On Mon, Jul 27, 2009 at 08:01:46AM -0700, Greg KH wrote:
> > + if (!pci_probe_reset_function(dev)) {
> > + retval = device_create_file(&dev->dev, &reset_attr);
> > + if (retval)
> > + goto error;
> > + }
>
> So you only add the file if there is a reset function, which is fine,
> but later on:
>
> > @@ -1037,6 +1073,7 @@ static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
> > }
> >
> > pcie_aspm_remove_sysfs_dev_files(dev);
> > + device_remove_file(&dev->dev, &reset_attr);
>
> You always remove the file, if it has been created or not. That could
> cause problems in the future, please only remove a file if you have
> actually added it to the sysfs tree.
>
> thanks,
>
> greg k-h
OK. I think, however, that it's better to avoid probing the function
on cleanup path just to figure out whether the file needs to be removed.
Can this info be stored in struct pci_dev?
Along the lines of:
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 85ebd02..bfb9d21 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -916,6 +916,28 @@ 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;
+
+ /* this can crash the machine when done on the "wrong" device */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ 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 +965,22 @@ 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 +1074,10 @@ 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 dbd0f94..f6d1c6c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2260,6 +2260,22 @@ 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 f73bcbe..60a3811 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
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 115fb7b..a90f940 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -276,6 +276,7 @@ struct pci_dev {
unsigned int state_saved:1;
unsigned int is_physfn:1;
unsigned int is_virtfn:1;
+ unsigned int reset_fn:1;
pci_dev_flags_t dev_flags;
atomic_t enable_cnt; /* pci_enable_device has been called */
--
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