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path: root/drivers/edac/edac_mc.c
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Diffstat (limited to 'drivers/edac/edac_mc.c')
-rw-r--r--drivers/edac/edac_mc.c25
1 files changed, 21 insertions, 4 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 78d8c7d6e76..34eb9703ed3 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -42,6 +42,12 @@
static DEFINE_MUTEX(mem_ctls_mutex);
static LIST_HEAD(mc_devices);
+/*
+ * Used to lock EDAC MC to just one module, avoiding two drivers e. g.
+ * apei/ghes and i7core_edac to be used at the same time.
+ */
+static void const *edac_mc_owner;
+
unsigned edac_dimm_info_location(struct dimm_info *dimm, char *buf,
unsigned len)
{
@@ -659,9 +665,9 @@ fail1:
return 1;
}
-static void del_mc_from_global_list(struct mem_ctl_info *mci)
+static int del_mc_from_global_list(struct mem_ctl_info *mci)
{
- atomic_dec(&edac_handlers);
+ int handlers = atomic_dec_return(&edac_handlers);
list_del_rcu(&mci->link);
/* these are for safe removal of devices from global list while
@@ -669,6 +675,8 @@ static void del_mc_from_global_list(struct mem_ctl_info *mci)
*/
synchronize_rcu();
INIT_LIST_HEAD(&mci->link);
+
+ return handlers;
}
/**
@@ -712,6 +720,7 @@ EXPORT_SYMBOL(edac_mc_find);
/* FIXME - should a warning be printed if no error detection? correction? */
int edac_mc_add_mc(struct mem_ctl_info *mci)
{
+ int ret = -EINVAL;
edac_dbg(0, "\n");
#ifdef CONFIG_EDAC_DEBUG
@@ -742,6 +751,11 @@ int edac_mc_add_mc(struct mem_ctl_info *mci)
#endif
mutex_lock(&mem_ctls_mutex);
+ if (edac_mc_owner && edac_mc_owner != mci->mod_name) {
+ ret = -EPERM;
+ goto fail0;
+ }
+
if (add_mc_to_global_list(mci))
goto fail0;
@@ -768,6 +782,8 @@ int edac_mc_add_mc(struct mem_ctl_info *mci)
edac_mc_printk(mci, KERN_INFO, "Giving out device to '%s' '%s':"
" DEV %s\n", mci->mod_name, mci->ctl_name, edac_dev_name(mci));
+ edac_mc_owner = mci->mod_name;
+
mutex_unlock(&mem_ctls_mutex);
return 0;
@@ -776,7 +792,7 @@ fail1:
fail0:
mutex_unlock(&mem_ctls_mutex);
- return 1;
+ return ret;
}
EXPORT_SYMBOL_GPL(edac_mc_add_mc);
@@ -802,7 +818,8 @@ struct mem_ctl_info *edac_mc_del_mc(struct device *dev)
return NULL;
}
- del_mc_from_global_list(mci);
+ if (!del_mc_from_global_list(mci))
+ edac_mc_owner = NULL;
mutex_unlock(&mem_ctls_mutex);
/* flush workq processes */