On 11/1/24 2:17 AM, shiju.jose@xxxxxxxxxx wrote:
> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
>
> CXL spec 3.1 section 8.2.9.9.11.2 describes the DDR5 ECS (Error Check
> Scrub) control feature.
> The Error Check Scrub (ECS) is a feature defined in JEDEC DDR5 SDRAM
> Specification (JESD79-5) and allows the DRAM to internally read, correct
> single-bit errors, and write back corrected data bits to the DRAM array
> while providing transparency to error counts.
>
> The ECS control allows the requester to change the log entry type, the ECS
> threshold count (provided the request falls within the limits specified in
> DDR5 mode registers), switch between codeword mode and row count mode, and
> reset the ECS counter.
>
> Register with EDAC device driver, which retrieves the ECS attribute
> descriptors from the EDAC ECS and exposes the ECS control attributes to
> userspace via sysfs. For example, the ECS control for the memory media FRU0
> in CXL mem0 device is located at /sys/bus/edac/devices/cxl_mem0/ecs_fru0/
>
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
> ---
> drivers/cxl/core/memfeature.c | 342 +++++++++++++++++++++++++++++++++-
> 1 file changed, 339 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cxl/core/memfeature.c b/drivers/cxl/core/memfeature.c
> index 41298acc01de..e641396a32f5 100644
> --- a/drivers/cxl/core/memfeature.c
> +++ b/drivers/cxl/core/memfeature.c
> @@ -17,7 +17,7 @@
> #include <cxl.h>
> #include <cxlmem.h>
>
> -#define CXL_DEV_NUM_RAS_FEATURES 1
> +#define CXL_DEV_NUM_RAS_FEATURES 2
> #define CXL_DEV_HOUR_IN_SECS 3600
>
> #define CXL_SCRUB_NAME_LEN 128
> @@ -309,15 +309,314 @@ static const struct edac_scrub_ops cxl_ps_scrub_ops = {
> .set_cycle_duration = cxl_patrol_scrub_write_scrub_cycle,
> };
>
> +/* CXL DDR5 ECS control definitions */
> +static const uuid_t cxl_ecs_uuid =
> + UUID_INIT(0xe5b13f22, 0x2328, 0x4a14, 0xb8, 0xba, 0xb9, 0x69, 0x1e, 0x89, 0x33, 0x86);
> +
> +struct cxl_ecs_context {
> + u16 num_media_frus;
> + u16 get_feat_size;
> + u16 set_feat_size;
> + u8 get_version;
> + u8 set_version;
> + u16 set_effects;
> + struct cxl_memdev *cxlmd;
> +};
> +
> +enum {
> + CXL_ECS_PARAM_LOG_ENTRY_TYPE,
> + CXL_ECS_PARAM_THRESHOLD,
> + CXL_ECS_PARAM_MODE,
> + CXL_ECS_PARAM_RESET_COUNTER,
> +};
> +
> +#define CXL_ECS_LOG_ENTRY_TYPE_MASK GENMASK(1, 0)
> +#define CXL_ECS_REALTIME_REPORT_CAP_MASK BIT(0)
> +#define CXL_ECS_THRESHOLD_COUNT_MASK GENMASK(2, 0)
> +#define CXL_ECS_COUNT_MODE_MASK BIT(3)
> +#define CXL_ECS_RESET_COUNTER_MASK BIT(4)
> +
> +enum {
> + ECS_THRESHOLD_256 = 3,
> + ECS_THRESHOLD_1024 = 4,
> + ECS_THRESHOLD_4096 = 5,
> +};
> +
> +static const u16 ecs_supp_threshold[] = {
> + [ECS_THRESHOLD_256] = 256,
> + [ECS_THRESHOLD_1024] = 1024,
> + [ECS_THRESHOLD_4096] = 4096,
> +};
> +
> +enum {
> + ECS_LOG_ENTRY_TYPE_DRAM = 0x0,
> + ECS_LOG_ENTRY_TYPE_MEM_MEDIA_FRU = 0x1,
> +};
> +
> +enum cxl_ecs_count_mode {
> + ECS_MODE_COUNTS_ROWS = 0,
> + ECS_MODE_COUNTS_CODEWORDS = 1,
> +};
> +
> +/**
> + * struct cxl_ecs_params - CXL memory DDR5 ECS parameter data structure.
> + * @log_entry_type: ECS log entry type, per DRAM or per memory media FRU.
> + * @threshold: ECS threshold count per GB of memory cells.
> + * @count_mode: codeword/row count mode
> + * 0 : ECS counts rows with errors
> + * 1 : ECS counts codeword with errors
> + * @reset_counter: [IN] reset ECC counter to default value.
> + */
> +struct cxl_ecs_params {
> + u8 log_entry_type;
> + u16 threshold;
> + enum cxl_ecs_count_mode count_mode;
> + u8 reset_counter;
> +};
> +
> +struct cxl_ecs_fru_rd_attrs {
> + u8 ecs_cap;
> + __le16 ecs_config;
> + u8 ecs_flags;
> +} __packed;
> +
> +struct cxl_ecs_rd_attrs {
> + u8 ecs_log_cap;
> + struct cxl_ecs_fru_rd_attrs fru_attrs[];
> +} __packed;
> +
> +struct cxl_ecs_fru_wr_attrs {
> + __le16 ecs_config;
> +} __packed;
> +
> +struct cxl_ecs_wr_attrs {
> + u8 ecs_log_cap;
> + struct cxl_ecs_fru_wr_attrs fru_attrs[];
> +} __packed;
> +
> +/* CXL DDR5 ECS control functions */
> +static int cxl_mem_ecs_get_attrs(struct device *dev,
> + struct cxl_ecs_context *cxl_ecs_ctx,
> + int fru_id, struct cxl_ecs_params *params)
> +{
> + struct cxl_memdev *cxlmd = cxl_ecs_ctx->cxlmd;
> + struct cxl_dev_state *cxlds = cxlmd->cxlds;
> + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
> + struct cxl_ecs_fru_rd_attrs *fru_rd_attrs;
> + size_t rd_data_size;
> + u8 threshold_index;
> + size_t data_size;
> +
> + rd_data_size = cxl_ecs_ctx->get_feat_size;
> +
> + struct cxl_ecs_rd_attrs *rd_attrs __free(kfree) =
> + kmalloc(rd_data_size, GFP_KERNEL);
> + if (!rd_attrs)
> + return -ENOMEM;
> +
> + params->log_entry_type = 0;
> + params->threshold = 0;
> + params->count_mode = 0;
> + data_size = cxl_get_feature(mds, cxl_ecs_uuid,
> + CXL_GET_FEAT_SEL_CURRENT_VALUE,
> + rd_attrs, rd_data_size);
> + if (!data_size)
> + return -EIO;
> +
> + fru_rd_attrs = rd_attrs->fru_attrs;
> + params->log_entry_type = FIELD_GET(CXL_ECS_LOG_ENTRY_TYPE_MASK,
> + rd_attrs->ecs_log_cap);
> + threshold_index = FIELD_GET(CXL_ECS_THRESHOLD_COUNT_MASK,
> + fru_rd_attrs[fru_id].ecs_config);
> + params->threshold = ecs_supp_threshold[threshold_index];
> + params->count_mode = FIELD_GET(CXL_ECS_COUNT_MODE_MASK,
> + fru_rd_attrs[fru_id].ecs_config);
> + return 0;
> +}
> +
> +static int cxl_mem_ecs_set_attrs(struct device *dev,
> + struct cxl_ecs_context *cxl_ecs_ctx,
> + int fru_id, struct cxl_ecs_params *params,
> + u8 param_type)
> +{
> + struct cxl_memdev *cxlmd = cxl_ecs_ctx->cxlmd;
> + struct cxl_dev_state *cxlds = cxlmd->cxlds;
> + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
> + struct cxl_ecs_fru_rd_attrs *fru_rd_attrs;
> + struct cxl_ecs_fru_wr_attrs *fru_wr_attrs;
> + size_t rd_data_size, wr_data_size;
> + u16 num_media_frus, count;
> + size_t data_size;
> + int ret;
> +
> + num_media_frus = cxl_ecs_ctx->num_media_frus;
> + rd_data_size = cxl_ecs_ctx->get_feat_size;
> + wr_data_size = cxl_ecs_ctx->set_feat_size;
> + struct cxl_ecs_rd_attrs *rd_attrs __free(kfree) =
> + kmalloc(rd_data_size, GFP_KERNEL);
> + if (!rd_attrs)
> + return -ENOMEM;
> +
> + data_size = cxl_get_feature(mds, cxl_ecs_uuid,
> + CXL_GET_FEAT_SEL_CURRENT_VALUE,
> + rd_attrs, rd_data_size);
> + if (!data_size)
> + return -EIO;
> +
> + struct cxl_ecs_wr_attrs *wr_attrs __free(kfree) =
> + kmalloc(wr_data_size, GFP_KERNEL);
> + if (!wr_attrs)
> + return -ENOMEM;
> +
> + /*
> + * Fill writable attributes from the current attributes read
> + * for all the media FRUs.
> + */
> + fru_rd_attrs = rd_attrs->fru_attrs;
> + fru_wr_attrs = wr_attrs->fru_attrs;
> + wr_attrs->ecs_log_cap = rd_attrs->ecs_log_cap;
> + for (count = 0; count < num_media_frus; count++)
> + fru_wr_attrs[count].ecs_config = fru_rd_attrs[count].ecs_config;
> +
> + /* Fill attribute to be set for the media FRU */
> + switch (param_type) {
> + case CXL_ECS_PARAM_LOG_ENTRY_TYPE:
> + if (params->log_entry_type != ECS_LOG_ENTRY_TYPE_DRAM &&
> + params->log_entry_type != ECS_LOG_ENTRY_TYPE_MEM_MEDIA_FRU) {
> + dev_err(dev,
> + "Invalid CXL ECS scrub log entry type(%d) to set\n",
> + params->log_entry_type);
> + dev_err(dev,
> + "Log Entry Type 0: per DRAM 1: per Memory Media FRU\n");
> + return -EINVAL;
> + }
> + wr_attrs->ecs_log_cap = FIELD_PREP(CXL_ECS_LOG_ENTRY_TYPE_MASK,
> + params->log_entry_type);
> + break;
> + case CXL_ECS_PARAM_THRESHOLD:
> + fru_wr_attrs[fru_id].ecs_config &= ~CXL_ECS_THRESHOLD_COUNT_MASK;
> + switch (params->threshold) {
> + case 256:
Why not just use the enums instead?
> + fru_wr_attrs[fru_id].ecs_config |= FIELD_PREP(CXL_ECS_THRESHOLD_COUNT_MASK,
> + ECS_THRESHOLD_256);
> + break;
> + case 1024:
> + fru_wr_attrs[fru_id].ecs_config |= FIELD_PREP(CXL_ECS_THRESHOLD_COUNT_MASK,
> + ECS_THRESHOLD_1024);
> + break;
> + case 4096:
> + fru_wr_attrs[fru_id].ecs_config |= FIELD_PREP(CXL_ECS_THRESHOLD_COUNT_MASK,
> + ECS_THRESHOLD_4096);
> + break;
> + default:
> + dev_err(dev,
> + "Invalid CXL ECS scrub threshold count(%d) to set\n",
> + params->threshold);
> + dev_err(dev,
> + "Supported scrub threshold counts: %u, %u, %u\n",
> + ecs_supp_threshold[ECS_THRESHOLD_256],
> + ecs_supp_threshold[ECS_THRESHOLD_1024],
> + ecs_supp_threshold[ECS_THRESHOLD_4096]);
> + return -EINVAL;
> + }
> + break;
> + case CXL_ECS_PARAM_MODE:
> + if (params->count_mode != ECS_MODE_COUNTS_ROWS &&
> + params->count_mode != ECS_MODE_COUNTS_CODEWORDS) {
> + dev_err(dev,
> + "Invalid CXL ECS scrub mode(%d) to set\n",
> + params->count_mode);
> + dev_err(dev,
> + "Supported ECS Modes: 0: ECS counts rows with errors,"
> + " 1: ECS counts codewords with errors\n");
> + return -EINVAL;
> + }
> + fru_wr_attrs[fru_id].ecs_config &= ~CXL_ECS_COUNT_MODE_MASK;
> + fru_wr_attrs[fru_id].ecs_config |= FIELD_PREP(CXL_ECS_COUNT_MODE_MASK,
> + params->count_mode);
> + break;
> + case CXL_ECS_PARAM_RESET_COUNTER:
> + if (params->reset_counter != 1)
Compare with magic number?
> + return -EINVAL;
> +
> + fru_wr_attrs[fru_id].ecs_config &= ~CXL_ECS_RESET_COUNTER_MASK;
> + fru_wr_attrs[fru_id].ecs_config |= FIELD_PREP(CXL_ECS_RESET_COUNTER_MASK,
> + params->reset_counter);
> + break;
> + default:
> + dev_err(dev, "Invalid CXL ECS parameter to set\n");
> + return -EINVAL;
> + }
> +
> + ret = cxl_set_feature(mds, cxl_ecs_uuid, cxl_ecs_ctx->set_version,
> + wr_attrs, wr_data_size,
> + CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET);
> + if (ret) {
> + dev_err(dev, "CXL ECS set feature failed ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +#define CXL_ECS_GET_ATTR(attrib) \
> +static int cxl_ecs_get_##attrib(struct device *dev, void *drv_data, \
> + int fru_id, u32 *val) \
> +{ \
> + struct cxl_ecs_context *ctx = drv_data; \
> + struct cxl_ecs_params params; \
> + int ret; \
> + \
> + ret = cxl_mem_ecs_get_attrs(dev, ctx, fru_id, ¶ms); \
> + if (ret) \
> + return ret; \
> + \
> + *val = params.attrib; \
> + \
> + return 0; \
> +}
> +
> +CXL_ECS_GET_ATTR(log_entry_type)
> +CXL_ECS_GET_ATTR(count_mode)
> +CXL_ECS_GET_ATTR(threshold)
> +
> +#define CXL_ECS_SET_ATTR(attrib, param_type) \
> +static int cxl_ecs_set_##attrib(struct device *dev, void *drv_data, \
> + int fru_id, u32 val) \
> +{ \
> + struct cxl_ecs_context *ctx = drv_data; \
> + struct cxl_ecs_params params = { \
> + .attrib = val, \
> + }; \
> + \
> + return cxl_mem_ecs_set_attrs(dev, ctx, fru_id, ¶ms, (param_type)); \
> +}
> +CXL_ECS_SET_ATTR(log_entry_type, CXL_ECS_PARAM_LOG_ENTRY_TYPE)
> +CXL_ECS_SET_ATTR(count_mode, CXL_ECS_PARAM_MODE)
> +CXL_ECS_SET_ATTR(reset_counter, CXL_ECS_PARAM_RESET_COUNTER)
> +CXL_ECS_SET_ATTR(threshold, CXL_ECS_PARAM_THRESHOLD)
> +
> +static const struct edac_ecs_ops cxl_ecs_ops = {
> + .get_log_entry_type = cxl_ecs_get_log_entry_type,
> + .set_log_entry_type = cxl_ecs_set_log_entry_type,
> + .get_mode = cxl_ecs_get_count_mode,
> + .set_mode = cxl_ecs_set_count_mode,
> + .reset = cxl_ecs_set_reset_counter,
> + .get_threshold = cxl_ecs_get_threshold,
> + .set_threshold = cxl_ecs_set_threshold,
> +};
> +
> int cxl_mem_ras_features_init(struct cxl_memdev *cxlmd, struct cxl_region *cxlr)
> {
> struct edac_dev_feature ras_features[CXL_DEV_NUM_RAS_FEATURES];
> struct cxl_patrol_scrub_context *cxl_ps_ctx;
> char cxl_dev_name[CXL_SCRUB_NAME_LEN];
> + struct cxl_ecs_context *cxl_ecs_ctx;
> struct cxl_feat_entry feat_entry;
> struct cxl_memdev_state *mds;
> struct cxl_dev_state *cxlds;
> int num_ras_features = 0;
> + int num_media_frus;
> u8 scrub_inst = 0;
> int rc, i;
>
> @@ -344,10 +643,10 @@ int cxl_mem_ras_features_init(struct cxl_memdev *cxlmd, struct cxl_region *cxlr)
> rc = cxl_get_supported_feature_entry(mds, &cxl_patrol_scrub_uuid,
> &feat_entry);
> if (rc < 0)
> - return rc;
> + goto feat_scrub_done;
>
> if (!(feat_entry.attr_flags & CXL_FEAT_ENTRY_FLAG_CHANGABLE))
> - return -EOPNOTSUPP;
> + goto feat_scrub_done;
> }
>
> cxl_ps_ctx = devm_kzalloc(&cxlmd->dev, sizeof(*cxl_ps_ctx), GFP_KERNEL);
> @@ -378,6 +677,43 @@ int cxl_mem_ras_features_init(struct cxl_memdev *cxlmd, struct cxl_region *cxlr)
> ras_features[num_ras_features].ctx = cxl_ps_ctx;
> num_ras_features++;
>
> +feat_scrub_done:
> + if (!cxlr) {
> + rc = cxl_get_supported_feature_entry(mds, &cxl_ecs_uuid,
> + &feat_entry);
> + if (rc < 0)
> + goto feat_ecs_done;
> +
> + if (!(feat_entry.attr_flags & CXL_FEAT_ENTRY_FLAG_CHANGABLE))
> + goto feat_ecs_done;
> + num_media_frus = (feat_entry.get_feat_size - sizeof(struct cxl_ecs_rd_attrs)) /
> + sizeof(struct cxl_ecs_fru_rd_attrs);
> + if (!num_media_frus)
> + goto feat_ecs_done;
> +
> + cxl_ecs_ctx = devm_kzalloc(&cxlmd->dev, sizeof(*cxl_ecs_ctx),
> + GFP_KERNEL);
> + if (!cxl_ecs_ctx)
> + goto feat_ecs_done;
> + *cxl_ecs_ctx = (struct cxl_ecs_context) {
> + .get_feat_size = feat_entry.get_feat_size,
> + .set_feat_size = feat_entry.set_feat_size,
> + .get_version = feat_entry.get_feat_ver,
> + .set_version = feat_entry.set_feat_ver,
> + .set_effects = feat_entry.set_effects,
> + .num_media_frus = num_media_frus,
> + .cxlmd = cxlmd,
> + };
> +
> + ras_features[num_ras_features].ft_type = RAS_FEAT_ECS;
> + ras_features[num_ras_features].ecs_ops = &cxl_ecs_ops;
> + ras_features[num_ras_features].ctx = cxl_ecs_ctx;
> + ras_features[num_ras_features].ecs_info.num_media_frus =
> + num_media_frus;
> + num_ras_features++;
> + }
The function is getting awfully large. Maybe a helper function?
DJ
> +
> +feat_ecs_done:
> return edac_dev_register(&cxlmd->dev, cxl_dev_name, NULL,
> num_ras_features, ras_features);
> }
