From c90570d9511d42421c85709b46bffd366185d835 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Mon, 9 Mar 2015 10:33:58 +0800 Subject: 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/sparc/kernel/pcic.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/sparc') 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); } /* -- cgit v1.2.2 From b97ea289cf6aff8d4cbcefe2b707bb9b00a73c73 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Mon, 16 Mar 2015 11:18:56 +0800 Subject: 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 Signed-off-by: Bjorn Helgaas CC: Richard Henderson CC: Ivan Kokshaysky CC: Matt Turner CC: David Howells CC: Tony Luck CC: Michal Simek CC: Ralf Baechle CC: Koichi Yasutake CC: Sebastian Ott CC: "David S. Miller" CC: Chris Metcalf CC: Chris Zankel CC: Max Filippov CC: Thomas Gleixner --- arch/sparc/kernel/leon_pci.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/sparc') diff --git a/arch/sparc/kernel/leon_pci.c b/arch/sparc/kernel/leon_pci.c index 899b7203a4e4..297107679fdf 100644 --- a/arch/sparc/kernel/leon_pci.c +++ b/arch/sparc/kernel/leon_pci.c @@ -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); } -- cgit v1.2.2 From a0c8a4d9f92d1ecd053eaa0e6cde7b4f24af97a8 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Thu, 12 Mar 2015 15:05:56 -0500 Subject: sparc/PCI: Claim bus resources before pci_bus_add_devices() Pci_claim_bus_resources() should be called before pci_bus_add_devices(), or driver may failed to load, because the resources had not claimed. Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas --- arch/sparc/kernel/pci.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c index 9ce5afe167ff..9e267cae683e 100644 --- a/arch/sparc/kernel/pci.c +++ b/arch/sparc/kernel/pci.c @@ -677,11 +677,10 @@ struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm, } pci_of_scan_bus(pbm, node, bus); - pci_bus_add_devices(bus); pci_bus_register_of_sysfs(bus); pci_claim_bus_resources(bus); - + pci_bus_add_devices(bus); return bus; } -- cgit v1.2.2 From 9e808eb6a7689b61399f772a2576d779161769ec Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 12 Mar 2015 15:07:04 -0500 Subject: PCI: Cleanup control flow Return errors immediately so the straightline path is the normal, no-error path. No functional change. Signed-off-by: Bjorn Helgaas --- arch/sparc/kernel/leon_pci.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/kernel/leon_pci.c b/arch/sparc/kernel/leon_pci.c index 297107679fdf..4371f72ff025 100644 --- a/arch/sparc/kernel/leon_pci.c +++ b/arch/sparc/kernel/leon_pci.c @@ -34,16 +34,17 @@ void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info) root_bus = pci_scan_root_bus(&ofdev->dev, 0, info->ops, info, &resources); - if (root_bus) { - /* Setup IRQs of all devices using custom routines */ - pci_fixup_irqs(pci_common_swizzle, info->map_irq); - - /* Assign devices with resources */ - pci_assign_unassigned_resources(); - pci_bus_add_devices(root_bus); - } else { + if (!root_bus) { pci_free_resource_list(&resources); + return; } + + /* Setup IRQs of all devices using custom routines */ + pci_fixup_irqs(pci_common_swizzle, info->map_irq); + + /* Assign devices with resources */ + pci_assign_unassigned_resources(); + pci_bus_add_devices(root_bus); } void pcibios_fixup_bus(struct pci_bus *pbus) -- cgit v1.2.2