diff mbox series

[v13,01/18] EDAC: Add support for EDAC device features control

Message ID 20241009124120.1124-2-shiju.jose@huawei.com (mailing list archive)
State Superseded, archived
Headers show
Series EDAC: Scrub: introduce generic EDAC RAS control feature driver + CXL/ACPI-RAS2 drivers | expand

Commit Message

Shiju Jose Oct. 9, 2024, 12:41 p.m. UTC
From: Shiju Jose <shiju.jose@huawei.com>

Add generic EDAC device features control supports registering
RAS features supported in the system. Driver exposes features
control attributes to 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/edac_device.c | 105 +++++++++++++++++++++++++++++++++++++
 include/linux/edac.h       |  32 +++++++++++
 2 files changed, 137 insertions(+)

Comments

Jonathan Cameron Oct. 14, 2024, 2:18 p.m. UTC | #1
On Wed, 9 Oct 2024 13:41:02 +0100
<shiju.jose@huawei.com> wrote:

> From: Shiju Jose <shiju.jose@huawei.com>
> 
> Add generic EDAC device features control supports registering
> RAS features supported in the system. Driver exposes features
> control attributes to 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>
Hi Shiju,

Spotted a few minor bugs in here that I'd missed in internal
review :( See below.

Jonathan

> ---
>  drivers/edac/edac_device.c | 105 +++++++++++++++++++++++++++++++++++++
>  include/linux/edac.h       |  32 +++++++++++
>  2 files changed, 137 insertions(+)
> 
> diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
> index 621dc2a5d034..0b8aa8150239 100644
> --- a/drivers/edac/edac_device.c
> +++ b/drivers/edac/edac_device.c


> +
> +/**
> + * edac_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.
> + *
> + * Return:
> + *  * %0       - Success.
> + *  * %-EINVAL - Invalid parameters passed.
> + *  * %-ENOMEM - Dynamic memory allocation failed.
> + *
> + * The new edac_dev_feat_ctx would be freed automatically.
> + */
> +int edac_dev_register(struct device *parent, char *name,
> +		      void *private, int num_features,
> +		      const struct edac_dev_feature *ras_features)
> +{

...

> +	ret = device_register(&ctx->dev);
> +	if (ret) {
> +		put_device(&ctx->dev);
> +		goto groups_free;
> +		return ret;

Unreachable line. However, shouldn't have the goto here
as put_device() should result in the release being called
in which case this is a double free. So drop the goto and keep
the return.


> +	}
> +
> +	return devm_add_action_or_reset(parent, edac_dev_unreg, &ctx->dev);
> +
> +groups_free:
> +	kfree(ras_attr_groups);
> +ctx_free:
> +	kfree(ctx);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(edac_dev_register);
> diff --git a/include/linux/edac.h b/include/linux/edac.h
> index b4ee8961e623..1db008a82690 100644
> --- a/include/linux/edac.h
> +++ b/include/linux/edac.h
> @@ -661,4 +661,36 @@ static inline struct dimm_info *edac_get_dimm(struct mem_ctl_info *mci,


> +/* EDAC device feature information structure */
> +struct edac_dev_data {
> +	u8 instance;
> +	void *private;
> +};
> +
> +struct device;

That forwards def doesn't work as this header needs to include
enough information to establish layout of struct edac_dev_feat_ctx.
Header already includes linux/device.h so just drop this.


> +
> +struct edac_dev_feat_ctx {
> +	struct device dev;
> +	void *private;
> +};
> +
> +struct edac_dev_feature {
> +	enum edac_dev_feat ft_type;
> +	u8 instance;
> +	void *ctx;
> +};
> +
> +int edac_dev_register(struct device *parent, char *dev_name,
> +		      void *parent_pvt_data, int num_features,
> +		      const struct edac_dev_feature *ras_features);
>  #endif /* _LINUX_EDAC_H_ */
Borislav Petkov Oct. 16, 2024, 10:58 a.m. UTC | #2
On Wed, Oct 09, 2024 at 01:41:02PM +0100, shiju.jose@huawei.com wrote:
> From: Shiju Jose <shiju.jose@huawei.com>
> 
> Add generic EDAC device features control supports registering
> RAS features supported in the system. Driver exposes features
> control attributes to userspace in
> /sys/bus/edac/devices/<dev-name>/<ras-feature>/

Chatgpt prompt:

| Please check the grammar in this English text: "Add generic EDAC device
| features control supports registering RAS features supported in the system.
| Driver exposes features control attributes to userspace in
| /sys/bus/edac/devices/<dev-name>/<ras-"feature>/

Response:

| Here’s a corrected version of the text:
| 
| "Add generic EDAC device feature control support for registering RAS features
| supported in the system. The driver exposes feature control attributes to
| userspace in /sys/bus/edac/devices/<dev-name>/<ras-feature>/."
| 
| Changes made:
| 
| * "features control" was changed to "feature control" for consistency and
| clarity.
| 
| * "supports registering" was changed to "support for registering" to match the
| structure of the sentence.
| 
| * Added "The" at the beginning of the second sentence for better flow.
| 
| * Corrected the syntax around the file path to ensure clarity and proper
| * punctuation.

Please run all your commit text through some LLM AI as they're apparently good
enough now to help me in correcting grammar.
 
> 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/edac_device.c | 105 +++++++++++++++++++++++++++++++++++++
>  include/linux/edac.h       |  32 +++++++++++
>  2 files changed, 137 insertions(+)
> 
> diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
> index 621dc2a5d034..0b8aa8150239 100644
> --- a/drivers/edac/edac_device.c
> +++ b/drivers/edac/edac_device.c
> @@ -570,3 +570,108 @@ void edac_device_handle_ue_count(struct edac_device_ctl_info *edac_dev,
>  		      block ? block->name : "N/A", count, msg);
>  }
>  EXPORT_SYMBOL_GPL(edac_device_handle_ue_count);
> +
> +/* EDAC device feature */
> +static void edac_dev_release(struct device *dev)
> +{
> +	struct edac_dev_feat_ctx *ctx = container_of(dev, struct edac_dev_feat_ctx, dev);
> +
> +	kfree(ctx->dev.groups);
> +	kfree(ctx);
> +}
> +
> +const struct device_type edac_dev_type = {
> +	.name = "edac_dev",
> +	.release = edac_dev_release,
> +};
> +
> +static void edac_dev_unreg(void *data)
> +{
> +	device_unregister(data);
> +}
> +
> +/**
> + * edac_dev_register - register device for RAS features with EDAC
> + * @parent: client device.

If this is a client device, why is the variable called "parent" and not
"client"?

I.e.,

	struct device *client;

For clarity and simplicity.

Or call it "parent" because you do:

	ctx->dev.parent = parent;

and forget "client" altogether.

> + * @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.
> + *
> + * Return:
> + *  * %0       - Success.
> + *  * %-EINVAL - Invalid parameters passed.
> + *  * %-ENOMEM - Dynamic memory allocation failed.
> + *
> + * The new edac_dev_feat_ctx would be freed automatically.

Why is this important to call out here?

It is a common coding pattern of freeing resources in the release function...

> + */
> +int edac_dev_register(struct device *parent, char *name,
> +		      void *private, int num_features,
> +		      const struct edac_dev_feature *ras_features)
> +{
> +	const struct attribute_group **ras_attr_groups;
> +	struct edac_dev_feat_ctx *ctx;
> +	int attr_gcnt = 0;
> +	int ret, feat;
> +
> +	if (!parent || !name || !num_features || !ras_features)
> +		return -EINVAL;
> +
> +	/* Double parse to make space for attributes */
> +	for (feat = 0; feat < num_features; feat++) {
> +		switch (ras_features[feat].ft_type) {
> +		/* Add feature specific code */
> +		default:
> +			return -EINVAL;
> +		}
> +	}
> +
> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->dev.parent = parent;
> +	ctx->private = private;
> +
> +	ras_attr_groups = kcalloc(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++) {
> +		switch (ras_features->ft_type) {
> +		/* Add feature specific code */
> +		default:
> +			ret = -EINVAL;
> +			goto groups_free;
> +		}
> +	}
> +
> +	ras_attr_groups[attr_gcnt] = NULL;
> +	ctx->dev.bus = edac_get_sysfs_subsys();
> +	ctx->dev.type = &edac_dev_type;
> +	ctx->dev.groups = ras_attr_groups;
> +	dev_set_drvdata(&ctx->dev, ctx);
> +
> +	ret = dev_set_name(&ctx->dev, name);
> +	if (ret)
> +		goto groups_free;
> +
> +	ret = device_register(&ctx->dev);
> +	if (ret) {
> +		put_device(&ctx->dev);
> +		goto groups_free;
> +		return ret;
		^^^^^^^^^^

Come again?!

There's code after a "goto"?
Shiju Jose Oct. 17, 2024, 8:37 a.m. UTC | #3
Hi Jonathan, 

>-----Original Message-----
>From: Jonathan Cameron <jonathan.cameron@huawei.com>
>Sent: 14 October 2024 15:18
>To: Shiju Jose <shiju.jose@huawei.com>
>Cc: linux-edac@vger.kernel.org; linux-cxl@vger.kernel.org; linux-
>acpi@vger.kernel.org; linux-mm@kvack.org; linux-kernel@vger.kernel.org;
>bp@alien8.de; tony.luck@intel.com; rafael@kernel.org; lenb@kernel.org;
>mchehab@kernel.org; dan.j.williams@intel.com; dave@stgolabs.net;
>dave.jiang@intel.com; alison.schofield@intel.com; vishal.l.verma@intel.com;
>ira.weiny@intel.com; david@redhat.com; Vilas.Sridharan@amd.com;
>leo.duran@amd.com; Yazen.Ghannam@amd.com; rientjes@google.com;
>jiaqiyan@google.com; Jon.Grimm@amd.com; dave.hansen@linux.intel.com;
>naoya.horiguchi@nec.com; james.morse@arm.com; jthoughton@google.com;
>somasundaram.a@hpe.com; erdemaktas@google.com; pgonda@google.com;
>duenwen@google.com; gthelen@google.com;
>wschwartz@amperecomputing.com; dferguson@amperecomputing.com;
>wbs@os.amperecomputing.com; nifan.cxl@gmail.com; tanxiaofei
><tanxiaofei@huawei.com>; Zengtao (B) <prime.zeng@hisilicon.com>; Roberto
>Sassu <roberto.sassu@huawei.com>; kangkang.shen@futurewei.com;
>wanghuiqiang <wanghuiqiang@huawei.com>; Linuxarm
><linuxarm@huawei.com>
>Subject: Re: [PATCH v13 01/18] EDAC: Add support for EDAC device features
>control
>
>On Wed, 9 Oct 2024 13:41:02 +0100
><shiju.jose@huawei.com> wrote:
>
>> From: Shiju Jose <shiju.jose@huawei.com>
>>
>> Add generic EDAC device features control supports registering RAS
>> features supported in the system. Driver exposes features control
>> attributes to 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>
>Hi Shiju,
>
>Spotted a few minor bugs in here that I'd missed in internal review :( See below.
>
>Jonathan

Thanks for reviewing.
>
>> ---
>>  drivers/edac/edac_device.c | 105
>+++++++++++++++++++++++++++++++++++++
>>  include/linux/edac.h       |  32 +++++++++++
>>  2 files changed, 137 insertions(+)
>>
>> diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
>> index 621dc2a5d034..0b8aa8150239 100644
>> --- a/drivers/edac/edac_device.c
>> +++ b/drivers/edac/edac_device.c
>
>
>> +
>> +/**
>> + * edac_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.
>> + *
>> + * Return:
>> + *  * %0       - Success.
>> + *  * %-EINVAL - Invalid parameters passed.
>> + *  * %-ENOMEM - Dynamic memory allocation failed.
>> + *
>> + * The new edac_dev_feat_ctx would be freed automatically.
>> + */
>> +int edac_dev_register(struct device *parent, char *name,
>> +		      void *private, int num_features,
>> +		      const struct edac_dev_feature *ras_features) {
>
>...
>
>> +	ret = device_register(&ctx->dev);
>> +	if (ret) {
>> +		put_device(&ctx->dev);
>> +		goto groups_free;
>> +		return ret;
>
>Unreachable line. However, shouldn't have the goto here as put_device() should
>result in the release being called in which case this is a double free. So drop the
>goto and keep the return.
Fixed.
>
>
>> +	}
>> +
>> +	return devm_add_action_or_reset(parent, edac_dev_unreg, &ctx->dev);
>> +
>> +groups_free:
>> +	kfree(ras_attr_groups);
>> +ctx_free:
>> +	kfree(ctx);
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(edac_dev_register);
>> diff --git a/include/linux/edac.h b/include/linux/edac.h index
>> b4ee8961e623..1db008a82690 100644
>> --- a/include/linux/edac.h
>> +++ b/include/linux/edac.h
>> @@ -661,4 +661,36 @@ static inline struct dimm_info
>> *edac_get_dimm(struct mem_ctl_info *mci,
>
>
>> +/* EDAC device feature information structure */ struct edac_dev_data
>> +{
>> +	u8 instance;
>> +	void *private;
>> +};
>> +
>> +struct device;
>
>That forwards def doesn't work as this header needs to include enough
>information to establish layout of struct edac_dev_feat_ctx.
>Header already includes linux/device.h so just drop this.
Deleted.
>
>
>> +
>> +struct edac_dev_feat_ctx {
>> +	struct device dev;
>> +	void *private;
>> +};
>> +
>> +struct edac_dev_feature {
>> +	enum edac_dev_feat ft_type;
>> +	u8 instance;
>> +	void *ctx;
>> +};
>> +
>> +int edac_dev_register(struct device *parent, char *dev_name,
>> +		      void *parent_pvt_data, int num_features,
>> +		      const struct edac_dev_feature *ras_features);
>>  #endif /* _LINUX_EDAC_H_ */


Thanks,
Shiju
Shiju Jose Oct. 17, 2024, 8:37 a.m. UTC | #4
Hi Boris,

Thanks for the comments.

>-----Original Message-----
>From: Borislav Petkov <bp@alien8.de>
>Sent: 16 October 2024 11:59
>To: Shiju Jose <shiju.jose@huawei.com>
>Cc: linux-edac@vger.kernel.org; linux-cxl@vger.kernel.org; linux-
>acpi@vger.kernel.org; linux-mm@kvack.org; linux-kernel@vger.kernel.org;
>tony.luck@intel.com; rafael@kernel.org; lenb@kernel.org;
>mchehab@kernel.org; dan.j.williams@intel.com; dave@stgolabs.net; Jonathan
>Cameron <jonathan.cameron@huawei.com>; dave.jiang@intel.com;
>alison.schofield@intel.com; vishal.l.verma@intel.com; ira.weiny@intel.com;
>david@redhat.com; Vilas.Sridharan@amd.com; leo.duran@amd.com;
>Yazen.Ghannam@amd.com; rientjes@google.com; jiaqiyan@google.com;
>Jon.Grimm@amd.com; dave.hansen@linux.intel.com;
>naoya.horiguchi@nec.com; james.morse@arm.com; jthoughton@google.com;
>somasundaram.a@hpe.com; erdemaktas@google.com; pgonda@google.com;
>duenwen@google.com; gthelen@google.com;
>wschwartz@amperecomputing.com; dferguson@amperecomputing.com;
>wbs@os.amperecomputing.com; nifan.cxl@gmail.com; tanxiaofei
><tanxiaofei@huawei.com>; Zengtao (B) <prime.zeng@hisilicon.com>; Roberto
>Sassu <roberto.sassu@huawei.com>; kangkang.shen@futurewei.com;
>wanghuiqiang <wanghuiqiang@huawei.com>; Linuxarm
><linuxarm@huawei.com>
>Subject: Re: [PATCH v13 01/18] EDAC: Add support for EDAC device features
>control
>
>On Wed, Oct 09, 2024 at 01:41:02PM +0100, shiju.jose@huawei.com wrote:
>> From: Shiju Jose <shiju.jose@huawei.com>
>>
>> Add generic EDAC device features control supports registering RAS
>> features supported in the system. Driver exposes features control
>> attributes to userspace in
>> /sys/bus/edac/devices/<dev-name>/<ras-feature>/
>
>Chatgpt prompt:
>
>| Please check the grammar in this English text: "Add generic EDAC
>| device features control supports registering RAS features supported in the
>system.
>| Driver exposes features control attributes to userspace in
>| /sys/bus/edac/devices/<dev-name>/<ras-"feature>/
>
>Response:
>
>| Here's a corrected version of the text:
>|
>| "Add generic EDAC device feature control support for registering RAS
>| features supported in the system. The driver exposes feature control
>| attributes to userspace in /sys/bus/edac/devices/<dev-name>/<ras-feature>/."
>|
>| Changes made:
>|
>| * "features control" was changed to "feature control" for consistency
>| and clarity.
>|
>| * "supports registering" was changed to "support for registering" to
>| match the structure of the sentence.
>|
>| * Added "The" at the beginning of the second sentence for better flow.
>|
>| * Corrected the syntax around the file path to ensure clarity and
>| proper
>| * punctuation.
>
>Please run all your commit text through some LLM AI as they're apparently good
>enough now to help me in correcting grammar.
Will do.
>
>> 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/edac_device.c | 105
>+++++++++++++++++++++++++++++++++++++
>>  include/linux/edac.h       |  32 +++++++++++
>>  2 files changed, 137 insertions(+)
>>
>> diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
>> index 621dc2a5d034..0b8aa8150239 100644
>> --- a/drivers/edac/edac_device.c
>> +++ b/drivers/edac/edac_device.c
>> @@ -570,3 +570,108 @@ void edac_device_handle_ue_count(struct
>edac_device_ctl_info *edac_dev,
>>  		      block ? block->name : "N/A", count, msg);  }
>> EXPORT_SYMBOL_GPL(edac_device_handle_ue_count);
>> +
>> +/* EDAC device feature */
>> +static void edac_dev_release(struct device *dev) {
>> +	struct edac_dev_feat_ctx *ctx = container_of(dev, struct
>> +edac_dev_feat_ctx, dev);
>> +
>> +	kfree(ctx->dev.groups);
>> +	kfree(ctx);
>> +}
>> +
>> +const struct device_type edac_dev_type = {
>> +	.name = "edac_dev",
>> +	.release = edac_dev_release,
>> +};
>> +
>> +static void edac_dev_unreg(void *data) {
>> +	device_unregister(data);
>> +}
>> +
>> +/**
>> + * edac_dev_register - register device for RAS features with EDAC
>> + * @parent: client device.
>
>If this is a client device, why is the variable called "parent" and not "client"?
>
>I.e.,
>
>	struct device *client;
>
>For clarity and simplicity.
>
>Or call it "parent" because you do:
>
>	ctx->dev.parent = parent;
>
>and forget "client" altogether.
Changed to "parent". 
>
>> + * @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.
>> + *
>> + * Return:
>> + *  * %0       - Success.
>> + *  * %-EINVAL - Invalid parameters passed.
>> + *  * %-ENOMEM - Dynamic memory allocation failed.
>> + *
>> + * The new edac_dev_feat_ctx would be freed automatically.
>
>Why is this important to call out here?
>
>It is a common coding pattern of freeing resources in the release function...
Deleted.
>
>> + */
>> +int edac_dev_register(struct device *parent, char *name,
>> +		      void *private, int num_features,
>> +		      const struct edac_dev_feature *ras_features) {
>> +	const struct attribute_group **ras_attr_groups;
>> +	struct edac_dev_feat_ctx *ctx;
>> +	int attr_gcnt = 0;
>> +	int ret, feat;
>> +
>> +	if (!parent || !name || !num_features || !ras_features)
>> +		return -EINVAL;
>> +
>> +	/* Double parse to make space for attributes */
>> +	for (feat = 0; feat < num_features; feat++) {
>> +		switch (ras_features[feat].ft_type) {
>> +		/* Add feature specific code */
>> +		default:
>> +			return -EINVAL;
>> +		}
>> +	}
>> +
>> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
>> +	if (!ctx)
>> +		return -ENOMEM;
>> +
>> +	ctx->dev.parent = parent;
>> +	ctx->private = private;
>> +
>> +	ras_attr_groups = kcalloc(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++) {
>> +		switch (ras_features->ft_type) {
>> +		/* Add feature specific code */
>> +		default:
>> +			ret = -EINVAL;
>> +			goto groups_free;
>> +		}
>> +	}
>> +
>> +	ras_attr_groups[attr_gcnt] = NULL;
>> +	ctx->dev.bus = edac_get_sysfs_subsys();
>> +	ctx->dev.type = &edac_dev_type;
>> +	ctx->dev.groups = ras_attr_groups;
>> +	dev_set_drvdata(&ctx->dev, ctx);
>> +
>> +	ret = dev_set_name(&ctx->dev, name);
>> +	if (ret)
>> +		goto groups_free;
>> +
>> +	ret = device_register(&ctx->dev);
>> +	if (ret) {
>> +		put_device(&ctx->dev);
>> +		goto groups_free;
>> +		return ret;
>		^^^^^^^^^^
>
>Come again?!
>
>There's code after a "goto"?
Fixed.
>
>--
>Regards/Gruss,
>    Boris.
>
>https://people.kernel.org/tglx/notes-about-netiquette

Thanks,
Shiju
diff mbox series

Patch

diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index 621dc2a5d034..0b8aa8150239 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -570,3 +570,108 @@  void edac_device_handle_ue_count(struct edac_device_ctl_info *edac_dev,
 		      block ? block->name : "N/A", count, msg);
 }
 EXPORT_SYMBOL_GPL(edac_device_handle_ue_count);
+
+/* EDAC device feature */
+static void edac_dev_release(struct device *dev)
+{
+	struct edac_dev_feat_ctx *ctx = container_of(dev, struct edac_dev_feat_ctx, dev);
+
+	kfree(ctx->dev.groups);
+	kfree(ctx);
+}
+
+const struct device_type edac_dev_type = {
+	.name = "edac_dev",
+	.release = edac_dev_release,
+};
+
+static void edac_dev_unreg(void *data)
+{
+	device_unregister(data);
+}
+
+/**
+ * edac_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.
+ *
+ * Return:
+ *  * %0       - Success.
+ *  * %-EINVAL - Invalid parameters passed.
+ *  * %-ENOMEM - Dynamic memory allocation failed.
+ *
+ * The new edac_dev_feat_ctx would be freed automatically.
+ */
+int edac_dev_register(struct device *parent, char *name,
+		      void *private, int num_features,
+		      const struct edac_dev_feature *ras_features)
+{
+	const struct attribute_group **ras_attr_groups;
+	struct edac_dev_feat_ctx *ctx;
+	int attr_gcnt = 0;
+	int ret, feat;
+
+	if (!parent || !name || !num_features || !ras_features)
+		return -EINVAL;
+
+	/* Double parse to make space for attributes */
+	for (feat = 0; feat < num_features; feat++) {
+		switch (ras_features[feat].ft_type) {
+		/* Add feature specific code */
+		default:
+			return -EINVAL;
+		}
+	}
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->dev.parent = parent;
+	ctx->private = private;
+
+	ras_attr_groups = kcalloc(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++) {
+		switch (ras_features->ft_type) {
+		/* Add feature specific code */
+		default:
+			ret = -EINVAL;
+			goto groups_free;
+		}
+	}
+
+	ras_attr_groups[attr_gcnt] = NULL;
+	ctx->dev.bus = edac_get_sysfs_subsys();
+	ctx->dev.type = &edac_dev_type;
+	ctx->dev.groups = ras_attr_groups;
+	dev_set_drvdata(&ctx->dev, ctx);
+
+	ret = dev_set_name(&ctx->dev, name);
+	if (ret)
+		goto groups_free;
+
+	ret = device_register(&ctx->dev);
+	if (ret) {
+		put_device(&ctx->dev);
+		goto groups_free;
+		return ret;
+	}
+
+	return devm_add_action_or_reset(parent, edac_dev_unreg, &ctx->dev);
+
+groups_free:
+	kfree(ras_attr_groups);
+ctx_free:
+	kfree(ctx);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(edac_dev_register);
diff --git a/include/linux/edac.h b/include/linux/edac.h
index b4ee8961e623..1db008a82690 100644
--- a/include/linux/edac.h
+++ b/include/linux/edac.h
@@ -661,4 +661,36 @@  static inline struct dimm_info *edac_get_dimm(struct mem_ctl_info *mci,
 
 	return mci->dimms[index];
 }
+
+/* EDAC device features */
+
+#define EDAC_FEAT_NAME_LEN	128
+
+/* RAS feature type */
+enum edac_dev_feat {
+	RAS_FEAT_MAX
+};
+
+/* EDAC device feature information structure */
+struct edac_dev_data {
+	u8 instance;
+	void *private;
+};
+
+struct device;
+
+struct edac_dev_feat_ctx {
+	struct device dev;
+	void *private;
+};
+
+struct edac_dev_feature {
+	enum edac_dev_feat ft_type;
+	u8 instance;
+	void *ctx;
+};
+
+int edac_dev_register(struct device *parent, char *dev_name,
+		      void *parent_pvt_data, int num_features,
+		      const struct edac_dev_feature *ras_features);
 #endif /* _LINUX_EDAC_H_ */