PCI: Move config space size macros to pci_regs.h

Move PCI configuration space size macros (PCI_CFG_SPACE_SIZE and
PCI_CFG_SPACE_EXP_SIZE) from drivers/pci/pci.h to
include/uapi/linux/pci_regs.h so they can be used by more drivers and
eliminate duplicate definitions.

[bhelgaas: Expand comment to include PCI-X details]
Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.h

 #ifndef DRIVERS_PCI_H
 #define DRIVERS_PCI_H
 
-#define PCI_CFG_SPACE_SIZE	256
-#define PCI_CFG_SPACE_EXP_SIZE	4096
-
 #define PCI_FIND_CAP_TTL	48
 
 extern const unsigned char pcie_link_speed[];

drivers/vfio/pci/vfio_pci_config.c

@@ -31,8 +31,6 @@
 
 #include "vfio_pci_private.h"
 
-#define PCI_CFG_SPACE_SIZE	256
-
 /* Fake capability ID for standard config space */
 #define PCI_CAP_ID_BASIC	0
 

include/uapi/linux/pci_regs.h

@@ -22,6 +22,14 @@
 #ifndef LINUX_PCI_REGS_H
 #define LINUX_PCI_REGS_H
 
+/*
+ * Conventional PCI and PCI-X Mode 1 devices have 256 bytes of
+ * configuration space.  PCI-X Mode 2 and PCIe devices have 4096 bytes of
+ * configuration space.
+ */
+#define PCI_CFG_SPACE_SIZE	256
+#define PCI_CFG_SPACE_EXP_SIZE	4096
+
 /*
  * Under PCI, each device has 256 bytes of configuration address space,
  * of which the first 64 bytes are standardized as follows: