edac: reduce stack pressure by using a pre-allocated buffer (c7ef7645) · Commits · EulixOS / Software / Kernel

drivers/edac/edac_mc.c

+48 −33

Original line number	Diff line number	Diff line
		@@ -1065,7 +1065,6 @@ 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_mc_handle_error - reports a memory event to userspace
		@@ -1097,19 +1096,28 @@ 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 detail[80];
		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
		@@ -1132,7 +1140,7 @@ 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;
		}

		/*
		@@ -1146,8 +1154,7 @@ 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++) {
		@@ -1161,8 +1168,8 @@ 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
		@@ -1170,8 +1177,13 @@ 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);
		}
		@@ -1198,12 +1210,12 @@ 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;
		@@ -1216,7 +1228,7 @@ 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)
		@@ -1226,32 +1238,35 @@ 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, 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);
		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, 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",
		page_frame_number, offset_in_page, grain);
		page_frame_number, offset_in_page, e->grain);

		edac_ue_error(mci, error_count, pos, msg, location, label,
		detail, other_detail, enable_per_layer_report);
		edac_ue_error(mci, e->error_count, pos, e->msg, e->location,
		e->label, detail, other_detail,
		e->enable_per_layer_report);
		}
		}
		EXPORT_SYMBOL_GPL(edac_mc_handle_error);

include/linux/edac.h

+56 −0

Original line number	Diff line number	Diff line
		@@ -47,8 +47,18 @@ static inline void opstate_init(void)
		return;
		}

		/* Max length of a DIMM label*/
		#define EDAC_MC_LABEL_LEN 31

		/* Maximum size of the location string */
		#define LOCATION_SIZE 80

		/* Defines the maximum number of labels that can be reported */
		#define EDAC_MAX_LABELS 8

		/* String used to join two or more labels */
		#define OTHER_LABEL " or "

		/**
		* enum dev_type - describe the type of memory DRAM chips used at the stick
		* @DEV_UNKNOWN: Can't be determined, or MC doesn't support detect it
		@@ -553,6 +563,46 @@ struct errcount_attribute_data {
		int layer0, layer1, layer2;
		};

		/**
		* edac_raw_error_desc - Raw error report structure
		* @grain: minimum granularity for an error report, in bytes
		* @error_count: number of errors of the same type
		* @top_layer: top layer of the error (layer[0])
		* @mid_layer: middle layer of the error (layer[1])
		* @low_layer: low layer of the error (layer[2])
		* @page_frame_number: page where the error happened
		* @offset_in_page: page offset
		* @syndrome: syndrome of the error (or 0 if unknown or if
		* the syndrome is not applicable)
		* @msg: error message
		* @location: location of the error
		* @label: label of the affected DIMM(s)
		* @other_detail: other driver-specific detail about the error
		* @enable_per_layer_report: if false, the error affects all layers
		* (typically, a memory controller error)
		*/
		struct edac_raw_error_desc {
		/*
		* NOTE: everything before grain won't be cleaned by
		* edac_raw_error_desc_clean()
		*/
		char location[LOCATION_SIZE];
		char label[(EDAC_MC_LABEL_LEN + 1 + sizeof(OTHER_LABEL)) * EDAC_MAX_LABELS];
		long grain;

		/* the vars below and grain will be cleaned on every new error report */
		u16 error_count;
		int top_layer;
		int mid_layer;
		int low_layer;
		unsigned long page_frame_number;
		unsigned long offset_in_page;
		unsigned long syndrome;
		const char *msg;
		const char *other_detail;
		bool enable_per_layer_report;
		};

		/* MEMORY controller information structure
		*/
		struct mem_ctl_info {
		@@ -660,6 +710,12 @@ struct mem_ctl_info {
		/* work struct for this MC */
		struct delayed_work work;

		/*
		* Used to report an error - by being at the global struct
		* makes the memory allocated by the EDAC core
		*/
		struct edac_raw_error_desc error_desc;

		/* the internal state of this controller instance */
		int op_state;