RE: [RFC PATCH v9 01/11] EDAC: Add generic EDAC RAS feature driver

[Shiju Jose <shiju.jose@huawei.com>]

Hi Fan,

Thanks for the feedback.

>-----Original Message-----
>From: fan <nifan.cxl@gmail.com>
>Sent: 16 July 2024 19:01
>To: Shiju Jose <shiju.jose@huawei.com>
>Cc: linux-edac@vger.kernel.org; linux-cxl@vger.kernel.org; linux-
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>Subject: Re: [RFC PATCH v9 01/11] EDAC: Add generic EDAC RAS feature driver
>
>On Tue, Jul 16, 2024 at 04:03:25PM +0100, shiju.jose@huawei.com wrote:
>> From: Shiju Jose <shiju.jose@huawei.com>
>>
>> Add generic EDAC driver supports registering RAS features supported in
>> the system. The driver exposes feature's control attributes to the
>> userspace in /sys/bus/edac/devices/<dev-name>/<ras-feature>/
>>
>> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>> Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
>> ---
>>  drivers/edac/Makefile            |   1 +
>>  drivers/edac/edac_ras_feature.c  | 155
>> +++++++++++++++++++++++++++++++  include/linux/edac_ras_feature.h |
>> 66 +++++++++++++
>>  3 files changed, 222 insertions(+)
>>  create mode 100755 drivers/edac/edac_ras_feature.c  create mode
>> 100755 include/linux/edac_ras_feature.h
>>
>> diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile index
>> 9c09893695b7..c532b57a6d8a 100644
>> --- a/drivers/edac/Makefile
>> +++ b/drivers/edac/Makefile
>> @@ -10,6 +10,7 @@ obj-$(CONFIG_EDAC)			:= edac_core.o
>>
>>  edac_core-y	:= edac_mc.o edac_device.o edac_mc_sysfs.o
>>  edac_core-y	+= edac_module.o edac_device_sysfs.o wq.o
>> +edac_core-y	+= edac_ras_feature.o
>>
>>  edac_core-$(CONFIG_EDAC_DEBUG)		+= debugfs.o
>>
>> diff --git a/drivers/edac/edac_ras_feature.c
>> b/drivers/edac/edac_ras_feature.c new file mode 100755 index
>> 000000000000..24a729fea66f
>> --- /dev/null
>> +++ b/drivers/edac/edac_ras_feature.c
>> @@ -0,0 +1,155 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * EDAC RAS control feature driver supports registering RAS
>> + * features with the EDAC and exposes the feature's control
>> + * attributes to the userspace in sysfs.
>> + *
>> + * Copyright (c) 2024 HiSilicon Limited.
>> + */
>> +
>> +#define pr_fmt(fmt)     "EDAC RAS CONTROL FEAT: " fmt
>> +
>> +#include <linux/edac_ras_feature.h>
>> +
>> +static void edac_ras_dev_release(struct device *dev) {
>> +	struct edac_ras_feat_ctx *ctx =
>> +		container_of(dev, struct edac_ras_feat_ctx, dev);
>> +
>> +	kfree(ctx);
>> +}
>> +
>> +const struct device_type edac_ras_dev_type = {
>> +	.name = "edac_ras_dev",
>> +	.release = edac_ras_dev_release,
>> +};
>> +
>> +static void edac_ras_dev_unreg(void *data) {
>> +	device_unregister(data);
>> +}
>> +
>> +static int edac_ras_feat_scrub_init(struct device *parent,
>> +				    struct edac_scrub_data *sdata,
>> +				    const struct edac_ras_feature *sfeat,
>> +				    const struct attribute_group **attr_groups) {
>> +	sdata->ops = sfeat->scrub_ops;
>> +	sdata->private = sfeat->scrub_ctx;
>> +
>> +	return 1;
>> +}
>> +
>> +static int edac_ras_feat_ecs_init(struct device *parent,
>> +				  struct edac_ecs_data *edata,
>> +				  const struct edac_ras_feature *efeat,
>> +				  const struct attribute_group **attr_groups) {
>> +	int num = efeat->ecs_info.num_media_frus;
>> +
>> +	edata->ops = efeat->ecs_ops;
>> +	edata->private = efeat->ecs_ctx;
>> +
>> +	return num;
>> +}
>> +
>> +/**
>> + * edac_ras_dev_register - register device for ras features with edac
>> + * @parent: client device.
>> + * @name: client device's name.
>> + * @private: parent driver's data to store in the context if any.
>> + * @num_features: number of ras features to register.
>> + * @ras_features: list of ras features to register.
>> + *
>> + * Returns 0 on success, error otherwise.
>> + * The new edac_ras_feat_ctx would be freed automatically.
>> + */
>> +int edac_ras_dev_register(struct device *parent, char *name,
>> +			  void *private, int num_features,
>> +			  const struct edac_ras_feature *ras_features) {
>> +	const struct attribute_group **ras_attr_groups;
>> +	struct edac_ras_feat_ctx *ctx;
>> +	int attr_gcnt = 0;
>> +	int ret, feat;
>> +
>> +	if (!parent || !name || !num_features || !ras_features)
>> +		return -EINVAL;
>> +
>> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
>> +	if (!ctx)
>> +		return -ENOMEM;
>> +
>> +	ctx->dev.parent = parent;
>> +	ctx->private = private;
>> +
>> +	/* Double parse so we can make space for attributes */
>> +	for (feat = 0; feat < num_features; feat++) {
>> +		switch (ras_features[feat].feat) {
>> +		case ras_feat_scrub:
>> +			attr_gcnt++;
>> +			break;
>> +		case ras_feat_ecs:
>> +			attr_gcnt +=
>ras_features[feat].ecs_info.num_media_frus;
>> +			break;
>> +		default:
>> +			ret = -EINVAL;
>> +			goto ctx_free;
>> +		}
>> +	}
>> +
>> +	ras_attr_groups = devm_kzalloc(parent,
>> +				       (attr_gcnt + 1) * sizeof(*ras_attr_groups),
>> +				       GFP_KERNEL);
>> +	if (!ras_attr_groups) {
>> +		ret = -ENOMEM;
>> +		goto ctx_free;
>> +	}
>> +
>> +	attr_gcnt = 0;
>> +	for (feat = 0; feat < num_features; feat++, ras_features++) {
>> +		if (ras_features->feat == ras_feat_scrub) {
>> +			if (!ras_features->scrub_ops)
>> +				continue;
>> +			ret = edac_ras_feat_scrub_init(parent, &ctx->scrub,
>> +						       ras_features,
>&ras_attr_groups[attr_gcnt]);
>> +			if (ret < 0)
>> +				goto ctx_free;
>> +
>> +			attr_gcnt += ret;
>> +		} else if (ras_features->feat == ras_feat_ecs) {
>> +			if (!ras_features->ecs_ops)
>> +				continue;
>> +			ret = edac_ras_feat_ecs_init(parent, &ctx->ecs,
>> +						     ras_features,
>&ras_attr_groups[attr_gcnt]);
>> +			if (ret < 0)
>> +				goto ctx_free;
>> +
>> +			attr_gcnt += ret;
>> +		} else {
>> +			ret = -EINVAL;
>> +			goto ctx_free;
>We already check this in the first pass, cannot be reached in the second pass.
Will change.

>> +		}
>Why use if/else instead of using switch/case as above?
Will do.

>> +	}
>> +	ras_attr_groups[attr_gcnt] = NULL;
>> +	ctx->dev.bus = edac_get_sysfs_subsys();
>> +	ctx->dev.type = &edac_ras_dev_type;
>> +	ctx->dev.groups = ras_attr_groups;
>> +	dev_set_drvdata(&ctx->dev, ctx);
>> +	ret = dev_set_name(&ctx->dev, name);
>> +	if (ret)
>> +		goto ctx_free;
>> +
>> +	ret = device_register(&ctx->dev);
>> +	if (ret) {
>> +		put_device(&ctx->dev);
>need to free ctx?
Will fix.

>> +		return ret;
>> +	}
>> +
>> +	return devm_add_action_or_reset(parent, edac_ras_dev_unreg,
>> +&ctx->dev);
>> +
>> +ctx_free:
>> +	kfree(ctx);
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(edac_ras_dev_register);
>> diff --git a/include/linux/edac_ras_feature.h
>> b/include/linux/edac_ras_feature.h
>> new file mode 100755
>> index 000000000000..000e99141023
>> --- /dev/null
>> +++ b/include/linux/edac_ras_feature.h
>> @@ -0,0 +1,66 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * EDAC RAS control features.
>> + *
>> + * Copyright (c) 2024 HiSilicon Limited.
>> + */
>> +
>> +#ifndef __EDAC_RAS_FEAT_H
>> +#define __EDAC_RAS_FEAT_H
>> +
>> +#include <linux/types.h>
>> +#include <linux/edac.h>
>> +
>> +#define EDAC_RAS_NAME_LEN	128
>> +
>> +enum edac_ras_feat {
>> +	ras_feat_scrub,
>> +	ras_feat_ecs,
>> +	ras_feat_max
>> +};
>Use uppercase for the strings.
Will do.

>
>Fan
>> +
>> +struct edac_ecs_ex_info {
>> +	u16 num_media_frus;
>> +};
>> +
>> +/*
>> + * EDAC RAS feature information structure  */ struct edac_scrub_data
>> +{
>> +	const struct edac_scrub_ops *ops;
>> +	void *private;
>> +};
>> +
>> +struct edac_ecs_data {
>> +	const struct edac_ecs_ops *ops;
>> +	void *private;
>> +};
>> +
>> +struct device;
>> +
>> +struct edac_ras_feat_ctx {
>> +	struct device dev;
>> +	void *private;
>> +	struct edac_scrub_data scrub;
>> +	struct edac_ecs_data ecs;
>> +};
>> +
>> +struct edac_ras_feature {
>> +	enum edac_ras_feat feat;
>> +	union {
>> +		const struct edac_scrub_ops *scrub_ops;
>> +		const struct edac_ecs_ops *ecs_ops;
>> +	};
>> +	union {
>> +		struct edac_ecs_ex_info ecs_info;
>> +	};
>> +	union {
>> +		void *scrub_ctx;
>> +		void *ecs_ctx;
>> +	};
>> +};
>> +
>> +int edac_ras_dev_register(struct device *parent, char *dev_name,
>> +			  void *parent_pvt_data, int num_features,
>> +			  const struct edac_ras_feature *ras_features); #endif
>/*
>> +__EDAC_RAS_FEAT_H */
>> --
>> 2.34.1
>>

Thanks,
Shiju