powerpc/pci: Fix various pseries PCI hotplug issues

The pseries PCI hotplug code has a number of issues, ranging from
incorrect resource setup to crashes, depending on what is added,
when, whether it contains a bridge, etc etc....

This fixes a whole bunch of these, while actually simplifying the code
a bit, using more generic code in the process and factoring out common
code between adding of a PHB, a slot or a device.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 30 insertions, 39 deletions

diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
index 9c2a22fed18b..4e3e0382c16e 100644
--- a/drivers/pci/hotplug/rpadlpar_core.c
+++ b/drivers/pci/hotplug/rpadlpar_core.c
@@ -14,6 +14,9 @@
  *      as published by the Free Software Foundation; either version
  *      2 of the License, or (at your option) any later version.
  */
+
+#undef DEBUG
+
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/string.h>
@@ -151,20 +154,20 @@ static void dlpar_pci_add_bus(struct device_node *dn)
                 return;
         }
 
+        /* Scan below the new bridge */
         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
             dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
                 of_scan_pci_bridge(dn, dev);
 
-        pcibios_fixup_new_pci_devices(dev->subordinate);
-
-        /* Claim new bus resources */
-        pcibios_claim_one_bus(dev->bus);
-
         /* Map IO space for child bus, which may or may not succeed */
         pcibios_map_io_space(dev->subordinate);
 
-        /* Add new devices to global lists.  Register in proc, sysfs. */
-        pci_bus_add_devices(phb->bus);
+        /* Finish adding it : resource allocation, adding devices, etc...
+         * Note that we need to perform the finish pass on the -parent-
+         * bus of the EADS bridge so the bridge device itself gets
+         * properly added
+         */
+        pcibios_finish_adding_to_bus(phb->bus);
 }
 
 static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
@@ -203,27 +206,6 @@ static int dlpar_add_pci_slot(char *drc_name, struct device_node *dn)
         return 0;
 }
 
-static int dlpar_remove_root_bus(struct pci_controller *phb)
-{
-        struct pci_bus *phb_bus;
-        int rc;
-
-        phb_bus = phb->bus;
-        if (!(list_empty(&phb_bus->children) &&
-              list_empty(&phb_bus->devices))) {
-                return -EBUSY;
-        }
-
-        rc = pcibios_remove_root_bus(phb);
-        if (rc)
-                return -EIO;
-
-        device_unregister(phb_bus->bridge);
-        pci_remove_bus(phb_bus);
-
-        return 0;
-}
-
 static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
 {
         struct slot *slot;
@@ -235,18 +217,15 @@ static int dlpar_remove_phb(char *drc_name, struct device_node *dn)
 
         /* If pci slot is hotplugable, use hotplug to remove it */
         slot = find_php_slot(dn);
-        if (slot) {
-                if (rpaphp_deregister_slot(slot)) {
-                        printk(KERN_ERR
-                                "%s: unable to remove hotplug slot %s\n",
-                                __func__, drc_name);
-                        return -EIO;
-                }
+        if (slot && rpaphp_deregister_slot(slot)) {
+                printk(KERN_ERR "%s: unable to remove hotplug slot %s\n",
+                       __func__, drc_name);
+                return -EIO;
         }
 
         pdn = dn->data;
         BUG_ON(!pdn || !pdn->phb);
-        rc = dlpar_remove_root_bus(pdn->phb);
+        rc = remove_phb_dynamic(pdn->phb);
         if (rc < 0)
                 return rc;
 
@@ -378,26 +357,38 @@ int dlpar_remove_pci_slot(char *drc_name, struct device_node *dn)
         if (!bus)
                 return -EINVAL;
 
-        /* If pci slot is hotplugable, use hotplug to remove it */
+        pr_debug("PCI: Removing PCI slot below EADS bridge %s\n",
+                 bus->self ? pci_name(bus->self) : "<!PHB!>");
+
         slot = find_php_slot(dn);
         if (slot) {
+                pr_debug("PCI: Removing hotplug slot for %04x:%02x...\n",
+                         pci_domain_nr(bus), bus->number);
+
                 if (rpaphp_deregister_slot(slot)) {
                         printk(KERN_ERR
                                 "%s: unable to remove hotplug slot %s\n",
                                 __func__, drc_name);
                         return -EIO;
                 }
-        } else
-                pcibios_remove_pci_devices(bus);
+        }
+
+        /* Remove all devices below slot */
+        pcibios_remove_pci_devices(bus);
 
+        /* Unmap PCI IO space */
         if (pcibios_unmap_io_space(bus)) {
                 printk(KERN_ERR "%s: failed to unmap bus range\n",
                         __func__);
                 return -ERANGE;
         }
 
+        /* Remove the EADS bridge device itself */
         BUG_ON(!bus->self);
+        pr_debug("PCI: Now removing bridge device %s\n", pci_name(bus->self));
+        eeh_remove_bus_device(bus->self);
         pci_remove_bus_device(bus->self);
+
         return 0;
 }