s390/pci: add recover sysfs knob

Add an arch specific attribute to recover a pci function from an
error state or config space blockage.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 29 insertions, 4 deletions

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 61167b1209a3..b0ccd424308a 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -791,6 +791,8 @@ int zpci_enable_device(struct zpci_dev *zdev)
         rc = zpci_dma_init_device(zdev);
         if (rc)
                 goto out_dma;
+
+        zdev->state = ZPCI_FN_STATE_ONLINE;
         return 0;
 
 out_dma:
@@ -819,8 +821,6 @@ int zpci_create_device(struct zpci_dev *zdev)
                 rc = zpci_enable_device(zdev);
                 if (rc)
                         goto out_free;
-
-                zdev->state = ZPCI_FN_STATE_ONLINE;
         }
         rc = zpci_scan_bus(zdev);
         if (rc)
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index e99a2557f186..cf8a12ff733b 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -48,11 +48,38 @@ static ssize_t show_pfgid(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(pfgid, S_IRUGO, show_pfgid, NULL);
 
+static void recover_callback(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct zpci_dev *zdev = get_zdev(pdev);
+        int ret;
+
+        pci_stop_and_remove_bus_device(pdev);
+        ret = zpci_disable_device(zdev);
+        if (ret)
+                return;
+
+        ret = zpci_enable_device(zdev);
+        if (ret)
+                return;
+
+        pci_rescan_bus(zdev->bus);
+}
+
+static ssize_t store_recover(struct device *dev, struct device_attribute *attr,
+                             const char *buf, size_t count)
+{
+        int rc = device_schedule_callback(dev, recover_callback);
+        return rc ? rc : count;
+}
+static DEVICE_ATTR(recover, S_IWUSR, NULL, store_recover);
+
 static struct device_attribute *zpci_dev_attrs[] = {
         &dev_attr_function_id,
         &dev_attr_function_handle,
         &dev_attr_pchid,
         &dev_attr_pfgid,
+        &dev_attr_recover,
         NULL,
 };
 
diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c
index 0d9c12fbcb3a..66e505ca24ef 100644
--- a/drivers/pci/hotplug/s390_pci_hpc.c
+++ b/drivers/pci/hotplug/s390_pci_hpc.c
@@ -79,8 +79,6 @@ static int enable_slot(struct hotplug_slot *hotplug_slot)
         if (rc)
                 goto out_deconfigure;
 
-        slot->zdev->state = ZPCI_FN_STATE_ONLINE;
-
         pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
         pci_bus_add_devices(slot->zdev->bus);