From faf29a4d93a98b4ccd8a10297353a9d0779d231f Mon Sep 17 00:00:00 2001
From: Niklas Schnelle <schnelle@linux.ibm.com>
Date: Thu, 11 Feb 2021 14:20:03 +0100
Subject: [PATCH] s390/pci: introduce zpci_bus_scan_device()
To match zpci_bus_scan_device() and the PCI common code terminology and
to remove some code duplication, we pull the multiple uses of
pci_scan_single_device() into a function. For now this has the side
effect of adding each device to the PCI bus separately and locking and
unlocking the rescan/remove lock for each instead of just once per bus.
This is clearly less efficient but provides a correct intermediate
behavior until a follow on change does both the adding and scanning only
once per bus.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
arch/s390/pci/pci.c | 9 ++-------
arch/s390/pci/pci_bus.c | 35 +++++++++++++++++++++++++----------
arch/s390/pci/pci_bus.h | 1 +
3 files changed, 28 insertions(+), 17 deletions(-)
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index dd14641b2d20b..0bce6078bfd63 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -757,7 +757,6 @@ error:
*/
int zpci_configure_device(struct zpci_dev *zdev, u32 fh)
{
- struct pci_dev *pdev;
int rc;
zdev->fh = fh;
@@ -777,14 +776,10 @@ int zpci_configure_device(struct zpci_dev *zdev, u32 fh)
if (!zdev->zbus->bus)
return 0;
- pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn);
- if (!pdev)
+ rc = zpci_bus_scan_device(zdev);
+ if (rc)
goto error_disable;
- pci_bus_add_device(pdev);
- pci_lock_rescan_remove();
- pci_bus_add_devices(zdev->zbus->bus);
- pci_unlock_rescan_remove();
return 0;
error_disable:
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c
index ace9dbbe3bc14..7b37c4316e35d 100644
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -30,6 +30,29 @@ static LIST_HEAD(zbus_list);
static DEFINE_SPINLOCK(zbus_list_lock);
static int zpci_nb_devices;
+/* zpci_bus_scan_device - Scan a single device adding it to the PCI core
+ * @zdev: the zdev to be scanned
+ *
+ * Scans the PCI function making it available to the common PCI code.
+ *
+ * Return: 0 on success, an error value otherwise
+ */
+int zpci_bus_scan_device(struct zpci_dev *zdev)
+{
+ struct pci_dev *pdev;
+
+ pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn);
+ if (!pdev)
+ return -ENODEV;
+
+ pci_bus_add_device(pdev);
+ pci_lock_rescan_remove();
+ pci_bus_add_devices(zdev->zbus->bus);
+ pci_unlock_rescan_remove();
+
+ return 0;
+}
+
/* zpci_bus_remove_device - Removes the given zdev from the PCI core
* @zdev: the zdev to be removed from the PCI core
* @set_error: if true the device's error state is set to permanent failure
@@ -176,10 +199,10 @@ void pcibios_bus_add_device(struct pci_dev *pdev)
static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
{
- struct pci_bus *bus;
struct resource_entry *window, *n;
struct resource *res;
struct pci_dev *pdev;
+ struct pci_bus *bus;
int rc;
bus = zbus->bus;
@@ -203,11 +226,7 @@ static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
pci_bus_add_resource(bus, res, 0);
}
- pdev = pci_scan_single_device(bus, zdev->devfn);
- if (pdev)
- pci_bus_add_device(pdev);
-
- return 0;
+ return zpci_bus_scan_device(zdev);
}
static void zpci_bus_add_devices(struct zpci_bus *zbus)
@@ -217,10 +236,6 @@ static void zpci_bus_add_devices(struct zpci_bus *zbus)
for (i = 1; i < ZPCI_FUNCTIONS_PER_BUS; i++)
if (zbus->function[i])
zpci_bus_add_device(zbus, zbus->function[i]);
-
- pci_lock_rescan_remove();
- pci_bus_add_devices(zbus->bus);
- pci_unlock_rescan_remove();
}
int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
diff --git a/arch/s390/pci/pci_bus.h b/arch/s390/pci/pci_bus.h
index e04ca06a71b64..2649238f6cde4 100644
--- a/arch/s390/pci/pci_bus.h
+++ b/arch/s390/pci/pci_bus.h
@@ -10,6 +10,7 @@
int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops);
void zpci_bus_device_unregister(struct zpci_dev *zdev);
+int zpci_bus_scan_device(struct zpci_dev *zdev);
void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error);
void zpci_release_device(struct kref *kref);
--
2.30.2