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authorGavin Shan <gwshan@linux.vnet.ibm.com>2015-08-28 11:57:00 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-09-29 19:26:04 +0200
commitf1ab3c0449ca09b72e6eea7eb077244bfffb7478 (patch)
tree40e3c2b1cbd8eec337e283e0034f63e22d082136 /arch
parent91552f87853c6e50b3968f6514ddb9084acb9f10 (diff)
powerpc/eeh: Fix fenced PHB caused by eeh_slot_error_detail()
commit 259800135c654a098d9f0adfdd3d1f20eef1f231 upstream. 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") Reported-by: Manvanthara B. Puttashankar <mputtash@in.ibm.com> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/eeh.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 1d94bc2a1047..cb565ad0a5b6 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -310,11 +310,26 @@ 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);