From c90570d9511d42421c85709b46bffd366185d835 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Mon, 9 Mar 2015 10:33:58 +0800 Subject: [PATCH] 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 Signed-off-by: Bjorn Helgaas CC: "David S. Miller" CC: Geert Uytterhoeven CC: Guan Xuetao CC: Richard Henderson CC: Ivan Kokshaysky CC: Matt Turner --- arch/alpha/kernel/sys_nautilus.c | 4 ++++ arch/m68k/coldfire/pci.c | 4 ++++ arch/sparc/kernel/pcic.c | 4 ++++ arch/unicore32/kernel/pci.c | 9 +-------- drivers/pci/hotplug/ibmphp_core.c | 8 ++++++-- drivers/pci/probe.c | 1 - 6 files changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c index 837c0fa58317..700686d04869 100644 --- 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 df9679238b6d..821de928dc3f 100644 --- 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 6cc78c213c01..24384e1dc33d 100644 --- 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 374a055a8e6b..d45fa5f3e9c4 100644 --- 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 96c5c729cdbc..15302475f5b7 100644 --- 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 8d2f400e96cb..88604f29d140 100644 --- 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); } -- 2.20.1