* [PATCH] powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state()
@ 2015-04-30 23:14 Gavin Shan
0 siblings, 0 replies; only message in thread
From: Gavin Shan @ 2015-04-30 23:14 UTC (permalink / raw)
To: linuxppc-dev; +Cc: clsoto, Gavin Shan
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>
---
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
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2015-04-30 23:15 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-04-30 23:14 [PATCH] powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state() Gavin Shan
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).