From mboxrd@z Thu Jan 1 00:00:00 1970 From: wangyijing@huawei.com (Yijing Wang) Date: Mon, 9 Mar 2015 10:33:58 +0800 Subject: [PATCH v6 01/30] PCI: Rip out pci_bus_add_devices() from pci_scan_bus() In-Reply-To: <1425868467-9667-1-git-send-email-wangyijing@huawei.com> References: <1425868467-9667-1-git-send-email-wangyijing@huawei.com> Message-ID: <1425868467-9667-2-git-send-email-wangyijing@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Pci_bus_add_devices() should not be placed in pci_scan_bus(). Now pci device will be added to driver core once its creation. All things left in pci_bus_add_devices() are driver attachment and other trivial sysfs things. Pci_scan_bus() should be the function responsible for scanning PCI devices, not including driver attachment. Other, some callers(m68k,unicore32,alpha) of pci_scan_bus() will call pci_bus_size_bridges() and pci_bus_assign_resources() after pci_scan_bus(). E.g. In m68k mcf_pci_init() pci_scan_bus() ... pci_bus_add_devices() --- try to attach driver pci_fixup_irqs() pci_bus_size_bridges() pci_bus_assign_resources() Above code flow make pci scan logic obscure, resources should be assigned correctly before attaching driver. Because pci_scan_bus() mostly be called in system boot path, when before drivers are loaded(in module_init), so no pci scan issues will occur. Most pci_scan_bus() callers additionally call pci_bus_size_bridges() and pci_bus_assign_resources() after pci_scan_bus(), we could rip out pci_bus_add_devices() for better code readability. After applied this patch, pci_scan_bus() should be used like: pci_scan_bus() (mandatory) pci_fixup_irqs() (optional) pci_bus_size_bridges() (optional) pci_pci_bus_assign_resources() (optional) pci_bus_add_devices() (mandatory) Signed-off-by: Yijing Wang CC: "David S. Miller" CC: Geert Uytterhoeven CC: Guan Xuetao CC: Richard Henderson CC: Ivan Kokshaysky CC: Matt Turner CC: linux-alpha at vger.kernel.org CC: linux-m68k at lists.linux-m68k.org CC: sparclinux at vger.kernel.org Signed-off-by: Bjorn Helgaas --- arch/alpha/kernel/sys_nautilus.c | 4 ++++ arch/m68k/coldfire/pci.c | 1 + arch/sparc/kernel/pcic.c | 3 +++ arch/unicore32/kernel/pci.c | 11 +++-------- drivers/pci/hotplug/ibmphp_core.c | 8 ++++++-- drivers/pci/probe.c | 1 - 6 files changed, 17 insertions(+), 11 deletions(-) diff --git a/arch/alpha/kernel/sys_nautilus.c b/arch/alpha/kernel/sys_nautilus.c index 837c0fa..700686d 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 df96792..d45f087 100644 --- a/arch/m68k/coldfire/pci.c +++ b/arch/m68k/coldfire/pci.c @@ -319,6 +319,7 @@ static int __init mcf_pci_init(void) 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..0f4dc6b 100644 --- a/arch/sparc/kernel/pcic.c +++ b/arch/sparc/kernel/pcic.c @@ -391,12 +391,15 @@ 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..3d82024 100644 --- a/arch/unicore32/kernel/pci.c +++ b/arch/unicore32/kernel/pci.c @@ -266,17 +266,12 @@ 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. - */ + /* Size the bridge windows. */ pci_bus_size_bridges(puv3_bus); - - /* - * Assign resources. - */ + /* 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 --- 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 --- 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); } -- 1.7.1