wrapper/irqdesc.c

   1 /* SPDX-License-Identifier: (GPL-2.0 OR LGPL-2.1)
   2  *
   3  * wrapper/irqdesc.c
   4  *
   5  * wrapper around irq_to_desc. Using KALLSYMS to get its address when
   6  * available, else we need to have a kernel that exports this function to GPL
   7  * modules.
   8  *
   9  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  */
  11
  12 #ifdef CONFIG_KALLSYMS
  13
  14 #include <linux/kallsyms.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irqnr.h>
  17 #include <wrapper/kallsyms.h>
  18 #include <wrapper/irqdesc.h>
  19
  20 static
  21 struct irq_desc *(*irq_to_desc_sym)(unsigned int irq);
  22
  23 struct irq_desc *wrapper_irq_to_desc(unsigned int irq)
  24 {
  25         if (!irq_to_desc_sym)
  26                 irq_to_desc_sym = (void *) kallsyms_lookup_funcptr("irq_to_desc");
  27         if (irq_to_desc_sym) {
  28                 return irq_to_desc_sym(irq);
  29         } else {
  30                 printk_once(KERN_WARNING "LTTng: irq_to_desc symbol lookup failed.\n");
  31                 return NULL;
  32         }
  33 }
  34
  35 #else
  36
  37 #include <linux/interrupt.h>
  38 #include <linux/irqnr.h>
  39
  40 struct irq_desc *wrapper_irq_to_desc(unsigned int irq)
  41 {
  42         return irq_to_desc(irq);
  43 }
  44
  45 #endif