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From:   Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
To:     Jason Gunthorpe <jgg@nvidia.com>
CC:     "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "alex.williamson@redhat.com" <alex.williamson@redhat.com>,
        "cohuck@redhat.com" <cohuck@redhat.com>,
        "mgurtovoy@nvidia.com" <mgurtovoy@nvidia.com>,
        "yishaih@nvidia.com" <yishaih@nvidia.com>,
        Linuxarm <linuxarm@huawei.com>,
        liulongfang <liulongfang@huawei.com>,
        "Zengtao (B)" <prime.zeng@hisilicon.com>,
        Jonathan Cameron <jonathan.cameron@huawei.com>,
        "Wangzhou (B)" <wangzhou1@hisilicon.com>
Subject: RE: [RFC v4 6/8] crypto: hisilicon/qm: Add helper to retrieve the PF
 qm data
Thread-Topic: [RFC v4 6/8] crypto: hisilicon/qm: Add helper to retrieve the PF
 qm data
Thread-Index: AQHYHPDtLJcNOLWDh0OuZhX3BN5rGayJtYqAgAAE/IA=
Date:   Tue, 8 Feb 2022 14:49:48 +0000
Message-ID: <05460d58380b435fb629d2e04a83a1aa@huawei.com>
References: <20220208133425.1096-1-shameerali.kolothum.thodi@huawei.com>
 <20220208133425.1096-7-shameerali.kolothum.thodi@huawei.com>
 <20220208142525.GE4160@nvidia.com>
In-Reply-To: <20220208142525.GE4160@nvidia.com>
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> -----Original Message-----
> From: Jason Gunthorpe [mailto:jgg@nvidia.com]
> Sent: 08 February 2022 14:25
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org;
> linux-crypto@vger.kernel.org; alex.williamson@redhat.com;
> cohuck@redhat.com; mgurtovoy@nvidia.com; yishaih@nvidia.com; Linuxarm
> <linuxarm@huawei.com>; liulongfang <liulongfang@huawei.com>; Zengtao (B)
> <prime.zeng@hisilicon.com>; Jonathan Cameron
> <jonathan.cameron@huawei.com>; Wangzhou (B) <wangzhou1@hisilicon.com>
> Subject: Re: [RFC v4 6/8] crypto: hisilicon/qm: Add helper to retrieve the PF
> qm data
> 
> On Tue, Feb 08, 2022 at 01:34:23PM +0000, Shameer Kolothum wrote:
> 
> > +struct hisi_qm *hisi_qm_get_pf_qm(struct pci_dev *pdev)
> > +{
> > +	struct hisi_qm	*pf_qm;
> > +	struct pci_driver *(*fn)(void) = NULL;
> > +
> > +	if (!pdev->is_virtfn)
> > +		return NULL;
> > +
> > +	switch (pdev->device) {
> > +	case PCI_DEVICE_ID_HUAWEI_SEC_VF:
> > +		fn = symbol_get(hisi_sec_get_pf_driver);
> > +		break;
> > +	case PCI_DEVICE_ID_HUAWEI_HPRE_VF:
> > +		fn = symbol_get(hisi_hpre_get_pf_driver);
> > +		break;
> > +	case PCI_DEVICE_ID_HUAWEI_ZIP_VF:
> > +		fn = symbol_get(hisi_zip_get_pf_driver);
> > +		break;
> > +	default:
> > +		return NULL;
> > +	}
> > +
> > +	if (!fn)
> > +		return NULL;
> > +
> > +	pf_qm = pci_iov_get_pf_drvdata(pdev, fn());
> > +
> > +	if (pdev->device == PCI_DEVICE_ID_HUAWEI_SEC_VF)
> > +		symbol_put(hisi_sec_get_pf_driver);
> > +	else if (pdev->device == PCI_DEVICE_ID_HUAWEI_HPRE_VF)
> > +		symbol_put(hisi_hpre_get_pf_driver);
> > +	else
> > +		symbol_put(hisi_zip_get_pf_driver);
> > +
> > +	return !IS_ERR(pf_qm) ? pf_qm : NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(hisi_qm_get_pf_qm);
> 
> Why put this in this driver, why not in the vfio driver? And why use
> symbol_get ?

QM driver provides a generic common interface for all HiSilicon ACC
drivers. So thought of placing it here. And symbol_get/put is used
to avoid having dependency of all the ACC drivers being built along
with the vfio driver. Is there a better way to retrieve the struct pci_driver *
associated with each ACC PF driver? Please let me know.

Thanks,
Shameer