Commit c90570d9 authored by Yijing Wang's avatar Yijing Wang Committed by Bjorn Helgaas
Browse files

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: default avatarYijing Wang <wangyijing@huawei.com>
Signed-off-by: default avatarBjorn 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>
parent c517d838

arch/alpha/kernel/sys_nautilus.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

}



/*

arch/m68k/coldfire/pci.c

+4 −0
Original line number Diff line number Diff line
@@ -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;

}

arch/sparc/kernel/pcic.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

}



/*

arch/unicore32/kernel/pci.c

+1 −8
Original line number Diff line number Diff line
@@ -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);

drivers/pci/hotplug/ibmphp_core.c

+6 −2
Original line number Diff line number Diff line
@@ -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;

		}

	}

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