The config space of some PCI devices can't be accessed when their
PEs are in frozen state. Otherwise, fenced PHB might be seen.
Those PEs are identified with flag EEH_PE_CFG_RESTRICTED, meaing
EEH_PE_CFG_BLOCKED is set automatically when the PE is put to
frozen state (EEH_PE_ISOLATED). eeh_slot_error_detail() restores
PCI device BARs with eeh_pe_restore_bars(), which then calls
eeh_ops->restore_config() to reinitialize the PCI device in
(OPAL) firmware. eeh_ops->restore_config() produces PCI config
access that causes fenced PHB. The problem was reported on below
adapter:
0001:01:00.0 0200: 14e4:168e (rev 10)
0001:01:00.0 Ethernet controller: Broadcom Corporation \
NetXtreme II BCM57810 10 Gigabit Ethernet (rev 10)
This fixes the issue by skipping eeh_pe_restore_bars() in
eeh_slot_error_detail() when EEH_PE_CFG_BLOCKED is set for the PE.
Fixes: b6541db1 ("powerpc/eeh: Block PCI config access upon frozen PE")
Cc: sta...@vger.kernel.org # v4.0+
Reported-by: Manvanthara B. Puttashankar <mputt...@in.ibm.com>
Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/eeh.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index af9b597..c7c6e5d 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -308,11 +308,26 @@ void eeh_slot_error_detail(struct eeh_pe *pe, int
severity)
if (!(pe->type & EEH_PE_PHB)) {
if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG))
eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
+
+ /*
+ * The config space of some PCI devices can't be accessed
+ * when their PEs are in frozen state. Otherwise, fenced
+ * PHB might be seen. Those PEs are identified with flag
+ * EEH_PE_CFG_RESTRICTED, indicating EEH_PE_CFG_BLOCKED
+ * is set automatically when the PE is put to EEH_PE_ISOLATED.
+ *
+ * Restoring BARs possibly triggers PCI config access in
+ * (OPAL) firmware and then causes fenced PHB. If the
+ * PCI config is blocked with flag EEH_PE_CFG_BLOCKED, it's
+ * pointless to restore BARs and dump config space.
+ */
eeh_ops->configure_bridge(pe);
- eeh_pe_restore_bars(pe);
+ if (!(pe->state & EEH_PE_CFG_BLOCKED)) {
+ eeh_pe_restore_bars(pe);
- pci_regs_buf[0] = 0;
- eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen);
+ pci_regs_buf[0] = 0;
+ eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen);
+ }
}
eeh_ops->get_log(pe, severity, pci_regs_buf, loglen);
--
2.1.0
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