From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp04.au.ibm.com (e23smtp04.au.ibm.com [202.81.31.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id B7E1C1A025F for ; Fri, 1 May 2015 09:15:14 +1000 (AEST) Received: from /spool/local by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 1 May 2015 09:15:12 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id D8BB82CE8040 for ; Fri, 1 May 2015 09:15:10 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t3UNF18O6357026 for ; Fri, 1 May 2015 09:15:10 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t3UNEamK024662 for ; Fri, 1 May 2015 09:14:36 +1000 From: Gavin Shan To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state() Date: Fri, 1 May 2015 09:14:11 +1000 Message-Id: <1430435651-13628-1-git-send-email-gwshan@linux.vnet.ibm.com> Cc: clsoto@us.ibm.com, Gavin Shan List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- arch/powerpc/kernel/eeh.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index 65f38d2..b798c86 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; }; -- 2.1.0