Merge branch 'pci/enumeration'

  - Enable PCIe services for host controller drivers that use managed host
    bridge alloc (Jean-Philippe Brucker)

  - Add quirk to clear PCIe Retrain Link bit to work around Pericom bridge
    erratum (Stefan Mätje)

  - Add "external-facing" DT property to identify cases where we require
    IOMMU protection from untrusted devices (Jean-Philippe Brucker)

  - Support fixed bus numbers from bridge Enhanced Allocation capabilities
    (Subbaraya Sundeep)

* pci/enumeration:
  PCI: Assign bus numbers present in EA capability for bridges
  PCI: OF: Support "external-facing" property
  dt-bindings: Add "external-facing" PCIe port property
  PCI: Rework pcie_retrain_link() wait loop
  PCI: Work around Pericom PCIe-to-PCI bridge Retrain Link erratum
  PCI: Factor out pcie_retrain_link() function
  PCI: Init PCIe feature bits for managed host bridge alloc

4 files changed, 122 insertions, 33 deletions

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 3d32da15c215..67376cf45880 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -31,10 +31,16 @@ void pci_release_of_node(struct pci_dev *dev)
 
 void pci_set_bus_of_node(struct pci_bus *bus)
 {
-	if (bus->self == NULL)
-		bus->dev.of_node = pcibios_get_phb_of_node(bus);
-	else
-		bus->dev.of_node = of_node_get(bus->self->dev.of_node);
+	struct device_node *node;
+
+	if (bus->self == NULL) {
+		node = pcibios_get_phb_of_node(bus);
+	} else {
+		node = of_node_get(bus->self->dev.of_node);
+		if (node && of_property_read_bool(node, "external-facing"))
+			bus->self->untrusted = true;
+	}
+	bus->dev.of_node = node;
 }
 
 void pci_release_bus_of_node(struct pci_bus *bus)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 727e3c1ef9a4..fd4cb75088f9 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -196,6 +196,36 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
 	link->clkpm_capable = (blacklist) ? 0 : capable;
 }
 
+static bool pcie_retrain_link(struct pcie_link_state *link)
+{
+	struct pci_dev *parent = link->pdev;
+	unsigned long end_jiffies;
+	u16 reg16;
+
+	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);
+	}
+
+	/* Wait for link training end. Break out after waiting for timeout */
+	end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
+	do {
+		pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
+		if (!(reg16 & PCI_EXP_LNKSTA_LT))
+			break;
+		msleep(1);
+	} while (time_before(jiffies, end_jiffies));
+	return !(reg16 & PCI_EXP_LNKSTA_LT);
+}
+
 /*
  * 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
@@ -205,7 +235,6 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
 {
 	int same_clock = 1;
 	u16 reg16, parent_reg, child_reg[8];
-	unsigned long start_jiffies;
 	struct pci_dev *child, *parent = link->pdev;
 	struct pci_bus *linkbus = parent->subordinate;
 	/*
@@ -263,21 +292,7 @@ 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);
 
-	/* Retrain link */
-	reg16 |= PCI_EXP_LNKCTL_RL;
-	pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16);
-
-	/* Wait for link training end. Break out after waiting for timeout */
-	start_jiffies = jiffies;
-	for (;;) {
-		pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16);
-		if (!(reg16 & PCI_EXP_LNKSTA_LT))
-			break;
-		if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT))
-			break;
-		msleep(1);
-	}
-	if (!(reg16 & PCI_EXP_LNKSTA_LT))
+	if (pcie_retrain_link(link))
 		return;
 
 	/* Training failed. Restore common clock configurations */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2ec0df04e0dc..a6874c306908 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -586,16 +586,9 @@ static void pci_release_host_bridge_dev(struct device *dev)
 	kfree(to_pci_host_bridge(dev));
 }
 
-struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
+static void pci_init_host_bridge(struct pci_host_bridge *bridge)
 {
-	struct pci_host_bridge *bridge;
-
-	bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL);
-	if (!bridge)
-		return NULL;
-
 	INIT_LIST_HEAD(&bridge->windows);
-	bridge->dev.release = pci_release_host_bridge_dev;
 
 	/*
 	 * We assume we can manage these PCIe features.  Some systems may
@@ -608,6 +601,18 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
 	bridge->native_shpc_hotplug = 1;
 	bridge->native_pme = 1;
 	bridge->native_ltr = 1;
+}
+
+struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
+{
+	struct pci_host_bridge *bridge;
+
+	bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL);
+	if (!bridge)
+		return NULL;
+
+	pci_init_host_bridge(bridge);
+	bridge->dev.release = pci_release_host_bridge_dev;
 
 	return bridge;
 }
@@ -622,7 +627,7 @@ struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,
 	if (!bridge)
 		return NULL;
 
-	INIT_LIST_HEAD(&bridge->windows);
+	pci_init_host_bridge(bridge);
 	bridge->dev.release = devm_pci_release_host_bridge_dev;
 
 	return bridge;
@@ -1081,6 +1086,36 @@ static void pci_enable_crs(struct pci_dev *pdev)
 
 static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
 					      unsigned int available_buses);
+/**
+ * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus
+ * numbers from EA capability.
+ * @dev: Bridge
+ * @sec: updated with secondary bus number from EA
+ * @sub: updated with subordinate bus number from EA
+ *
+ * If @dev is a bridge with EA capability, update @sec and @sub with
+ * fixed bus numbers from the capability and return true.  Otherwise,
+ * return false.
+ */
+static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub)
+{
+	int ea, offset;
+	u32 dw;
+
+	if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
+		return false;
+
+	/* find PCI EA capability in list */
+	ea = pci_find_capability(dev, PCI_CAP_ID_EA);
+	if (!ea)
+		return false;
+
+	offset = ea + PCI_EA_FIRST_ENT;
+	pci_read_config_dword(dev, offset, &dw);
+	*sec =  dw & PCI_EA_SEC_BUS_MASK;
+	*sub = (dw & PCI_EA_SUB_BUS_MASK) >> PCI_EA_SUB_BUS_SHIFT;
+	return true;
+}
 
 /*
  * pci_scan_bridge_extend() - Scan buses behind a bridge
@@ -1115,6 +1150,9 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 	u16 bctl;
 	u8 primary, secondary, subordinate;
 	int broken = 0;
+	bool fixed_buses;
+	u8 fixed_sec, fixed_sub;
+	int next_busnr;
 
 	/*
 	 * Make sure the bridge is powered on to be able to access config
@@ -1214,17 +1252,24 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 		/* Clear errors */
 		pci_write_config_word(dev, PCI_STATUS, 0xffff);
 
+		/* Read bus numbers from EA Capability (if present) */
+		fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub);
+		if (fixed_buses)
+			next_busnr = fixed_sec;
+		else
+			next_busnr = max + 1;
+
 		/*
 		 * Prevent assigning a bus number that already exists.
 		 * This can happen when a bridge is hot-plugged, so in this
 		 * case we only re-scan this bus.
 		 */
-		child = pci_find_bus(pci_domain_nr(bus), max+1);
+		child = pci_find_bus(pci_domain_nr(bus), next_busnr);
 		if (!child) {
-			child = pci_add_new_bus(bus, dev, max+1);
+			child = pci_add_new_bus(bus, dev, next_busnr);
 			if (!child)
 				goto out;
-			pci_bus_insert_busn_res(child, max+1,
+			pci_bus_insert_busn_res(child, next_busnr,
 						bus->busn_res.end);
 		}
 		max++;
@@ -1285,7 +1330,13 @@ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
 			max += i;
 		}
 
-		/* Set subordinate bus number to its real value */
+		/*
+		 * Set subordinate bus number to its real value.
+		 * If fixed subordinate bus number exists from EA
+		 * capability then use it.
+		 */
+		if (fixed_buses)
+			max = fixed_sub;
 		pci_bus_update_busn_res_end(child, max);
 		pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
 	}
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a59ad09ce911..6f34e17c98f4 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2245,6 +2245,23 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x10f1, quirk_disable_aspm_l0s);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x10f4, quirk_disable_aspm_l0s);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1508, quirk_disable_aspm_l0s);
 
+/*
+ * Some Pericom PCIe-to-PCI bridges in reverse mode need the PCIe Retrain
+ * Link bit cleared after starting the link retrain process to allow this
+ * process to finish.
+ *
+ * Affected devices: PI7C9X110, PI7C9X111SL, PI7C9X130.  See also the
+ * Pericom Errata Sheet PI7C9X111SLB_errata_rev1.2_102711.pdf.
+ */
+static void quirk_enable_clear_retrain_link(struct pci_dev *dev)
+{
+	dev->clear_retrain_link = 1;
+	pci_info(dev, "Enable PCIe Retrain Link quirk\n");
+}
+DECLARE_PCI_FIXUP_HEADER(0x12d8, 0xe110, quirk_enable_clear_retrain_link);
+DECLARE_PCI_FIXUP_HEADER(0x12d8, 0xe111, quirk_enable_clear_retrain_link);
+DECLARE_PCI_FIXUP_HEADER(0x12d8, 0xe130, quirk_enable_clear_retrain_link);
+
 static void fixup_rev1_53c810(struct pci_dev *dev)
 {
 	u32 class = dev->class;