2 * Copyright (C) 2012 ARM Ltd.
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.
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.
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/>.
19 #include <linux/const.h>
21 /* Values for secondary_data.status */
22 #define CPU_STUCK_REASON_SHIFT (8)
23 #define CPU_BOOT_STATUS_MASK ((UL(1) << CPU_STUCK_REASON_SHIFT) - 1)
25 #define CPU_MMU_OFF (-1)
26 #define CPU_BOOT_SUCCESS (0)
27 /* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */
28 #define CPU_KILL_ME (1)
29 /* The cpu couldn't die gracefully and is looping in the kernel */
30 #define CPU_STUCK_IN_KERNEL (2)
31 /* Fatal system error detected by secondary CPU, crash the system */
32 #define CPU_PANIC_KERNEL (3)
34 #define CPU_STUCK_REASON_52_BIT_VA (UL(1) << CPU_STUCK_REASON_SHIFT)
35 #define CPU_STUCK_REASON_NO_GRAN (UL(2) << CPU_STUCK_REASON_SHIFT)
39 #include <asm/percpu.h>
41 #include <linux/threads.h>
42 #include <linux/cpumask.h>
43 #include <linux/thread_info.h>
45 DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
48 * We don't use this_cpu_read(cpu_number) as that has implicit writes to
49 * preempt_count, and associated (compiler) barriers, that we'd like to avoid
50 * the expense of. If we're preemptible, the value can be stale at use anyway.
51 * And we can't use this_cpu_ptr() either, as that winds up recursing back
52 * here under CONFIG_DEBUG_PREEMPT=y.
54 #define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number))
57 * Logical CPU mapping.
59 extern u64 __cpu_logical_map[NR_CPUS];
60 #define cpu_logical_map(cpu) __cpu_logical_map[cpu]
65 * generate IPI list text
67 extern void show_ipi_list(struct seq_file *p, int prec);
70 * Called from C code, this handles an IPI.
72 extern void handle_IPI(int ipinr, struct pt_regs *regs);
75 * Discover the set of possible CPUs and determine their
78 extern void smp_init_cpus(void);
81 * Provide a function to raise an IPI cross call on CPUs in callmap.
83 extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int));
85 extern void (*__smp_cross_call)(const struct cpumask *, unsigned int);
88 * Called from the secondary holding pen, this is the secondary CPU entry point.
90 asmlinkage void secondary_start_kernel(void);
93 * Initial data for bringing up a secondary CPU.
94 * @stack - sp for the secondary CPU
95 * @status - Result passed back from the secondary CPU to
98 struct secondary_data {
100 struct task_struct *task;
104 extern struct secondary_data secondary_data;
105 extern long __early_cpu_boot_status;
106 extern void secondary_entry(void);
108 extern void arch_send_call_function_single_ipi(int cpu);
109 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
111 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
112 extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
114 static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
120 extern int __cpu_disable(void);
122 extern void __cpu_die(unsigned int cpu);
123 extern void cpu_die(void);
124 extern void cpu_die_early(void);
126 static inline void cpu_park_loop(void)
134 static inline void update_cpu_boot_status(int val)
136 WRITE_ONCE(secondary_data.status, val);
137 /* Ensure the visibility of the status update */
142 * The calling secondary CPU has detected serious configuration mismatch,
143 * which calls for a kernel panic. Update the boot status and park the calling
146 static inline void cpu_panic_kernel(void)
148 update_cpu_boot_status(CPU_PANIC_KERNEL);
153 * If a secondary CPU enters the kernel but fails to come online,
154 * (e.g. due to mismatched features), and cannot exit the kernel,
155 * we increment cpus_stuck_in_kernel and leave the CPU in a
156 * quiesecent loop within the kernel text. The memory containing
157 * this loop must not be re-used for anything else as the 'stuck'
158 * core is executing it.
160 * This function is used to inhibit features like kexec and hibernate.
162 bool cpus_are_stuck_in_kernel(void);
164 extern void crash_smp_send_stop(void);
165 extern bool smp_crash_stop_failed(void);
167 #endif /* ifndef __ASSEMBLY__ */
169 #endif /* ifndef __ASM_SMP_H */