Re: [PATCH v12 10/17] cxl/memfeature: Add CXL memory device patrol scrub control feature

From: Fan Ni
Date: Tue Oct 01 2024 - 15:47:30 EST

On Wed, Sep 11, 2024 at 10:04:39AM +0100, shiju.jose@xxxxxxxxxx wrote:
> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
>
> CXL spec 3.1 section 8.2.9.9.11.1 describes the device patrol scrub control
> feature. The device patrol scrub proactively locates and makes corrections
> to errors in regular cycle.
>
> Allow specifying the number of hours within which the patrol scrub must be
> completed, subject to minimum and maximum limits reported by the device.
> Also allow disabling scrub allowing trade-off error rates against
> performance.
>
> Add support for CXL memory device based patrol scrub control.
> Register with EDAC RAS control feature driver, which gets the scrub attr
> descriptors from the EDAC scrub and expose sysfs scrub control attributes
> to the userspace.
> For example CXL device based scrub control for the CXL mem0 device is
> exposed in /sys/bus/edac/devices/cxl_mem0/scrub*/
>
> Also add support for region based CXL memory patrol scrub control.
> CXL memory region may be interleaved across one or more CXL memory devices.
> For example region based scrub control for CXL region1 is exposed in
> /sys/bus/edac/devices/cxl_region1/scrub*/
>
> Open Questions:
> Q1: CXL 3.1 spec defined patrol scrub control feature at CXL memory devices
> with supporting set scrub cycle and enable/disable scrub. but not based on
> HPA range. Thus presently scrub control for a region is implemented based
> on all associated CXL memory devices.
> What is the exact use case for the CXL region based scrub control?
> How the HPA range, which Dan asked for region based scrubbing is used?
> Does spec change is required for patrol scrub control feature with support
> for setting the HPA range?
>
> Q2: Both CXL device based and CXL region based scrub control would be
> enabled at the same time in a system?
>
> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
> ---
> Documentation/edac/edac-scrub.rst | 74 ++++++
> drivers/cxl/Kconfig | 18 ++
> drivers/cxl/core/Makefile | 1 +
> drivers/cxl/core/memfeature.c | 372 ++++++++++++++++++++++++++++++
> drivers/cxl/core/region.c | 6 +
> drivers/cxl/cxlmem.h | 7 +
> drivers/cxl/mem.c | 4 +
> 7 files changed, 482 insertions(+)
> create mode 100644 Documentation/edac/edac-scrub.rst
> create mode 100644 drivers/cxl/core/memfeature.c
>
> diff --git a/Documentation/edac/edac-scrub.rst b/Documentation/edac/edac-scrub.rst
> new file mode 100644
> index 000000000000..243035957e99
> --- /dev/null
> +++ b/Documentation/edac/edac-scrub.rst
> @@ -0,0 +1,74 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +===================
> +EDAC Scrub control
> +===================
> +
> +Copyright (c) 2024 HiSilicon Limited.
> +
> +:Author: Shiju Jose <shiju.jose@xxxxxxxxxx>
> +:License: The GNU Free Documentation License, Version 1.2
> + (dual licensed under the GPL v2)
> +:Original Reviewers:
> +
> +- Written for: 6.12
> +- Updated for:
> +
> +Introduction
> +------------
> +The EDAC enhancement for RAS featurues exposes interfaces for controlling
> +the memory scrubbers in the system. The scrub device drivers in the
> +system register with the EDAC scrub. The driver exposes the
> +scrub controls to user in the sysfs.
> +
> +The File System
> +---------------
> +
> +The control attributes of the registered scrubber instance could be
> +accessed in the /sys/bus/edac/devices/<dev-name>/scrub*/
> +
> +sysfs
> +-----
> +
> +Sysfs files are documented in
> +`Documentation/ABI/testing/sysfs-edac-scrub-control`.
> +
> +Example
> +-------
> +
> +The usage takes the form shown in this example::
> +
> +1. CXL memory device patrol scrubber
> +1.1 device based
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_mem0/scrub0/min_cycle_duration
> +3600
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_mem0/scrub0/max_cycle_duration
> +918000
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_mem0/scrub0/current_cycle_duration
> +43200
> +root@localhost:~# echo 54000 > /sys/bus/edac/devices/cxl_mem0/scrub0/current_cycle_duration
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_mem0/scrub0/current_cycle_duration
> +54000
> +root@localhost:~# echo 1 > /sys/bus/edac/devices/cxl_mem0/scrub0/enable_background
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_mem0/scrub0/enable_background
> +1
> +root@localhost:~# echo 0 > /sys/bus/edac/devices/cxl_mem0/scrub0/enable_background
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_mem0/scrub0/enable_background
> +0
> +
> +1.2. region based
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_region0/scrub0/min_cycle_duration
> +3600
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_region0/scrub0/max_cycle_duration
> +918000
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_region0/scrub0/current_cycle_duration
> +43200
> +root@localhost:~# echo 54000 > /sys/bus/edac/devices/cxl_region0/scrub0/current_cycle_duration
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_region0/scrub0/current_cycle_duration
> +54000
> +root@localhost:~# echo 1 > /sys/bus/edac/devices/cxl_region0/scrub0/enable_background
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_region0/scrub0/enable_background
> +1
> +root@localhost:~# echo 0 > /sys/bus/edac/devices/cxl_region0/scrub0/enable_background
> +root@localhost:~# cat /sys/bus/edac/devices/cxl_region0/scrub0/enable_background
> +0
> diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
> index 99b5c25be079..394bdbc4de87 100644
> --- a/drivers/cxl/Kconfig
> +++ b/drivers/cxl/Kconfig
> @@ -145,4 +145,22 @@ config CXL_REGION_INVALIDATION_TEST
> If unsure, or if this kernel is meant for production environments,
> say N.
>
> +config CXL_RAS_FEAT
> + bool "CXL: Memory RAS features"

If EDAC is compiled as module, it will lead to a situlation where EDAC is a
module, and CXL_RAS_FEAT is compiled in, and causing compile issue like below

----
CC [M] arch/arm64/crypto/aes-neon-blk.mod.o
CC [M] arch/arm64/crypto/sha512-arm64.mod.o
CC [M] arch/arm64/crypto/chacha-neon.mod.o
CC [M] arch/arm64/crypto/aes-neon-bs.mod.o
CC [M] fs/nfs/blocklayout/blocklayoutdriver.mod.o
CC [M] fs/pstore/ramoops.mod.o
CC [M] fs/ubifs/ubifs.mod.o
CC [M] fs/fuse/fuse.mod.o
CC [M] fs/fuse/cuse.mod.o
CC [M] fs/overlayfs/overlay.mod.o
CC [M] fs/btrfs/btrfs.mod.o
aarch64-linux-gnu-ld: drivers/cxl/core/memfeature.o: in function `cxl_mem_ras_features_init':
/home/fan/cxl/linux-edac/drivers/cxl/core/memfeature.c:1133:(.text+0x3ac): undefined reference to `edac_dev_register'
----
I think it should be "tristate" instead of "bool" like blew.

diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index 394bdbc4de87..b717a152d2a5 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -146,7 +146,7 @@ config CXL_REGION_INVALIDATION_TEST
say N.

config CXL_RAS_FEAT
- bool "CXL: Memory RAS features"
+ tristate "CXL: Memory RAS features"
depends on CXL_PCI
depends on CXL_MEM
depends on EDAC


Fan

> + depends on CXL_PCI
> + depends on CXL_MEM
> + depends on EDAC
> + help
> + The CXL memory RAS feature control is optional allows host to control
> + the RAS features configurations of CXL Type 3 devices.
> +
> + Registers with the EDAC device subsystem to expose control attributes
> + of CXL memory device's RAS features to the user.
> + Provides interface functions to support configuring the CXL memory
> + device's RAS features.
> +
> + Say 'y/n' to enable/disable CXL.mem device'ss RAS features control.
> + See section 8.2.9.9.11 of CXL 3.1 specification for the detailed
> + information of CXL memory device features.
> +
> endif
> diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
> index 9259bcc6773c..2a3c7197bc23 100644
> --- a/drivers/cxl/core/Makefile
> +++ b/drivers/cxl/core/Makefile
> @@ -16,3 +16,4 @@ cxl_core-y += pmu.o
> cxl_core-y += cdat.o
> cxl_core-$(CONFIG_TRACING) += trace.o
> cxl_core-$(CONFIG_CXL_REGION) += region.o
> +cxl_core-$(CONFIG_CXL_RAS_FEAT) += memfeature.o
> diff --git a/drivers/cxl/core/memfeature.c b/drivers/cxl/core/memfeature.c
> new file mode 100644
> index 000000000000..90c68d20b02b
> --- /dev/null
> +++ b/drivers/cxl/core/memfeature.c
> @@ -0,0 +1,372 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * CXL memory RAS feature driver.
> + *
> + * Copyright (c) 2024 HiSilicon Limited.
> + *
> + * - Supports functions to configure RAS features of the
> + * CXL memory devices.
> + * - Registers with the EDAC device subsystem driver to expose
> + * the features sysfs attributes to the user for configuring
> + * CXL memory RAS feature.
> + */
> +
> +#define pr_fmt(fmt) "CXL MEM FEAT: " fmt
> +
> +#include <cxlmem.h>
> +#include <linux/cleanup.h>
> +#include <linux/limits.h>
> +#include <cxl.h>
> +#include <linux/edac.h>
> +
> +#define CXL_DEV_NUM_RAS_FEATURES 1
> +#define CXL_DEV_HOUR_IN_SECS 3600
> +
> +#define CXL_SCRUB_NAME_LEN 128
> +
> +/* CXL memory patrol scrub control definitions */
> +static const uuid_t cxl_patrol_scrub_uuid =
> + UUID_INIT(0x96dad7d6, 0xfde8, 0x482b, 0xa7, 0x33, 0x75, 0x77, 0x4e, \
> + 0x06, 0xdb, 0x8a);
> +
> +/* CXL memory patrol scrub control functions */
> +struct cxl_patrol_scrub_context {
> + u8 instance;
> + u16 get_feat_size;
> + u16 set_feat_size;
> + u8 get_version;
> + u8 set_version;
> + u16 set_effects;
> + struct cxl_memdev *cxlmd;
> + struct cxl_region *cxlr;
> +};
> +
> +/**
> + * struct cxl_memdev_ps_params - CXL memory patrol scrub parameter data structure.
> + * @enable: [IN & OUT] enable(1)/disable(0) patrol scrub.
> + * @scrub_cycle_changeable: [OUT] scrub cycle attribute of patrol scrub is changeable.
> + * @scrub_cycle_hrs: [IN] Requested patrol scrub cycle in hours.
> + * [OUT] Current patrol scrub cycle in hours.
> + * @min_scrub_cycle_hrs:[OUT] minimum patrol scrub cycle in hours supported.
> + */
> +struct cxl_memdev_ps_params {
> + bool enable;
> + bool scrub_cycle_changeable;
> + u16 scrub_cycle_hrs;
> + u16 min_scrub_cycle_hrs;
> +};
> +
> +enum cxl_scrub_param {
> + CXL_PS_PARAM_ENABLE,
> + CXL_PS_PARAM_SCRUB_CYCLE,
> +};
> +
> +#define CXL_MEMDEV_PS_SCRUB_CYCLE_CHANGE_CAP_MASK BIT(0)
> +#define CXL_MEMDEV_PS_SCRUB_CYCLE_REALTIME_REPORT_CAP_MASK BIT(1)
> +#define CXL_MEMDEV_PS_CUR_SCRUB_CYCLE_MASK GENMASK(7, 0)
> +#define CXL_MEMDEV_PS_MIN_SCRUB_CYCLE_MASK GENMASK(15, 8)
> +#define CXL_MEMDEV_PS_FLAG_ENABLED_MASK BIT(0)
> +
> +struct cxl_memdev_ps_rd_attrs {
> + u8 scrub_cycle_cap;
> + __le16 scrub_cycle_hrs;
> + u8 scrub_flags;
> +} __packed;
> +
> +struct cxl_memdev_ps_wr_attrs {
> + u8 scrub_cycle_hrs;
> + u8 scrub_flags;
> +} __packed;
> +
> +static int cxl_mem_ps_get_attrs(struct cxl_dev_state *cxlds,
> + struct cxl_memdev_ps_params *params)
> +{
> + size_t rd_data_size = sizeof(struct cxl_memdev_ps_rd_attrs);
> + size_t data_size;
> + struct cxl_memdev_ps_rd_attrs *rd_attrs __free(kfree) =
> + kmalloc(rd_data_size, GFP_KERNEL);
> + if (!rd_attrs)
> + return -ENOMEM;
> +
> + data_size = cxl_get_feature(cxlds, cxl_patrol_scrub_uuid,
> + CXL_GET_FEAT_SEL_CURRENT_VALUE,
> + rd_attrs, rd_data_size);
> + if (!data_size)
> + return -EIO;
> +
> + params->scrub_cycle_changeable = FIELD_GET(CXL_MEMDEV_PS_SCRUB_CYCLE_CHANGE_CAP_MASK,
> + rd_attrs->scrub_cycle_cap);
> + params->enable = FIELD_GET(CXL_MEMDEV_PS_FLAG_ENABLED_MASK,
> + rd_attrs->scrub_flags);
> + params->scrub_cycle_hrs = FIELD_GET(CXL_MEMDEV_PS_CUR_SCRUB_CYCLE_MASK,
> + rd_attrs->scrub_cycle_hrs);
> + params->min_scrub_cycle_hrs = FIELD_GET(CXL_MEMDEV_PS_MIN_SCRUB_CYCLE_MASK,
> + rd_attrs->scrub_cycle_hrs);
> +
> + return 0;
> +}
> +
> +static int cxl_ps_get_attrs(struct device *dev, void *drv_data,
> + struct cxl_memdev_ps_params *params)
> +{
> + struct cxl_patrol_scrub_context *cxl_ps_ctx = drv_data;
> + struct cxl_memdev *cxlmd;
> + struct cxl_dev_state *cxlds;
> + u16 min_scrub_cycle = 0;
> + int i, ret;
> +
> + if (cxl_ps_ctx->cxlr) {
> + struct cxl_region *cxlr = cxl_ps_ctx->cxlr;
> + struct cxl_region_params *p = &cxlr->params;
> +
> + for (i = p->interleave_ways - 1; i >= 0; i--) {
> + struct cxl_endpoint_decoder *cxled = p->targets[i];
> +
> + cxlmd = cxled_to_memdev(cxled);
> + cxlds = cxlmd->cxlds;
> + ret = cxl_mem_ps_get_attrs(cxlds, params);
> + if (ret)
> + return ret;
> +
> + if (params->min_scrub_cycle_hrs > min_scrub_cycle)
> + min_scrub_cycle = params->min_scrub_cycle_hrs;
> + }
> + params->min_scrub_cycle_hrs = min_scrub_cycle;
> + return 0;
> + }
> + cxlmd = cxl_ps_ctx->cxlmd;
> + cxlds = cxlmd->cxlds;
> +
> + return cxl_mem_ps_get_attrs(cxlds, params);
> +}
> +
> +static int cxl_mem_ps_set_attrs(struct device *dev, void *drv_data,
> + struct cxl_dev_state *cxlds,
> + struct cxl_memdev_ps_params *params,
> + enum cxl_scrub_param param_type)
> +{
> + struct cxl_patrol_scrub_context *cxl_ps_ctx = drv_data;
> + struct cxl_memdev_ps_wr_attrs wr_attrs;
> + struct cxl_memdev_ps_params rd_params;
> + int ret;
> +
> + ret = cxl_mem_ps_get_attrs(cxlds, &rd_params);
> + if (ret) {
> + dev_err(dev, "Get cxlmemdev patrol scrub params failed ret=%d\n",
> + ret);
> + return ret;
> + }
> +
> + switch (param_type) {
> + case CXL_PS_PARAM_ENABLE:
> + wr_attrs.scrub_flags = FIELD_PREP(CXL_MEMDEV_PS_FLAG_ENABLED_MASK,
> + params->enable);
> + wr_attrs.scrub_cycle_hrs = FIELD_PREP(CXL_MEMDEV_PS_CUR_SCRUB_CYCLE_MASK,
> + rd_params.scrub_cycle_hrs);
> + break;
> + case CXL_PS_PARAM_SCRUB_CYCLE:
> + if (params->scrub_cycle_hrs < rd_params.min_scrub_cycle_hrs) {
> + dev_err(dev, "Invalid CXL patrol scrub cycle(%d) to set\n",
> + params->scrub_cycle_hrs);
> + dev_err(dev, "Minimum supported CXL patrol scrub cycle in hour %d\n",
> + params->min_scrub_cycle_hrs);
> + return -EINVAL;
> + }
> + wr_attrs.scrub_cycle_hrs = FIELD_PREP(CXL_MEMDEV_PS_CUR_SCRUB_CYCLE_MASK,
> + params->scrub_cycle_hrs);
> + wr_attrs.scrub_flags = FIELD_PREP(CXL_MEMDEV_PS_FLAG_ENABLED_MASK,
> + rd_params.enable);
> + break;
> + }
> +
> + ret = cxl_set_feature(cxlds, cxl_patrol_scrub_uuid,
> + cxl_ps_ctx->set_version,
> + &wr_attrs, sizeof(wr_attrs),
> + CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET);
> + if (ret) {
> + dev_err(dev, "CXL patrol scrub set feature failed ret=%d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int cxl_ps_set_attrs(struct device *dev, void *drv_data,
> + struct cxl_memdev_ps_params *params,
> + enum cxl_scrub_param param_type)
> +{
> + struct cxl_patrol_scrub_context *cxl_ps_ctx = drv_data;
> + struct cxl_memdev *cxlmd;
> + struct cxl_dev_state *cxlds;
> + int ret, i;
> +
> + if (cxl_ps_ctx->cxlr) {
> + struct cxl_region *cxlr = cxl_ps_ctx->cxlr;
> + struct cxl_region_params *p = &cxlr->params;
> +
> + for (i = p->interleave_ways - 1; i >= 0; i--) {
> + struct cxl_endpoint_decoder *cxled = p->targets[i];
> +
> + cxlmd = cxled_to_memdev(cxled);
> + cxlds = cxlmd->cxlds;
> + ret = cxl_mem_ps_set_attrs(dev, drv_data, cxlds,
> + params, param_type);
> + if (ret)
> + return ret;
> + }
> + } else {
> + cxlmd = cxl_ps_ctx->cxlmd;
> + cxlds = cxlmd->cxlds;
> +
> + return cxl_mem_ps_set_attrs(dev, drv_data, cxlds, params, param_type);
> + }
> +
> + return 0;
> +}
> +
> +static int cxl_patrol_scrub_get_enabled_bg(struct device *dev, void *drv_data, bool *enabled)
> +{
> + struct cxl_memdev_ps_params params;
> + int ret;
> +
> + ret = cxl_ps_get_attrs(dev, drv_data, &params);
> + if (ret)
> + return ret;
> +
> + *enabled = params.enable;
> +
> + return 0;
> +}
> +
> +static int cxl_patrol_scrub_set_enabled_bg(struct device *dev, void *drv_data, bool enable)
> +{
> + struct cxl_memdev_ps_params params = {
> + .enable = enable,
> + };
> +
> + return cxl_ps_set_attrs(dev, drv_data, &params, CXL_PS_PARAM_ENABLE);
> +}
> +
> +static int cxl_patrol_scrub_read_min_scrub_cycle(struct device *dev, void *drv_data,
> + u32 *min)
> +{
> + struct cxl_memdev_ps_params params;
> + int ret;
> +
> + ret = cxl_ps_get_attrs(dev, drv_data, &params);
> + if (ret)
> + return ret;
> + *min = params.min_scrub_cycle_hrs * CXL_DEV_HOUR_IN_SECS;
> +
> + return 0;
> +}
> +
> +static int cxl_patrol_scrub_read_max_scrub_cycle(struct device *dev, void *drv_data,
> + u32 *max)
> +{
> + *max = U8_MAX * CXL_DEV_HOUR_IN_SECS; /* Max set by register size */
> +
> + return 0;
> +}
> +
> +static int cxl_patrol_scrub_read_scrub_cycle(struct device *dev, void *drv_data,
> + u32 *scrub_cycle_secs)
> +{
> + struct cxl_memdev_ps_params params;
> + int ret;
> +
> + ret = cxl_ps_get_attrs(dev, drv_data, &params);
> + if (ret)
> + return ret;
> +
> + *scrub_cycle_secs = params.scrub_cycle_hrs * CXL_DEV_HOUR_IN_SECS;
> +
> + return 0;
> +}
> +
> +static int cxl_patrol_scrub_write_scrub_cycle(struct device *dev, void *drv_data,
> + u32 scrub_cycle_secs)
> +{
> + struct cxl_memdev_ps_params params = {
> + .scrub_cycle_hrs = scrub_cycle_secs / CXL_DEV_HOUR_IN_SECS,
> + };
> +
> + return cxl_ps_set_attrs(dev, drv_data, &params, CXL_PS_PARAM_SCRUB_CYCLE);
> +}
> +
> +static const struct edac_scrub_ops cxl_ps_scrub_ops = {
> + .get_enabled_bg = cxl_patrol_scrub_get_enabled_bg,
> + .set_enabled_bg = cxl_patrol_scrub_set_enabled_bg,
> + .min_cycle_read = cxl_patrol_scrub_read_min_scrub_cycle,
> + .max_cycle_read = cxl_patrol_scrub_read_max_scrub_cycle,
> + .cycle_duration_read = cxl_patrol_scrub_read_scrub_cycle,
> + .cycle_duration_write = cxl_patrol_scrub_write_scrub_cycle,
> +};
> +
> +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_dev_state *cxlds;
> + struct cxl_patrol_scrub_context *cxl_ps_ctx;
> + struct cxl_feat_entry feat_entry;
> + char cxl_dev_name[CXL_SCRUB_NAME_LEN];
> + int rc, i, num_ras_features = 0;
> +
> + if (cxlr) {
> + struct cxl_region_params *p = &cxlr->params;
> +
> + for (i = p->interleave_ways - 1; i >= 0; i--) {
> + struct cxl_endpoint_decoder *cxled = p->targets[i];
> +
> + cxlmd = cxled_to_memdev(cxled);
> + cxlds = cxlmd->cxlds;
> + memset(&feat_entry, 0, sizeof(feat_entry));
> + rc = cxl_get_supported_feature_entry(cxlds, &cxl_patrol_scrub_uuid,
> + &feat_entry);
> + if (rc < 0)
> + return rc;
> + if (!(feat_entry.attr_flags & CXL_FEAT_ENTRY_FLAG_CHANGABLE))
> + return -EOPNOTSUPP;
> + }
> + } else {
> + cxlds = cxlmd->cxlds;
> + rc = cxl_get_supported_feature_entry(cxlds, &cxl_patrol_scrub_uuid,
> + &feat_entry);
> + if (rc < 0)
> + return rc;
> +
> + if (!(feat_entry.attr_flags & CXL_FEAT_ENTRY_FLAG_CHANGABLE))
> + return -EOPNOTSUPP;
> + }
> +
> + cxl_ps_ctx = devm_kzalloc(&cxlmd->dev, sizeof(*cxl_ps_ctx), GFP_KERNEL);
> + if (!cxl_ps_ctx)
> + return -ENOMEM;
> +
> + *cxl_ps_ctx = (struct cxl_patrol_scrub_context) {
> + .instance = cxl_ps_ctx->instance,
> + .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,
> + };
> + if (cxlr) {
> + snprintf(cxl_dev_name, sizeof(cxl_dev_name),
> + "cxl_region%d", cxlr->id);
> + cxl_ps_ctx->cxlr = cxlr;
> + } else {
> + snprintf(cxl_dev_name, sizeof(cxl_dev_name),
> + "%s_%s", "cxl", dev_name(&cxlmd->dev));
> + cxl_ps_ctx->cxlmd = cxlmd;
> + }
> +
> + ras_features[num_ras_features].ft_type = RAS_FEAT_SCRUB;
> + ras_features[num_ras_features].scrub_ops = &cxl_ps_scrub_ops;
> + ras_features[num_ras_features].ctx = cxl_ps_ctx;
> + num_ras_features++;
> +
> + return edac_dev_register(&cxlmd->dev, cxl_dev_name, NULL,
> + num_ras_features, ras_features);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_mem_ras_features_init, CXL);
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 21ad5f242875..1cc29ec9ffac 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -3434,6 +3434,12 @@ static int cxl_region_probe(struct device *dev)
> p->res->start, p->res->end, cxlr,
> is_system_ram) > 0)
> return 0;
> +
> + rc = cxl_mem_ras_features_init(NULL, cxlr);
> + if (rc)
> + dev_warn(&cxlr->dev, "CXL RAS features init for region_id=%d failed\n",
> + cxlr->id);
> +
> return devm_cxl_add_dax_region(cxlr);
> default:
> dev_dbg(&cxlr->dev, "unsupported region mode: %d\n",
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index b565a061a4e3..2187c3378eaa 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -889,6 +889,13 @@ int cxl_trigger_poison_list(struct cxl_memdev *cxlmd);
> int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa);
> int cxl_clear_poison(struct cxl_memdev *cxlmd, u64 dpa);
>
> +#ifdef CONFIG_CXL_RAS_FEAT
> +int cxl_mem_ras_features_init(struct cxl_memdev *cxlmd, struct cxl_region *cxlr);
> +#else
> +static inline int cxl_mem_ras_features_init(struct cxl_memdev *cxlmd, struct cxl_region *cxlr)
> +{ return 0; }
> +#endif
> +
> #ifdef CONFIG_CXL_SUSPEND
> void cxl_mem_active_inc(void);
> void cxl_mem_active_dec(void);
> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> index 7de232eaeb17..be2e69548909 100644
> --- a/drivers/cxl/mem.c
> +++ b/drivers/cxl/mem.c
> @@ -117,6 +117,10 @@ static int cxl_mem_probe(struct device *dev)
> if (!cxlds->media_ready)
> return -EBUSY;
>
> + rc = cxl_mem_ras_features_init(cxlmd, NULL);
> + if (rc)
> + dev_warn(&cxlmd->dev, "CXL RAS features init failed\n");
> +
> /*
> * Someone is trying to reattach this device after it lost its port
> * connection (an endpoint port previously registered by this memdev was
> --
> 2.34.1
>

--
Fan Ni