1 files changed, 99 insertions, 53 deletions

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index d1e9eb191f2b..cdb81aa73ab7 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)
 {
@@ -441,13 +447,6 @@ struct mem_ctl_info *edac_mc_alloc(unsigned mc_num,
 
 	mci->op_state = OP_ALLOC;
 
-	/* at this point, the root kobj is valid, and in order to
-	 * 'free' the object, then the function:
-	 *      edac_mc_unregister_sysfs_main_kobj() must be called
-	 * which will perform kobj unregistration and the actual free
-	 * will occur during the kobject callback operation
-	 */
-
 	return mci;
 
 error:
@@ -666,9 +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
@@ -676,6 +675,8 @@ static void del_mc_from_global_list(struct mem_ctl_info *mci)
 	 */
 	synchronize_rcu();
 	INIT_LIST_HEAD(&mci->link);
+
+	return handlers;
 }
 
 /**
@@ -719,6 +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
@@ -749,6 +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;
 
@@ -775,6 +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;
 
@@ -783,7 +792,7 @@ fail1:
 
 fail0:
 	mutex_unlock(&mem_ctls_mutex);
-	return 1;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(edac_mc_add_mc);
 
@@ -809,7 +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 */
@@ -907,6 +917,7 @@ const char *edac_layer_name[] = {
 	[EDAC_MC_LAYER_CHANNEL] = "channel",
 	[EDAC_MC_LAYER_SLOT] = "slot",
 	[EDAC_MC_LAYER_CHIP_SELECT] = "csrow",
+	[EDAC_MC_LAYER_ALL_MEM] = "memory",
 };
 EXPORT_SYMBOL_GPL(edac_layer_name);
 
@@ -1054,7 +1065,46 @@ static void edac_ue_error(struct mem_ctl_info *mci,
 	edac_inc_ue_error(mci, enable_per_layer_report, pos, error_count);
 }
 
-#define OTHER_LABEL " or "
+/**
+ * edac_raw_mc_handle_error - reports a memory event to userspace without doing
+ *			      anything to discover the error location
+ *
+ * @type:		severity of the error (CE/UE/Fatal)
+ * @mci:		a struct mem_ctl_info pointer
+ * @e:			error description
+ *
+ * This raw function is used internally by edac_mc_handle_error(). It should
+ * only be called directly when the hardware error come directly from BIOS,
+ * like in the case of APEI GHES driver.
+ */
+void edac_raw_mc_handle_error(const enum hw_event_mc_err_type type,
+			      struct mem_ctl_info *mci,
+			      struct edac_raw_error_desc *e)
+{
+	char detail[80];
+	int pos[EDAC_MAX_LAYERS] = { e->top_layer, e->mid_layer, e->low_layer };
+
+	/* Memory type dependent details about the error */
+	if (type == HW_EVENT_ERR_CORRECTED) {
+		snprintf(detail, sizeof(detail),
+			"page:0x%lx offset:0x%lx grain:%ld syndrome:0x%lx",
+			e->page_frame_number, e->offset_in_page,
+			e->grain, e->syndrome);
+		edac_ce_error(mci, e->error_count, pos, e->msg, e->location, e->label,
+			      detail, e->other_detail, e->enable_per_layer_report,
+			      e->page_frame_number, e->offset_in_page, e->grain);
+	} else {
+		snprintf(detail, sizeof(detail),
+			"page:0x%lx offset:0x%lx grain:%ld",
+			e->page_frame_number, e->offset_in_page, e->grain);
+
+		edac_ue_error(mci, e->error_count, pos, e->msg, e->location, e->label,
+			      detail, e->other_detail, e->enable_per_layer_report);
+	}
+
+
+}
+EXPORT_SYMBOL_GPL(edac_raw_mc_handle_error);
 
 /**
  * edac_mc_handle_error - reports a memory event to userspace
@@ -1086,19 +1136,27 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 			  const char *msg,
 			  const char *other_detail)
 {
-	/* FIXME: too much for stack: move it to some pre-alocated area */
-	char detail[80], location[80];
-	char label[(EDAC_MC_LABEL_LEN + 1 + sizeof(OTHER_LABEL)) * mci->tot_dimms];
 	char *p;
 	int row = -1, chan = -1;
 	int pos[EDAC_MAX_LAYERS] = { top_layer, mid_layer, low_layer };
-	int i;
-	long grain;
-	bool enable_per_layer_report = false;
+	int i, n_labels = 0;
 	u8 grain_bits;
+	struct edac_raw_error_desc *e = &mci->error_desc;
 
 	edac_dbg(3, "MC%d\n", mci->mc_idx);
 
+	/* Fills the error report buffer */
+	memset(e, 0, sizeof (*e));
+	e->error_count = error_count;
+	e->top_layer = top_layer;
+	e->mid_layer = mid_layer;
+	e->low_layer = low_layer;
+	e->page_frame_number = page_frame_number;
+	e->offset_in_page = offset_in_page;
+	e->syndrome = syndrome;
+	e->msg = msg;
+	e->other_detail = other_detail;
+
 	/*
 	 * Check if the event report is consistent and if the memory
 	 * location is known. If it is known, enable_per_layer_report will be
@@ -1121,7 +1179,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 			pos[i] = -1;
 		}
 		if (pos[i] >= 0)
-			enable_per_layer_report = true;
+			e->enable_per_layer_report = true;
 	}
 
 	/*
@@ -1135,8 +1193,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 	 * where each memory belongs to a separate channel within the same
 	 * branch.
 	 */
-	grain = 0;
-	p = label;
+	p = e->label;
 	*p = '\0';
 
 	for (i = 0; i < mci->tot_dimms; i++) {
@@ -1150,8 +1207,8 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 			continue;
 
 		/* get the max grain, over the error match range */
-		if (dimm->grain > grain)
-			grain = dimm->grain;
+		if (dimm->grain > e->grain)
+			e->grain = dimm->grain;
 
 		/*
 		 * If the error is memory-controller wide, there's no need to
@@ -1159,8 +1216,13 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 		 * channel/memory controller/...  may be affected.
 		 * Also, don't show errors for empty DIMM slots.
 		 */
-		if (enable_per_layer_report && dimm->nr_pages) {
-			if (p != label) {
+		if (e->enable_per_layer_report && dimm->nr_pages) {
+			if (n_labels >= EDAC_MAX_LABELS) {
+				e->enable_per_layer_report = false;
+				break;
+			}
+			n_labels++;
+			if (p != e->label) {
 				strcpy(p, OTHER_LABEL);
 				p += strlen(OTHER_LABEL);
 			}
@@ -1187,12 +1249,12 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 		}
 	}
 
-	if (!enable_per_layer_report) {
-		strcpy(label, "any memory");
+	if (!e->enable_per_layer_report) {
+		strcpy(e->label, "any memory");
 	} else {
 		edac_dbg(4, "csrow/channel to increment: (%d,%d)\n", row, chan);
-		if (p == label)
-			strcpy(label, "unknown memory");
+		if (p == e->label)
+			strcpy(e->label, "unknown memory");
 		if (type == HW_EVENT_ERR_CORRECTED) {
 			if (row >= 0) {
 				mci->csrows[row]->ce_count += error_count;
@@ -1205,7 +1267,7 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 	}
 
 	/* Fill the RAM location data */
-	p = location;
+	p = e->location;
 
 	for (i = 0; i < mci->n_layers; i++) {
 		if (pos[i] < 0)
@@ -1215,32 +1277,16 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,
 			     edac_layer_name[mci->layers[i].type],
 			     pos[i]);
 	}
-	if (p > location)
+	if (p > e->location)
 		*(p - 1) = '\0';
 
 	/* Report the error via the trace interface */
-	grain_bits = fls_long(grain) + 1;
-	trace_mc_event(type, msg, label, error_count,
-		       mci->mc_idx, top_layer, mid_layer, low_layer,
-		       PAGES_TO_MiB(page_frame_number) | offset_in_page,
-		       grain_bits, syndrome, other_detail);
+	grain_bits = fls_long(e->grain) + 1;
+	trace_mc_event(type, e->msg, e->label, e->error_count,
+		       mci->mc_idx, e->top_layer, e->mid_layer, e->low_layer,
+		       PAGES_TO_MiB(e->page_frame_number) | e->offset_in_page,
+		       grain_bits, e->syndrome, e->other_detail);
 
-	/* Memory type dependent details about the error */
-	if (type == HW_EVENT_ERR_CORRECTED) {
-		snprintf(detail, sizeof(detail),
-			"page:0x%lx offset:0x%lx grain:%ld syndrome:0x%lx",
-			page_frame_number, offset_in_page,
-			grain, syndrome);
-		edac_ce_error(mci, error_count, pos, msg, location, label,
-			      detail, other_detail, enable_per_layer_report,
-			      page_frame_number, offset_in_page, grain);
-	} else {
-		snprintf(detail, sizeof(detail),
-			"page:0x%lx offset:0x%lx grain:%ld",
-			page_frame_number, offset_in_page, grain);
-
-		edac_ue_error(mci, error_count, pos, msg, location, label,
-			      detail, other_detail, enable_per_layer_report);
-	}
+	edac_raw_mc_handle_error(type, mci, e);
 }
 EXPORT_SYMBOL_GPL(edac_mc_handle_error);