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 /* Values for secondary_data.status */
20 #define CPU_STUCK_REASON_SHIFT (8)
21 #define CPU_BOOT_STATUS_MASK ((1U << CPU_STUCK_REASON_SHIFT) - 1)
23 #define CPU_MMU_OFF (-1)
24 #define CPU_BOOT_SUCCESS (0)
25 /* The cpu invoked ops->cpu_die, synchronise it with cpu_kill */
26 #define CPU_KILL_ME (1)
27 /* The cpu couldn't die gracefully and is looping in the kernel */
28 #define CPU_STUCK_IN_KERNEL (2)
29 /* Fatal system error detected by secondary CPU, crash the system */
30 #define CPU_PANIC_KERNEL (3)
32 #define CPU_STUCK_REASON_52_BIT_VA (1U << CPU_STUCK_REASON_SHIFT)
33 #define CPU_STUCK_REASON_NO_GRAN (2U << CPU_STUCK_REASON_SHIFT)
37 #include <asm/percpu.h>
39 #include <linux/threads.h>
40 #include <linux/cpumask.h>
41 #include <linux/thread_info.h>
43 DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
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.
52 #define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number))
57 * generate IPI list text
59 extern void show_ipi_list(struct seq_file *p, int prec);
62 * Called from C code, this handles an IPI.
64 extern void handle_IPI(int ipinr, struct pt_regs *regs);
67 * Discover the set of possible CPUs and determine their
70 extern void smp_init_cpus(void);
73 * Provide a function to raise an IPI cross call on CPUs in callmap.
75 extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int));
77 extern void (*__smp_cross_call)(const struct cpumask *, unsigned int);
80 * Called from the secondary holding pen, this is the secondary CPU entry point.
82 asmlinkage void secondary_start_kernel(void);
85 * Initial data for bringing up a secondary CPU.
86 * @stack - sp for the secondary CPU
87 * @status - Result passed back from the secondary CPU to
90 struct secondary_data {
92 struct task_struct *task;
96 extern struct secondary_data secondary_data;
97 extern long __early_cpu_boot_status;
98 extern void secondary_entry(void);
100 extern void arch_send_call_function_single_ipi(int cpu);
101 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
103 #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
104 extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
106 static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
112 extern int __cpu_disable(void);
114 extern void __cpu_die(unsigned int cpu);
115 extern void cpu_die(void);
116 extern void cpu_die_early(void);
118 static inline void cpu_park_loop(void)
126 static inline void update_cpu_boot_status(int val)
128 WRITE_ONCE(secondary_data.status, val);
129 /* Ensure the visibility of the status update */
134 * The calling secondary CPU has detected serious configuration mismatch,
135 * which calls for a kernel panic. Update the boot status and park the calling
138 static inline void cpu_panic_kernel(void)
140 update_cpu_boot_status(CPU_PANIC_KERNEL);
145 * If a secondary CPU enters the kernel but fails to come online,
146 * (e.g. due to mismatched features), and cannot exit the kernel,
147 * we increment cpus_stuck_in_kernel and leave the CPU in a
148 * quiesecent loop within the kernel text. The memory containing
149 * this loop must not be re-used for anything else as the 'stuck'
150 * core is executing it.
152 * This function is used to inhibit features like kexec and hibernate.
154 bool cpus_are_stuck_in_kernel(void);
156 extern void crash_smp_send_stop(void);
157 extern bool smp_crash_stop_failed(void);
159 #endif /* ifndef __ASSEMBLY__ */
161 #endif /* ifndef __ASM_SMP_H */