2023-03-07 08:36:08

by Xinghui Li

[permalink] [raw]
Subject: [PATCH v2] 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: on, off. The default param is "NULL",
the goal is not to affect the existing settings of the device.

Signed-off-by: Xinghui Li <[email protected]>
Reviewed-by: Nirmal Patel <[email protected]>
---
drivers/pci/controller/vmd.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 990630ec57c6..8b42b2c1d949 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -34,6 +34,20 @@
#define MB2_SHADOW_OFFSET 0x2000
#define MB2_SHADOW_SIZE 16

+/*
+ * The VMD msi_remap module parameter provides the alternative way
+ * to adjust msi mode when loading vmd.ko other than vmd_ids table.
+ * There are two params could be recognized:
+ *
+ * 1-off
+ * 2-on
+ *
+ * The default param is "NULL", the goal is not to affect the existing
+ * settings of the device.
+ */
+char *msi_remap = "NULL";
+module_param(msi_remap, charp, 0444);
+
enum vmd_features {
/*
* Device may contain registers which hint the physical location of the
@@ -875,6 +889,7 @@ 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)
@@ -887,6 +902,7 @@ 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]);
@@ -955,6 +971,14 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
return 0;
}

+static void vmd_config_msi_remap_param(unsigned long *features)
+{
+ if (strcmp(msi_remap, "on") == 0)
+ *features &= ~(VMD_FEAT_CAN_BYPASS_MSI_REMAP);
+ else if (strcmp(msi_remap, "off") == 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;
@@ -984,6 +1008,8 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (err < 0)
goto out_release_instance;

+ vmd_config_msi_remap_param(&features);
+
vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
if (!vmd->cfgbar) {
err = -ENOMEM;
--
2.31.1



2023-03-08 22:57:29

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH v2] PCI:vmd: add the module param to adjust msi mode

Please adjust the subject line to match previous history, e.g.,

PCI: vmd: Add ... MSI ...

On Tue, Mar 07, 2023 at 04:35:59PM +0800, [email protected] wrote:
> 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: on, off. The default param is "NULL",
> the goal is not to affect the existing settings of the device.

Please add a space after the period that ends each sentence.
Capitalize "MSI" to match usage in spec.

> Signed-off-by: Xinghui Li <[email protected]>
> Reviewed-by: Nirmal Patel <[email protected]>

I didn't see a response from Nirmal on the mailing list with the
Reviewed-by. I think it's better if Nirmal responds to the patch
directly on the mailing list with the Reviewed-by, and whoever applies
the patch can incorporate it. Otherwise we have no visibility into
any interaction between you and Nirmal.

> ---
> drivers/pci/controller/vmd.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> index 990630ec57c6..8b42b2c1d949 100644
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@ -34,6 +34,20 @@
> #define MB2_SHADOW_OFFSET 0x2000
> #define MB2_SHADOW_SIZE 16
>
> +/*
> + * The VMD msi_remap module parameter provides the alternative way
> + * to adjust msi mode when loading vmd.ko other than vmd_ids table.
> + * There are two params could be recognized:
> + *
> + * 1-off
> + * 2-on

It looks like your code matches either "on" or "off", not "1" or "2".

> + * The default param is "NULL", the goal is not to affect the existing
> + * settings of the device.
> + */
> +char *msi_remap = "NULL";

Looks like this should be static? And using "NULL" (as opposed to
something like the empty string "") suggests some intrinsic meaning of
"NULL", but I think there is no intrinsic meaning and the only point
is that "NULL" doesn't match either "on" or "off".

> +module_param(msi_remap, charp, 0444);
> +
> enum vmd_features {
> /*
> * Device may contain registers which hint the physical location of the
> @@ -875,6 +889,7 @@ 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)
> @@ -887,6 +902,7 @@ 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]);
> @@ -955,6 +971,14 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
> return 0;
> }
>
> +static void vmd_config_msi_remap_param(unsigned long *features)
> +{
> + if (strcmp(msi_remap, "on") == 0)
> + *features &= ~(VMD_FEAT_CAN_BYPASS_MSI_REMAP);
> + else if (strcmp(msi_remap, "off") == 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;
> @@ -984,6 +1008,8 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
> if (err < 0)
> goto out_release_instance;
>
> + vmd_config_msi_remap_param(&features);
> +
> vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
> if (!vmd->cfgbar) {
> err = -ENOMEM;
> --
> 2.31.1
>

2023-03-09 12:30:58

by Xinghui Li

[permalink] [raw]
Subject: Re: [PATCH v2] PCI:vmd: add the module param to adjust msi mode

Bjorn Helgaas <[email protected]> 于2023年3月9日周四 06:57写道:
>
> Please adjust the subject line to match previous history, e.g.,
>
> PCI: vmd: Add ... MSI ...
>
OK. I will fix it. Sorry for ignoring the subject format.

> > 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: on, off. The default param is "NULL",
> > the goal is not to affect the existing settings of the device.
>
> Please add a space after the period that ends each sentence.
> Capitalize "MSI" to match usage in spec.
>
Sorry for the format issue. I neglected them. My bad~

> > Signed-off-by: Xinghui Li <[email protected]>
> > Reviewed-by: Nirmal Patel <[email protected]>
>
> I didn't see a response from Nirmal on the mailing list with the
> Reviewed-by. I think it's better if Nirmal responds to the patch
> directly on the mailing list with the Reviewed-by, and whoever applies
> the patch can incorporate it. Otherwise we have no visibility into
> any interaction between you and Nirmal.
>
I pinged Nirmal to reply to this patch, It seems he forgot to cc the
mail list in the previous version's discussion.

> > +/*
> > + * The VMD msi_remap module parameter provides the alternative way
> > + * to adjust msi mode when loading vmd.ko other than vmd_ids table.
> > + * There are two params could be recognized:
> > + *
> > + * 1-off
> > + * 2-on
>
> It looks like your code matches either "on" or "off", not "1" or "2".
>
I will change the comment. It does mislead the reader. I mean the No.1
param is "on" and the No.2 param is "off"

> > + * The default param is "NULL", the goal is not to affect the existing
> > + * settings of the device.
> > + */
> > +char *msi_remap = "NULL";
>
> Looks like this should be static? And using "NULL" (as opposed to
> something like the empty string "") suggests some intrinsic meaning of
> "NULL", but I think there is no intrinsic meaning and the only point
> is that "NULL" doesn't match either "on" or "off".
>
The "static" one is better, I will add it.
Initial parameters with "NULL" just aim to mismatch "on" or "off". Do
you prefer to init it without the default string?

2023-03-15 21:49:15

by Nirmal Patel

[permalink] [raw]
Subject: Re: [PATCH v2] PCI:vmd: add the module param to adjust msi mode

On 3/9/2023 5:31 AM, Xinghui Li wrote:
> Bjorn Helgaas <[email protected]> 于2023年3月9日周四 06:57写道:
>> Please adjust the subject line to match previous history, e.g.,
>>
>> PCI: vmd: Add ... MSI ...
>>
> OK. I will fix it. Sorry for ignoring the subject format.
>
>>> 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: on, off. The default param is "NULL",
>>> the goal is not to affect the existing settings of the device.
>> Please add a space after the period that ends each sentence.
>> Capitalize "MSI" to match usage in spec.
>>
> Sorry for the format issue. I neglected them. My bad~
>
>>> Signed-off-by: Xinghui Li <[email protected]>
>>> Reviewed-by: Nirmal Patel <[email protected]>
>> I didn't see a response from Nirmal on the mailing list with the
>> Reviewed-by. I think it's better if Nirmal responds to the patch
>> directly on the mailing list with the Reviewed-by, and whoever applies
>> the patch can incorporate it. Otherwise we have no visibility into
>> any interaction between you and Nirmal.
>>
> I pinged Nirmal to reply to this patch, It seems he forgot to cc the
> mail list in the previous version's discussion.
>
>>> +/*
>>> + * The VMD msi_remap module parameter provides the alternative way
>>> + * to adjust msi mode when loading vmd.ko other than vmd_ids table.
>>> + * There are two params could be recognized:
>>> + *
>>> + * 1-off
>>> + * 2-on
>> It looks like your code matches either "on" or "off", not "1" or "2".
>>
> I will change the comment. It does mislead the reader. I mean the No.1
> param is "on" and the No.2 param is "off"
>
>>> + * The default param is "NULL", the goal is not to affect the existing
>>> + * settings of the device.
>>> + */
>>> +char *msi_remap = "NULL";
>> Looks like this should be static? And using "NULL" (as opposed to
>> something like the empty string "") suggests some intrinsic meaning of
>> "NULL", but I think there is no intrinsic meaning and the only point
>> is that "NULL" doesn't match either "on" or "off".
>>
> The "static" one is better, I will add it.
> Initial parameters with "NULL" just aim to mismatch "on" or "off". Do
> you prefer to init it without the default string?

Please address Bjorn's comments. Thank you.

Reviewed-by: Nirmal Patel <[email protected]>