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.
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 6ef2df258673..36f43af0af53 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -368,6 +368,7 @@ 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 6f7485c44a4b..c1b91bce1530 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4587,8 +4587,11 @@ 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
Hi Jacob,
On 2022/3/30 5:00, Jacob Pan wrote:
> Hi BaoLu,
>
> On Tue, 29 Mar 2022 13:37:50 +0800, Lu Baolu<[email protected]>
> 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.
>>
>> 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 6ef2df258673..36f43af0af53 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -368,6 +368,7 @@ struct dev_iommu {
>> struct iommu_fwspec *fwspec;
>> struct iommu_device *iommu_dev;
>> void *priv;
>> + unsigned int pasid_bits;
> pasid_width?
> PCI spec uses "Max PASID Width"
>
My understanding is that this field represents "the pasid bits that the
device is able to use with its IOMMU". This field considers the
capabilities of both device and IOMMU. This is the reason why I put it
in the per-device iommu object and initialize it in the iommu
probe_device() callback.
Best regards,
baolu
Hi BaoLu,
On Tue, 29 Mar 2022 13:37:50 +0800, Lu Baolu <[email protected]>
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.
>
> 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 6ef2df258673..36f43af0af53 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -368,6 +368,7 @@ struct dev_iommu {
> struct iommu_fwspec *fwspec;
> struct iommu_device *iommu_dev;
> void *priv;
> + unsigned int pasid_bits;
pasid_width?
PCI spec uses "Max PASID Width"
> };
>
> 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 6f7485c44a4b..c1b91bce1530 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4587,8 +4587,11 @@ 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)
> &&
Thanks,
Jacob
On 2022/3/30 15:05, Tian, Kevin wrote:
>> From: Lu Baolu<[email protected]>
>> Sent: Tuesday, March 29, 2022 1:38 PM
>>
>> 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.
> Miss a clarification for non-PCI SVA as discussed here:
>
> https://lore.kernel.org/all/[email protected]/
Yes. Thanks for the reminding.
Best regards,
baolu
> From: Lu Baolu <[email protected]>
> Sent: Tuesday, March 29, 2022 1:38 PM
>
> 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.
Miss a clarification for non-PCI SVA as discussed here:
https://lore.kernel.org/all/[email protected]/
>
> 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 6ef2df258673..36f43af0af53 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -368,6 +368,7 @@ 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 6f7485c44a4b..c1b91bce1530 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4587,8 +4587,11 @@ 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