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PCI: expose function reset capability in sysfs

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Some devices allow an individual function to be reset without affecting
other functions in the same device: that's what pci_reset_function does.
For devices that have this support, expose reset attribite in sysfs.

This is useful e.g. for virtualization, where a qemu userspace
process wants to reset the device when the guest is reset,
to emulate machine reboot as closely as possible.

Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Michael S. Tsirkin
2009-07-27 23:37:48 +03:00
committed by Jesse Barnes
parent 5228a828ee
commit 711d57796f
5 changed files with 65 additions and 0 deletions
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37
drivers/pci/pci-sysfs.c
View File

@ -916,6 +916,24 @@ int __attribute__ ((weak)) pcibios_add_platform_entries(struct pci_dev *dev)
return 0;
}
static ssize_t reset_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
struct pci_dev *pdev = to_pci_dev(dev);
unsigned long val;
ssize_t result = strict_strtoul(buf, 0, &val);
if (result < 0)
return result;
if (val != 1)
return -EINVAL;
return pci_reset_function(pdev);
}
static struct device_attribute reset_attr = __ATTR(reset, 0200, NULL, reset_store);
static int pci_create_capabilities_sysfs(struct pci_dev *dev)
{
int retval;
@ -943,7 +961,22 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
/* Active State Power Management */
pcie_aspm_create_sysfs_dev_files(dev);
if (!pci_probe_reset_function(dev)) {
retval = device_create_file(&dev->dev, &reset_attr);
if (retval)
goto error;
dev->reset_fn = 1;
}
return 0;
error:
pcie_aspm_remove_sysfs_dev_files(dev);
if (dev->vpd && dev->vpd->attr) {
sysfs_remove_bin_file(&dev->dev.kobj, dev->vpd->attr);
kfree(dev->vpd->attr);
}
return retval;
}
int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
@ -1037,6 +1070,10 @@ static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
}
pcie_aspm_remove_sysfs_dev_files(dev);
if (dev->reset_fn) {
device_remove_file(&dev->dev, &reset_attr);
dev->reset_fn = 0;
}
}
/**