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

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

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