linux/arch/arm64/include/asm/smp.h
Suzuki K Poulose c4bc34d202 arm64: Add a helper for parking CPUs in a loop
Adds a routine which can be used to park CPUs (spinning in kernel)
when they can't be killed.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:44 +00:00

90 lines
2.2 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_SMP_H
#define __ASM_SMP_H
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/thread_info.h>
#define raw_smp_processor_id() (current_thread_info()->cpu)
struct seq_file;
/*
* generate IPI list text
*/
extern void show_ipi_list(struct seq_file *p, int prec);
/*
* Called from C code, this handles an IPI.
*/
extern void handle_IPI(int ipinr, struct pt_regs *regs);
/*
* Discover the set of possible CPUs and determine their
* SMP operations.
*/
extern void smp_init_cpus(void);
/*
* Provide a function to raise an IPI cross call on CPUs in callmap.
*/
extern void set_smp_cross_call(void (*)(const struct cpumask *, unsigned int));
extern void (*__smp_cross_call)(const struct cpumask *, unsigned int);
/*
* Called from the secondary holding pen, this is the secondary CPU entry point.
*/
asmlinkage void secondary_start_kernel(void);
/*
* Initial data for bringing up a secondary CPU.
*/
struct secondary_data {
void *stack;
};
extern struct secondary_data secondary_data;
extern void secondary_entry(void);
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
extern void arch_send_wakeup_ipi_mask(const struct cpumask *mask);
#else
static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
{
BUILD_BUG();
}
#endif
extern int __cpu_disable(void);
extern void __cpu_die(unsigned int cpu);
extern void cpu_die(void);
static inline void cpu_park_loop(void)
{
for (;;) {
wfe();
wfi();
}
}
#endif /* ifndef __ASM_SMP_H */