[v14,03/14] EDAC: Add ECS control feature

diff --git a/Documentation/ABI/testing/sysfs-edac-ecs b/Documentation/ABI/testing/sysfs-edac-ecs
new file mode 100644
index 000000000000..b94cc09f9222
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-edac-ecs
@@ -0,0 +1,76 @@ 
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		The sysfs EDAC bus devices /<dev-name>/ecs_fruX subdirectory
+		belongs to the memory media ECS (Error Check Scrub) control
+		feature, where <dev-name> directory corresponds to a device
+		registered with the EDAC device driver for the ECS feature.
+		/ecs_fruX belongs to the media FRUs (Field Replaceable Unit)
+		under the memory device.
+		The sysfs ECS attr nodes are only present if the client
+		driver has implemented the corresponding attr callback
+		function and passed in ops to the EDAC RAS feature driver
+		during registration.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/log_entry_type
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RW) The log entry type of how the DDR5 ECS log is reported.
+		00b - per DRAM.
+		01b - per memory media FRU.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/log_entry_type_per_dram
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RO) True if current log entry type is per DRAM.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/log_entry_type_per_memory_media
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RO) True if current log entry type is per memory media FRU.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/mode
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RW) The mode of how the DDR5 ECS counts the errors.
+		0 - ECS counts rows with errors.
+		1 - ECS counts codewords with errors.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/mode_counts_rows
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RO) True if current mode is ECS counts rows with errors.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/mode_counts_codewords
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RO) True if current mode is ECS counts codewords with errors.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/reset
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(WO) ECS reset ECC counter.
+		1 - reset ECC counter to the default value.
+
+What:		/sys/bus/edac/devices/<dev-name>/ecs_fruX/threshold
+Date:		Jan 2025
+KernelVersion:	6.13
+Contact:	linux-edac@vger.kernel.org
+Description:
+		(RW) ECS threshold count per gigabits of memory cells.
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 188501e676c7..b24c2c112d9c 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -10,7 +10,7 @@  obj-$(CONFIG_EDAC)			:= edac_core.o
 
 edac_core-y	:= edac_mc.o edac_device.o edac_mc_sysfs.o
 edac_core-y	+= edac_module.o edac_device_sysfs.o wq.o
-edac_core-y	+= scrub.o
+edac_core-y	+= scrub.o ecs.o
 
 edac_core-$(CONFIG_EDAC_DEBUG)		+= debugfs.o
 
diff --git a/drivers/edac/ecs.c b/drivers/edac/ecs.c
new file mode 100755
index 000000000000..a2b64d7bf6b6
--- /dev/null
+++ b/drivers/edac/ecs.c
@@ -0,0 +1,240 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic ECS driver in order to support control the on die
+ * error check scrub (e.g. DDR5 ECS). The common sysfs ECS
+ * interface abstracts the control of an arbitrary ECS
+ * functionality to a common set of functions.
+ *
+ * Copyright (c) 2024 HiSilicon Limited.
+ */
+
+#define pr_fmt(fmt)     "EDAC ECS: " fmt
+
+#include <linux/edac.h>
+
+#define EDAC_ECS_FRU_NAME "ecs_fru"
+
+enum edac_ecs_attributes {
+	ECS_LOG_ENTRY_TYPE,
+	ECS_LOG_ENTRY_TYPE_PER_DRAM,
+	ECS_LOG_ENTRY_TYPE_PER_MEMORY_MEDIA,
+	ECS_MODE,
+	ECS_MODE_COUNTS_ROWS,
+	ECS_MODE_COUNTS_CODEWORDS,
+	ECS_RESET,
+	ECS_THRESHOLD,
+	ECS_MAX_ATTRS
+};
+
+struct edac_ecs_dev_attr {
+	struct device_attribute dev_attr;
+	int fru_id;
+};
+
+struct edac_ecs_fru_context {
+	char name[EDAC_FEAT_NAME_LEN];
+	struct edac_ecs_dev_attr ecs_dev_attr[ECS_MAX_ATTRS];
+	struct attribute *ecs_attrs[ECS_MAX_ATTRS + 1];
+	struct attribute_group group;
+};
+
+struct edac_ecs_context {
+	u16 num_media_frus;
+	struct edac_ecs_fru_context *fru_ctxs;
+};
+
+#define TO_ECS_DEV_ATTR(_dev_attr)	\
+	container_of(_dev_attr, struct edac_ecs_dev_attr, dev_attr)
+
+#define EDAC_ECS_ATTR_SHOW(attrib, cb, type, format)				\
+static ssize_t attrib##_show(struct device *ras_feat_dev,			\
+			     struct device_attribute *attr, char *buf)		\
+{										\
+	struct edac_ecs_dev_attr *ecs_dev_attr = TO_ECS_DEV_ATTR(attr);		\
+	struct edac_dev_feat_ctx *ctx = dev_get_drvdata(ras_feat_dev);		\
+	const struct edac_ecs_ops *ops = ctx->ecs.ecs_ops;			\
+	type data;								\
+	int ret;								\
+										\
+	ret = ops->cb(ras_feat_dev->parent, ctx->ecs.private,			\
+		      ecs_dev_attr->fru_id, &data);				\
+	if (ret)								\
+		return ret;							\
+										\
+	return sysfs_emit(buf, format, data);					\
+}
+
+EDAC_ECS_ATTR_SHOW(log_entry_type, get_log_entry_type, u32, "%u\n")
+EDAC_ECS_ATTR_SHOW(log_entry_type_per_dram, get_log_entry_type_per_dram, u32, "%u\n")
+EDAC_ECS_ATTR_SHOW(log_entry_type_per_memory_media, get_log_entry_type_per_memory_media,
+		   u32, "%u\n")
+EDAC_ECS_ATTR_SHOW(mode, get_mode, u32, "%u\n")
+EDAC_ECS_ATTR_SHOW(mode_counts_rows, get_mode_counts_rows, u32, "%u\n")
+EDAC_ECS_ATTR_SHOW(mode_counts_codewords, get_mode_counts_codewords, u32, "%u\n")
+EDAC_ECS_ATTR_SHOW(threshold, get_threshold, u32, "%u\n")
+
+#define EDAC_ECS_ATTR_STORE(attrib, cb, type, conv_func)			\
+static ssize_t attrib##_store(struct device *ras_feat_dev,			\
+			      struct device_attribute *attr,			\
+			      const char *buf, size_t len)			\
+{										\
+	struct edac_ecs_dev_attr *ecs_dev_attr = TO_ECS_DEV_ATTR(attr);		\
+	struct edac_dev_feat_ctx *ctx = dev_get_drvdata(ras_feat_dev);		\
+	const struct edac_ecs_ops *ops = ctx->ecs.ecs_ops;			\
+	type data;								\
+	int ret;								\
+										\
+	ret = conv_func(buf, 0, &data);						\
+	if (ret < 0)								\
+		return ret;							\
+										\
+	ret = ops->cb(ras_feat_dev->parent, ctx->ecs.private,			\
+		      ecs_dev_attr->fru_id, data);				\
+	if (ret)								\
+		return ret;							\
+										\
+	return len;								\
+}
+
+EDAC_ECS_ATTR_STORE(log_entry_type, set_log_entry_type, unsigned long, kstrtoul)
+EDAC_ECS_ATTR_STORE(mode, set_mode, unsigned long, kstrtoul)
+EDAC_ECS_ATTR_STORE(reset, reset, unsigned long, kstrtoul)
+EDAC_ECS_ATTR_STORE(threshold, set_threshold, unsigned long, kstrtoul)
+
+static umode_t ecs_attr_visible(struct kobject *kobj, struct attribute *a, int attr_id)
+{
+	struct device *ras_feat_dev = kobj_to_dev(kobj);
+	struct edac_dev_feat_ctx *ctx = dev_get_drvdata(ras_feat_dev);
+	const struct edac_ecs_ops *ops = ctx->ecs.ecs_ops;
+
+	switch (attr_id) {
+	case ECS_LOG_ENTRY_TYPE:
+		if (ops->get_log_entry_type)  {
+			if (ops->set_log_entry_type)
+				return a->mode;
+			else
+				return 0444;
+		}
+		break;
+	case ECS_LOG_ENTRY_TYPE_PER_DRAM:
+		if (ops->get_log_entry_type_per_dram)
+			return a->mode;
+		break;
+	case ECS_LOG_ENTRY_TYPE_PER_MEMORY_MEDIA:
+		if (ops->get_log_entry_type_per_memory_media)
+			return a->mode;
+		break;
+	case ECS_MODE:
+		if (ops->get_mode) {
+			if (ops->set_mode)
+				return a->mode;
+			else
+				return 0444;
+		}
+		break;
+	case ECS_MODE_COUNTS_ROWS:
+		if (ops->get_mode_counts_rows)
+			return a->mode;
+		break;
+	case ECS_MODE_COUNTS_CODEWORDS:
+		if (ops->get_mode_counts_codewords)
+			return a->mode;
+		break;
+	case ECS_RESET:
+		if (ops->reset)
+			return a->mode;
+		break;
+	case ECS_THRESHOLD:
+		if (ops->get_threshold) {
+			if (ops->set_threshold)
+				return a->mode;
+			else
+				return 0444;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+#define EDAC_ECS_ATTR_RO(_name, _fru_id)       \
+	((struct edac_ecs_dev_attr) { .dev_attr = __ATTR_RO(_name), \
+				     .fru_id = _fru_id })
+
+#define EDAC_ECS_ATTR_WO(_name, _fru_id)       \
+	((struct edac_ecs_dev_attr) { .dev_attr = __ATTR_WO(_name), \
+				     .fru_id = _fru_id })
+
+#define EDAC_ECS_ATTR_RW(_name, _fru_id)       \
+	((struct edac_ecs_dev_attr) { .dev_attr = __ATTR_RW(_name), \
+				     .fru_id = _fru_id })
+
+static int ecs_create_desc(struct device *ecs_dev,
+			   const struct attribute_group **attr_groups, u16 num_media_frus)
+{
+	struct edac_ecs_context *ecs_ctx;
+	u32 fru;
+
+	ecs_ctx = devm_kzalloc(ecs_dev, sizeof(*ecs_ctx), GFP_KERNEL);
+	if (!ecs_ctx)
+		return -ENOMEM;
+
+	ecs_ctx->num_media_frus = num_media_frus;
+	ecs_ctx->fru_ctxs = devm_kcalloc(ecs_dev, num_media_frus,
+					 sizeof(*ecs_ctx->fru_ctxs),
+					 GFP_KERNEL);
+	if (!ecs_ctx->fru_ctxs)
+		return -ENOMEM;
+
+	for (fru = 0; fru < num_media_frus; fru++) {
+		struct edac_ecs_fru_context *fru_ctx = &ecs_ctx->fru_ctxs[fru];
+		struct attribute_group *group = &fru_ctx->group;
+		int i;
+
+		fru_ctx->ecs_dev_attr[ECS_LOG_ENTRY_TYPE] = EDAC_ECS_ATTR_RW(log_entry_type, fru);
+		fru_ctx->ecs_dev_attr[ECS_LOG_ENTRY_TYPE_PER_DRAM] =
+					EDAC_ECS_ATTR_RO(log_entry_type_per_dram, fru);
+		fru_ctx->ecs_dev_attr[ECS_LOG_ENTRY_TYPE_PER_MEMORY_MEDIA] =
+					EDAC_ECS_ATTR_RO(log_entry_type_per_memory_media, fru);
+		fru_ctx->ecs_dev_attr[ECS_MODE] = EDAC_ECS_ATTR_RW(mode, fru);
+		fru_ctx->ecs_dev_attr[ECS_MODE_COUNTS_ROWS] =
+					EDAC_ECS_ATTR_RO(mode_counts_rows, fru);
+		fru_ctx->ecs_dev_attr[ECS_MODE_COUNTS_CODEWORDS] =
+					EDAC_ECS_ATTR_RO(mode_counts_codewords, fru);
+		fru_ctx->ecs_dev_attr[ECS_RESET] = EDAC_ECS_ATTR_WO(reset, fru);
+		fru_ctx->ecs_dev_attr[ECS_THRESHOLD] = EDAC_ECS_ATTR_RW(threshold, fru);
+		for (i = 0; i < ECS_MAX_ATTRS; i++)
+			fru_ctx->ecs_attrs[i] = &fru_ctx->ecs_dev_attr[i].dev_attr.attr;
+
+		sprintf(fru_ctx->name, "%s%d", EDAC_ECS_FRU_NAME, fru);
+		group->name = fru_ctx->name;
+		group->attrs = fru_ctx->ecs_attrs;
+		group->is_visible  = ecs_attr_visible;
+
+		attr_groups[fru] = group;
+	}
+
+	return 0;
+}
+
+/**
+ * edac_ecs_get_desc - get EDAC ECS descriptors
+ * @ecs_dev: client device, supports ECS feature
+ * @attr_groups: pointer to attribute group container
+ * @num_media_frus: number of media FRUs in the device
+ *
+ * Return:
+ *  * %0	- Success.
+ *  * %-EINVAL	- Invalid parameters passed.
+ *  * %-ENOMEM	- Dynamic memory allocation failed.
+ */
+int edac_ecs_get_desc(struct device *ecs_dev,
+		      const struct attribute_group **attr_groups, u16 num_media_frus)
+{
+	if (!ecs_dev || !attr_groups || !num_media_frus)
+		return -EINVAL;
+
+	return ecs_create_desc(ecs_dev, attr_groups, num_media_frus);
+}
diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index 91552271b34a..5fc3ec7f25eb 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -626,6 +626,9 @@  int edac_dev_register(struct device *parent, char *name,
 			attr_gcnt++;
 			scrub_cnt++;
 			break;
+		case RAS_FEAT_ECS:
+			attr_gcnt += ras_features[feat].ecs_info.num_media_frus;
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -667,6 +670,18 @@  int edac_dev_register(struct device *parent, char *name,
 			scrub_inst++;
 			attr_gcnt++;
 			break;
+		case RAS_FEAT_ECS:
+			if (!ras_features->ecs_ops)
+				goto data_mem_free;
+			dev_data = &ctx->ecs;
+			dev_data->ecs_ops = ras_features->ecs_ops;
+			dev_data->private = ras_features->ctx;
+			ret = edac_ecs_get_desc(parent, &ras_attr_groups[attr_gcnt],
+						ras_features->ecs_info.num_media_frus);
+			if (ret)
+				goto data_mem_free;
+			attr_gcnt += ras_features->ecs_info.num_media_frus;
+			break;
 		default:
 			ret = -EINVAL;
 			goto data_mem_free;
diff --git a/include/linux/edac.h b/include/linux/edac.h
index 3620a09c0476..077d3c252e99 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -669,6 +669,7 @@  static inline struct dimm_info *edac_get_dimm(struct mem_ctl_info *mci,
 /* RAS feature type */
 enum edac_dev_feat {
 	RAS_FEAT_SCRUB,
+	RAS_FEAT_ECS,
 	RAS_FEAT_MAX
 };
 
@@ -702,9 +703,50 @@  int edac_scrub_get_desc(struct device *scrub_dev,
 			const struct attribute_group **attr_groups,
 			u8 instance);
 
+/**
+ * struct edac_ecs_ops - ECS device operations (all elements optional)
+ * @get_log_entry_type: read the log entry type value.
+ * @set_log_entry_type: set the log entry type value.
+ * @get_log_entry_type_per_dram: read the log entry type per dram value.
+ * @get_log_entry_type_memory_media: read the log entry type per memory media value.
+ * @get_mode: read the mode value.
+ * @set_mode: set the mode value.
+ * @get_mode_counts_rows: read the mode counts rows value.
+ * @get_mode_counts_codewords: read the mode counts codewords value.
+ * @reset: reset the ECS counter.
+ * @get_threshold: read the threshold count per gigabits of memory cells.
+ * @set_threshold: set the threshold count per gigabits of memory cells.
+ */
+struct edac_ecs_ops {
+	int (*get_log_entry_type)(struct device *dev, void *drv_data, int fru_id, u32 *val);
+	int (*set_log_entry_type)(struct device *dev, void *drv_data, int fru_id, u32 val);
+	int (*get_log_entry_type_per_dram)(struct device *dev, void *drv_data,
+					   int fru_id, u32 *val);
+	int (*get_log_entry_type_per_memory_media)(struct device *dev, void *drv_data,
+						   int fru_id, u32 *val);
+	int (*get_mode)(struct device *dev, void *drv_data, int fru_id, u32 *val);
+	int (*set_mode)(struct device *dev, void *drv_data, int fru_id, u32 val);
+	int (*get_mode_counts_rows)(struct device *dev, void *drv_data, int fru_id, u32 *val);
+	int (*get_mode_counts_codewords)(struct device *dev, void *drv_data, int fru_id, u32 *val);
+	int (*reset)(struct device *dev, void *drv_data, int fru_id, u32 val);
+	int (*get_threshold)(struct device *dev, void *drv_data, int fru_id, u32 *threshold);
+	int (*set_threshold)(struct device *dev, void *drv_data, int fru_id, u32 threshold);
+};
+
+struct edac_ecs_ex_info {
+	u16 num_media_frus;
+};
+
+int edac_ecs_get_desc(struct device *ecs_dev,
+		      const struct attribute_group **attr_groups,
+		      u16 num_media_frus);
+
 /* EDAC device feature information structure */
 struct edac_dev_data {
-	const struct edac_scrub_ops *scrub_ops;
+	union {
+		const struct edac_scrub_ops *scrub_ops;
+		const struct edac_ecs_ops *ecs_ops;
+	};
 	u8 instance;
 	void *private;
 };
@@ -713,13 +755,18 @@  struct edac_dev_feat_ctx {
 	struct device dev;
 	void *private;
 	struct edac_dev_data *scrub;
+	struct edac_dev_data ecs;
 };
 
 struct edac_dev_feature {
 	enum edac_dev_feat ft_type;
 	u8 instance;
-	const struct edac_scrub_ops *scrub_ops;
+	union {
+		const struct edac_scrub_ops *scrub_ops;
+		const struct edac_ecs_ops *ecs_ops;
+	};
 	void *ctx;
+	struct edac_ecs_ex_info ecs_info;
 };
 
 int edac_dev_register(struct device *parent, char *dev_name,