Re: [PATCH] ibft: Expose iBFT acpi header via sysfs

[Konrad Rzeszutek Wilk]

On Wed, Mar 23, 2016 at 09:49:26PM -0400, David Bond wrote:
> 
> Some ethernet adapter vendors are supplying products which support optional
> (payed license) features. On some adapters this includes a hardware iscsi
> initiator.  The same adapters in a normal (no extra licenses) mode of
> operation can be used as a software iscsi initiator.  In addition, software
> iscsi boot initiators are becoming a standard part of many vendors uefi
> implementations.  This is creating difficulties during early boot/install
> determining the proper configuration method for these adapters when they
> are used as a boot device.
> 
> The attached patch creates sysfs entries to expose information from the
> acpi header of the ibft table.  This information allows for a method to
> easily determining if an ibft table was created by a ethernet card's
> firmware or the system uefi/bios.  In the case of a hardware initiator this
> information in combination with the pci vendor and device id can be used
> to ascertain any vendor specific behaviors that need to be accommodated.

Heya!

Is there an patch in iscsiadm for this as well? Or is this 
> 
> Reviewed-by: Lee Duncan <lduncan@xxxxxxxx>
> Signed-off-by: David Bond <dbond@xxxxxxxx>
> ---
>  Documentation/ABI/testing/sysfs-ibft | 10 ++++++
>  drivers/firmware/iscsi_ibft.c        | 64 +++++++++++++++++++++++++++++++++++-
>  drivers/scsi/iscsi_boot_sysfs.c      | 62 ++++++++++++++++++++++++++++++++++
>  include/linux/iscsi_boot_sysfs.h     | 13 ++++++++
>  4 files changed, 148 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-ibft b/Documentation/ABI/testing/sysfs-ibft
> index cac3930..7d6725f 100644
> --- a/Documentation/ABI/testing/sysfs-ibft
> +++ b/Documentation/ABI/testing/sysfs-ibft
> @@ -21,3 +21,13 @@ Contact:	Konrad Rzeszutek <ketuzsezr@xxxxxxxxxx>
>  Description:	The /sys/firmware/ibft/ethernetX directory will contain
>  		files that expose the iSCSI Boot Firmware Table NIC data.
>  		Usually this contains the IP address, MAC, and gateway of the NIC.
> +
> +What:		/sys/firmware/ibft/acpi_header
> +Date:		March 2016
> +Contact:	David Bond <dbond@xxxxxxxx>
> +Description:	The /sys/firmware/ibft/acpi_header directory will contain files
> +		that expose the SIGNATURE, OEM_ID, and OEM_TABLE_ID fields of the
> +		acpi table header of the iBFT structure.  This will allow for
> +		identification of the creator of the table which is useful in
> +		determining quirks associated with some adapters when used in
> +		hardware vs software iscsi initiator mode.
> diff --git a/drivers/firmware/iscsi_ibft.c b/drivers/firmware/iscsi_ibft.c
> index 81037e5..2b1900b 100644
> --- a/drivers/firmware/iscsi_ibft.c
> +++ b/drivers/firmware/iscsi_ibft.c
> @@ -418,6 +418,31 @@ static ssize_t ibft_attr_show_target(void *data, int type, char *buf)
>  	return str - buf;
>  }
>  
> +static ssize_t ibft_attr_show_acpitbl(void *data, int type, char *buf)
> +{
> +	struct ibft_kobject *entry = data;
> +	char *str = buf;
> +
> +	switch (type) {
> +	case ISCSI_BOOT_ACPITBL_SIGNATURE:
> +		str += sprintf_string(str, ACPI_NAME_SIZE,
> +				      entry->header->header.signature);
> +		break;
> +	case ISCSI_BOOT_ACPITBL_OEM_ID:
> +		str += sprintf_string(str, ACPI_OEM_ID_SIZE,
> +				      entry->header->header.oem_id);
> +		break;
> +	case ISCSI_BOOT_ACPITBL_OEM_TABLE_ID:
> +		str += sprintf_string(str, ACPI_OEM_TABLE_ID_SIZE,
> +				      entry->header->header.oem_table_id);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return str - buf;
> +}
> +
>  static int __init ibft_check_device(void)
>  {
>  	int len;
> @@ -576,6 +601,24 @@ static umode_t __init ibft_check_initiator_for(void *data, int type)
>  	return rc;
>  }
>  
> +static umode_t __init ibft_check_acpitbl_for(void *data, int type)
> +{
> +
> +	umode_t rc = 0;
> +
> +	switch (type) {
> +	case ISCSI_BOOT_ACPITBL_SIGNATURE:
> +	case ISCSI_BOOT_ACPITBL_OEM_ID:
> +	case ISCSI_BOOT_ACPITBL_OEM_TABLE_ID:
> +		rc = S_IRUGO;
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return rc;
> +}
> +
>  static void ibft_kobj_release(void *data)
>  {
>  	kfree(data);
> @@ -699,6 +742,8 @@ free_ibft_obj:
>  static int __init ibft_register_kobjects(struct acpi_table_ibft *header)
>  {
>  	struct ibft_control *control = NULL;
> +	struct iscsi_boot_kobj *boot_kobj;
> +	struct ibft_kobject *ibft_kobj;
>  	void *ptr, *end;
>  	int rc = 0;
>  	u16 offset;
> @@ -727,6 +772,23 @@ static int __init ibft_register_kobjects(struct acpi_table_ibft *header)
>  		}
>  	}
>  

What about the rc earlier (from the loop)? You end up ignoring it.
Should we have:

if (rc)
	return rc;

?
> +	ibft_kobj = kzalloc(sizeof(*ibft_kobj), GFP_KERNEL);
> +	if (!ibft_kobj)
> +		return -ENOMEM;
> +
> +	ibft_kobj->header = header;
> +	ibft_kobj->hdr = NULL; /*for ibft_unregister*/
> +
> +	boot_kobj = iscsi_boot_create_acpitbl(boot_kset, 0,
> +					ibft_kobj,
> +					ibft_attr_show_acpitbl,
> +					ibft_check_acpitbl_for,
> +					ibft_kobj_release);

There something off with the offset here, but I presume it is just the
tabs and them not showing up properly in my editor.

> +	if (!boot_kobj)  {
> +		kfree(ibft_kobj);
> +		rc = -ENOMEM;
> +	}
> +
>  	return rc;
>  }
>  
> @@ -738,7 +800,7 @@ static void ibft_unregister(void)
>  	list_for_each_entry_safe(boot_kobj, tmp_kobj,
>  				 &boot_kset->kobj_list, list) {
>  		ibft_kobj = boot_kobj->data;
> -		if (ibft_kobj->hdr->id == id_nic)
> +		if (ibft_kobj->hdr && ibft_kobj->hdr->id == id_nic)
>  			sysfs_remove_link(&boot_kobj->kobj, "device");
>  	};
>  }
> diff --git a/drivers/scsi/iscsi_boot_sysfs.c b/drivers/scsi/iscsi_boot_sysfs.c
> index 8f0ea97..b472f56 100644
> --- a/drivers/scsi/iscsi_boot_sysfs.c
> +++ b/drivers/scsi/iscsi_boot_sysfs.c
> @@ -306,6 +306,42 @@ static struct attribute_group iscsi_boot_initiator_attr_group = {
>  	.is_visible = iscsi_boot_ini_attr_is_visible,
>  };
>  
> +/* iBFT ACPI Table attributes */
> +iscsi_boot_rd_attr(acpitbl_signature, signature, ISCSI_BOOT_ACPITBL_SIGNATURE);
> +iscsi_boot_rd_attr(acpitbl_oem_id, oem_id, ISCSI_BOOT_ACPITBL_OEM_ID);
> +iscsi_boot_rd_attr(acpitbl_oem_table_id, oem_table_id,
> +		   ISCSI_BOOT_ACPITBL_OEM_TABLE_ID);
> +
> +static struct attribute *acpitbl_attrs[] = {
> +	&iscsi_boot_attr_acpitbl_signature.attr,
> +	&iscsi_boot_attr_acpitbl_oem_id.attr,
> +	&iscsi_boot_attr_acpitbl_oem_table_id.attr,
> +	NULL
> +};
> +
> +static umode_t iscsi_boot_acpitbl_attr_is_visible(struct kobject *kobj,
> +					     struct attribute *attr, int i)
> +{
> +	struct iscsi_boot_kobj *boot_kobj =
> +			container_of(kobj, struct iscsi_boot_kobj, kobj);
> +
> +	if (attr ==  &iscsi_boot_attr_acpitbl_signature.attr)
> +		return boot_kobj->is_visible(boot_kobj->data,
> +					     ISCSI_BOOT_ACPITBL_SIGNATURE);
> +	if (attr ==  &iscsi_boot_attr_acpitbl_oem_id.attr)
> +		return boot_kobj->is_visible(boot_kobj->data,
> +					     ISCSI_BOOT_ACPITBL_OEM_ID);
> +	if (attr ==  &iscsi_boot_attr_acpitbl_oem_table_id.attr)
> +		return boot_kobj->is_visible(boot_kobj->data,
> +					     ISCSI_BOOT_ACPITBL_OEM_TABLE_ID);
> +	return 0;
> +}
> +
> +static struct attribute_group iscsi_boot_acpitbl_attr_group = {
> +	.attrs = acpitbl_attrs,
> +	.is_visible = iscsi_boot_acpitbl_attr_is_visible,
> +};
> +
>  static struct iscsi_boot_kobj *
>  iscsi_boot_create_kobj(struct iscsi_boot_kset *boot_kset,
>  		       struct attribute_group *attr_group,
> @@ -436,6 +472,32 @@ iscsi_boot_create_ethernet(struct iscsi_boot_kset *boot_kset, int index,
>  EXPORT_SYMBOL_GPL(iscsi_boot_create_ethernet);
>  
>  /**
> + * iscsi_boot_create_acpitbl() - create boot acpi table sysfs dir
> + * @boot_kset: boot kset
> + * @index: not used
> + * @data: driver specific data
> + * @show: attr show function
> + * @is_visible: attr visibility function
> + * @release: release function
> + *
> + * Note: The boot sysfs lib will free the data passed in for the caller
> + * when all refs to the acpitbl kobject have been released.
> + */
> +struct iscsi_boot_kobj *
> +iscsi_boot_create_acpitbl(struct iscsi_boot_kset *boot_kset, int index,
> +			   void *data,
> +			   ssize_t (*show)(void *data, int type, char *buf),
> +			   umode_t (*is_visible)(void *data, int type),
> +			   void (*release)(void *data))
> +{
> +	return iscsi_boot_create_kobj(boot_kset,
> +				      &iscsi_boot_acpitbl_attr_group,
> +				      "acpi_header", index, data, show,
> +				      is_visible, release);
> +}
> +EXPORT_SYMBOL_GPL(iscsi_boot_create_acpitbl);
> +
> +/**
>   * iscsi_boot_create_kset() - creates root sysfs tree
>   * @set_name: name of root dir
>   */
> diff --git a/include/linux/iscsi_boot_sysfs.h b/include/linux/iscsi_boot_sysfs.h
> index 548d553..10923d7 100644
> --- a/include/linux/iscsi_boot_sysfs.h
> +++ b/include/linux/iscsi_boot_sysfs.h
> @@ -64,6 +64,12 @@ enum iscsi_boot_initiator_properties_enum {
>  	ISCSI_BOOT_INI_END_MARKER,
>  };
>  
> +enum iscsi_boot_acpitbl_properties_enum {
> +	ISCSI_BOOT_ACPITBL_SIGNATURE,
> +	ISCSI_BOOT_ACPITBL_OEM_ID,
> +	ISCSI_BOOT_ACPITBL_OEM_TABLE_ID,
> +};
> +
>  struct attribute_group;
>  
>  struct iscsi_boot_kobj {
> @@ -127,6 +133,13 @@ iscsi_boot_create_target(struct iscsi_boot_kset *boot_kset, int index,
>  			 umode_t (*is_visible) (void *data, int type),
>  			 void (*release) (void *data));
>  
> +struct iscsi_boot_kobj *
> +iscsi_boot_create_acpitbl(struct iscsi_boot_kset *boot_kset, int index,
> +			  void *data,
> +			  ssize_t (*show)(void *data, int type, char *buf),
> +			  umode_t (*is_visible)(void *data, int type),
> +			  void (*release)(void *data));
> +
>  struct iscsi_boot_kset *iscsi_boot_create_kset(const char *set_name);
>  struct iscsi_boot_kset *iscsi_boot_create_host_kset(unsigned int hostno);
>  void iscsi_boot_destroy_kset(struct iscsi_boot_kset *boot_kset);
> -- 
> 2.6.2
>