[PATCH 5/5] PCI/powerpc/eeh: Add pcibios hooks for preparing to rescan
From: Sergey Miroshnichenko <hidden>
Date: 2018-09-05 15:40:30
Subsystem:
linux for powerpc (32-bit and 64-bit), pci enhanced error handling (eeh) for powerpc, pci subsystem, the rest · Maintainers:
Madhavan Srinivasan, Mahesh J Salgaonkar, Bjorn Helgaas, Linus Torvalds
Reading an empty slot returns all ones, which triggers a false EEH error event on PowerNV. New callbacks pcibios_rescan_prepare/done are introduced to pause/resume the EEH during rescan. Signed-off-by: Sergey Miroshnichenko <redacted> --- arch/powerpc/include/asm/eeh.h | 2 ++ arch/powerpc/kernel/eeh.c | 14 ++++++++++++++ arch/powerpc/platforms/powernv/eeh-powernv.c | 20 ++++++++++++++++++++ drivers/pci/probe.c | 14 ++++++++++++++ include/linux/pci.h | 2 ++ 5 files changed, 52 insertions(+)
diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index 219637ea69a1..926c3e31df99 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h@@ -219,6 +219,8 @@ struct eeh_ops { int (*next_error)(struct eeh_pe **pe); int (*restore_config)(struct pci_dn *pdn); int (*notify_resume)(struct pci_dn *pdn); + int (*pause)(struct pci_bus *bus); + int (*resume)(struct pci_bus *bus); }; extern int eeh_subsystem_flags;
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 6ebba3e48b01..dce9b0978cb5 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c@@ -1831,3 +1831,17 @@ static int __init eeh_init_proc(void) return 0; } __initcall(eeh_init_proc); + +void pcibios_rescan_prepare(struct pci_bus *bus) +{ + if (eeh_ops && eeh_ops->pause) { + eeh_ops->pause(bus); + } +} + +void pcibios_rescan_done(struct pci_bus *bus) +{ + if (eeh_ops && eeh_ops->resume) { + eeh_ops->resume(bus); + } +}
diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 3c1beae29f2d..9c9213d92550 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c@@ -59,6 +59,24 @@ void pnv_pcibios_bus_add_device(struct pci_dev *pdev) eeh_sysfs_add_device(pdev); } +static int pnv_eeh_pause(struct pci_bus *bus) +{ + struct pci_controller *hose = pci_bus_to_host(bus); + struct pnv_phb *phb = hose->private_data; + phb->flags &= ~PNV_PHB_FLAG_EEH; + disable_irq(eeh_event_irq); + return 0; +} + +static int pnv_eeh_resume(struct pci_bus *bus) +{ + struct pci_controller *hose = pci_bus_to_host(bus); + struct pnv_phb *phb = hose->private_data; + enable_irq(eeh_event_irq); + phb->flags |= PNV_PHB_FLAG_EEH; + return 0; +} + static int pnv_eeh_init(void) { struct pci_controller *hose;
@@ -1710,6 +1728,8 @@ static struct eeh_ops pnv_eeh_ops = { .write_config = pnv_eeh_write_config, .next_error = pnv_eeh_next_error, .restore_config = pnv_eeh_restore_config, + .pause = pnv_eeh_pause, + .resume = pnv_eeh_resume, .notify_resume = NULL };
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ec784009a36b..203368566896 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c@@ -2893,6 +2893,14 @@ void __weak pcibios_remove_bus(struct pci_bus *bus) { } +void __weak pcibios_rescan_prepare(struct pci_bus *bus) +{ +} + +void __weak pcibios_rescan_done(struct pci_bus *bus) +{ +} + struct pci_bus *pci_create_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources) {
@@ -3147,9 +3155,15 @@ unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge) unsigned int pci_rescan_bus(struct pci_bus *bus) { unsigned int max; + struct pci_bus *root = bus; + while (!pci_is_root_bus(root)) { + root = root->parent; + } + pcibios_rescan_prepare(root); max = pci_scan_child_bus(bus); pci_assign_unassigned_bus_resources(bus); + pcibios_rescan_done(root); pci_bus_add_devices(bus); return max;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e72ca8dd6241..d7fe72aa53b3 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h@@ -1952,6 +1952,8 @@ void pcibios_penalize_isa_irq(int irq, int active); int pcibios_alloc_irq(struct pci_dev *dev); void pcibios_free_irq(struct pci_dev *dev); resource_size_t pcibios_default_alignment(void); +void pcibios_rescan_prepare(struct pci_bus *bus); +void pcibios_rescan_done(struct pci_bus *bus); #ifdef CONFIG_HIBERNATE_CALLBACKS extern struct dev_pm_ops pcibios_pm_ops;
--
2.17.1