diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2009-07-27 23:37:48 +0300 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2009-09-09 13:29:24 -0700 |
| commit | 711d57796f5ce2d02d6e62c9034afbb16aedda31 (patch) | |
| tree | 935861fee775b171cafc96de57fe4fbfa19892eb /drivers | |
| parent | 5228a828ee044834d78abdf25306bf46b19dcc4d (diff) | |
PCI: expose function reset capability in sysfs
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/pci-sysfs.c | 37 | ||||
| -rw-r--r-- | drivers/pci/pci.c | 16 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 1 |
3 files changed, 54 insertions, 0 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 85ebd02a64a7..0f6382f090ee 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -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; + } } /** diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7b70312181d7..7d55039ffa05 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2262,6 +2262,22 @@ int __pci_reset_function(struct pci_dev *dev) EXPORT_SYMBOL_GPL(__pci_reset_function); /** + * pci_probe_reset_function - check whether the device can be safely reset + * @dev: PCI device to reset + * + * Some devices allow an individual function to be reset without affecting + * other functions in the same device. The PCI device must be responsive + * to PCI config space in order to use this function. + * + * Returns 0 if the device function can be reset or negative if the + * device doesn't support resetting a single function. + */ +int pci_probe_reset_function(struct pci_dev *dev) +{ + return pci_dev_reset(dev, 1); +} + +/** * pci_reset_function - quiesce and reset a PCI device function * @dev: PCI device to reset * diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 5ff4d25bf0e9..73d9d92715a0 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -16,6 +16,7 @@ extern void pci_cleanup_rom(struct pci_dev *dev); extern int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma); #endif +int pci_probe_reset_function(struct pci_dev *dev); /** * struct pci_platform_pm_ops - Firmware PM callbacks |