1 files changed, 67 insertions, 8 deletions

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 71222814c1ec..6892601fc76f 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -68,7 +68,8 @@ struct pcie_link_state {
         struct aspm_latency acceptable[8];
 };
 
-static int aspm_disabled, aspm_force;
+static int aspm_disabled, aspm_force, aspm_clear_state;
+static bool aspm_support_enabled = true;
 static DEFINE_MUTEX(aspm_lock);
 static LIST_HEAD(link_list);
 
@@ -139,7 +140,7 @@ static void pcie_set_clkpm(struct pcie_link_state *link, int enable)
 {
         /* Don't enable Clock PM if the link is not Clock PM capable */
         if (!link->clkpm_capable && enable)
-                return;
+                enable = 0;
         /* Need nothing if the specified equals to current state */
         if (link->clkpm_enabled == enable)
                 return;
@@ -498,6 +499,10 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
         struct pci_dev *child;
         int pos;
         u32 reg32;
+
+        if (aspm_clear_state)
+                return -EINVAL;
+
         /*
          * Some functions in a slot might not all be PCIe functions,
          * very strange. Disable ASPM for the whole slot
@@ -563,12 +568,15 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
         struct pcie_link_state *link;
         int blacklist = !!pcie_aspm_sanity_check(pdev);
 
-        if (aspm_disabled || !pci_is_pcie(pdev) || pdev->link_state)
+        if (!pci_is_pcie(pdev) || pdev->link_state)
                 return;
         if (pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&
             pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)
                 return;
 
+        if (aspm_disabled && !aspm_clear_state)
+                return;
+
         /* VIA has a strange chipset, root port is under a bridge */
         if (pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT &&
             pdev->bus->self)
@@ -600,7 +608,7 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
          * the BIOS's expectation, we'll do so once pci_enable_device() is
          * called.
          */
-        if (aspm_policy != POLICY_POWERSAVE) {
+        if (aspm_policy != POLICY_POWERSAVE || aspm_clear_state) {
                 pcie_config_aspm_path(link);
                 pcie_set_clkpm(link, policy_to_clkpm_state(link));
         }
@@ -641,7 +649,7 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)
         struct pci_dev *parent = pdev->bus->self;
         struct pcie_link_state *link, *root, *parent_link;
 
-        if (aspm_disabled || !pci_is_pcie(pdev) ||
+        if ((aspm_disabled && !aspm_clear_state) || !pci_is_pcie(pdev) ||
             !parent || !parent->link_state)
                 return;
         if ((parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT) &&
@@ -700,11 +708,33 @@ void pcie_aspm_pm_state_change(struct pci_dev *pdev)
         up_read(&pci_bus_sem);
 }
 
+void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
+{
+        struct pcie_link_state *link = pdev->link_state;
+
+        if (aspm_disabled || !pci_is_pcie(pdev) || !link)
+                return;
+
+        if (aspm_policy != POLICY_POWERSAVE)
+                return;
+
+        if ((pdev->pcie_type != PCI_EXP_TYPE_ROOT_PORT) &&
+            (pdev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM))
+                return;
+
+        down_read(&pci_bus_sem);
+        mutex_lock(&aspm_lock);
+        pcie_config_aspm_path(link);
+        pcie_set_clkpm(link, policy_to_clkpm_state(link));
+        mutex_unlock(&aspm_lock);
+        up_read(&pci_bus_sem);
+}
+
 /*
  * pci_disable_link_state - disable pci device's link state, so the link will
  * never enter specific states
  */
-void pci_disable_link_state(struct pci_dev *pdev, int state)
+static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
 {
         struct pci_dev *parent = pdev->bus->self;
         struct pcie_link_state *link;
@@ -717,7 +747,8 @@ void pci_disable_link_state(struct pci_dev *pdev, int state)
         if (!parent || !parent->link_state)
                 return;
 
-        down_read(&pci_bus_sem);
+        if (sem)
+                down_read(&pci_bus_sem);
         mutex_lock(&aspm_lock);
         link = parent->link_state;
         if (state & PCIE_LINK_STATE_L0S)
@@ -731,7 +762,19 @@ void pci_disable_link_state(struct pci_dev *pdev, int state)
                 pcie_set_clkpm(link, 0);
         }
         mutex_unlock(&aspm_lock);
-        up_read(&pci_bus_sem);
+        if (sem)
+                up_read(&pci_bus_sem);
+}
+
+void pci_disable_link_state_locked(struct pci_dev *pdev, int state)
+{
+        __pci_disable_link_state(pdev, state, false);
+}
+EXPORT_SYMBOL(pci_disable_link_state_locked);
+
+void pci_disable_link_state(struct pci_dev *pdev, int state)
+{
+        __pci_disable_link_state(pdev, state, true);
 }
 EXPORT_SYMBOL(pci_disable_link_state);
 
@@ -740,6 +783,8 @@ static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp)
         int i;
         struct pcie_link_state *link;
 
+        if (aspm_disabled)
+                return -EPERM;
         for (i = 0; i < ARRAY_SIZE(policy_str); i++)
                 if (!strncmp(val, policy_str[i], strlen(policy_str[i])))
                         break;
@@ -794,6 +839,8 @@ static ssize_t link_state_store(struct device *dev,
         struct pcie_link_state *link, *root = pdev->link_state->root;
         u32 val = buf[0] - '0', state = 0;
 
+        if (aspm_disabled)
+                return -EPERM;
         if (n < 1 || val > 3)
                 return -EINVAL;
 
@@ -889,6 +936,7 @@ static int __init pcie_aspm_disable(char *str)
 {
         if (!strcmp(str, "off")) {
                 aspm_disabled = 1;
+                aspm_support_enabled = false;
                 printk(KERN_INFO "PCIe ASPM is disabled\n");
         } else if (!strcmp(str, "force")) {
                 aspm_force = 1;
@@ -899,6 +947,12 @@ static int __init pcie_aspm_disable(char *str)
 
 __setup("pcie_aspm=", pcie_aspm_disable);
 
+void pcie_clear_aspm(void)
+{
+        if (!aspm_force)
+                aspm_clear_state = 1;
+}
+
 void pcie_no_aspm(void)
 {
         if (!aspm_force)
@@ -917,3 +971,8 @@ int pcie_aspm_enabled(void)
 }
 EXPORT_SYMBOL(pcie_aspm_enabled);
 
+bool pcie_aspm_support_enabled(void)
+{
+        return aspm_support_enabled;
+}
+EXPORT_SYMBOL(pcie_aspm_support_enabled);