Merge branch 'pci/enumeration'

- Add PCI_EXT_CAP_ID_PL_32GT define (Ben Dooks)

- Propagate firmware node by calling device_set_node() for better
  modularity (Andy Shevchenko)

- Discover Data Link Layer Link Active Reporting earlier so quirks can take
  advantage of it (Maciej W. Rozycki)

- Use cached Data Link Layer Link Active Reporting capability in pciehp,
  powerpc/eeh, and mlx5 (Maciej W. Rozycki)

- Run quirk for devices that require OS to clear Retrain Link earlier, so
  later quirks can rely on it (Maciej W. Rozycki)

- Export pcie_retrain_link() for use outside ASPM (Maciej W. Rozycki)

- Add Data Link Layer Link Active Reporting as another way for
  pcie_retrain_link() to determine the link is up (Maciej W. Rozycki)

- Work around link training failures (especially on the ASMedia ASM2824
  switch) by training first at 2.5GT/s and then attempting higher rates
  (Maciej W. Rozycki)

* pci/enumeration:
  PCI: Add failed link recovery for device reset events
  PCI: Work around PCIe link training failures
  PCI: Use pcie_wait_for_link_status() in pcie_wait_for_link_delay()
  PCI: Add support for polling DLLLA to pcie_retrain_link()
  PCI: Export pcie_retrain_link() for use outside ASPM
  PCI: Export PCIe link retrain timeout
  PCI: Execute quirk_enable_clear_retrain_link() earlier
  PCI/ASPM: Factor out waiting for link training to complete
  PCI/ASPM: Avoid unnecessary pcie_link_state use
  PCI/ASPM: Use distinct local vars in pcie_retrain_link()
  net/mlx5: Rely on dev->link_active_reporting
  powerpc/eeh: Rely on dev->link_active_reporting
  PCI: pciehp: Rely on dev->link_active_reporting
  PCI: Initialize dev->link_active_reporting earlier
  PCI: of: Propagate firmware node by calling device_set_node()
  PCI: Add PCI_EXT_CAP_ID_PL_32GT define

# Conflicts:
#	drivers/pci/pcie/aspm.c

Author: bjorn-helgaas

arch/powerpc/kernel/eeh_pe.c

@@ -671,9 +671,8 @@ static void eeh_bridge_check_link(struct eeh_dev *edev)
 	eeh_ops->write_config(edev, cap + PCI_EXP_LNKCTL, 2, val);
 
 	/* Check link */
-	eeh_ops->read_config(edev, cap + PCI_EXP_LNKCAP, 4, &val);
-	if (!(val & PCI_EXP_LNKCAP_DLLLARC)) {
-		eeh_edev_dbg(edev, "No link reporting capability (0x%08x) \n", val);
+	if (!edev->pdev->link_active_reporting) {
+		eeh_edev_dbg(edev, "No link reporting capability\n");
 		msleep(1000);
 		return;
 	}

drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c

@@ -307,7 +307,6 @@ static int mlx5_pci_link_toggle(struct mlx5_core_dev *dev)
 	unsigned long timeout;
 	struct pci_dev *sdev;
 	int cap, err;
-	u32 reg32;
 
 	/* Check that all functions under the pci bridge are PFs of
 	 * this device otherwise fail this function.
@@ -346,11 +345,8 @@ static int mlx5_pci_link_toggle(struct mlx5_core_dev *dev)
 		return err;
 
 	/* Check link */
-	err = pci_read_config_dword(bridge, cap + PCI_EXP_LNKCAP, &reg32);
-	if (err)
-		return err;
-	if (!(reg32 & PCI_EXP_LNKCAP_DLLLARC)) {
-		mlx5_core_warn(dev, "No PCI link reporting capability (0x%08x)\n", reg32);
+	if (!bridge->link_active_reporting) {
+		mlx5_core_warn(dev, "No PCI link reporting capability\n");
 		msleep(1000);
 		goto restore;
 	}

drivers/pci/hotplug/pciehp_hpc.c

@@ -984,7 +984,7 @@ static inline int pcie_hotplug_depth(struct pci_dev *dev)
 struct controller *pcie_init(struct pcie_device *dev)
 {
 	struct controller *ctrl;
-	u32 slot_cap, slot_cap2, link_cap;
+	u32 slot_cap, slot_cap2;
 	u8 poweron;
 	struct pci_dev *pdev = dev->port;
 	struct pci_bus *subordinate = pdev->subordinate;
@@ -1030,9 +1030,6 @@ struct controller *pcie_init(struct pcie_device *dev)
 	if (dmi_first_match(inband_presence_disabled_dmi_table))
 		ctrl->inband_presence_disabled = 1;
 
-	/* Check if Data Link Layer Link Active Reporting is implemented */
-	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
-
 	/* Clear all remaining event bits in Slot Status register. */
 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
 		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
@@ -1051,7 +1048,7 @@ struct controller *pcie_init(struct pcie_device *dev)
 		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
 		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
 		FLAG(slot_cap2, PCI_EXP_SLTCAP2_IBPD),
-		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC),
+		FLAG(pdev->link_active_reporting, true),
 		pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : "");
 
 	/*

drivers/pci/of.c

@@ -39,16 +39,14 @@ int pci_set_of_node(struct pci_dev *dev)
 		return -ENODEV;
 	}
 
-	dev->dev.of_node = node;
-	dev->dev.fwnode = &node->fwnode;
+	device_set_node(&dev->dev, of_fwnode_handle(node));
 	return 0;
 }
 
 void pci_release_of_node(struct pci_dev *dev)
 {
 	of_node_put(dev->dev.of_node);
-	dev->dev.of_node = NULL;
-	dev->dev.fwnode = NULL;
+	device_set_node(&dev->dev, NULL);
 }
 
 void pci_set_bus_of_node(struct pci_bus *bus)
@@ -63,17 +61,13 @@ void pci_set_bus_of_node(struct pci_bus *bus)
 			bus->self->external_facing = true;
 	}
 
-	bus->dev.of_node = node;
-
-	if (bus->dev.of_node)
-		bus->dev.fwnode = &bus->dev.of_node->fwnode;
+	device_set_node(&bus->dev, of_fwnode_handle(node));
 }
 
 void pci_release_bus_of_node(struct pci_bus *bus)
 {
 	of_node_put(bus->dev.of_node);
-	bus->dev.of_node = NULL;
-	bus->dev.fwnode = NULL;
+	device_set_node(&bus->dev, NULL);
 }
 
 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)

drivers/pci/pci.c

@@ -1156,7 +1156,14 @@ void pci_resume_bus(struct pci_bus *bus)
 static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 {
 	int delay = 1;
-	u32 id;
+	bool retrain = false;
+	struct pci_dev *bridge;
+
+	if (pci_is_pcie(dev)) {
+		bridge = pci_upstream_bridge(dev);
+		if (bridge)
+			retrain = true;
+	}
 
 	/*
 	 * After reset, the device should not silently discard config
@@ -1170,21 +1177,33 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 	 * Command register instead of Vendor ID so we don't have to
 	 * contend with the CRS SV value.
 	 */
-	pci_read_config_dword(dev, PCI_COMMAND, &id);
-	while (PCI_POSSIBLE_ERROR(id)) {
+	for (;;) {
+		u32 id;
+
+		pci_read_config_dword(dev, PCI_COMMAND, &id);
+		if (!PCI_POSSIBLE_ERROR(id))
+			break;
+
 		if (delay > timeout) {
 			pci_warn(dev, "not ready %dms after %s; giving up\n",
 				 delay - 1, reset_type);
 			return -ENOTTY;
 		}
 
-		if (delay > PCI_RESET_WAIT)
+		if (delay > PCI_RESET_WAIT) {
+			if (retrain) {
+				retrain = false;
+				if (pcie_failed_link_retrain(bridge)) {
+					delay = 1;
+					continue;
+				}
+			}
 			pci_info(dev, "not ready %dms after %s; waiting\n",
 				 delay - 1, reset_type);
+		}
 
 		msleep(delay);
 		delay *= 2;
-		pci_read_config_dword(dev, PCI_COMMAND, &id);
 	}
 
 	if (delay > PCI_RESET_WAIT)
@@ -4856,6 +4875,79 @@ static int pci_pm_reset(struct pci_dev *dev, bool probe)
 	return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS);
 }
 
+/**
+ * pcie_wait_for_link_status - Wait for link status change
+ * @pdev: Device whose link to wait for.
+ * @use_lt: Use the LT bit if TRUE, or the DLLLA bit if FALSE.
+ * @active: Waiting for active or inactive?
+ *
+ * Return 0 if successful, or -ETIMEDOUT if status has not changed within
+ * PCIE_LINK_RETRAIN_TIMEOUT_MS milliseconds.
+ */
+static int pcie_wait_for_link_status(struct pci_dev *pdev,
+				     bool use_lt, bool active)
+{
+	u16 lnksta_mask, lnksta_match;
+	unsigned long end_jiffies;
+	u16 lnksta;
+
+	lnksta_mask = use_lt ? PCI_EXP_LNKSTA_LT : PCI_EXP_LNKSTA_DLLLA;
+	lnksta_match = active ? lnksta_mask : 0;
+
+	end_jiffies = jiffies + msecs_to_jiffies(PCIE_LINK_RETRAIN_TIMEOUT_MS);
+	do {
+		pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnksta);
+		if ((lnksta & lnksta_mask) == lnksta_match)
+			return 0;
+		msleep(1);
+	} while (time_before(jiffies, end_jiffies));
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * pcie_retrain_link - Request a link retrain and wait for it to complete
+ * @pdev: Device whose link to retrain.
+ * @use_lt: Use the LT bit if TRUE, or the DLLLA bit if FALSE, for status.
+ *
+ * Retrain completion status is retrieved from the Link Status Register
+ * according to @use_lt.  It is not verified whether the use of the DLLLA
+ * bit is valid.
+ *
+ * Return 0 if successful, or -ETIMEDOUT if training has not completed
+ * within PCIE_LINK_RETRAIN_TIMEOUT_MS milliseconds.
+ */
+int pcie_retrain_link(struct pci_dev *pdev, bool use_lt)
+{
+	int rc;
+	u16 lnkctl;
+
+	/*
+	 * Ensure the updated LNKCTL parameters are used during link
+	 * training by checking that there is no ongoing link training to
+	 * avoid LTSSM race as recommended in Implementation Note at the
+	 * end of PCIe r6.0.1 sec 7.5.3.7.
+	 */
+	rc = pcie_wait_for_link_status(pdev, use_lt, !use_lt);
+	if (rc)
+		return rc;
+
+	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnkctl);
+	lnkctl |= PCI_EXP_LNKCTL_RL;
+	pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnkctl);
+	if (pdev->clear_retrain_link) {
+		/*
+		 * Due to an erratum in some devices the Retrain Link bit
+		 * needs to be cleared again manually to allow the link
+		 * training to succeed.
+		 */
+		lnkctl &= ~PCI_EXP_LNKCTL_RL;
+		pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnkctl);
+	}
+
+	return pcie_wait_for_link_status(pdev, use_lt, !use_lt);
+}
+
 /**
  * pcie_wait_for_link_delay - Wait until link is active or inactive
  * @pdev: Bridge device
@@ -4867,16 +4959,14 @@ static int pci_pm_reset(struct pci_dev *dev, bool probe)
 static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
 				     int delay)
 {
-	int timeout = 1000;
-	bool ret;
-	u16 lnk_status;
+	int rc;
 
 	/*
 	 * Some controllers might not implement link active reporting. In this
 	 * case, we wait for 1000 ms + any delay requested by the caller.
 	 */
 	if (!pdev->link_active_reporting) {
-		msleep(timeout + delay);
+		msleep(PCIE_LINK_RETRAIN_TIMEOUT_MS + delay);
 		return true;
 	}
 
@@ -4891,20 +4981,21 @@ static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active,
 	 */
 	if (active)
 		msleep(20);
-	for (;;) {
-		pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
-		ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
-		if (ret == active)
-			break;
-		if (timeout <= 0)
-			break;
-		msleep(10);
-		timeout -= 10;
-	}
-	if (active && ret)
+	rc = pcie_wait_for_link_status(pdev, false, active);
+	if (active) {
+		if (rc)
+			rc = pcie_failed_link_retrain(pdev);
+		if (rc)
+			return false;
+
 		msleep(delay);
+		return true;
+	}
+
+	if (rc)
+		return false;
 
-	return ret == active;
+	return true;
 }
 
 /**

drivers/pci/pci.h

@@ -11,6 +11,8 @@
 
 #define PCI_VSEC_ID_INTEL_TBT	0x1234	/* Thunderbolt */
 
+#define PCIE_LINK_RETRAIN_TIMEOUT_MS	1000
+
 extern const unsigned char pcie_link_speed[];
 extern bool pci_early_dump;
 
@@ -541,6 +543,7 @@ void pci_acs_init(struct pci_dev *dev);
 int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
 int pci_dev_specific_enable_acs(struct pci_dev *dev);
 int pci_dev_specific_disable_acs_redir(struct pci_dev *dev);
+bool pcie_failed_link_retrain(struct pci_dev *dev);
 #else
 static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev,
 					       u16 acs_flags)
@@ -555,6 +558,10 @@ static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
 {
 	return -ENOTTY;
 }
+static inline bool pcie_failed_link_retrain(struct pci_dev *dev)
+{
+	return false;
+}
 #endif
 
 /* PCI error reporting and recovery */
@@ -563,6 +570,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 		pci_ers_result_t (*reset_subordinates)(struct pci_dev *pdev));
 
 bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
+int pcie_retrain_link(struct pci_dev *pdev, bool use_lt);
 #ifdef CONFIG_PCIEASPM
 void pcie_aspm_init_link_state(struct pci_dev *pdev);
 void pcie_aspm_exit_link_state(struct pci_dev *pdev);

drivers/pci/pcie/aspm.c

@@ -90,8 +90,6 @@ static const char *policy_str[] = {
 	[POLICY_POWER_SUPERSAVE] = "powersupersave"
 };
 
-#define LINK_RETRAIN_TIMEOUT HZ
-
 /*
  * The L1 PM substate capability is only implemented in function 0 in a
  * multi function device.
@@ -193,55 +191,6 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
 	link->clkpm_disable = blacklist ? 1 : 0;
 }
 
-static int pcie_wait_for_retrain(struct pci_dev *pdev)
-{
-	unsigned long end_jiffies;
-	u16 reg16;
-
-	/* Wait for Link Training to be cleared by hardware */
-	end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
-	do {
-		pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &reg16);
-		if (!(reg16 & PCI_EXP_LNKSTA_LT))
-			return 0;
-		msleep(1);
-	} while (time_before(jiffies, end_jiffies));
-
-	return -ETIMEDOUT;
-}
-
-static int pcie_retrain_link(struct pcie_link_state *link)
-{
-	struct pci_dev *parent = link->pdev;
-	int rc;
-	u16 reg16;
-
-	/*
-	 * Ensure the updated LNKCTL parameters are used during link
-	 * training by checking that there is no ongoing link training to
-	 * avoid LTSSM race as recommended in Implementation Note at the
-	 * end of PCIe r6.0.1 sec 7.5.3.7.
-	 */
-	rc = pcie_wait_for_retrain(parent);
-	if (rc)
-		return rc;
-
-	pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16);
-	reg16 |= PCI_EXP_LNKCTL_RL;
-	pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
-	if (parent->clear_retrain_link) {
-		/*
-		 * Due to an erratum in some devices the Retrain Link bit
-		 * needs to be cleared again manually to allow the link
-		 * training to succeed.
-		 */
-		reg16 &= ~PCI_EXP_LNKCTL_RL;
-		pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
-	}
-
-	return pcie_wait_for_retrain(parent);
-}
-
 /*
  * pcie_aspm_configure_common_clock: check if the 2 ends of a link
  *   could use common clock. If they are, configure them to use the
@@ -308,7 +257,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
 		reg16 &= ~PCI_EXP_LNKCTL_CCC;
 	pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
 
-	if (pcie_retrain_link(link)) {
+	if (pcie_retrain_link(link->pdev, true)) {
 
 		/* Training failed. Restore common clock configurations */
 		pci_err(parent, "ASPM: Could not configure common clock\n");