From: Neil Horman <nhorman@tuxdriver.com>

Date: Thu, 6 Oct 2011 18:08:18 +0000 (-0400)

Subject: PCI/sysfs: add per pci device msi[x] irq listing (v5)

X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fjbarnes%2Fpci.git;a=commitdiff_plain;h=933aa5c1f69aa650f59ba783307fc7ed7cc5fafa

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: Greg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

---

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci

index 349ecf2..34f5110 100644

--- a/Documentation/ABI/testing/sysfs-bus-pci

+++ b/Documentation/ABI/testing/sysfs-bus-pci

@@ -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>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c

index 2f10328..73613e2 100644

--- a/drivers/pci/msi.c

+++ b/drivers/pci/msi.c

@@ -322,6 +322,8 @@ 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);

 	}

@@ -402,6 +404,98 @@ 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

@@ -453,6 +547,13 @@ 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);

@@ -573,6 +674,12 @@ 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;

@@ -731,6 +838,8 @@ 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);

@@ -829,6 +938,8 @@ 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);

diff --git a/include/linux/msi.h b/include/linux/msi.h

index 05acced..ce93a34 100644

--- a/include/linux/msi.h

+++ b/include/linux/msi.h

@@ -1,6 +1,7 @@

 #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;

 };

 /*

diff --git a/include/linux/pci.h b/include/linux/pci.h

index 7cda65b..84225c7 100644

--- a/include/linux/pci.h

+++ b/include/linux/pci.h

@@ -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