[PATCH RFC v4 3/9] powerpc/pci: Create pci_dn on demand

[Sergey Miroshnichenko <s.miroshnichenko@yadro.com>]

If a struct pci_dn hasn't yet been created for the PCIe device (there was
no DT node for it), allocate this structure and fill with info read from
the device directly.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
---
 arch/powerpc/kernel/pci_dn.c | 79 ++++++++++++++++++++++++++++++++----
 1 file changed, 72 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index 341ed71250f1..67ccd7be8344 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -33,6 +33,8 @@
 #include <asm/firmware.h>
 #include <asm/eeh.h>
 
+static struct pci_dn *create_pdn(struct pci_dev *pdev, struct pci_dn *parent);
+
 /*
  * The function is used to find the firmware data of one
  * specific PCI device, which is attached to the indicated
@@ -65,6 +67,9 @@ struct pci_dn *pci_bus_to_pdn(struct pci_bus *bus)
 	dn = pci_bus_to_OF_node(pbus);
 	pdn = dn ? PCI_DN(dn) : NULL;
 
+	if (!pdn && pbus->self)
+		pdn = pbus->self->dev.archdata.pci_data;
+
 	return pdn;
 }
 
@@ -74,10 +79,13 @@ struct pci_dn *pci_get_pdn_by_devfn(struct pci_bus *bus,
 	struct device_node *dn = NULL;
 	struct pci_dn *parent, *pdn;
 	struct pci_dev *pdev = NULL;
+	bool pdev_found = false;
 
 	/* Fast path: fetch from PCI device */
 	list_for_each_entry(pdev, &bus->devices, bus_list) {
 		if (pdev->devfn == devfn) {
+			pdev_found = true;
+
 			if (pdev->dev.archdata.pci_data)
 				return pdev->dev.archdata.pci_data;
 
@@ -86,6 +94,9 @@ struct pci_dn *pci_get_pdn_by_devfn(struct pci_bus *bus,
 		}
 	}
 
+	if (!pdev_found)
+		pdev = NULL;
+
 	/* Fast path: fetch from device node */
 	pdn = dn ? PCI_DN(dn) : NULL;
 	if (pdn)
@@ -98,9 +109,12 @@ struct pci_dn *pci_get_pdn_by_devfn(struct pci_bus *bus,
 
 	list_for_each_entry(pdn, &parent->child_list, list) {
 		if (pdn->busno == bus->number &&
-                    pdn->devfn == devfn)
-                        return pdn;
-        }
+		    pdn->devfn == devfn) {
+			if (pdev)
+				pdev->dev.archdata.pci_data = pdn;
+			return pdn;
+		}
+	}
 
 	return NULL;
 }
@@ -130,14 +144,15 @@ struct pci_dn *pci_get_pdn(struct pci_dev *pdev)
 
 	list_for_each_entry(pdn, &parent->child_list, list) {
 		if (pdn->busno == pdev->bus->number &&
-		    pdn->devfn == pdev->devfn)
+		    pdn->devfn == pdev->devfn) {
+			pdev->dev.archdata.pci_data = pdn;
 			return pdn;
+		}
 	}
 
-	return NULL;
+	return create_pdn(pdev, parent);
 }
 
-#ifdef CONFIG_PCI_IOV
 static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
 					   int vf_index,
 					   int busno, int devfn)
@@ -156,7 +171,9 @@ static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
 	pdn->parent = parent;
 	pdn->busno = busno;
 	pdn->devfn = devfn;
+	#ifdef CONFIG_PCI_IOV
 	pdn->vf_index = vf_index;
+	#endif /* CONFIG_PCI_IOV */
 	pdn->pe_number = IODA_INVALID_PE;
 	INIT_LIST_HEAD(&pdn->child_list);
 	INIT_LIST_HEAD(&pdn->list);
@@ -164,7 +181,55 @@ static struct pci_dn *add_one_dev_pci_data(struct pci_dn *parent,
 
 	return pdn;
 }
-#endif
+
+static struct pci_dn *create_pdn(struct pci_dev *pdev, struct pci_dn *parent)
+{
+	struct pci_dn *pdn = NULL;
+
+	if (!parent)
+		return NULL;
+
+	pdn = add_one_dev_pci_data(parent, 0, pdev->bus->busn_res.start, pdev->devfn);
+	dev_info(&pdev->dev, "Create a new pdn for devfn %2x\n", pdev->devfn / 8);
+
+	if (pdn) {
+		#ifdef CONFIG_EEH
+		struct eeh_dev *edev;
+		#endif /* CONFIG_EEH */
+		u32 class_code;
+		u16 device_id;
+		u16 vendor_id;
+
+		#ifdef CONFIG_EEH
+		edev = eeh_dev_init(pdn);
+		if (!edev) {
+			kfree(pdn);
+			dev_err(&pdev->dev, "%s: Failed to allocate edev\n", __func__);
+			return NULL;
+		}
+		#endif /* CONFIG_EEH */
+
+		pci_bus_read_config_word(pdev->bus, pdev->devfn,
+					 PCI_VENDOR_ID, &vendor_id);
+		pdn->vendor_id = vendor_id;
+
+		pci_bus_read_config_word(pdev->bus, pdev->devfn,
+					 PCI_DEVICE_ID, &device_id);
+		pdn->device_id = device_id;
+
+		pci_bus_read_config_dword(pdev->bus, pdev->devfn,
+					  PCI_CLASS_REVISION, &class_code);
+		class_code >>= 8;
+		pdn->class_code = class_code;
+
+		pdn->pci_ext_config_space = 0;
+		pdev->dev.archdata.pci_data = pdn;
+	} else {
+		dev_err(&pdev->dev, "%s: Failed to allocate pdn\n", __func__);
+	}
+
+	return pdn;
+}
 
 struct pci_dn *add_dev_pci_data(struct pci_dev *pdev)
 {
-- 
2.20.1