Commit 1c51b50c authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman Committed by Bjorn Helgaas
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PCI/MSI: Export MSI mode using attributes, not kobjects 



The PCI MSI sysfs code is a mess with kobjects for things that don't really
need to be kobjects.  This patch creates attributes dynamically for the MSI
interrupts instead of using kobjects.

Note, this removes a directory from sysfs.  Old MSI kobjects:

  pci_device
     └── msi_irqs
         └── 40
             └── mode

New MSI attributes:

  pci_device
     └── msi_irqs
         └── 40

As there was only one file "mode" with the kobject model, the interrupt
number is now a file that returns the "mode" of the interrupt (msi vs.
msix).

Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
parent 6ce4eac1

Documentation/ABI/testing/sysfs-bus-pci

+4 −7
Original line number Diff line number Diff line
@@ -70,18 +70,15 @@ 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

		of files, with each file being named after a corresponding msi

		irq vector allocated to that device.



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

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

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)

		the file is in (msi vs. msix)



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

Date:		January 2009

drivers/pci/msi.c

+91 −75
Original line number Diff line number Diff line
@@ -363,6 +363,9 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg) 
static void free_msi_irqs(struct pci_dev *dev)

{

	struct msi_desc *entry, *tmp;

	struct attribute **msi_attrs;

	struct device_attribute *dev_attr;

	int count = 0;



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

		int i, nvec;
@@ -398,6 +401,22 @@ static void free_msi_irqs(struct pci_dev *dev) 
		list_del(&entry->list);

		kfree(entry);

	}



	if (dev->msi_irq_groups) {

		sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups);

		msi_attrs = dev->msi_irq_groups[0]->attrs;

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

			dev_attr = container_of(msi_attrs[count],

						struct device_attribute, attr);

			kfree(dev_attr->attr.name);

			kfree(dev_attr);

			++count;

		}

		kfree(msi_attrs);

		kfree(dev->msi_irq_groups[0]);

		kfree(dev->msi_irq_groups);

		dev->msi_irq_groups = NULL;

	}

}



static struct msi_desc *alloc_msi_entry(struct pci_dev *dev)
@@ -471,94 +490,95 @@ 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,

static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,

			     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);

	struct pci_dev *pdev = to_pci_dev(dev);

	struct msi_desc *entry;

	unsigned long irq;

	int retval;



	if (!attribute->show)

		return -EIO;

	retval = kstrtoul(attr->attr.name, 10, &irq);

	if (retval)

		return retval;



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

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

		if (entry->irq == irq) {

			return sprintf(buf, "%s\n",

				       entry->msi_attrib.is_msix ? "msix" : "msi");

		}



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);





static struct attribute *msi_irq_default_attrs[] = {

	&mode_attribute.attr,

	NULL

};



static 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,

};

	return -ENODEV;

}



static int populate_msi_sysfs(struct pci_dev *pdev)

{

	struct attribute **msi_attrs;

	struct attribute *msi_attr;

	struct device_attribute *msi_dev_attr;

	struct attribute_group *msi_irq_group;

	const struct attribute_group **msi_irq_groups;

	struct msi_desc *entry;

	struct kobject *kobj;

	int ret;

	int ret = -ENOMEM;

	int num_msi = 0;

	int count = 0;



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

	if (!pdev->msi_kset)

		return -ENOMEM;

	/* Determine how many msi entries we have */

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

		++num_msi;

	}

	if (!num_msi)

		return 0;



	/* Dynamically create the MSI attributes for the PCI device */

	msi_attrs = kzalloc(sizeof(void *) * (num_msi + 1), GFP_KERNEL);

	if (!msi_attrs)

		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);

		char *name = kmalloc(20, GFP_KERNEL);

		msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL);

		if (!msi_dev_attr)

			goto error_attrs;

		sprintf(name, "%d", entry->irq);

		sysfs_attr_init(&msi_dev_attr->attr);

		msi_dev_attr->attr.name = name;

		msi_dev_attr->attr.mode = S_IRUGO;

		msi_dev_attr->show = msi_mode_show;

		msi_attrs[count] = &msi_dev_attr->attr;

		++count;

	}



	msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL);

	if (!msi_irq_group)

		goto error_attrs;

	msi_irq_group->name = "msi_irqs";

	msi_irq_group->attrs = msi_attrs;



	msi_irq_groups = kzalloc(sizeof(void *) * 2, GFP_KERNEL);

	if (!msi_irq_groups)

		goto error_irq_group;

	msi_irq_groups[0] = msi_irq_group;



	ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);

	if (ret)

			goto out_unroll;



		count++;

	}

		goto error_irq_groups;

	pdev->msi_irq_groups = msi_irq_groups;



	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--;

error_irq_groups:

	kfree(msi_irq_groups);

error_irq_group:

	kfree(msi_irq_group);

error_attrs:

	count = 0;

	msi_attr = msi_attrs[count];

	while (msi_attr) {

		msi_dev_attr = container_of(msi_attr, struct device_attribute, attr);

		kfree(msi_attr->name);

		kfree(msi_dev_attr);

		++count;

		msi_attr = msi_attrs[count];

	}

	return ret;

}
@@ -925,8 +945,6 @@ 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);
@@ -1023,8 +1041,6 @@ 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/pci.h

+1 −1
Original line number Diff line number Diff line
@@ -351,7 +351,7 @@ 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;

	const struct attribute_group **msi_irq_groups;

#endif

	struct pci_vpd *vpd;

#ifdef CONFIG_PCI_ATS

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