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Commit 60b332e7 authored by Michael Ellerman's avatar Michael Ellerman Committed by Paul Mackerras
Browse files

[POWERPC] Export virq mapping via debugfs 



This adds a debugfs file "powerpc/virq_mapping", which shows the virtual
to real mapping of irq numbers.  Enable it with CONFIG_VIRQ_DEBUG.

Signed-off-by: default avatarZhang Wei <wei.zhang@freescale.com>
Signed-off-by: default avatarChen Gong <G.Chen@freescale.com>
Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 7866291d

arch/powerpc/Kconfig.debug

+10 −0
Original line number Diff line number Diff line
@@ -124,6 +124,16 @@ config IRQSTACKS 
	  for handling hard and soft interrupts.  This can help avoid

	  overflowing the process kernel stacks.



config VIRQ_DEBUG

	bool "Expose hardware/virtual IRQ mapping via debugfs"

	depends on DEBUG_FS && PPC_MERGE

	help

	  This option will show the mapping relationship between hardware irq

	  numbers and virtual irq numbers. The mapping is exposed via debugfs

	  in the file powerpc/virq_mapping.



	  If you don't know what this means you don't need it.



config BDI_SWITCH

	bool "Include BDI-2000 user context switcher"

	depends on DEBUG_KERNEL && PPC32

arch/powerpc/kernel/irq.c

+63 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ 
#include <linux/mutex.h>

#include <linux/bootmem.h>

#include <linux/pci.h>

#include <linux/debugfs.h>



#include <asm/uaccess.h>

#include <asm/system.h>
@@ -1006,6 +1007,68 @@ static int irq_late_init(void) 
}

arch_initcall(irq_late_init);



#ifdef CONFIG_VIRQ_DEBUG

static int virq_debug_show(struct seq_file *m, void *private)

{

	unsigned long flags;

	irq_desc_t *desc;

	const char *p;

	char none[] = "none";

	int i;



	seq_printf(m, "%-5s  %-7s  %-15s  %s\n", "virq", "hwirq",

		      "chip name", "host name");



	for (i = 1; i < NR_IRQS; i++) {

		desc = get_irq_desc(i);

		spin_lock_irqsave(&desc->lock, flags);



		if (desc->action && desc->action->handler) {

			seq_printf(m, "%5d  ", i);

			seq_printf(m, "0x%05lx  ", virq_to_hw(i));



			if (desc->chip && desc->chip->typename)

				p = desc->chip->typename;

			else

				p = none;

			seq_printf(m, "%-15s  ", p);



			if (irq_map[i].host && irq_map[i].host->of_node)

				p = irq_map[i].host->of_node->full_name;

			else

				p = none;

			seq_printf(m, "%s\n", p);

		}



		spin_unlock_irqrestore(&desc->lock, flags);

	}



	return 0;

}



static int virq_debug_open(struct inode *inode, struct file *file)

{

	return single_open(file, virq_debug_show, inode->i_private);

}



static const struct file_operations virq_debug_fops = {

	.open = virq_debug_open,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = single_release,

};



static int __init irq_debugfs_init(void)

{

	if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,

				 NULL, &virq_debug_fops))

		return -ENOMEM;



	return 0;

}

__initcall(irq_debugfs_init);

#endif /* CONFIG_VIRQ_DEBUG */



#endif /* CONFIG_PPC_MERGE */



#ifdef CONFIG_PPC64