PCI ASPM: remove get_root_port_link

By having a pointer to the root port link, we can remove loops in
get_root_port_link() to search the root port link.

Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 04b6a30985059b7a809b64acf81e52b4f0317f04..3d27c97e0486c9ed5b6d29b3e496723181111b32 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -33,6 +33,7 @@ struct aspm_latency {
 
 struct pcie_link_state {
        struct pci_dev *pdev;           /* Upstream component of the Link */
+       struct pcie_link_state *root;   /* pointer to the root port link */
        struct pcie_link_state *parent; /* pointer to the parent Link state */
        struct list_head sibling;       /* node in link_list */
        struct list_head children;      /* list of child link states */
@@ -486,26 +487,17 @@ static void __pcie_aspm_config_link(struct pcie_link_state *link, u32 state)
        link->aspm_enabled = state;
 }
 
-static struct pcie_link_state *get_root_port_link(struct pcie_link_state *link)
-{
-       struct pcie_link_state *root_port_link = link;
-       while (root_port_link->parent)
-               root_port_link = root_port_link->parent;
-       return root_port_link;
-}
-
 /* Check the whole hierarchy, and configure each link in the hierarchy */
 static void __pcie_aspm_configure_link_state(struct pcie_link_state *link,
                                             u32 state)
 {
-       struct pcie_link_state *leaf, *root = get_root_port_link(link);
+       struct pcie_link_state *leaf, *root = link->root;
 
        state &= (PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
        /* Check all links who have specific root port link */
        list_for_each_entry(leaf, &link_list, sibling) {
-               if (!list_empty(&leaf->children) ||
-                   get_root_port_link(leaf) != root)
+               if (!list_empty(&leaf->children) || (leaf->root != root))
                        continue;
                state = pcie_aspm_check_state(leaf, state);
        }
@@ -519,12 +511,12 @@ static void __pcie_aspm_configure_link_state(struct pcie_link_state *link,
         **/
        if (state & PCIE_LINK_STATE_L1) {
                list_for_each_entry(leaf, &link_list, sibling) {
-                       if (get_root_port_link(leaf) == root)
+                       if (leaf->root == root)
                                __pcie_aspm_config_link(leaf, state);
                }
        } else {
                list_for_each_entry_reverse(leaf, &link_list, sibling) {
-                       if (get_root_port_link(leaf) == root)
+                       if (leaf->root == root)
                                __pcie_aspm_config_link(leaf, state);
                }
        }
@@ -600,6 +592,12 @@ static struct pcie_link_state *pcie_aspm_setup_link_state(struct pci_dev *pdev)
                link->parent = parent;
                list_add(&link->link, &parent->children);
        }
+       /* Setup a pointer to the root port link */
+       if (!link->parent)
+               link->root = link;
+       else
+               link->root = link->parent->root;
+
        list_add(&link->sibling, &link_list);
 
        pdev->link_state = link;