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Date:   Tue, 27 Sep 2022 09:38:30 +0100
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Subject: Re: [PATCH v4 1/8] scsi: libsas: introduce sas address comparison
 helpers
To:     Jason Yan <yanaijie@huawei.com>, <martin.petersen@oracle.com>,
        <jejb@linux.ibm.com>
CC:     <linux-scsi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <hare@suse.com>, <hch@lst.de>, <bvanassche@acm.org>,
        <jinpu.wang@cloud.ionos.com>, <damien.lemoal@opensource.wdc.com>
References: <20220927032605.78103-1-yanaijie@huawei.com>
 <20220927032605.78103-2-yanaijie@huawei.com>
From:   John Garry <john.garry@huawei.com>
In-Reply-To: <20220927032605.78103-2-yanaijie@huawei.com>
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On 27/09/2022 04:25, Jason Yan wrote:
> Sas address comparison is widely used in libsas. However they are all
> opencoded and to avoid the line spill over 80 columns, are mostly split
> into multi-lines. Introduce some helpers to prepare some refactor.
> 
> Signed-off-by: Jason Yan <yanaijie@huawei.com>
> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Reviewed-by: John Garry <john.garry@huawei.com>

> ---
>   drivers/scsi/libsas/sas_internal.h | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
> index 8d0ad3abc7b5..3384429b7eb0 100644
> --- a/drivers/scsi/libsas/sas_internal.h
> +++ b/drivers/scsi/libsas/sas_internal.h
> @@ -111,6 +111,23 @@ static inline void sas_smp_host_handler(struct bsg_job *job,
>   }
>   #endif
>   
> +static inline bool sas_phy_match_dev_addr(struct domain_device *dev,
> +					 struct ex_phy *phy)
> +{
> +	return SAS_ADDR(dev->sas_addr) == SAS_ADDR(phy->attached_sas_addr);
> +}
> +
> +static inline bool sas_phy_match_port_addr(struct asd_sas_port *port,
> +					   struct ex_phy *phy)
> +{
> +	return SAS_ADDR(port->sas_addr) == SAS_ADDR(phy->attached_sas_addr);
> +}
> +
> +static inline bool sas_phy_addr_match(struct ex_phy *p1, struct ex_phy *p2)
> +{
> +	return  SAS_ADDR(p1->attached_sas_addr) == SAS_ADDR(p2->attached_sas_addr);
> +}
> +

note: I did think that we could use a macro as a generic matching API, like:

#define sas_phy_match_addr_common(x, ex_phy) \
	({ typeof(x) __dummy; \
	if (__builtin_types_compatible_p(typeof(__dummy), struct asd_sas_port))\
	sas_phy_match_port_addr(x, ex_phy);\
	if (__builtin_types_compatible_p(typeof(__dummy), struct domain_device))\
	sas_phy_match_dev_addr(x, ex_phy);\
	0; \
})

But I couldn't get it to work after 60 minutes of messing ... indeed, 
that latest code doesn't even compile..

Thanks,
John

>   static inline void sas_fail_probe(struct domain_device *dev, const char *func, int err)
>   {
>   	pr_warn("%s: for %s device %016llx returned %d\n",