2022-05-02 23:06:01

by Lu Baolu

[permalink] [raw]
Subject: [PATCH v5 02/12] iommu: Add pasid_bits field in struct dev_iommu

Use this field to save the pasid/ssid bits that a device is able to
support with its IOMMU hardware. It is a generic attribute of a device
and lifting it into the per-device dev_iommu struct makes it possible
to allocate a PASID for device without calls into the IOMMU drivers.
Any iommu driver which suports PASID related features should set this
field before features are enabled on the devices.

For initialization of this field in the VT-d driver, the
info->pasid_supported is only set for PCI devices. So the status is
that non-PCI SVA hasn't been supported yet. Setting this field only for
PCI devices has no functional change.

Signed-off-by: Lu Baolu <[email protected]>
---
include/linux/iommu.h | 1 +
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 ++
drivers/iommu/intel/iommu.c | 5 ++++-
3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 5e1afe169549..b8ffaf2cb1d0 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -373,6 +373,7 @@ struct dev_iommu {
struct iommu_fwspec *fwspec;
struct iommu_device *iommu_dev;
void *priv;
+ unsigned int pasid_bits;
};

int iommu_device_register(struct iommu_device *iommu,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 627a3ed5ee8f..afc63fce6107 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2681,6 +2681,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
master->stall_enabled = true;

+ dev->iommu->pasid_bits = master->ssid_bits;
+
return &smmu->iommu;

err_free_master:
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cf43e8f9091b..170eb777d57b 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4611,8 +4611,11 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
if (pasid_supported(iommu)) {
int features = pci_pasid_features(pdev);

- if (features >= 0)
+ if (features >= 0) {
info->pasid_supported = features | 1;
+ dev->iommu->pasid_bits =
+ fls(pci_max_pasids(pdev)) - 1;
+ }
}

if (info->ats_supported && ecap_prs(iommu->ecap) &&
--
2.25.1


2022-05-04 00:21:29

by Jean-Philippe Brucker

[permalink] [raw]
Subject: Re: [PATCH v5 02/12] iommu: Add pasid_bits field in struct dev_iommu

On Mon, May 02, 2022 at 09:48:32AM +0800, Lu Baolu wrote:
> Use this field to save the pasid/ssid bits that a device is able to
> support with its IOMMU hardware. It is a generic attribute of a device
> and lifting it into the per-device dev_iommu struct makes it possible
> to allocate a PASID for device without calls into the IOMMU drivers.
> Any iommu driver which suports PASID related features should set this
> field before features are enabled on the devices.
>
> For initialization of this field in the VT-d driver, the
> info->pasid_supported is only set for PCI devices. So the status is
> that non-PCI SVA hasn't been supported yet. Setting this field only for
> PCI devices has no functional change.
>
> Signed-off-by: Lu Baolu <[email protected]>

Reviewed-by: Jean-Philippe Brucker <[email protected]>

> ---
> include/linux/iommu.h | 1 +
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 ++
> drivers/iommu/intel/iommu.c | 5 ++++-
> 3 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 5e1afe169549..b8ffaf2cb1d0 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -373,6 +373,7 @@ struct dev_iommu {
> struct iommu_fwspec *fwspec;
> struct iommu_device *iommu_dev;
> void *priv;
> + unsigned int pasid_bits;
> };
>
> int iommu_device_register(struct iommu_device *iommu,
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 627a3ed5ee8f..afc63fce6107 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2681,6 +2681,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
> smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
> master->stall_enabled = true;
>
> + dev->iommu->pasid_bits = master->ssid_bits;
> +
> return &smmu->iommu;
>
> err_free_master:
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index cf43e8f9091b..170eb777d57b 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4611,8 +4611,11 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
> if (pasid_supported(iommu)) {
> int features = pci_pasid_features(pdev);
>
> - if (features >= 0)
> + if (features >= 0) {
> info->pasid_supported = features | 1;
> + dev->iommu->pasid_bits =
> + fls(pci_max_pasids(pdev)) - 1;
> + }
> }
>
> if (info->ats_supported && ecap_prs(iommu->ecap) &&
> --
> 2.25.1
>

2022-05-06 14:37:40

by Lu Baolu

[permalink] [raw]
Subject: Re: [PATCH v5 02/12] iommu: Add pasid_bits field in struct dev_iommu

On 2022/5/4 02:02, Jean-Philippe Brucker wrote:
> On Mon, May 02, 2022 at 09:48:32AM +0800, Lu Baolu wrote:
>> Use this field to save the pasid/ssid bits that a device is able to
>> support with its IOMMU hardware. It is a generic attribute of a device
>> and lifting it into the per-device dev_iommu struct makes it possible
>> to allocate a PASID for device without calls into the IOMMU drivers.
>> Any iommu driver which suports PASID related features should set this
>> field before features are enabled on the devices.
>>
>> For initialization of this field in the VT-d driver, the
>> info->pasid_supported is only set for PCI devices. So the status is
>> that non-PCI SVA hasn't been supported yet. Setting this field only for
>> PCI devices has no functional change.
>>
>> Signed-off-by: Lu Baolu<[email protected]>
> Reviewed-by: Jean-Philippe Brucker<[email protected]>

Thank you! Very appreciated for reviewing my patches.

Best regards,
baolu