2023-02-27 06:48:09

by Xinghui Li

[permalink] [raw]
Subject: [PATCH] PCI:vmd: add the module param to adjust msi mode

From: Xinghui Li <[email protected]>

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 <[email protected]>
---
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



2023-02-27 06:56:59

by Xinghui Li

[permalink] [raw]
Subject: Re: [PATCH] PCI:vmd: add the module param to adjust msi mode

<[email protected]> 于2023年2月27日周一 14:48写道:
>
> From: Xinghui Li <[email protected]>
>
> 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 <[email protected]>
> ---
> 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.