Re: [PATCH 08/46] libata: Add ata_port_classify() helper

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

On 2/4/20 5:55 PM, Hannes Reinecke wrote:
> Add an ata_port_classify() helper to print out the results from
> the device classification and remove the debugging statements
> from ata_dev_classify(). Also provide a mapping ata_dev_class_string()
> to provide a string representation for those instances calling
> ata_dev_classify() directly.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>  drivers/ata/libahci.c       |  2 +-
>  drivers/ata/libata-core.c   | 68 ++++++++++++++++++++++++++++++++++-----------
>  drivers/ata/libata-sff.c    |  5 ++++
>  drivers/ata/sata_fsl.c      |  2 +-
>  drivers/ata/sata_inic162x.c |  2 +-
>  drivers/ata/sata_sil24.c    |  2 +-
>  include/linux/libata.h      |  3 ++
>  7 files changed, 64 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index 4055071f213f..c1bc973ecc16 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -1276,7 +1276,7 @@ unsigned int ahci_dev_classify(struct ata_port *ap)
>  	tf.lbal		= (tmp >> 8)	& 0xff;
>  	tf.nsect	= (tmp)		& 0xff;
>  
> -	return ata_dev_classify(&tf);
> +	return ata_port_classify(ap, &tf);
>  }
>  EXPORT_SYMBOL_GPL(ahci_dev_classify);
>  
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 0f5715cfa1c4..b2b96420a2f2 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -1025,6 +1025,27 @@ const char *sata_spd_string(unsigned int spd)
>  	return spd_str[spd - 1];
>  }
>  
> +const char *ata_dev_class_string(unsigned int class)
> +{
> +	static const char * const class_str[] = {
> +		"unknown",
> +		"ATA",
> +		"ATA (unsupported)",
> +		"ATAPI",
> +		"ATAPI (unsupported",
> +		"PMP",
> +		"PMP (unsupported)",
> +		"SEMB",
> +		"SEMB (unsupported)",
> +		"ZAC",
> +		"ZAC (unsupported)",
> +		"none",
> +	};
> +	if (class == 0 || (class - 1) >= ARRAY_SIZE(class_str))
> +		return "unknown";
> +	return class_str[class - 1];
> +}
> +
>  /**
>   *	ata_dev_classify - determine device type based on ATA-spec signature
>   *	@tf: ATA taskfile register set for device to be identified
> @@ -1063,35 +1084,48 @@ unsigned int ata_dev_classify(const struct ata_taskfile *tf)
>  	 * SEMB signature.  This is worked around in
>  	 * ata_dev_read_id().
>  	 */
> -	if ((tf->lbam == 0) && (tf->lbah == 0)) {
> -		DPRINTK("found ATA device by sig\n");
> +	if ((tf->lbam == 0) && (tf->lbah == 0))
>  		return ATA_DEV_ATA;
> -	}
>  
> -	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
> -		DPRINTK("found ATAPI device by sig\n");
> +	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb))
>  		return ATA_DEV_ATAPI;
> -	}
>  
> -	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
> -		DPRINTK("found PMP device by sig\n");
> +	if ((tf->lbam == 0x69) && (tf->lbah == 0x96))
>  		return ATA_DEV_PMP;
> -	}
>  
> -	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
> -		DPRINTK("found SEMB device by sig (could be ATA device)\n");
> +	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3))
>  		return ATA_DEV_SEMB;
> -	}
>  
> -	if ((tf->lbam == 0xcd) && (tf->lbah == 0xab)) {
> -		DPRINTK("found ZAC device by sig\n");
> +	if ((tf->lbam == 0xcd) && (tf->lbah == 0xab))
>  		return ATA_DEV_ZAC;
> -	}
>  
> -	DPRINTK("unknown device\n");
>  	return ATA_DEV_UNKNOWN;
>  }
>  
> +/**
> + *	ata_port_classify - determine device type based on ATA-spec signature
> + *	@ap: ATA port device on which the classification should be run
> + *	@tf: ATA taskfile register set for device to be identified
> + *
> + *	A wrapper around ata_dev_classify() to provide additional logging
> + *
> + *	RETURNS:
> + *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP,
> + *	%ATA_DEV_ZAC, or %ATA_DEV_UNKNOWN the event of failure.
> + */
> +unsigned int ata_port_classify(struct ata_port *ap,
> +			      const struct ata_taskfile *tf)
> +{
> +	unsigned int class = ata_dev_classify(tf);
> +
> +	if (class != ATA_DEV_UNKNOWN)
> +		ata_port_dbg(ap, "found %s device by sig\n",
> +			     ata_dev_class_string(class));
> +	else
> +		ata_port_dbg(ap, "found unknown device\n");
> +	return class;
> +}
> +
>  /**
>   *	ata_id_string - Convert IDENTIFY DEVICE page into string
>   *	@id: IDENTIFY DEVICE results we will examine
> @@ -7267,6 +7301,7 @@ EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);
>  EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);
>  EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);
>  EXPORT_SYMBOL_GPL(ata_mode_string);
> +EXPORT_SYMBOL_GPL(ata_dev_class_string);

This is not needed currently, please remove it.

Also EXPORT_SYMBOL_GPL() for ata_dev_classify() should be now
removed too.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

>  EXPORT_SYMBOL_GPL(ata_id_xfermask);
>  EXPORT_SYMBOL_GPL(ata_do_set_mode);
>  EXPORT_SYMBOL_GPL(ata_std_qc_defer);
> @@ -7282,6 +7317,7 @@ EXPORT_SYMBOL_GPL(sata_link_hardreset);
>  EXPORT_SYMBOL_GPL(sata_std_hardreset);
>  EXPORT_SYMBOL_GPL(ata_std_postreset);
>  EXPORT_SYMBOL_GPL(ata_dev_classify);
> +EXPORT_SYMBOL_GPL(ata_port_classify);
>  EXPORT_SYMBOL_GPL(ata_dev_pair);
>  EXPORT_SYMBOL_GPL(ata_ratelimit);
>  EXPORT_SYMBOL_GPL(ata_msleep);
> diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
> index 931ae61d69fb..60509997137f 100644
> --- a/drivers/ata/libata-sff.c
> +++ b/drivers/ata/libata-sff.c
> @@ -1839,6 +1839,11 @@ unsigned int ata_sff_dev_classify(struct ata_device *dev, int present,
>  
>  	/* determine if device is ATA or ATAPI */
>  	class = ata_dev_classify(&tf);
> +	if (class != ATA_DEV_UNKNOWN)
> +		ata_dev_dbg(dev, "found %s device by sig\n",
> +			     ata_dev_class_string(class));
> +	else
> +		ata_dev_dbg(dev, "found unknown device\n");
>  
>  	if (class == ATA_DEV_UNKNOWN) {
>  		/* If the device failed diagnostic, it's likely to
> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
> index d55ee244d693..0864c4fafa39 100644
> --- a/drivers/ata/sata_fsl.c
> +++ b/drivers/ata/sata_fsl.c
> @@ -812,7 +812,7 @@ static unsigned int sata_fsl_dev_classify(struct ata_port *ap)
>  	tf.lbal = (temp >> 8) & 0xff;
>  	tf.nsect = temp & 0xff;
>  
> -	return ata_dev_classify(&tf);
> +	return ata_port_classify(ap, &tf);
>  }
>  
>  static int sata_fsl_hardreset(struct ata_link *link, unsigned int *class,
> diff --git a/drivers/ata/sata_inic162x.c b/drivers/ata/sata_inic162x.c
> index a6b76cc12a66..12f189f2ab1e 100644
> --- a/drivers/ata/sata_inic162x.c
> +++ b/drivers/ata/sata_inic162x.c
> @@ -657,7 +657,7 @@ static int inic_hardreset(struct ata_link *link, unsigned int *class,
>  		}
>  
>  		inic_tf_read(ap, &tf);
> -		*class = ata_dev_classify(&tf);
> +		*class = ata_port_classify(ap, &tf);
>  	}
>  
>  	return 0;
> diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
> index 560070d4f1d0..2373cf5d8d14 100644
> --- a/drivers/ata/sata_sil24.c
> +++ b/drivers/ata/sata_sil24.c
> @@ -677,7 +677,7 @@ static int sil24_softreset(struct ata_link *link, unsigned int *class,
>  	}
>  
>  	sil24_read_tf(ap, 0, &tf);
> -	*class = ata_dev_classify(&tf);
> +	*class = ata_port_classify(ap, &tf);
>  
>  	DPRINTK("EXIT, class=%u\n", *class);
>  	return 0;
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 437d2f27bfdd..c7ffe6fb39f1 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -1173,7 +1173,10 @@ extern int ata_std_qc_defer(struct ata_queued_cmd *qc);
>  extern enum ata_completion_errors ata_noop_qc_prep(struct ata_queued_cmd *qc);
>  extern void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
>  		 unsigned int n_elem);
> +extern const char *ata_dev_class_string(unsigned int class);
>  extern unsigned int ata_dev_classify(const struct ata_taskfile *tf);
> +extern unsigned int ata_port_classify(struct ata_port *ap,
> +				      const struct ata_taskfile *tf);
>  extern void ata_dev_disable(struct ata_device *adev);
>  extern void ata_id_string(const u16 *id, unsigned char *s,
>  			  unsigned int ofs, unsigned int len);
>