Re: [PATCH V7 3/4] PCI: vmd: Add vmd_device_data

From: Bjorn Helgaas
Date: Fri Oct 28 2022 - 15:13:46 EST


On Mon, Oct 24, 2022 at 05:44:10PM -0700, David E. Box wrote:
> Add vmd_device_data to allow adding additional info for driver data.

> {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
> - .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
> - VMD_FEAT_HAS_BUS_RESTRICTIONS |
> - VMD_FEAT_OFFSET_FIRST_VECTOR,},
> + (kernel_ulong_t)&(struct vmd_device_data) {
> + .features = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
> + VMD_FEAT_HAS_BUS_RESTRICTIONS |
> + VMD_FEAT_OFFSET_FIRST_VECTOR,
> + },
> + },

It looks like these devices come in families where several device IDs
share the same features. I think this would be more readable if you
defined each family outside this table and simply referenced the
family here. E.g., you could do something like:

static struct vmd_device_data vmd_v1 = {
.features = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
VMD_FEAT_HAS_BUS_RESTRICTIONS |
VMD_FEAT_OFFSET_FIRST_VECTOR,
};

{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
.driver_data = (kernel_ulong_t) &vmd_v1,

Then you can add VMD_FEAT_BIOS_PM_QUIRK and the .ltr value in one place
instead of repeating it a half dozen times.

> {0,}
> };
> MODULE_DEVICE_TABLE(pci, vmd_ids);
> --
> 2.25.1
>