[PATCH v6 10/24] PCI/sysfs: Limit pci_sysfs_init() late_initcall compile scope

[Krzysztof Wilczyński]

Currently, pci_sysfs_init() and sysfs_initialized compile
unconditionally, even on platforms where static attribute
groups handle all resource file creation.

Thus, place them behind a new HAVE_PCI_SYSFS_INIT macro,
especially as the late_initcall is only needed when:

  - HAVE_PCI_LEGACY is set, to iterate buses and create legacy
    I/O and memory files.

  - Neither HAVE_PCI_MMAP nor ARCH_GENERIC_PCI_MMAP_RESOURCE is
    set, to iterate devices and create resource files via the
    __weak pci_create_resource_files() stub override (this is
    how the Alpha architecture handles this currently).

On most systems both conditions are false and the entire
late_initcall compiles away.

Signed-off-by: Krzysztof Wilczyński <kwilczynski at kernel.org>
---
 drivers/pci/pci-sysfs.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 517efb6d71cc..d22bc5c48bc0 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -37,7 +37,14 @@
 #define ARCH_PCI_DEV_GROUPS
 #endif
 
+#if defined(HAVE_PCI_LEGACY) || \
+	!defined(HAVE_PCI_MMAP) && !defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
+#define HAVE_PCI_SYSFS_INIT
+#endif
+
+#ifdef HAVE_PCI_SYSFS_INIT
 static int sysfs_initialized;	/* = 0 */
+#endif
 
 /* show configuration fields */
 #define pci_config_attr(field, format_string)				\
@@ -1792,6 +1799,7 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 }
 #endif
 
+#ifdef HAVE_PCI_SYSFS_INIT
 static int __init pci_sysfs_init(void)
 {
 #if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
@@ -1818,6 +1826,7 @@ static int __init pci_sysfs_init(void)
 	return 0;
 }
 late_initcall(pci_sysfs_init);
+#endif
 
 static struct attribute *pci_dev_dev_attrs[] = {
 	&dev_attr_boot_vga.attr,
-- 
2.54.0