From: "luobin (L)" <luobin9@huawei.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: <davem@davemloft.net>, <linux-kernel@vger.kernel.org>,
<netdev@vger.kernel.org>, <luoxianjun@huawei.com>,
<yin.yinshi@huawei.com>, <cloud.wangxiaoyun@huawei.com>
Subject: Re: [PATCH net-next 2/3] hinic: add sriov feature support
Date: Thu, 23 Apr 2020 20:17:32 +0800 [thread overview]
Message-ID: <f739eabf-4254-04ae-53e9-35a6ccf0c831@huawei.com> (raw)
In-Reply-To: <20200421112121.2f0ddf30@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
These bit locks are mainly used for extendibility, and other opinions are accepted.Thanks for your review.
On 2020/4/22 2:21, Jakub Kicinski wrote:
> On Tue, 21 Apr 2020 04:56:34 +0000 Luo bin wrote:
>> +int hinic_pci_sriov_disable(struct pci_dev *pdev)
>> +{
>> + struct hinic_sriov_info *sriov_info;
>> + u16 tmp_vfs;
>> +
>> + sriov_info = hinic_get_sriov_info_by_pcidev(pdev);
>> + /* if SR-IOV is already disabled then nothing will be done */
>> + if (!sriov_info->sriov_enabled)
>> + return 0;
> Can't happen see below.
>
>> + if (test_and_set_bit(HINIC_SRIOV_DISABLE, &sriov_info->state)) {
>> + dev_err(&pdev->dev,
>> + "SR-IOV disable in process, please wait");
>> + return -EPERM;
>> + }
> Hm. I don't understand why you need these bit locks.
>
>> + /* If our VFs are assigned we cannot shut down SR-IOV
>> + * without causing issues, so just leave the hardware
>> + * available but disabled
>> + */
>> + if (pci_vfs_assigned(sriov_info->pdev)) {
>> + clear_bit(HINIC_SRIOV_DISABLE, &sriov_info->state);
>> + dev_warn(&pdev->dev, "Unloading driver while VFs are assigned - VFs will not be deallocated\n");
>> + return -EPERM;
>> + }
>> + sriov_info->sriov_enabled = false;
>> +
>> + /* disable iov and allow time for transactions to clear */
>> + pci_disable_sriov(sriov_info->pdev);
>> +
>> + tmp_vfs = (u16)sriov_info->num_vfs;
>> + sriov_info->num_vfs = 0;
>> + hinic_deinit_vf_hw(sriov_info, OS_VF_ID_TO_HW(0),
>> + OS_VF_ID_TO_HW(tmp_vfs - 1));
>> +
>> + clear_bit(HINIC_SRIOV_DISABLE, &sriov_info->state);
>> +
>> + return 0;
>> +}
>> +
>> +int hinic_pci_sriov_enable(struct pci_dev *pdev, int num_vfs)
>> +{
>> + struct hinic_sriov_info *sriov_info;
>> + int pre_existing_vfs = 0;
>> + int err = 0;
>> +
>> + sriov_info = hinic_get_sriov_info_by_pcidev(pdev);
>> +
>> + if (test_and_set_bit(HINIC_SRIOV_ENABLE, &sriov_info->state)) {
>> + dev_err(&pdev->dev,
>> + "SR-IOV enable in process, please wait, num_vfs %d\n",
>> + num_vfs);
>> + return -EPERM;
>> + }
> This should never happen, PCI core code will prevent SR-IOV from being
> enabled twice in a row, and concurrently. See sriov_numvfs_store().
>
>> + pre_existing_vfs = pci_num_vf(sriov_info->pdev);
>> +
>> + if (num_vfs > pci_sriov_get_totalvfs(sriov_info->pdev)) {
>> + clear_bit(HINIC_SRIOV_ENABLE, &sriov_info->state);
>> + return -ERANGE;
>> + }
> Again, can't happen.
>
>> + if (pre_existing_vfs && pre_existing_vfs != num_vfs) {
>> + err = hinic_pci_sriov_disable(sriov_info->pdev);
>> + if (err) {
>> + clear_bit(HINIC_SRIOV_ENABLE, &sriov_info->state);
>> + return err;
>> + }
> And this.
>
>> + } else if (pre_existing_vfs == num_vfs) {
> Or this.
>
>> + clear_bit(HINIC_SRIOV_ENABLE, &sriov_info->state);
>> + return num_vfs;
>> + }
>> +
>> + err = pci_enable_sriov(sriov_info->pdev, num_vfs);
>> + if (err) {
>> + dev_err(&pdev->dev,
>> + "Failed to enable SR-IOV, error %d\n", err);
>> + clear_bit(HINIC_SRIOV_ENABLE, &sriov_info->state);
>> + return err;
>> + }
>> +
>> + sriov_info->sriov_enabled = true;
>> + sriov_info->num_vfs = num_vfs;
>> + clear_bit(HINIC_SRIOV_ENABLE, &sriov_info->state);
>> +
>> + return num_vfs;
>> +}
>> +
>> +int hinic_pci_sriov_configure(struct pci_dev *dev, int num_vfs)
>> +{
>> + struct hinic_sriov_info *sriov_info;
>> +
>> + sriov_info = hinic_get_sriov_info_by_pcidev(dev);
>> +
>> + if (test_bit(HINIC_FUNC_REMOVE, &sriov_info->state))
>> + return -EFAULT;
> I don't think EFAULT is not a correct error code here. Use EBUSY, or
> ENODEV?
>
>> + if (!num_vfs)
>> + return hinic_pci_sriov_disable(dev);
>> + else
>> + return hinic_pci_sriov_enable(dev, num_vfs);
>> +}
> .
next prev parent reply other threads:[~2020-04-23 12:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-21 4:56 [PATCH net-next 0/3] hinic: add SR-IOV support Luo bin
2020-04-21 4:56 ` [PATCH net-next 1/3] hinic: add mailbox function support Luo bin
2020-04-21 18:13 ` Jakub Kicinski
2020-04-23 12:08 ` luobin (L)
2020-04-21 4:56 ` [PATCH net-next 2/3] hinic: add sriov feature support Luo bin
2020-04-21 18:21 ` Jakub Kicinski
2020-04-23 12:17 ` luobin (L) [this message]
2020-04-21 4:56 ` [PATCH net-next 3/3] hinic: add net_device_ops associated with vf Luo bin
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