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 get_current(void)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