From: Thadeu Lima de Souza Cascardo Date: Fri, 28 Dec 2012 09:13:19 +0000 (+0000) Subject: powerpc/eeh: Fix crash when adding a device in a slot with DDW X-Git-Tag: v3.2.40~145 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=066f289835f09a3f744d6bac96f25e25d20b3ded;p=karo-tx-linux.git powerpc/eeh: Fix crash when adding a device in a slot with DDW commit 6a040ce72598159a74969a2d01ab0ba5ee6536b3 upstream. The DDW code uses a eeh_dev struct from the pci_dev. However, this is not set until eeh_add_device_late is called. Since pci_bus_add_devices is called before eeh_add_device_late, the PCI devices are added to the bus, making drivers' probe hooks to be called. These will call set_dma_mask, which will call the DDW code, which will require the eeh_dev struct from pci_dev. This would result in a crash, due to a NULL dereference. Calling eeh_add_device_late after pci_bus_add_devices would make the system BUG, because device files shouldn't be added to devices there were not added to the system. So, a new function is needed to add such files only after pci_bus_add_devices have been called. Signed-off-by: Thadeu Lima de Souza Cascardo Acked-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h index 66ea9b8b95c5..21165a4c759f 100644 --- a/arch/powerpc/include/asm/eeh.h +++ b/arch/powerpc/include/asm/eeh.h @@ -61,6 +61,7 @@ void __init pci_addr_cache_build(void); */ void eeh_add_device_tree_early(struct device_node *); void eeh_add_device_tree_late(struct pci_bus *); +void eeh_add_sysfs_files(struct pci_bus *); /** * eeh_remove_device_recursive - undo EEH for device & children. @@ -105,6 +106,8 @@ static inline void eeh_add_device_tree_early(struct device_node *dn) { } static inline void eeh_add_device_tree_late(struct pci_bus *bus) { } +static inline void eeh_add_sysfs_files(struct pci_bus *bus) { } + static inline void eeh_remove_bus_device(struct pci_dev *dev) { } #define EEH_POSSIBLE_ERROR(val, type) (0) #define EEH_IO_ERROR_VALUE(size) (-1UL) diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c index e1612dfb4a93..b10beef561bc 100644 --- a/arch/powerpc/kernel/of_platform.c +++ b/arch/powerpc/kernel/of_platform.c @@ -91,6 +91,9 @@ static int __devinit of_pci_phb_probe(struct platform_device *dev) /* Add probed PCI devices to the device model */ pci_bus_add_devices(phb->bus); + /* sysfs files should only be added after devices are added */ + eeh_add_sysfs_files(phb->bus); + return 0; } diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 458ed3bee663..a3cd94948468 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1536,11 +1536,14 @@ void pcibios_finish_adding_to_bus(struct pci_bus *bus) pcibios_allocate_bus_resources(bus); pcibios_claim_one_bus(bus); + /* Fixup EEH */ + eeh_add_device_tree_late(bus); + /* Add new devices to global lists. Register in proc, sysfs. */ pci_bus_add_devices(bus); - /* Fixup EEH */ - eeh_add_device_tree_late(bus); + /* sysfs files should only be added after devices are added */ + eeh_add_sysfs_files(bus); } EXPORT_SYMBOL_GPL(pcibios_finish_adding_to_bus); diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c index 565869022e3d..389e06b2f1f1 100644 --- a/arch/powerpc/platforms/pseries/eeh.c +++ b/arch/powerpc/platforms/pseries/eeh.c @@ -1238,7 +1238,6 @@ static void eeh_add_device_late(struct pci_dev *dev) pdn->pcidev = dev; pci_addr_cache_insert_device(dev); - eeh_sysfs_add_device(dev); } void eeh_add_device_tree_late(struct pci_bus *bus) @@ -1256,6 +1255,29 @@ void eeh_add_device_tree_late(struct pci_bus *bus) } EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); +/** + * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus + * @bus: PCI bus + * + * This routine must be used to add EEH sysfs files for PCI + * devices which are attached to the indicated PCI bus. The PCI bus + * is added after system boot through hotplug or dlpar. + */ +void eeh_add_sysfs_files(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + eeh_sysfs_add_device(dev); + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + struct pci_bus *subbus = dev->subordinate; + if (subbus) + eeh_add_sysfs_files(subbus); + } + } +} +EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); + /** * eeh_remove_device - undo EEH setup for the indicated pci device * @dev: pci device to be removed