1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_CURRENT_H
3#define _ASM_X86_CURRENT_H
4
5#include <linux/build_bug.h>
6#include <linux/compiler.h>
7
8#ifndef __ASSEMBLY__
9
10#include <linux/cache.h>
11#include <asm/percpu.h>
12
13struct task_struct;
14
15struct pcpu_hot {
16	union {
17		struct {
18			struct task_struct	*current_task;
19			int			preempt_count;
20			int			cpu_number;
21#ifdef CONFIG_MITIGATION_CALL_DEPTH_TRACKING
22			u64			call_depth;
23#endif
24			unsigned long		top_of_stack;
25			void			*hardirq_stack_ptr;
26			u16			softirq_pending;
27#ifdef CONFIG_X86_64
28			bool			hardirq_stack_inuse;
29#else
30			void			*softirq_stack_ptr;
31#endif
32		};
33		u8	pad[64];
34	};
35};
36static_assert(sizeof(struct pcpu_hot) == 64);
37
38DECLARE_PER_CPU_ALIGNED(struct pcpu_hot, pcpu_hot);
39
40/* const-qualified alias to pcpu_hot, aliased by linker. */
41DECLARE_PER_CPU_ALIGNED(const struct pcpu_hot __percpu_seg_override,
42			const_pcpu_hot);
43
44static __always_inline struct task_struct *get_current(void)
45{
46	if (IS_ENABLED(CONFIG_USE_X86_SEG_SUPPORT))
47		return this_cpu_read_const(const_pcpu_hot.current_task);
48
49	return this_cpu_read_stable(pcpu_hot.current_task);
50}
51
52#define current get_current()
53
54#endif /* __ASSEMBLY__ */
55
56#endif /* _ASM_X86_CURRENT_H */
57