Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
Message-ID: <053e89dd-8de9-43f3-8530-1f65181efd46@linux.intel.com>
Date:   Thu, 16 Nov 2023 11:23:56 +0800
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Cc:     baolu.lu@linux.intel.com,
        "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/4] iommu/vt-d: Introduce dev_to_iommu()
To:     "Tian, Kevin" <kevin.tian@intel.com>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jason Gunthorpe <jgg@ziepe.ca>
References: <20231116015048.29675-1-baolu.lu@linux.intel.com>
 <20231116015048.29675-2-baolu.lu@linux.intel.com>
 <BN9PR11MB5276CF0833BF362C1BE5F2268CB0A@BN9PR11MB5276.namprd11.prod.outlook.com>
Content-Language: en-US
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <BN9PR11MB5276CF0833BF362C1BE5F2268CB0A@BN9PR11MB5276.namprd11.prod.outlook.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 11/16/23 11:19 AM, Tian, Kevin wrote:
>> From: Lu Baolu <baolu.lu@linux.intel.com>
>> Sent: Thursday, November 16, 2023 9:51 AM
>>
>> +static inline struct intel_iommu *dev_to_iommu(struct device *dev)
>> +{
>> +	/*
>> +	 * Assume that valid per-device iommu structure must be installed
>> +	 * if iommu_probe_device() has succeeded. This helper could only
>> +	 * be used after device is probed.
>> +	 */
>> +	return ((struct device_domain_info *)dev_iommu_priv_get(dev))-
>>> iommu;
>> +}
> 
> Not sure whether this helper is useful. This is only used by 2 out of 5
> post-probe users. Probably just open-coding in all 5 places is clearer.

I thought it should get more users in the future development.

Best regards,
baolu