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, 81 insertions, 82 deletions

diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c
index 7190493e9bdc..5e1ed3d60ee5 100644
--- a/arch/powerpc/platforms/pseries/pci_dlpar.c
+++ b/arch/powerpc/platforms/pseries/pci_dlpar.c
@@ -25,6 +25,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#undef DEBUG
+
 #include <linux/pci.h>
 #include <asm/pci-bridge.h>
 #include <asm/ppc-pci.h>
@@ -69,74 +71,25 @@ EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
  * Remove all of the PCI devices under this bus both from the
  * linux pci device tree, and from the powerpc EEH address cache.
  */
-void
-pcibios_remove_pci_devices(struct pci_bus *bus)
+void pcibios_remove_pci_devices(struct pci_bus *bus)
 {
-        struct pci_dev *dev, *tmp;
+        struct pci_dev *dev, *tmp;
+        struct pci_bus *child_bus;
+
+        /* First go down child busses */
+        list_for_each_entry(child_bus, &bus->children, node)
+                pcibios_remove_pci_devices(child_bus);
 
+        pr_debug("PCI: Removing devices on bus %04x:%02x\n",
+                 pci_domain_nr(bus),  bus->number);
         list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
+                pr_debug("     * Removing %s...\n", pci_name(dev));
                 eeh_remove_bus_device(dev);
-                pci_remove_bus_device(dev);
-        }
+                pci_remove_bus_device(dev);
+        }
 }
 EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices);
 
-/* Must be called before pci_bus_add_devices */
-void
-pcibios_fixup_new_pci_devices(struct pci_bus *bus)
-{
-        struct pci_dev *dev;
-
-        list_for_each_entry(dev, &bus->devices, bus_list) {
-                /* Skip already-added devices */
-                if (!dev->is_added) {
-                        int i;
-
-                        /* Fill device archdata and setup iommu table */
-                        pcibios_setup_new_device(dev);
-
-                        pci_read_irq_line(dev);
-                        for (i = 0; i < PCI_NUM_RESOURCES; i++) {
-                                struct resource *r = &dev->resource[i];
-
-                                if (r->parent || !r->start || !r->flags)
-                                        continue;
-                                pci_claim_resource(dev, i);
-                        }
-                }
-        }
-}
-EXPORT_SYMBOL_GPL(pcibios_fixup_new_pci_devices);
-
-static int
-pcibios_pci_config_bridge(struct pci_dev *dev)
-{
-        u8 sec_busno;
-        struct pci_bus *child_bus;
-
-        /* Get busno of downstream bus */
-        pci_read_config_byte(dev, PCI_SECONDARY_BUS, &sec_busno);
-
-        /* Add to children of PCI bridge dev->bus */
-        child_bus = pci_add_new_bus(dev->bus, dev, sec_busno);
-        if (!child_bus) {
-                printk (KERN_ERR "%s: could not add second bus\n", __func__);
-                return -EIO;
-        }
-        sprintf(child_bus->name, "PCI Bus #%02x", child_bus->number);
-
-        pci_scan_child_bus(child_bus);
-
-        /* Fixup new pci devices */
-        pcibios_fixup_new_pci_devices(child_bus);
-
-        /* Make the discovered devices available */
-        pci_bus_add_devices(child_bus);
-
-        eeh_add_device_tree_late(child_bus);
-        return 0;
-}
-
 /**
  * pcibios_add_pci_devices - adds new pci devices to bus
  *
@@ -147,10 +100,9 @@ pcibios_pci_config_bridge(struct pci_dev *dev)
  * is how this routine differs from other, similar pcibios
  * routines.)
  */
-void
-pcibios_add_pci_devices(struct pci_bus * bus)
+void pcibios_add_pci_devices(struct pci_bus * bus)
 {
-        int slotno, num, mode;
+        int slotno, num, mode, pass, max;
         struct pci_dev *dev;
         struct device_node *dn = pci_bus_to_OF_node(bus);
 
@@ -162,26 +114,23 @@ pcibios_add_pci_devices(struct pci_bus * bus)
 
         if (mode == PCI_PROBE_DEVTREE) {
                 /* use ofdt-based probe */
-                of_scan_bus(dn, bus);
-                if (!list_empty(&bus->devices)) {
-                        pcibios_fixup_new_pci_devices(bus);
-                        pci_bus_add_devices(bus);
-                        eeh_add_device_tree_late(bus);
-                }
+                of_rescan_bus(dn, bus);
         } else if (mode == PCI_PROBE_NORMAL) {
                 /* use legacy probe */
                 slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
                 num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
-                if (num) {
-                        pcibios_fixup_new_pci_devices(bus);
-                        pci_bus_add_devices(bus);
-                        eeh_add_device_tree_late(bus);
+                if (!num)
+                        return;
+                pcibios_setup_bus_devices(bus);
+                max = bus->secondary;
+                for (pass=0; pass < 2; pass++)
+                        list_for_each_entry(dev, &bus->devices, bus_list) {
+                        if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
+                            dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
+                                max = pci_scan_bridge(bus, dev, max, pass);
                 }
-
-                list_for_each_entry(dev, &bus->devices, bus_list)
-                        if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
-                                pcibios_pci_config_bridge(dev);
         }
+        pcibios_finish_adding_to_bus(bus);
 }
 EXPORT_SYMBOL_GPL(pcibios_add_pci_devices);
 
@@ -190,6 +139,8 @@ struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn)
         struct pci_controller *phb;
         int primary;
 
+        pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);
+
         primary = list_empty(&hose_list);
         phb = pcibios_alloc_controller(dn);
         if (!phb)
@@ -203,11 +154,59 @@ struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn)
                 eeh_add_device_tree_early(dn);
 
         scan_phb(phb);
-        pcibios_allocate_bus_resources(phb->bus);
-        pcibios_fixup_new_pci_devices(phb->bus);
-        pci_bus_add_devices(phb->bus);
-        eeh_add_device_tree_late(phb->bus);
+        pcibios_finish_adding_to_bus(phb->bus);
 
         return phb;
 }
 EXPORT_SYMBOL_GPL(init_phb_dynamic);
+
+/* RPA-specific bits for removing PHBs */
+int remove_phb_dynamic(struct pci_controller *phb)
+{
+        struct pci_bus *b = phb->bus;
+        struct resource *res;
+        int rc, i;
+
+        pr_debug("PCI: Removing PHB %04x:%02x... \n",
+                 pci_domain_nr(b), b->number);
+
+        /* We cannot to remove a root bus that has children */
+        if (!(list_empty(&b->children) && list_empty(&b->devices)))
+                return -EBUSY;
+
+        /* We -know- there aren't any child devices anymore at this stage
+         * and thus, we can safely unmap the IO space as it's not in use
+         */
+        res = &phb->io_resource;
+        if (res->flags & IORESOURCE_IO) {
+                rc = pcibios_unmap_io_space(b);
+                if (rc) {
+                        printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
+                               __func__, b->name);
+                        return 1;
+                }
+        }
+
+        /* Unregister the bridge device from sysfs and remove the PCI bus */
+        device_unregister(b->bridge);
+        phb->bus = NULL;
+        pci_remove_bus(b);
+
+        /* Now release the IO resource */
+        if (res->flags & IORESOURCE_IO)
+                release_resource(res);
+
+        /* Release memory resources */
+        for (i = 0; i < 3; ++i) {
+                res = &phb->mem_resources[i];
+                if (!(res->flags & IORESOURCE_MEM))
+                        continue;
+                release_resource(res);
+        }
+
+        /* Free pci_controller data structure */
+        pcibios_free_controller(phb);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(remove_phb_dynamic);