From f5c57710dd62dd06f176934a8b4b8accbf00f9f8 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 24 Jul 2013 10:24:58 +0800 Subject: powerpc/eeh: Use partial hotplug for EEH unaware drivers When EEH error happens to one specific PE, some devices with drivers supporting EEH won't except hotplug on the device. However, there might have other deivces without driver, or with driver without EEH support. For the case, we need do partial hotplug in order to make sure that the PE becomes absolutely quite during reset. Otherise, the PE reset might fail and leads to failure of error recovery. The current code doesn't handle that 'mixed' case properly, it either uses the error callbacks to the drivers, or tries hotplug, but doesn't handle a PE (EEH domain) composed of a combination of the two. The patch intends to support so-called "partial" hotplug for EEH: Before we do reset, we stop and remove those PCI devices without EEH sensitive driver. The corresponding EEH devices are not detached from its PE, but with special flag. After the reset is done, those EEH devices with the special flag will be scanned one by one. Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/eeh_sysfs.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/powerpc/kernel/eeh_sysfs.c') diff --git a/arch/powerpc/kernel/eeh_sysfs.c b/arch/powerpc/kernel/eeh_sysfs.c index e7ae3484918c..61e2a1452131 100644 --- a/arch/powerpc/kernel/eeh_sysfs.c +++ b/arch/powerpc/kernel/eeh_sysfs.c @@ -68,6 +68,13 @@ void eeh_sysfs_add_device(struct pci_dev *pdev) void eeh_sysfs_remove_device(struct pci_dev *pdev) { + /* + * The parent directory might have been removed. We needn't + * continue for that case. + */ + if (!pdev->dev.kobj.sd) + return; + device_remove_file(&pdev->dev, &dev_attr_eeh_mode); device_remove_file(&pdev->dev, &dev_attr_eeh_config_addr); device_remove_file(&pdev->dev, &dev_attr_eeh_pe_config_addr); -- cgit v1.2.1 From ab55d2187da27414f78056810713c92f9a4350c2 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Wed, 24 Jul 2013 10:25:01 +0800 Subject: powerpc/eeh: Introdce flag to protect sysfs The patch introduces flag EEH_DEV_SYSFS to keep track that the sysfs entries for the corresponding EEH device (then PCI device) has been added or removed, in order to avoid race condition. Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/eeh_sysfs.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/eeh_sysfs.c') diff --git a/arch/powerpc/kernel/eeh_sysfs.c b/arch/powerpc/kernel/eeh_sysfs.c index 61e2a1452131..5d753d4f2c75 100644 --- a/arch/powerpc/kernel/eeh_sysfs.c +++ b/arch/powerpc/kernel/eeh_sysfs.c @@ -56,26 +56,40 @@ EEH_SHOW_ATTR(eeh_pe_config_addr, pe_config_addr, "0x%x"); void eeh_sysfs_add_device(struct pci_dev *pdev) { + struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev); int rc=0; + if (edev && (edev->mode & EEH_DEV_SYSFS)) + return; + rc += device_create_file(&pdev->dev, &dev_attr_eeh_mode); rc += device_create_file(&pdev->dev, &dev_attr_eeh_config_addr); rc += device_create_file(&pdev->dev, &dev_attr_eeh_pe_config_addr); if (rc) printk(KERN_WARNING "EEH: Unable to create sysfs entries\n"); + else if (edev) + edev->mode |= EEH_DEV_SYSFS; } void eeh_sysfs_remove_device(struct pci_dev *pdev) { + struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev); + /* * The parent directory might have been removed. We needn't * continue for that case. */ - if (!pdev->dev.kobj.sd) + if (!pdev->dev.kobj.sd) { + if (edev) + edev->mode &= ~EEH_DEV_SYSFS; return; + } device_remove_file(&pdev->dev, &dev_attr_eeh_mode); device_remove_file(&pdev->dev, &dev_attr_eeh_config_addr); device_remove_file(&pdev->dev, &dev_attr_eeh_pe_config_addr); + + if (edev) + edev->mode &= ~EEH_DEV_SYSFS; } -- cgit v1.2.1