<korantwork@xxxxxxxxx> 于2023年2月27日周一 14:48写道：
>
> From: Xinghui Li <korantli@xxxxxxxxxxx>
>
> In the legacy, the vmd msi-mode can only be adjusted by configing
> vmd_ids table.This patch adds another way to adjust msi mode by
> adjusting module param, which allow users easier to adjust the vmd
> according to the I/O scenario without rebuilding driver.There are two
> params could be recognized: remapping, bypass.
>
> Signed-off-by: Xinghui Li <korantli@xxxxxxxxxxx>
> ---
> drivers/pci/controller/vmd.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> index 769eedeb8802..6d3272f5598d 100644
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@ -34,6 +34,18 @@
> #define MB2_SHADOW_OFFSET 0x2000
> #define MB2_SHADOW_SIZE 16
>
> +/*
> + * The VMD msi_mode module parameter provides the alternative way
> + * to adjust msi_mode when load vmd.ko other than vmd_ids table.
> + * There are two params could be recognized:
> + *
> + * 1-remapping
> + * 2-bypass
> + *
> + */
> +char *msi_mode = "default";
> +module_param(msi_mode, charp, 0444);
> +
> enum vmd_features {
> /*
> * Device may contain registers which hint the physical location of the
> @@ -820,6 +832,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
> return ret;
>
> vmd_set_msi_remapping(vmd, true);
> + dev_info(&vmd->dev->dev, "init vmd with remapping msi-x\n");
>
> ret = vmd_create_irq_domain(vmd);
> if (ret)
> @@ -832,6 +845,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
> irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
> } else {
> vmd_set_msi_remapping(vmd, false);
> + dev_info(&vmd->dev->dev, "init vmd with bypass msi-x\n");
> }
>
> pci_add_resource(&resources, &vmd->resources[0]);
> @@ -898,6 +912,14 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
> return 0;
> }
>
> +static void vmd_config_msi_mode_param(unsigned long *features)
> +{
> + if (strcmp(msi_mode, "remapping") == 0)
> + *features &= ~(VMD_FEAT_CAN_BYPASS_MSI_REMAP);
> + else if (strcmp(msi_mode, "bypass") == 0)
> + *features |= VMD_FEAT_CAN_BYPASS_MSI_REMAP;
> +}
> +
> static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
> {
> unsigned long features = (unsigned long) id->driver_data;
> @@ -927,6 +949,8 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
> if (err < 0)
> goto out_release_instance;
>
> + vmd_config_msi_mode_param(&features);
> +
> vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
> if (!vmd->cfgbar) {
> err = -ENOMEM;
> --
> 2.34.1
>
Hi all:
As we discussed in last patch (PCI: vmd: Do not disable MSI-X
remapping in VMD 28C0 controller).
I add the module param in vmd driver to adjust msi-x working mode. I
try not to modify the default mode.
And as for the `programmatic way`, I design to add the `automatic`
parameter in the next patch, which needs
more testing of different IO scenarios.
