Messages in this thread | | | Subject | Re: [PATCH] nitro_enclaves: set master in the procedure of NE probe | From | "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" <> | Date | Mon, 25 Jan 2021 11:45:14 +0800 |
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在 2021/1/20 18:27, Paraschiv, Andra-Irina 写道: > > > On 19/01/2021 05:30, Longpeng(Mike) wrote: >> According the PCI spec: >> Bus Master Enable – Controls the ability of a PCI Express >> Endpoint to issue Memory and I/O Read/Write Requests, and >> the ability of a Root or Switch Port to forward Memory and >> I/O Read/Write Requests in the Upstream direction >> >> Set BusMaster to make the driver to be PCI conformant. > > Could update the commit title and message body to reflect more the why and what for the change. One option can be: > > nitro_enclaves: Set Bus Master for the NE PCI device > > Enable Bus Master for the NE PCI device, according to the PCI spec > for submitting memory or I/O requests: > Bus Master Enable ... > > > > Please include the changelog in the commit message for the next revision(s). > > + Greg in CC, as the patches for the Nitro Enclaves kernel driver are first included in the char misc tree, then in the linux next and finally in the mainline. > Will update the commit message in V2.
>> >> Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> >> --- >> drivers/virt/nitro_enclaves/ne_pci_dev.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/virt/nitro_enclaves/ne_pci_dev.c b/drivers/virt/nitro_enclaves/ne_pci_dev.c >> index b9c1de4..143207e 100644 >> --- a/drivers/virt/nitro_enclaves/ne_pci_dev.c >> +++ b/drivers/virt/nitro_enclaves/ne_pci_dev.c >> @@ -480,6 +480,8 @@ static int ne_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) >> goto free_ne_pci_dev; >> } >> >> + pci_set_master(pdev); > > I was looking if we need the reverse for this - pci_clear_master() [1] - on the error and remove / shutdown codebase paths, but pci_disable_device() seems to include the bus master disable logic [2][3]. > No need to call pci_clear_master.
> Thanks, > Andra > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/pci.c?h=v5.11-rc4#n4312 > [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/pci.c?h=v5.11-rc4#n2104 > [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/pci.c?h=v5.11-rc4#n4242 > >> + >> rc = pci_request_regions_exclusive(pdev, "nitro_enclaves"); >> if (rc < 0) { >> dev_err(&pdev->dev, "Error in pci request regions [rc=%d]\n", rc); >> -- >> 1.8.3.1 >> > > > > > Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
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