tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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
14struct pt_regs;
15
16DECLARE_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
43extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
44
45static inline int nr_legacy_irqs(void)
46{
47 return 0;
48}
49
50static 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