xref: /linux/arch/arm64/include/asm/irq.h (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 #ifndef __ASM_IRQ_H
2 #define __ASM_IRQ_H
3 
4 #define IRQ_STACK_SIZE			THREAD_SIZE
5 #define IRQ_STACK_START_SP		THREAD_START_SP
6 
7 #ifndef __ASSEMBLER__
8 
9 #include <linux/percpu.h>
10 
11 #include <asm-generic/irq.h>
12 #include <asm/thread_info.h>
13 
14 struct pt_regs;
15 
16 DECLARE_PER_CPU(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
17 
18 /*
19  * The highest address on the stack, and the first to be used. Used to
20  * find the dummy-stack frame put down by el?_irq() in entry.S, which
21  * is structured as follows:
22  *
23  *       ------------
24  *       |          |  <- irq_stack_ptr
25  *   top ------------
26  *       |   x19    | <- irq_stack_ptr - 0x08
27  *       ------------
28  *       |   x29    | <- irq_stack_ptr - 0x10
29  *       ------------
30  *
31  * where x19 holds a copy of the task stack pointer where the struct pt_regs
32  * from kernel_entry can be found.
33  *
34  */
35 #define IRQ_STACK_PTR(cpu) ((unsigned long)per_cpu(irq_stack, cpu) + IRQ_STACK_START_SP)
36 
37 /*
38  * The offset from irq_stack_ptr where entry.S will store the original
39  * stack pointer. Used by unwind_frame() and dump_backtrace().
40  */
41 #define IRQ_STACK_TO_TASK_STACK(ptr) (*((unsigned long *)((ptr) - 0x08)))
42 
43 extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
44 
45 static inline int nr_legacy_irqs(void)
46 {
47 	return 0;
48 }
49 
50 static inline bool on_irq_stack(unsigned long sp, int cpu)
51 {
52 	/* variable names the same as kernel/stacktrace.c */
53 	unsigned long low = (unsigned long)per_cpu(irq_stack, cpu);
54 	unsigned long high = low + IRQ_STACK_START_SP;
55 
56 	return (low <= sp && sp <= high);
57 }
58 
59 #endif /* !__ASSEMBLER__ */
60 #endif
61