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authorGavin Shan <gwshan@linux.vnet.ibm.com>2015-05-01 09:14:11 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2015-05-01 13:52:09 +1000
commit1ae79b78bc52b910a224f3795122538516e07b5f (patch)
treed934d597c7c63219901eec7ab644d960ed48b7a7
parentf32393c943e297b8ae180c8f83d81a156c7d0412 (diff)
powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state()
When asserting reset in pcibios_set_pcie_reset_state(), the PE is enforced to (hardware) frozen state in order to drop unexpected PCI transactions (except PCI config read/write) automatically by hardware during reset, which would cause recursive EEH error. However, the (software) frozen state EEH_PE_ISOLATED is missed. When users get 0xFF from PCI config or MMIO read, EEH_PE_ISOLATED is set in PE state retrival backend. Unfortunately, nobody (the reset handler or the EEH recovery functinality in host) will clear EEH_PE_ISOLATED when the PE has been passed through to guest. The patch sets and clears EEH_PE_ISOLATED properly during reset in function pcibios_set_pcie_reset_state() to fix the issue. Fixes: 28158cd ("Enhance pcibios_set_pcie_reset_state()") Reported-by: Carol L. Soto <clsoto@us.ibm.com> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Tested-by: Carol L. Soto <clsoto@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/kernel/eeh.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 44b480e3a5af..fa046ca6d0fa 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -749,21 +749,24 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat
eeh_unfreeze_pe(pe, false);
eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED);
eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev);
+ eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
break;
case pcie_hot_reset:
+ eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
eeh_ops->reset(pe, EEH_RESET_HOT);
break;
case pcie_warm_reset:
+ eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL);
break;
default:
- eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED);
+ eeh_pe_state_clear(pe, EEH_PE_ISOLATED | EEH_PE_CFG_BLOCKED);
return -EINVAL;
};