PCI: Assign resources before drivers claim devices (pci_scan_bus())

Previously, pci_scan_bus() created a root PCI bus, enumerated the devices
on it, and called pci_bus_add_devices(), which made the devices available
for drivers to claim them.

Most callers assigned resources to devices after pci_scan_bus() returns,
which may be after drivers have claimed the devices.  This is incorrect;
the PCI core should not change device resources while a driver is managing
the device.

Remove pci_bus_add_devices() from pci_scan_bus() and do it after any
resource assignment in the callers.

[bhelgaas: changelog, check for failure in mcf_pci_init()]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Guan Xuetao <gxt@mprc.pku.edu.cn>
CC: Richard Henderson <rth@twiddle.net>
CC: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
CC: Matt Turner <mattst88@gmail.com>

diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c
index 837c0fa..700686d 100644 (file)
--- a/arch/alpha/kernel/sys_nautilus.c
+++ b/arch/alpha/kernel/sys_nautilus.c
@@ -207,6 +207,9 @@ nautilus_init_pci(void)
 
        /* Scan our single hose.  */
        bus = pci_scan_bus(0, alpha_mv.pci_ops, hose);
+       if (!bus)
+               return;
+
        hose->bus = bus;
        pcibios_claim_one_bus(bus);
 
@@ -253,6 +256,7 @@ nautilus_init_pci(void)
           for the root bus, so just clear it. */
        bus->self = NULL;
        pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq);
+       pci_bus_add_devices(bus);
 }
 
 /*

diff --git a/arch/m68k/coldfire/pci.c b/arch/m68k/coldfire/pci.c
index df96792..821de92 100644 (file)
--- a/arch/m68k/coldfire/pci.c
+++ b/arch/m68k/coldfire/pci.c
@@ -313,12 +313,16 @@ static int __init mcf_pci_init(void)
        schedule_timeout(msecs_to_jiffies(200));
 
        rootbus = pci_scan_bus(0, &mcf_pci_ops, NULL);
+       if (!rootbus)
+               return -ENODEV;
+
        rootbus->resource[0] = &mcf_pci_io;
        rootbus->resource[1] = &mcf_pci_mem;
 
        pci_fixup_irqs(pci_common_swizzle, mcf_pci_map_irq);
        pci_bus_size_bridges(rootbus);
        pci_bus_assign_resources(rootbus);
+       pci_bus_add_devices(rootbus);
        return 0;
 }
 

diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
index 6cc78c2..24384e1 100644 (file)
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -391,12 +391,16 @@ static void __init pcic_pbm_scan_bus(struct linux_pcic *pcic)
        struct linux_pbm_info *pbm = &pcic->pbm;
 
        pbm->pci_bus = pci_scan_bus(pbm->pci_first_busno, &pcic_ops, pbm);
+       if (!pbm->pci_bus)
+               return;
+
 #if 0 /* deadwood transplanted from sparc64 */
        pci_fill_in_pbm_cookies(pbm->pci_bus, pbm, pbm->prom_node);
        pci_record_assignments(pbm, pbm->pci_bus);
        pci_assign_unassigned(pbm, pbm->pci_bus);
        pci_fixup_irq(pbm, pbm->pci_bus);
 #endif
+       pci_bus_add_devices(pbm->pci_bus);
 }
 
 /*

diff --git a/arch/unicore32/kernel/pci.c b/arch/unicore32/kernel/pci.c
index 374a055..d45fa5f 100644 (file)
--- a/arch/unicore32/kernel/pci.c
+++ b/arch/unicore32/kernel/pci.c
@@ -266,17 +266,10 @@ static int __init pci_common_init(void)
        pci_fixup_irqs(pci_common_swizzle, pci_puv3_map_irq);
 
        if (!pci_has_flag(PCI_PROBE_ONLY)) {
-               /*
-                * Size the bridge windows.
-                */
                pci_bus_size_bridges(puv3_bus);
-
-               /*
-                * Assign resources.
-                */
                pci_bus_assign_resources(puv3_bus);
        }
-
+       pci_bus_add_devices(puv3_bus);
        return 0;
 }
 subsys_initcall(pci_common_init);

diff --git a/drivers/pci/hotplug/ibmphp_core.c b/drivers/pci/hotplug/ibmphp_core.c
index 96c5c72..1530247 100644 (file)
--- a/drivers/pci/hotplug/ibmphp_core.c
+++ b/drivers/pci/hotplug/ibmphp_core.c
@@ -738,7 +738,7 @@ static void ibm_unconfigure_device(struct pci_func *func)
  */
 static u8 bus_structure_fixup(u8 busno)
 {
-       struct pci_bus *bus;
+       struct pci_bus *bus, *b;
        struct pci_dev *dev;
        u16 l;
 
@@ -765,7 +765,11 @@ static u8 bus_structure_fixup(u8 busno)
                                        (l != 0x0000) && (l != 0xffff)) {
                        debug("%s - Inside bus_structure_fixup()\n",
                                                        __func__);
-                       pci_scan_bus(busno, ibmphp_pci_bus->ops, NULL);
+                       b = pci_scan_bus(busno, ibmphp_pci_bus->ops, NULL);
+                       if (!b)
+                               continue;
+
+                       pci_bus_add_devices(b);
                        break;
                }
        }

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8d2f400..88604f2 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2123,7 +2123,6 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
        b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
        if (b) {
                pci_scan_child_bus(b);
-               pci_bus_add_devices(b);
        } else {
                pci_free_resource_list(&resources);
        }