extern struct secondary_data secondary_data; 80 extern long __early_cpu_boot_status; 81 extern void secondary_entry(void); 82 83 extern void arch_send_call_function_single_ipi(int cpu); 84 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); 85 86 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL 87 extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask); 88 #else 89 static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask) 90 { 91 BUILD_BUG(); 92 } 93 #endif 94 95 extern int __cpu_disable(void); 96 97 extern void __cpu_die(unsigned int cpu); 98 extern void cpu_die(void); 99 extern void cpu_die_early(void); 100 101 static inline void cpu_park_loop(void) 102 { 103 for (;;) { 104 wfe(); 105 wfi(); 106 } 107 } 108 109 static inline void update_cpu_boot_status(int val) 110 { 111 WRITE_ONCE(secondary_data.status, val); 112 /* Ensure the visibility of the status update */ 113 dsb(ishst); 114 } 115 116 /* 117 * The calling secondary CPU has detected serious configuration mismatch, 118 * which calls for a kernel panic. Update the boot status and park the calling 119 * CPU. 120 */ 121 static inline void cpu_panic_kernel(void) 122 { 123 update_cpu_boot_status(CPU_PANIC_KERNEL); 124 cpu_park_loop(); 125 } 126 127 /* 128 * If a secondary CPU enters the kernel but fails to come online, 129 * (e.g. due to mismatched features), and cannot exit the kernel, 130 * we increment cpus_stuck_in_kernel and leave the CPU in a 131 * quiesecent loop within the kernel text. The memory containing 132 * this loop must not be re-used for anything else as the 'stuck' 133 * core is executing it. 134 * 135 * This function is used to inhibit features like kexec and hibernate. 136 */ 137 bool cpus_are_stuck_in_kernel(void); 138 139 #endif /* ifndef __ASSEMBLY__ */ 140 141 #endif /* ifndef __ASM_SMP_H */ 142