On 7/20/2021 3:42 PM, Bjorn Helgaas wrote:
> On Tue, Jul 20, 2021 at 01:50:09PM -0700, Nirmal Patel wrote:
>> In order to properly re-initialize the VMD domain during repetitive driver
>> attachment or reboot tests, ensure that the VMD root ports are re-initialized
>> to a blank state that can be re-enumerated appropriately by the PCI core.
>> This is performed by re-initializing all of the bridge windows to ensure
>> that PCI core enumeration does not detect potentially invalid bridge windows
>> and misinterpret them as firmware-assigned windows, when they simply may be
>> invalid bridge window information from a previous boot.
> Rewrap commit log to fit in 75 columns. No problem about v2 vs v1.
I will take care of it.
>
>> Signed-off-by: Nirmal Patel <nirmal.patel@xxxxxxxxxxxxxxx>
>> Reviewed-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>
>> ---
>> drivers/pci/controller/vmd.c | 35 +++++++++++++++++++++++++++++++++++
>> 1 file changed, 35 insertions(+)
>>
>> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
>> index 6e1c60048774..e52bdb95218e 100644
>> --- a/drivers/pci/controller/vmd.c
>> +++ b/drivers/pci/controller/vmd.c
>> @@ -651,6 +651,39 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd)
>> return 0;
>> }
>>
>> +
> Remove spurious blank line here.
Sure.
>
>> +static void vmd_domain_reset_windows(struct vmd_dev *vmd)
>> +{
>> + u8 hdr_type;
>> + char __iomem *addr;
>> + int dev_seq;
>> + u8 functions;
>> + u8 fn_seq;
>> + int max_devs = resource_size(&vmd->resources[0]) * 32;
>> +
>> + for (dev_seq = 0; dev_seq < max_devs; dev_seq++) {
>> + addr = VMD_DEVICE_BASE(vmd, dev_seq) + PCI_VENDOR_ID;
>> + if (readw(addr) != PCI_VENDOR_ID_INTEL)
>> + continue;
>> +
>> + addr = VMD_DEVICE_BASE(vmd, dev_seq) + PCI_HEADER_TYPE;
>> + hdr_type = readb(addr) & PCI_HEADER_TYPE_MASK;
>> + if (hdr_type != PCI_HEADER_TYPE_BRIDGE)
>> + continue;
>> +
>> + functions = !!(hdr_type & 0x80) ? 8 : 1;
>> + for (fn_seq = 0; fn_seq < functions; fn_seq++)
>> + {
> Put "{" on previous line.
>
> Looks quite parallel to vmd_domain_sbr(), except that here we iterate
> through functions as well. Why does vmd_domain_sbr() not need to
> iterate through functions?
I am not sure if there is VMD hardware with non zero functions.
>
>> + addr = VMD_FUNCTION_BASE(vmd, dev_seq, fn_seq) + PCI_VENDOR_ID;
>> + if (readw(addr) != PCI_VENDOR_ID_INTEL)
>> + continue;
>> +
>> + memset_io((VMD_FUNCTION_BASE(vmd, dev_seq, fn_seq) + PCI_IO_BASE),
>> + 0, PCI_ROM_ADDRESS1 - PCI_IO_BASE);
> Make the lines above fit in 80 columns.
Sure.
>
>> + }
>> + }
>> +}
>> +
>> static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
>> {
>> struct pci_sysdata *sd = &vmd->sysdata;
>> @@ -741,6 +774,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
>> .parent = res,
>> };
>>
>> + vmd_domain_reset_windows(vmd);
>> +
>> sd->vmd_dev = vmd->dev;
>> sd->domain = vmd_find_free_domain();
>> if (sd->domain < 0)
>> --
>> 2.27.0
>>
