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
13 struct task_struct;
14
15 struct 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 };
36 static_assert(sizeof(struct pcpu_hot) == 64);
37
38 DECLARE_PER_CPU_ALIGNED(struct pcpu_hot, pcpu_hot);
39
40 /* const-qualified alias to pcpu_hot, aliased by linker. */
41 DECLARE_PER_CPU_ALIGNED(const struct pcpu_hot __percpu_seg_override,
42 const_pcpu_hot);
43
44 static __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
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