[PATCH pciutils 2/4] libpci: sysfs: Implement support for PCI_FILL_PARENT

[Pali Rohár <pali@xxxxxxxxxx>]

---
 lib/sysfs.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/lib/sysfs.c b/lib/sysfs.c
index 0dbd127ff53b..1db1b1a7752b 100644
--- a/lib/sysfs.c
+++ b/lib/sysfs.c
@@ -390,6 +390,37 @@ sysfs_fill_info(struct pci_dev *d, unsigned int flags)
 	{
 	  done |= sysfs_get_resources(d);
 	}
+      if (flags & PCI_FILL_PARENT)
+	{
+	  unsigned int domain, bus, dev, func;
+	  char *path_abs, *path_canon, *name;
+	  char path_rel[OBJNAMELEN];
+	  struct pci_dev *parent;
+
+	  /* Construct sysfs path for parent device */
+	  sysfs_obj_name(d, "..", path_rel);
+	  path_abs = realpath(path_rel, NULL);
+	  name = path_abs ? strrchr(path_abs, '/') : NULL;
+	  name = name ? name+1 : name;
+	  parent = NULL;
+
+	  if (name && sscanf(name, "%x:%x:%x.%d", &domain, &bus, &dev, &func) == 4 && domain <= 0x7fffffff)
+	    for (parent = d->access->devices; parent; parent = parent->next)
+	      if (parent->domain == (int)domain && parent->bus == bus && parent->dev == dev && parent->func == func)
+	        break;
+
+	  if (parent)
+	    {
+	      /* Check if parsed BDF address from parent sysfs device is really expected PCI device */
+	      sysfs_obj_name(parent, ".", path_rel);
+	      path_canon = realpath(path_rel, NULL);
+	      if (path_canon && strcmp(path_canon, path_abs) == 0)
+		{
+		  d->parent = parent;
+		  done |= PCI_FILL_PARENT;
+		}
+	    }
+	}
     }
 
   if (flags & PCI_FILL_PHYS_SLOT)
-- 
2.20.1