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>
This commit is contained in:
Neil Horman 2011-10-06 14:08:18 -04:00 committed by Jesse Barnes
parent 8e8da023f5
commit b50cac55bf
4 changed files with 133 additions and 0 deletions

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@ -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>

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@ -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);

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@ -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;
};
/*

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@ -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