Re: [PATCH] ahci: Introduce ahci_ignore_port() helper

[Niklas Cassel <cassel@kernel.org>]

On Mon, Jan 06, 2025 at 02:27:01PM +0900, Damien Le Moal wrote:
> libahci and AHCI drivers may ignore some ports if the port is invalid
> (its ID does not correspond to a valid physical port) or if the user
> explicitly requested the port to be ignored with the mask_port_map
> ahci module parameter. Such port that shall be ignored can be identified
> by checking that the bit corresponding to the port ID is not set in the
> mask_port_map field of struct ahci_host_priv. E.g. code such as:
> "if (!(hpriv->mask_port_map & (1 << portid)))".
> 
> Replace all direct use of the mask_port_map field to detect such port
> with the new helper inline function ahci_ignore_port() to make the code
> more readable/easier to understand.
> 
> The comment describing the mask_port_map field of struct ahci_host_priv
> is also updated to be more accurate.
> 
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> ---
>  drivers/ata/ahci.h             | 13 ++++++++++++-
>  drivers/ata/ahci_brcm.c        |  2 +-
>  drivers/ata/ahci_ceva.c        |  4 ++--
>  drivers/ata/libahci_platform.c |  6 +++---
>  4 files changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
> index 8f40f75ba08c..aea30df50c58 100644
> --- a/drivers/ata/ahci.h
> +++ b/drivers/ata/ahci.h
> @@ -328,7 +328,7 @@ struct ahci_port_priv {
>  struct ahci_host_priv {
>  	/* Input fields */
>  	unsigned int		flags;		/* AHCI_HFLAG_* */
> -	u32			mask_port_map;	/* mask out particular bits */
> +	u32			mask_port_map;	/* Mask of valid ports */
>  
>  	void __iomem *		mmio;		/* bus-independent mem map */
>  	u32			cap;		/* cap to use */
> @@ -379,6 +379,17 @@ struct ahci_host_priv {
>  						  int port);
>  };
>  
> +/*
> + * Return true if a port should be ignored because it is excluded from
> + * the host port map.
> + */
> +static inline bool ahci_ignore_port(struct ahci_host_priv *hpriv,
> +				    unsigned int portid)
> +{
> +	return portid >= hpriv->nports ||
> +		!(hpriv->mask_port_map & (1 << portid));
> +}
> +
>  extern int ahci_ignore_sss;
>  
>  extern const struct attribute_group *ahci_shost_groups[];
> diff --git a/drivers/ata/ahci_brcm.c b/drivers/ata/ahci_brcm.c
> index 24c471b485ab..29be74fedcf0 100644
> --- a/drivers/ata/ahci_brcm.c
> +++ b/drivers/ata/ahci_brcm.c
> @@ -288,7 +288,7 @@ static unsigned int brcm_ahci_read_id(struct ata_device *dev,
>  
>  	/* Re-initialize and calibrate the PHY */
>  	for (i = 0; i < hpriv->nports; i++) {
> -		if (!(hpriv->mask_port_map & (1 << i)))
> +		if (ahci_ignore_port(hpriv, i))
>  			continue;
>  
>  		rc = phy_init(hpriv->phys[i]);
> diff --git a/drivers/ata/ahci_ceva.c b/drivers/ata/ahci_ceva.c
> index f2e20ed11ec7..2d6a08c23d6a 100644
> --- a/drivers/ata/ahci_ceva.c
> +++ b/drivers/ata/ahci_ceva.c
> @@ -206,7 +206,7 @@ static int ceva_ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
>  		goto disable_clks;
>  
>  	for (i = 0; i < hpriv->nports; i++) {
> -		if (!(hpriv->mask_port_map & (1 << i)))
> +		if (ahci_ignore_port(hpriv, i))
>  			continue;
>  
>  		rc = phy_init(hpriv->phys[i]);
> @@ -218,7 +218,7 @@ static int ceva_ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
>  	ahci_platform_deassert_rsts(hpriv);
>  
>  	for (i = 0; i < hpriv->nports; i++) {
> -		if (!(hpriv->mask_port_map & (1 << i)))
> +		if (ahci_ignore_port(hpriv, i))
>  			continue;
>  
>  		rc = phy_power_on(hpriv->phys[i]);
> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> index b68777841f7a..53b2c7719dc5 100644
> --- a/drivers/ata/libahci_platform.c
> +++ b/drivers/ata/libahci_platform.c
> @@ -49,7 +49,7 @@ int ahci_platform_enable_phys(struct ahci_host_priv *hpriv)
>  	int rc, i;
>  
>  	for (i = 0; i < hpriv->nports; i++) {
> -		if (!(hpriv->mask_port_map & (1 << i)))
> +		if (ahci_ignore_port(hpriv, i))
>  			continue;
>  
>  		rc = phy_init(hpriv->phys[i]);
> @@ -73,7 +73,7 @@ int ahci_platform_enable_phys(struct ahci_host_priv *hpriv)
>  
>  disable_phys:
>  	while (--i >= 0) {
> -		if (!(hpriv->mask_port_map & (1 << i)))
> +		if (ahci_ignore_port(hpriv, i))
>  			continue;
>  
>  		phy_power_off(hpriv->phys[i]);
> @@ -94,7 +94,7 @@ void ahci_platform_disable_phys(struct ahci_host_priv *hpriv)
>  	int i;
>  
>  	for (i = 0; i < hpriv->nports; i++) {
> -		if (!(hpriv->mask_port_map & (1 << i)))
> +		if (ahci_ignore_port(hpriv, i))
>  			continue;
>  
>  		phy_power_off(hpriv->phys[i]);
> -- 
> 2.47.1
> 

Reviewed-by: Niklas Cassel <cassel@kernel.org>