Re: [PATCH v5 05/15] scsi: ufs: add support to read device and string descriptors

[Hannes Reinecke <hare@suse.de>]

On 02/28/2016 09:32 PM, Yaniv Gardi wrote:
> This change adds support to read device descriptor and string descriptor
> from a UFS device
> 
> Reviewed-by: Gilad Broner <gbroner@codeaurora.org>
> Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
> 
> ---
>  drivers/scsi/ufs/ufs.h    |  1 +
>  drivers/scsi/ufs/ufshcd.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++-
>  drivers/scsi/ufs/ufshcd.h |  7 ++++
>  3 files changed, 95 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 54a16ce..aacb235 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -43,6 +43,7 @@
>  #define GENERAL_UPIU_REQUEST_SIZE 32
>  #define QUERY_DESC_MAX_SIZE       255
>  #define QUERY_DESC_MIN_SIZE       2
> +#define QUERY_DESC_HDR_SIZE       2
>  #define QUERY_OSF_SIZE            (GENERAL_UPIU_REQUEST_SIZE - \
>  					(sizeof(struct utp_upiu_header)))
>  
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 80031e6..e2ed415 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -39,7 +39,7 @@
>  
>  #include <linux/async.h>
>  #include <linux/devfreq.h>
> -
> +#include <linux/nls.h>
>  #include <linux/of.h>
>  #include "ufshcd.h"
>  #include "unipro.h"
> @@ -232,6 +232,16 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba)
>  	}
>  }
>  
> +/* replace non-printable or non-ASCII characters with spaces */
> +static inline void ufshcd_remove_non_printable(char *val)
> +{
> +	if (!val)
> +		return;
> +
> +	if (*val < 0x20 || *val > 0x7e)
> +		*val = ' ';
> +}
> +
>  /*
>   * ufshcd_wait_for_register - wait for register value to change
>   * @hba - per-adapter interface
> @@ -2021,6 +2031,82 @@ static inline int ufshcd_read_power_desc(struct ufs_hba *hba,
>  	return ufshcd_read_desc(hba, QUERY_DESC_IDN_POWER, 0, buf, size);
>  }
>  
> +int ufshcd_read_device_desc(struct ufs_hba *hba, u8 *buf, u32 size)
> +{
> +	return ufshcd_read_desc(hba, QUERY_DESC_IDN_DEVICE, 0, buf, size);
> +}
> +EXPORT_SYMBOL(ufshcd_read_device_desc);
> +
> +/**
> + * ufshcd_read_string_desc - read string descriptor
> + * @hba: pointer to adapter instance
> + * @desc_index: descriptor index
> + * @buf: pointer to buffer where descriptor would be read
> + * @size: size of buf
> + * @ascii: if true convert from unicode to ascii characters
> + *
> + * Return 0 in case of success, non-zero otherwise
> + */
> +int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index, u8 *buf,
> +				u32 size, bool ascii)
> +{
> +	int err = 0;
> +
> +	err = ufshcd_read_desc(hba,
> +				QUERY_DESC_IDN_STRING, desc_index, buf, size);
> +
> +	if (err) {
> +		dev_err(hba->dev, "%s: reading String Desc failed after %d retries. err = %d\n",
> +			__func__, QUERY_REQ_RETRIES, err);
> +		goto out;
> +	}
> +
> +	if (ascii) {
> +		int desc_len;
> +		int ascii_len;
> +		int i;
> +		char *buff_ascii;
> +
> +		desc_len = buf[0];
> +		/* remove header and divide by 2 to move from UTF16 to UTF8 */
> +		ascii_len = (desc_len - QUERY_DESC_HDR_SIZE) / 2 + 1;
> +		if (size < ascii_len + QUERY_DESC_HDR_SIZE) {
> +			dev_err(hba->dev, "%s: buffer allocated size is too small\n",
> +					__func__);
> +			err = -ENOMEM;
> +			goto out;
> +		}
> +
> +		buff_ascii = kmalloc(ascii_len, GFP_KERNEL);
> +		if (!buff_ascii) {
> +			err = -ENOMEM;
> +			goto out_free_buff;
> +		}
> +
> +		/*
> +		 * the descriptor contains string in UTF16 format
> +		 * we need to convert to utf-8 so it can be displayed
> +		 */
> +		utf16s_to_utf8s((wchar_t *)&buf[QUERY_DESC_HDR_SIZE],
> +				desc_len - QUERY_DESC_HDR_SIZE,
> +				UTF16_BIG_ENDIAN, buff_ascii, ascii_len);
> +
> +		/* replace non-printable or non-ASCII characters with spaces */
> +		for (i = 0; i < ascii_len; i++)
> +			ufshcd_remove_non_printable(&buff_ascii[i]);
> +
> +		memset(buf + QUERY_DESC_HDR_SIZE, 0,
> +				size - QUERY_DESC_HDR_SIZE);
> +		memcpy(buf + QUERY_DESC_HDR_SIZE, buff_ascii, ascii_len);
> +		buf[QUERY_DESC_LENGTH_OFFSET] = ascii_len + QUERY_DESC_HDR_SIZE;
> +out_free_buff:
> +		kfree(buff_ascii);
> +	}
> +out:
> +	return err;
> +}
> +EXPORT_SYMBOL(ufshcd_read_string_desc);
> +
>  /**
>   * ufshcd_read_unit_desc_param - read the specified unit descriptor parameter
>   * @hba: Pointer to adapter instance
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index a6d3572..54e13cc 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -678,6 +678,13 @@ static inline int ufshcd_dme_peer_get(struct ufs_hba *hba,
>  	return ufshcd_dme_get_attr(hba, attr_sel, mib_val, DME_PEER);
>  }
>  
> +int ufshcd_read_device_desc(struct ufs_hba *hba, u8 *buf, u32 size);
> +
> +#define ASCII_STD true
> +
> +int ufshcd_read_string_desc(struct ufs_hba *hba, int desc_index, u8 *buf,
> +				u32 size, bool ascii);
> +
>  /* Expose Query-Request API */
>  int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
>  	enum flag_idn idn, bool *flag_res);
> 

Probably shows my ignorance, but _where_ is this function actually used?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
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