diff options
| -rw-r--r-- | drivers/edac/edac_mc.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index 78d8c7d6e76a..34eb9703ed33 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 */ |