PCI/sysfs: Compile pci-sysfs.c only if CONFIG_SYSFS=y

It is possible to enable CONFIG_PCI but disable CONFIG_SYSFS and for
space-constrained devices such as routers, such a configuration may
actually make sense.

However pci-sysfs.c is compiled even if CONFIG_SYSFS is disabled,
unnecessarily increasing the kernel's size.

To rectify that:

* Move pci_mmap_fits() to mmap.c.  It is not only needed by
  pci-sysfs.c, but also proc.c.

* Move pci_dev_type to probe.c and make it private.  It references
  pci_dev_attr_groups in pci-sysfs.c.  Make that public instead for
  consistency with pci_dev_groups, pcibus_groups and pci_bus_groups,
  which are likewise public and referenced by struct definitions in
  pci-driver.c and probe.c.

* Define pci_dev_groups, pci_dev_attr_groups, pcibus_groups and
  pci_bus_groups to NULL if CONFIG_SYSFS is disabled.  Provide empty
  static inlines for pci_{create,remove}_legacy_files() and
  pci_{create,remove}_sysfs_dev_files().

Result:

vmlinux size is reduced by 122996 bytes in my arm 32-bit test build.

Link: https://lore.kernel.org/r/85ca95ae8e4d57ccf082c5c069b8b21eb141846e.1698668982.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/pci/mmap.c b/drivers/pci/mmap.c
index 4504039056d1..8da3347a95c4 100644
--- a/drivers/pci/mmap.c
+++ b/drivers/pci/mmap.c
@@ -11,6 +11,8 @@
 #include <linux/mm.h>
 #include <linux/pci.h>
 
+#include "pci.h"
+
 #ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
 
 static const struct vm_operations_struct pci_phys_vm_ops = {
@@ -50,3 +52,30 @@ int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
 }
 
 #endif
+
+#if (defined(CONFIG_SYSFS) || defined(CONFIG_PROC_FS)) && \
+    (defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE))
+
+int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
+		  enum pci_mmap_api mmap_api)
+{
+	resource_size_t pci_start = 0, pci_end;
+	unsigned long nr, start, size;
+
+	if (pci_resource_len(pdev, resno) == 0)
+		return 0;
+	nr = vma_pages(vma);
+	start = vma->vm_pgoff;
+	size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
+	if (mmap_api == PCI_MMAP_PROCFS) {
+		pci_resource_to_user(pdev, resno, &pdev->resource[resno],
+				     &pci_start, &pci_end);
+		pci_start >>= PAGE_SHIFT;
+	}
+	if (start >= pci_start && start < pci_start + size &&
+	    start + nr <= pci_start + size)
+		return 1;
+	return 0;
+}
+
+#endif