On Thu, Mar 06, 2025 at 09:31:06AM -0800, Bao D. Nguyen wrote:
> The device JEDEC standard version 4.1 adds support for the device
> level exception events. To support this new device level exception
> feature, expose two new sysfs nodes below to provide
> the user space access to the device level exception information.
> /sys/bus/platform/drivers/ufshcd/*/device_lvl_exception
> /sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_id
>
> The device_lvl_exception sysfs node reports the number of
> device level exceptions that have occurred since the last time
> this variable is reset.
> The device_lvl_exception_id sysfs node reports the exception ID
> which is the JEDEC standard qDeviceLevelExceptionID attribute.
> The user space application can query these sysfs nodes to get more
> information about the device level exception.
>
> Signed-off-by: Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-driver-ufs | 23 +++++++++++
> drivers/ufs/core/ufs-sysfs.c | 54 ++++++++++++++++++++++++++
> drivers/ufs/core/ufshcd-priv.h | 1 +
> drivers/ufs/core/ufshcd.c | 61 ++++++++++++++++++++++++++++++
> include/uapi/scsi/scsi_bsg_ufs.h | 9 +++++
> include/ufs/ufs.h | 5 ++-
> include/ufs/ufshcd.h | 5 +++
> 7 files changed, 157 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
> index ae01912..5cf3f43 100644
> --- a/Documentation/ABI/testing/sysfs-driver-ufs
> +++ b/Documentation/ABI/testing/sysfs-driver-ufs
> @@ -1604,3 +1604,26 @@ Description:
> prevent the UFS from frequently performing clock gating/ungating.
>
> The attribute is read/write.
> +
> +What: /sys/bus/platform/drivers/ufshcd/*/device_lvl_exception
> +What: /sys/bus/platform/devices/*.ufs/device_lvl_exception
> +Date: March 2025
> +Contact: Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx>
> +Description:
> + The device_lvl_exception is a counter indicating the number
> + of times the device level exceptions have occurred since the
> + last time this variable is reset. Read the device_lvl_exception_id
> + sysfs node to know more information about the exception.
> + The file is read only.
No. This attribute is RW and the write of 0 will reset the counter. Please
change it here and also in commit message.
Also document the spec version requirement for these attributes.
> +
> +What: /sys/bus/platform/drivers/ufshcd/*/device_lvl_exception_id
> +What: /sys/bus/platform/devices/*.ufs/device_lvl_exception_id
> +Date: March 2025
> +Contact: Bao D. Nguyen <quic_nguyenb@xxxxxxxxxxx>
> +Description:
> + Reading the device_lvl_exception_id returns the device JEDEC
> + standard's qDeviceLevelExceptionID attribute. The definition of the
> + qDeviceLevelExceptionID is the ufs device vendor specific design.
> + Refer to the device manufacturer datasheet for more information
> + on the meaning of the qDeviceLevelExceptionID attribute value.
> + The file is read only.
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
> index 90b5ab6..0248288a 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -466,6 +466,56 @@ static ssize_t critical_health_show(struct device *dev,
> return sysfs_emit(buf, "%d\n", hba->critical_health_count);
> }
>
[...]
> +int ufshcd_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id)
> +{
> + struct utp_upiu_query_response_v4_0 *upiu_resp;
> + struct ufs_query_req *request = NULL;
> + struct ufs_query_res *response = NULL;
> + int err;
> +
> + if (hba->dev_info.wspecversion < 0x410)
> + return -EOPNOTSUPP;
> +
> + ufshcd_hold(hba);
> + mutex_lock(&hba->dev_cmd.lock);
> +
> + ufshcd_init_query(hba, &request, &response,
> + UPIU_QUERY_OPCODE_READ_ATTR,
> + QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID, 0, 0);
> +
> + request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
> +
> + err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);
> +
> + if (err) {
> + dev_err(hba->dev, "%s: failed to read device level exception %d\n",
> + __func__, err);
> + goto out;
> + }
> +
> + upiu_resp = (struct utp_upiu_query_response_v4_0 *)response;
> + *exception_id = get_unaligned_be64(&upiu_resp->value);
> +
> +out:
> + mutex_unlock(&hba->dev_cmd.lock);
> + ufshcd_release(hba);
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(ufshcd_read_device_lvl_exception_id);
There is no need to export this function.
- Mani
--
மணிவண்ணன் சதாசிவம்
