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Commit b50cac55 authored by Neil Horman's avatar Neil Horman Committed by Jesse Barnes
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PCI/sysfs: add per pci device msi[x] irq listing (v5) 



This patch adds a per-pci-device subdirectory in sysfs called:
/sys/bus/pci/devices/<device>/msi_irqs

This sub-directory exports the set of msi vectors allocated by a given
pci device, by creating a numbered sub-directory for each vector beneath
msi_irqs.  For each vector various attributes can be exported.
Currently the only attribute is called mode, which tracks the
operational mode of that vector (msi vs. msix)

Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 8e8da023

Documentation/ABI/testing/sysfs-bus-pci

+18 −0
Original line number Diff line number Diff line
@@ -66,6 +66,24 @@ Description: 
		re-discover previously removed devices.

		Depends on CONFIG_HOTPLUG.



What:		/sys/bus/pci/devices/.../msi_irqs/

Date:		September, 2011

Contact:	Neil Horman <nhorman@tuxdriver.com>

Description:

		The /sys/devices/.../msi_irqs directory contains a variable set

		of sub-directories, with each sub-directory being named after a

		corresponding msi irq vector allocated to that device.  Each

		numbered sub-directory N contains attributes of that irq.

		Note that this directory is not created for device drivers which

		do not support msi irqs



What:		/sys/bus/pci/devices/.../msi_irqs/<N>/mode

Date:		September 2011

Contact:	Neil Horman <nhorman@tuxdriver.com>

Description:

		This attribute indicates the mode that the irq vector named by

		the parent directory is in (msi vs. msix)



What:		/sys/bus/pci/devices/.../remove

Date:		January 2009

Contact:	Linux PCI developers <linux-pci@vger.kernel.org>

drivers/pci/msi.c

+111 −0
Original line number Diff line number Diff line
@@ -323,6 +323,8 @@ static void free_msi_irqs(struct pci_dev *dev) 
			if (list_is_last(&entry->list, &dev->msi_list))

				iounmap(entry->mask_base);

		}

		kobject_del(&entry->kobj);

		kobject_put(&entry->kobj);

		list_del(&entry->list);

		kfree(entry);

	}
@@ -403,6 +405,98 @@ void pci_restore_msi_state(struct pci_dev *dev) 
}

EXPORT_SYMBOL_GPL(pci_restore_msi_state);





#define to_msi_attr(obj) container_of(obj, struct msi_attribute, attr)

#define to_msi_desc(obj) container_of(obj, struct msi_desc, kobj)



struct msi_attribute {

	struct attribute        attr;

	ssize_t (*show)(struct msi_desc *entry, struct msi_attribute *attr,

			char *buf);

	ssize_t (*store)(struct msi_desc *entry, struct msi_attribute *attr,

			 const char *buf, size_t count);

};



static ssize_t show_msi_mode(struct msi_desc *entry, struct msi_attribute *atr,

			     char *buf)

{

	return sprintf(buf, "%s\n", entry->msi_attrib.is_msix ? "msix" : "msi");

}



static ssize_t msi_irq_attr_show(struct kobject *kobj,

				 struct attribute *attr, char *buf)

{

	struct msi_attribute *attribute = to_msi_attr(attr);

	struct msi_desc *entry = to_msi_desc(kobj);



	if (!attribute->show)

		return -EIO;



	return attribute->show(entry, attribute, buf);

}



static const struct sysfs_ops msi_irq_sysfs_ops = {

	.show = msi_irq_attr_show,

};



static struct msi_attribute mode_attribute =

	__ATTR(mode, S_IRUGO, show_msi_mode, NULL);





struct attribute *msi_irq_default_attrs[] = {

	&mode_attribute.attr,

	NULL

};



void msi_kobj_release(struct kobject *kobj)

{

	struct msi_desc *entry = to_msi_desc(kobj);



	pci_dev_put(entry->dev);

}



static struct kobj_type msi_irq_ktype = {

	.release = msi_kobj_release,

	.sysfs_ops = &msi_irq_sysfs_ops,

	.default_attrs = msi_irq_default_attrs,

};



static int populate_msi_sysfs(struct pci_dev *pdev)

{

	struct msi_desc *entry;

	struct kobject *kobj;

	int ret;

	int count = 0;



	pdev->msi_kset = kset_create_and_add("msi_irqs", NULL, &pdev->dev.kobj);

	if (!pdev->msi_kset)

		return -ENOMEM;



	list_for_each_entry(entry, &pdev->msi_list, list) {

		kobj = &entry->kobj;

		kobj->kset = pdev->msi_kset;

		pci_dev_get(pdev);

		ret = kobject_init_and_add(kobj, &msi_irq_ktype, NULL,

				     "%u", entry->irq);

		if (ret)

			goto out_unroll;



		count++;

	}



	return 0;



out_unroll:

	list_for_each_entry(entry, &pdev->msi_list, list) {

		if (!count)

			break;

		kobject_del(&entry->kobj);

		kobject_put(&entry->kobj);

		count--;

	}

	return ret;

}



/**

 * msi_capability_init - configure device's MSI capability structure

 * @dev: pointer to the pci_dev data structure of MSI device function
@@ -454,6 +548,13 @@ static int msi_capability_init(struct pci_dev *dev, int nvec) 
		return ret;

	}



	ret = populate_msi_sysfs(dev);

	if (ret) {

		msi_mask_irq(entry, mask, ~mask);

		free_msi_irqs(dev);

		return ret;

	}



	/* Set MSI enabled bits	 */

	pci_intx_for_msi(dev, 0);

	msi_set_enable(dev, pos, 1);
@@ -574,6 +675,12 @@ static int msix_capability_init(struct pci_dev *dev, 


	msix_program_entries(dev, entries);



	ret = populate_msi_sysfs(dev);

	if (ret) {

		ret = 0;

		goto error;

	}



	/* Set MSI-X enabled bits and unmask the function */

	pci_intx_for_msi(dev, 0);

	dev->msix_enabled = 1;
@@ -732,6 +839,8 @@ void pci_disable_msi(struct pci_dev *dev) 


	pci_msi_shutdown(dev);

	free_msi_irqs(dev);

	kset_unregister(dev->msi_kset);

	dev->msi_kset = NULL;

}

EXPORT_SYMBOL(pci_disable_msi);
@@ -830,6 +939,8 @@ void pci_disable_msix(struct pci_dev *dev) 


	pci_msix_shutdown(dev);

	free_msi_irqs(dev);

	kset_unregister(dev->msi_kset);

	dev->msi_kset = NULL;

}

EXPORT_SYMBOL(pci_disable_msix);

include/linux/msi.h

+3 −0
Original line number Diff line number Diff line 
#ifndef LINUX_MSI_H

#define LINUX_MSI_H



#include <linux/kobject.h>

#include <linux/list.h>



struct msi_msg {
@@ -44,6 +45,8 @@ struct msi_desc { 


	/* Last set MSI message */

	struct msi_msg msg;



	struct kobject kobj;

};



/*

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -336,6 +336,7 @@ struct pci_dev { 
	struct bin_attribute *res_attr_wc[DEVICE_COUNT_RESOURCE]; /* sysfs file for WC mapping of resources */

#ifdef CONFIG_PCI_MSI

	struct list_head msi_list;

	struct kset *msi_kset;

#endif

	struct pci_vpd *vpd;

#ifdef CONFIG_PCI_ATS