From 9e5c6e5a3be0b2e17ff61b9b74adef4a2c9e6934 Mon Sep 17 00:00:00 2001 From: Mike Qiu Date: Tue, 15 Jul 2014 01:42:22 -0400 Subject: [PATCH] powerpc/eeh: Wrong place to call pci_get_slot() pci_get_slot() is called with hold of PCI bus semaphore and it's not safe to be called in interrupt context. However, we possibly checks EEH error and calls the function in interrupt context. To avoid using pci_get_slot(), we turn into device tree for fetching location code. Otherwise, we might run into WARN_ON() as following messages indicate: WARNING: at drivers/pci/search.c:223 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc3+ #72 task: c000000001367af0 ti: c000000001444000 task.ti: c000000001444000 NIP: c000000000497b70 LR: c000000000037530 CTR: 000000003003d114 REGS: c000000001446fa0 TRAP: 0700 Not tainted (3.16.0-rc3+) MSR: 9000000000029032 CR: 48002422 XER: 20000000 CFAR: c00000000003752c SOFTE: 0 : NIP [c000000000497b70] .pci_get_slot+0x40/0x110 LR [c000000000037530] .eeh_pe_loc_get+0x150/0x190 Call Trace: .of_get_property+0x30/0x60 (unreliable) .eeh_pe_loc_get+0x150/0x190 .eeh_dev_check_failure+0x1b4/0x550 .eeh_check_failure+0x90/0xf0 .lpfc_sli_check_eratt+0x504/0x7c0 [lpfc] .lpfc_poll_eratt+0x64/0x100 [lpfc] .call_timer_fn+0x64/0x190 .run_timer_softirq+0x2cc/0x3e0 Cc: stable@vger.kernel.org Signed-off-by: Mike Qiu Acked-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/eeh_pe.c | 46 +++++++++++++------------------------------- 1 file changed, 13 insertions(+), 33 deletions(-) diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c index 1dce071a9ac3..418d79c9eaa4 100644 --- a/arch/powerpc/kernel/eeh_pe.c +++ b/arch/powerpc/kernel/eeh_pe.c @@ -791,53 +791,33 @@ void eeh_pe_restore_bars(struct eeh_pe *pe) */ const char *eeh_pe_loc_get(struct eeh_pe *pe) { - struct pci_controller *hose; struct pci_bus *bus = eeh_pe_bus_get(pe); - struct pci_dev *pdev; - struct device_node *dn; - const char *loc; + struct device_node *dn = pci_bus_to_OF_node(bus); + const char *loc = NULL; - if (!bus) - return "N/A"; + if (!dn) + goto out; /* PHB PE or root PE ? */ if (pci_is_root_bus(bus)) { - hose = pci_bus_to_host(bus); - loc = of_get_property(hose->dn, - "ibm,loc-code", NULL); - if (loc) - return loc; - loc = of_get_property(hose->dn, - "ibm,io-base-loc-code", NULL); + loc = of_get_property(dn, "ibm,loc-code", NULL); + if (!loc) + loc = of_get_property(dn, "ibm,io-base-loc-code", NULL); if (loc) - return loc; - - pdev = pci_get_slot(bus, 0x0); - } else { - pdev = bus->self; - } - - if (!pdev) { - loc = "N/A"; - goto out; - } + goto out; - dn = pci_device_to_OF_node(pdev); - if (!dn) { - loc = "N/A"; - goto out; + /* Check the root port */ + dn = dn->child; + if (!dn) + goto out; } loc = of_get_property(dn, "ibm,loc-code", NULL); if (!loc) loc = of_get_property(dn, "ibm,slot-location-code", NULL); - if (!loc) - loc = "N/A"; out: - if (pci_is_root_bus(bus) && pdev) - pci_dev_put(pdev); - return loc; + return loc ? loc : "N/A"; } /** -- 2.11.0