Merge branch 'pci/enumeration' into next

* pci/enumeration:
  PCI: Include PCI-to-PCIe bridges as "Downstream Ports"
  PCI: Improve __pci_read_base() robustness
  PCI: Short-circuit pci_device_is_present() for disconnected devices
  PCI/MSI: Skip disabling disconnected devices
  PCI: Don't attempt config access to disconnected devices
  PCI: Add device disconnected state
  PCI: Export PCI device config accessors

7 files changed, 92 insertions, 3 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 8b7382705bf2..9b09cd31158c 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -700,7 +700,8 @@ static bool pcie_downstream_port(const struct pci_dev *dev)
 	int type = pci_pcie_type(dev);
 
 	return type == PCI_EXP_TYPE_ROOT_PORT ||
-	       type == PCI_EXP_TYPE_DOWNSTREAM;
+	       type == PCI_EXP_TYPE_DOWNSTREAM ||
+	       type == PCI_EXP_TYPE_PCIE_BRIDGE;
 }
 
 bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
@@ -890,3 +891,59 @@ int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos,
 	return ret;
 }
 EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
+
+int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
+{
+	if (pci_dev_is_disconnected(dev)) {
+		*val = ~0;
+		return -ENODEV;
+	}
+	return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
+}
+EXPORT_SYMBOL(pci_read_config_byte);
+
+int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
+{
+	if (pci_dev_is_disconnected(dev)) {
+		*val = ~0;
+		return -ENODEV;
+	}
+	return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
+}
+EXPORT_SYMBOL(pci_read_config_word);
+
+int pci_read_config_dword(const struct pci_dev *dev, int where,
+					u32 *val)
+{
+	if (pci_dev_is_disconnected(dev)) {
+		*val = ~0;
+		return -ENODEV;
+	}
+	return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
+}
+EXPORT_SYMBOL(pci_read_config_dword);
+
+int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val)
+{
+	if (pci_dev_is_disconnected(dev))
+		return -ENODEV;
+	return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val);
+}
+EXPORT_SYMBOL(pci_write_config_byte);
+
+int pci_write_config_word(const struct pci_dev *dev, int where, u16 val)
+{
+	if (pci_dev_is_disconnected(dev))
+		return -ENODEV;
+	return pci_bus_write_config_word(dev->bus, dev->devfn, where, val);
+}
+EXPORT_SYMBOL(pci_write_config_word);
+
+int pci_write_config_dword(const struct pci_dev *dev, int where,
+					 u32 val)
+{
+	if (pci_dev_is_disconnected(dev))
+		return -ENODEV;
+	return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val);
+}
+EXPORT_SYMBOL(pci_write_config_dword);
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 9e69403be632..19f30a9f461d 100644
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -109,6 +109,12 @@ int pciehp_unconfigure_device(struct slot *p_slot)
 				break;
 			}
 		}
+		if (!presence) {
+			pci_dev_set_disconnected(dev, NULL);
+			if (pci_has_subordinate(dev))
+				pci_walk_bus(dev->subordinate,
+					     pci_dev_set_disconnected, NULL);
+		}
 		pci_stop_and_remove_bus_device(dev);
 		/*
 		 * Ensure that no new Requests will be generated from
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d571bc330686..33e766a9dd91 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -298,7 +298,7 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
 {
 	struct pci_dev *dev = msi_desc_to_pci_dev(entry);
 
-	if (dev->current_state != PCI_D0) {
+	if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
 		/* Don't touch the hardware now */
 	} else if (entry->msi_attrib.is_msix) {
 		void __iomem *base = pci_msix_desc_addr(entry);
@@ -1001,6 +1001,11 @@ void pci_msix_shutdown(struct pci_dev *dev)
 	if (!pci_msi_enable || !dev || !dev->msix_enabled)
 		return;
 
+	if (pci_dev_is_disconnected(dev)) {
+		dev->msix_enabled = 0;
+		return;
+	}
+
 	/* Return the device with MSI-X masked as initial states */
 	for_each_pci_msi_entry(entry, dev) {
 		/* Keep cached states to be restored */
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c87d1edf0203..f85774b3da1e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4934,6 +4934,8 @@ bool pci_device_is_present(struct pci_dev *pdev)
 {
 	u32 v;
 
+	if (pci_dev_is_disconnected(pdev))
+		return false;
 	return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
 }
 EXPORT_SYMBOL_GPL(pci_device_is_present);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 8dd38e69d6f2..245719c3e409 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -274,6 +274,20 @@ struct pci_sriov {
 	resource_size_t barsz[PCI_SRIOV_NUM_BARS];	/* VF BAR size */
 };
 
+/* pci_dev priv_flags */
+#define PCI_DEV_DISCONNECTED 0
+
+static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)
+{
+	set_bit(PCI_DEV_DISCONNECTED, &dev->priv_flags);
+	return 0;
+}
+
+static inline bool pci_dev_is_disconnected(const struct pci_dev *dev)
+{
+	return test_bit(PCI_DEV_DISCONNECTED, &dev->priv_flags);
+}
+
 #ifdef CONFIG_PCI_ATS
 void pci_restore_ats_state(struct pci_dev *dev);
 #else
diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
index d4d70ef4a2d7..77d2ca99d2ec 100644
--- a/drivers/pci/pcie/pcie-dpc.c
+++ b/drivers/pci/pcie/pcie-dpc.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/pcieport_if.h>
+#include "../pci.h"
 
 struct dpc_dev {
 	struct pcie_device	*dev;
@@ -66,6 +67,10 @@ static void interrupt_event_handler(struct work_struct *work)
 	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
 					 bus_list) {
 		pci_dev_get(dev);
+		pci_dev_set_disconnected(dev, NULL);
+		if (pci_has_subordinate(dev))
+			pci_walk_bus(dev->subordinate,
+				     pci_dev_set_disconnected, NULL);
 		pci_stop_and_remove_bus_device(dev);
 		pci_dev_put(dev);
 	}
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index dfc9a2794141..f2bd0024cb88 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -175,7 +175,7 @@ static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar)
 int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 		    struct resource *res, unsigned int pos)
 {
-	u32 l, sz, mask;
+	u32 l = 0, sz = 0, mask;
 	u64 l64, sz64, mask64;
 	u16 orig_cmd;
 	struct pci_bus_region region, inverted_region;