Commit 07557ccb authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

genirq/msi: Capture device name for debugfs 



For debugging the allocation of unused or potentially leaked interrupt
descriptor it's helpful to have some information about the site which
allocated them. In case of MSI this is simple because the caller hands the
device struct pointer into the domain allocation function.

Duplicate the device name and show it in the debugfs entry of the interrupt
descriptor.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarJuergen Gross <jgross@suse.com>
Tested-by: default avatarYu Chen <yu.c.chen@intel.com>
Acked-by: default avatarJuergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.433038426@linutronix.de
parent e0b47794

include/linux/irqdesc.h

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ struct irq_desc { 
#endif

#ifdef CONFIG_GENERIC_IRQ_DEBUGFS

	struct dentry		*debugfs_file;

	const char		*dev_name;

#endif

#ifdef CONFIG_SPARSE_IRQ

	struct rcu_head		rcu;

kernel/irq/debugfs.c

+10 −0
Original line number Diff line number Diff line
@@ -149,6 +149,7 @@ static int irq_debug_show(struct seq_file *m, void *p) 
	raw_spin_lock_irq(&desc->lock);

	data = irq_desc_get_irq_data(desc);

	seq_printf(m, "handler:  %pf\n", desc->handle_irq);

	seq_printf(m, "device:   %s\n", desc->dev_name);

	seq_printf(m, "status:   0x%08x\n", desc->status_use_accessors);

	irq_debug_show_bits(m, 0, desc->status_use_accessors, irqdesc_states,

			    ARRAY_SIZE(irqdesc_states));
@@ -226,6 +227,15 @@ static const struct file_operations dfs_irq_ops = { 
	.release	= single_release,

};



void irq_debugfs_copy_devname(int irq, struct device *dev)

{

	struct irq_desc *desc = irq_to_desc(irq);

	const char *name = dev_name(dev);



	if (name)

		desc->dev_name = kstrdup(name, GFP_KERNEL);

}



void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *desc)

{

	char name [10];

kernel/irq/internals.h

+5 −0
Original line number Diff line number Diff line
@@ -443,7 +443,9 @@ void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *desc); 
static inline void irq_remove_debugfs_entry(struct irq_desc *desc)

{

	debugfs_remove(desc->debugfs_file);

	kfree(desc->dev_name);

}

void irq_debugfs_copy_devname(int irq, struct device *dev);

# ifdef CONFIG_IRQ_DOMAIN

void irq_domain_debugfs_init(struct dentry *root);

# else
@@ -458,4 +460,7 @@ static inline void irq_add_debugfs_entry(unsigned int irq, struct irq_desc *d) 
static inline void irq_remove_debugfs_entry(struct irq_desc *d)

{

}

static inline void irq_debugfs_copy_devname(int irq, struct device *dev)

{

}

#endif /* CONFIG_GENERIC_IRQ_DEBUGFS */

kernel/irq/msi.c

+5 −1
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ 
#include <linux/msi.h>

#include <linux/slab.h>



#include "internals.h"



/**

 * alloc_msi_entry - Allocate an initialize msi_entry

 * @dev:	Pointer to the device for which this is allocated
@@ -373,8 +375,10 @@ int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, 
			return ret;

		}



		for (i = 0; i < desc->nvec_used; i++)

		for (i = 0; i < desc->nvec_used; i++) {

			irq_set_msi_desc_off(virq, i, desc);

			irq_debugfs_copy_devname(virq + i, dev);

		}

	}



	if (ops->msi_finish)

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