powerpc/eeh: Allow to set maximal frozen times

When PE's frozen count hits maximal allowed frozen times, which is
5 currently, it will be forced to be offline permanently. Once the
PE is removed permanently, rebooting machine is required to bring
the PE back. It's not convienent when testing EEH functionality.

The patch exports the maximal allowed frozen times through debugfs
entry (/sys/kernel/debug/powerpc/eeh_max_freezes).

Requested-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index e1b6d8e17289..3b2252e7731b 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -104,6 +104,13 @@
 int eeh_subsystem_flags;
 EXPORT_SYMBOL(eeh_subsystem_flags);
 
+/*
+ * EEH allowed maximal frozen times. If one particular PE's
+ * frozen count in last hour exceeds this limit, the PE will
+ * be forced to be offline permanently.
+ */
+int eeh_max_freezes = 5;
+
 /* Platform dependent EEH operations */
 struct eeh_ops *eeh_ops = NULL;
 
@@ -1652,8 +1659,22 @@ static int eeh_enable_dbgfs_get(void *data, u64 *val)
 	return 0;
 }
 
+static int eeh_freeze_dbgfs_set(void *data, u64 val)
+{
+	eeh_max_freezes = val;
+	return 0;
+}
+
+static int eeh_freeze_dbgfs_get(void *data, u64 *val)
+{
+	*val = eeh_max_freezes;
+	return 0;
+}
+
 DEFINE_SIMPLE_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get,
 			eeh_enable_dbgfs_set, "0x%llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(eeh_freeze_dbgfs_ops, eeh_freeze_dbgfs_get,
+			eeh_freeze_dbgfs_set, "0x%llx\n");
 #endif
 
 static int __init eeh_init_proc(void)
@@ -1664,6 +1685,9 @@ static int __init eeh_init_proc(void)
 		debugfs_create_file("eeh_enable", 0600,
                                     powerpc_debugfs_root, NULL,
                                     &eeh_enable_dbgfs_ops);
+		debugfs_create_file("eeh_max_freezes", 0600,
+				    powerpc_debugfs_root, NULL,
+				    &eeh_freeze_dbgfs_ops);
 #endif
 	}