[PATCH v2] PCI: hv: fix pci-hyperv build when SYSFS not enabled

[Randy Dunlap <rdunlap@infradead.org>]

From: Randy Dunlap <rdunlap@infradead.org>

Fix build of drivers/pci/controller/pci-hyperv.o when
CONFIG_SYSFS is not set/enabled by adding stubs for
pci_create_slot() and pci_destroy_slot().

Fixes these build errors:

ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!

Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot information")

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-hyperv@vger.kernel.org
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Yuehaibing <yuehaibing@huawei.com>
---
v2:
- provide non-CONFIG_SYSFS stubs for pci_create_slot() and
  pci_destroy_slot() [suggested by Matthew Wilcox <willy@infradead.org>]
- use the correct Fixes: tag [Dexuan Cui <decui@microsoft.com>]

 include/linux/pci.h |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- lnx-52-rc7.orig/include/linux/pci.h
+++ lnx-52-rc7/include/linux/pci.h
@@ -25,6 +25,7 @@
 #include <linux/ioport.h>
 #include <linux/list.h>
 #include <linux/compiler.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/kobject.h>
 #include <linux/atomic.h>
@@ -947,14 +948,21 @@ int pci_scan_root_bus_bridge(struct pci_
 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
 				int busnr);
 void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
+#ifdef CONFIG_SYSFS
+void pci_dev_assign_slot(struct pci_dev *dev);
 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 				 const char *name,
 				 struct hotplug_slot *hotplug);
 void pci_destroy_slot(struct pci_slot *slot);
-#ifdef CONFIG_SYSFS
-void pci_dev_assign_slot(struct pci_dev *dev);
 #else
 static inline void pci_dev_assign_slot(struct pci_dev *dev) { }
+static inline struct pci_slot *pci_create_slot(struct pci_bus *parent,
+					       int slot_nr,
+					       const char *name,
+					       struct hotplug_slot *hotplug) {
+	return ERR_PTR(-EINVAL);
+}
+static inline void pci_destroy_slot(struct pci_slot *slot) { }
 #endif
 int pci_scan_slot(struct pci_bus *bus, int devfn);
 struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn);