5 files changed, 162 insertions, 2 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index ff571f9298e0..dd00fd556a60 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1231,6 +1231,11 @@ and is between 256 and 4096 characters. It is defined in the file
                                 machine check when some devices' config space
                                 is read. But various workarounds are disabled
                                 and some IOMMU drivers will not work.
+                bfsort          Sort PCI devices into breadth-first order.
+                                This sorting is done to get a device
+                                order compatible with older (<= 2.4) kernels.
+                nobfsort        Don't sort PCI devices into breadth-first order.
+
         pcmv=           [HW,PCMCIA] BadgePAD 4
 
         pd.             [PARIDE]
diff --git a/arch/i386/pci/common.c b/arch/i386/pci/common.c
index 68bce194e688..6d5ace845e44 100644
--- a/arch/i386/pci/common.c
+++ b/arch/i386/pci/common.c
@@ -20,6 +20,7 @@
 unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
                                 PCI_PROBE_MMCONF;
 
+int pci_bf_sort;
 int pci_routeirq;
 int pcibios_last_bus = -1;
 unsigned long pirq_table_addr;
@@ -118,6 +119,20 @@ void __devinit  pcibios_fixup_bus(struct pci_bus *b)
 }
 
 /*
+ * Only use DMI information to set this if nothing was passed
+ * on the kernel command line (which was parsed earlier).
+ */
+
+static int __devinit set_bf_sort(struct dmi_system_id *d)
+{
+        if (pci_bf_sort == pci_bf_sort_default) {
+                pci_bf_sort = pci_dmi_bf;
+                printk(KERN_INFO "PCI: %s detected, enabling pci=bfsort.\n", d->ident);
+        }
+        return 0;
+}
+
+/*
  * Enable renumbering of PCI bus# ranges to reach all PCI busses (Cardbus)
  */
 #ifdef __i386__
@@ -130,11 +145,11 @@ static int __devinit assign_all_busses(struct dmi_system_id *d)
 }
 #endif
 
+static struct dmi_system_id __devinitdata pciprobe_dmi_table[] = {
+#ifdef __i386__
 /*
  * Laptops which need pci=assign-busses to see Cardbus cards
  */
-static struct dmi_system_id __devinitdata pciprobe_dmi_table[] = {
-#ifdef __i386__
         {
                 .callback = assign_all_busses,
                 .ident = "Samsung X20 Laptop",
@@ -144,6 +159,38 @@ static struct dmi_system_id __devinitdata pciprobe_dmi_table[] = {
                 },
         },
 #endif          /* __i386__ */
+        {
+                .callback = set_bf_sort,
+                .ident = "Dell PowerEdge 1950",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1950"),
+                },
+        },
+        {
+                .callback = set_bf_sort,
+                .ident = "Dell PowerEdge 1955",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1955"),
+                },
+        },
+        {
+                .callback = set_bf_sort,
+                .ident = "Dell PowerEdge 2900",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2900"),
+                },
+        },
+        {
+                .callback = set_bf_sort,
+                .ident = "Dell PowerEdge 2950",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2950"),
+                },
+        },
         {}
 };
 
@@ -189,6 +236,8 @@ static int __init pcibios_init(void)
 
         pcibios_resource_survey();
 
+        if (pci_bf_sort >= pci_force_bf)
+                pci_sort_breadthfirst();
 #ifdef CONFIG_PCI_BIOS
         if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
                 pcibios_sort();
@@ -203,6 +252,12 @@ char * __devinit  pcibios_setup(char *str)
         if (!strcmp(str, "off")) {
                 pci_probe = 0;
                 return NULL;
+        } else if (!strcmp(str, "bfsort")) {
+                pci_bf_sort = pci_force_bf;
+                return NULL;
+        } else if (!strcmp(str, "nobfsort")) {
+                pci_bf_sort = pci_force_nobf;
+                return NULL;
         }
 #ifdef CONFIG_PCI_BIOS
         else if (!strcmp(str, "bios")) {
diff --git a/arch/i386/pci/pci.h b/arch/i386/pci/pci.h
index 1814f74569c6..ad065cebd7b9 100644
--- a/arch/i386/pci/pci.h
+++ b/arch/i386/pci/pci.h
@@ -30,6 +30,13 @@
 extern unsigned int pci_probe;
 extern unsigned long pirq_table_addr;
 
+enum pci_bf_sort_state {
+        pci_bf_sort_default,
+        pci_force_nobf,
+        pci_force_bf,
+        pci_dmi_bf,
+};
+
 /* pci-i386.c */
 
 extern unsigned int pcibios_max_latency;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index a3b0a5eb5054..e159d6604494 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1067,3 +1067,95 @@ EXPORT_SYMBOL(pci_scan_bridge);
 EXPORT_SYMBOL(pci_scan_single_device);
 EXPORT_SYMBOL_GPL(pci_scan_child_bus);
 #endif
+
+static int __init pci_sort_bf_cmp(const struct pci_dev *a, const struct pci_dev *b)
+{
+        if      (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
+        else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return  1;
+
+        if      (a->bus->number < b->bus->number) return -1;
+        else if (a->bus->number > b->bus->number) return  1;
+
+        if      (a->devfn < b->devfn) return -1;
+        else if (a->devfn > b->devfn) return  1;
+
+        return 0;
+}
+
+/*
+ * Yes, this forcably breaks the klist abstraction temporarily.  It
+ * just wants to sort the klist, not change reference counts and
+ * take/drop locks rapidly in the process.  It does all this while
+ * holding the lock for the list, so objects can't otherwise be
+ * added/removed while we're swizzling.
+ */
+static void __init pci_insertion_sort_klist(struct pci_dev *a, struct list_head *list)
+{
+        struct list_head *pos;
+        struct klist_node *n;
+        struct device *dev;
+        struct pci_dev *b;
+
+        list_for_each(pos, list) {
+                n = container_of(pos, struct klist_node, n_node);
+                dev = container_of(n, struct device, knode_bus);
+                b = to_pci_dev(dev);
+                if (pci_sort_bf_cmp(a, b) <= 0) {
+                        list_move_tail(&a->dev.knode_bus.n_node, &b->dev.knode_bus.n_node);
+                        return;
+                }
+        }
+        list_move_tail(&a->dev.knode_bus.n_node, list);
+}
+
+static void __init pci_sort_breadthfirst_klist(void)
+{
+        LIST_HEAD(sorted_devices);
+        struct list_head *pos, *tmp;
+        struct klist_node *n;
+        struct device *dev;
+        struct pci_dev *pdev;
+
+        spin_lock(&pci_bus_type.klist_devices.k_lock);
+        list_for_each_safe(pos, tmp, &pci_bus_type.klist_devices.k_list) {
+                n = container_of(pos, struct klist_node, n_node);
+                dev = container_of(n, struct device, knode_bus);
+                pdev = to_pci_dev(dev);
+                pci_insertion_sort_klist(pdev, &sorted_devices);
+        }
+        list_splice(&sorted_devices, &pci_bus_type.klist_devices.k_list);
+        spin_unlock(&pci_bus_type.klist_devices.k_lock);
+}
+
+static void __init pci_insertion_sort_devices(struct pci_dev *a, struct list_head *list)
+{
+        struct pci_dev *b;
+
+        list_for_each_entry(b, list, global_list) {
+                if (pci_sort_bf_cmp(a, b) <= 0) {
+                        list_move_tail(&a->global_list, &b->global_list);
+                        return;
+                }
+        }
+        list_move_tail(&a->global_list, list);
+}
+
+static void __init pci_sort_breadthfirst_devices(void)
+{
+        LIST_HEAD(sorted_devices);
+        struct pci_dev *dev, *tmp;
+
+        down_write(&pci_bus_sem);
+        list_for_each_entry_safe(dev, tmp, &pci_devices, global_list) {
+                pci_insertion_sort_devices(dev, &sorted_devices);
+        }
+        list_splice(&sorted_devices, &pci_devices);
+        up_write(&pci_bus_sem);
+}
+
+void __init pci_sort_breadthfirst(void)
+{
+        pci_sort_breadthfirst_devices();
+        pci_sort_breadthfirst_klist();
+}
+
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 09bf88fc80c5..4689e2a699c0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -443,6 +443,7 @@ extern void pci_remove_bus(struct pci_bus *b);
 extern void pci_remove_bus_device(struct pci_dev *dev);
 extern void pci_stop_bus_device(struct pci_dev *dev);
 void pci_setup_cardbus(struct pci_bus *bus);
+extern void pci_sort_breadthfirst(void);
 
 /* Generic PCI functions exported to card drivers */