PCI: Assign resources before drivers claim devices (pci_scan_root_bus()) (b97ea289) · Commits · 戴 / test

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>

arch/alpha/kernel/pci.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}
		}

arch/frv/mb93090-mb00/pci-vdk.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}

arch/ia64/sn/kernel/io_init.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}

		/*

arch/microblaze/pci/pci-common.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

arch/mips/pci/pci.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}
		}

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