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

Previously, pci_scan_root_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_root_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_root_bus() and do it after any
resource assignment in the callers.

Note that ARM's pci_common_init_dev() already called pci_bus_add_devices()
after pci_scan_root_bus(), so we only need to remove the first call:

  pci_common_init_dev
    pcibios_init_hw
      pci_scan_root_bus
        pci_bus_add_devices        # first call
    pci_bus_assign_resources
    pci_bus_add_devices            # second call

[bhelgaas: changelog, drop "root_bus" var in alpha common_init_pci(),
return failure earlier in mn10300, add "return" in x86 pcibios_scan_root(),
return early if xtensa platform_pcibios_fixup() fails]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
CC: Matt Turner <mattst88@gmail.com>
CC: David Howells <dhowells@redhat.com>
CC: Tony Luck <tony.luck@intel.com>
CC: Michal Simek <monstr@monstr.eu>
CC: Ralf Baechle <ralf@linux-mips.org>
CC: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Chris Metcalf <cmetcalf@ezchip.com>
CC: Chris Zankel <chris@zankel.net>
CC: Max Filippov <jcmvbkbc@gmail.com>
CC: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Yijing Wang 2015-03-16 11:18:56 +08:00 committed by Bjorn Helgaas
parent c90570d951
commit b97ea289cf
15 changed files with 47 additions and 6 deletions

View File

@ -338,6 +338,8 @@ common_init_pci(void)
bus = pci_scan_root_bus(NULL, next_busno, alpha_mv.pci_ops,
hose, &resources);
if (!bus)
continue;
hose->bus = bus;
hose->need_domain_info = need_domain_info;
next_busno = bus->busn_res.end + 1;
@ -353,6 +355,11 @@ common_init_pci(void)
pci_assign_unassigned_resources();
pci_fixup_irqs(alpha_mv.pci_swizzle, alpha_mv.pci_map_irq);
for (hose = hose_head; hose; hose = hose->next) {
bus = hose->bus;
if (bus)
pci_bus_add_devices(bus);
}
}

View File

@ -316,6 +316,7 @@ void pcibios_fixup_bus(struct pci_bus *bus)
int __init pcibios_init(void)
{
struct pci_bus *bus;
struct pci_ops *dir = NULL;
LIST_HEAD(resources);
@ -383,12 +384,15 @@ int __init pcibios_init(void)
printk("PCI: Probing PCI hardware\n");
pci_add_resource(&resources, &pci_ioport_resource);
pci_add_resource(&resources, &pci_iomem_resource);
pci_scan_root_bus(NULL, 0, pci_root_ops, NULL, &resources);
bus = pci_scan_root_bus(NULL, 0, pci_root_ops, NULL, &resources);
pcibios_irq_init();
pcibios_fixup_irqs();
pcibios_resource_survey();
if (!bus)
return 0;
pci_bus_add_devices(bus);
return 0;
}

View File

@ -271,7 +271,9 @@ sn_pci_controller_fixup(int segment, int busnum, struct pci_bus *bus)
if (bus == NULL) {
kfree(res);
kfree(controller);
return;
}
pci_bus_add_devices(bus);
}
/*

View File

@ -1382,6 +1382,10 @@ static int __init pcibios_init(void)
/* Call common code to handle resource allocation */
pcibios_resource_survey();
list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
if (hose->bus)
pci_bus_add_devices(hose->bus);
}
return 0;
}

View File

@ -114,6 +114,7 @@ static void pcibios_scanbus(struct pci_controller *hose)
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
}
pci_bus_add_devices(bus);
}
}

View File

@ -342,6 +342,7 @@ static int __init pcibios_init(void)
{
resource_size_t io_offset, mem_offset;
LIST_HEAD(resources);
struct pci_bus *bus;
ioport_resource.start = 0xA0000000;
ioport_resource.end = 0xDFFFFFFF;
@ -371,11 +372,14 @@ static int __init pcibios_init(void)
pci_add_resource_offset(&resources, &pci_ioport_resource, io_offset);
pci_add_resource_offset(&resources, &pci_iomem_resource, mem_offset);
pci_scan_root_bus(NULL, 0, &pci_direct_ampci, NULL, &resources);
bus = pci_scan_root_bus(NULL, 0, &pci_direct_ampci, NULL, &resources);
if (!bus)
return 0;
pcibios_irq_init();
pcibios_fixup_irqs();
pcibios_resource_survey();
pci_bus_add_devices(bus);
return 0;
}

View File

@ -776,8 +776,8 @@ static int zpci_scan_bus(struct zpci_dev *zdev)
zpci_cleanup_bus_resources(zdev);
return -EIO;
}
zdev->bus->max_bus_speed = zdev->max_bus_speed;
pci_bus_add_devices(zdev->bus);
return 0;
}

View File

@ -69,6 +69,7 @@ static void pcibios_scanbus(struct pci_channel *hose)
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
pci_bus_add_devices(bus);
} else {
pci_free_resource_list(&resources);
}

View File

@ -40,6 +40,7 @@ void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
/* Assign devices with resources */
pci_assign_unassigned_resources();
pci_bus_add_devices(root_bus);
} else {
pci_free_resource_list(&resources);
}

View File

@ -339,6 +339,8 @@ int __init pcibios_init(void)
struct pci_bus *next_bus;
struct pci_dev *dev;
pci_bus_add_devices(root_bus);
list_for_each_entry(dev, &root_bus->devices, bus_list) {
/*
* Find the PCI host controller, ie. the 1st

View File

@ -1030,6 +1030,8 @@ int __init pcibios_init(void)
alloc_mem_map_failed:
break;
}
pci_bus_add_devices(root_bus);
}
return 0;

View File

@ -490,7 +490,9 @@ void pcibios_scan_root(int busnum)
if (!bus) {
pci_free_resource_list(&resources);
kfree(sd);
return;
}
pci_bus_add_devices(bus);
}
void __init pcibios_set_cache_line_size(void)

View File

@ -174,7 +174,7 @@ static int __init pcibios_init(void)
struct pci_controller *pci_ctrl;
struct list_head resources;
struct pci_bus *bus;
int next_busno = 0;
int next_busno = 0, ret;
printk("PCI: Probing PCI hardware\n");
@ -185,14 +185,25 @@ static int __init pcibios_init(void)
pci_controller_apertures(pci_ctrl, &resources);
bus = pci_scan_root_bus(NULL, pci_ctrl->first_busno,
pci_ctrl->ops, pci_ctrl, &resources);
if (!bus)
continue;
pci_ctrl->bus = bus;
pci_ctrl->last_busno = bus->busn_res.end;
if (next_busno <= pci_ctrl->last_busno)
next_busno = pci_ctrl->last_busno+1;
}
pci_bus_count = next_busno;
ret = platform_pcibios_fixup();
if (ret)
return ret;
return platform_pcibios_fixup();
for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
if (pci_ctrl->bus)
pci_bus_add_devices(pci_ctrl->bus);
}
return 0;
}
subsys_initcall(pcibios_init);

View File

@ -214,6 +214,7 @@ static int versatile_pci_probe(struct platform_device *pdev)
pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
pci_assign_unassigned_bus_resources(bus);
pci_bus_add_devices(bus);
return 0;
}

View File

@ -2087,7 +2087,6 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
if (!found)
pci_bus_update_busn_res_end(b, max);
pci_bus_add_devices(b);
return b;
}
EXPORT_SYMBOL(pci_scan_root_bus);