arch/arm64/include/asm/irq.h

   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