From: Gavin Shan Date: Thu, 30 Apr 2015 23:14:11 +0000 (+1000) Subject: powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state() X-Git-Tag: firefly_0821_release~176^2~1828^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1ae79b78bc52b910a224f3795122538516e07b5f;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Gavin Shan Tested-by: Carol L. Soto Signed-off-by: Michael Ellerman --- 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; };