diff mbox series

[v7,1/7] iommu/arm-smmu-v3: Make default domain type of HiSilicon PTT device to identity

Message ID 20220407125841.3678-2-yangyicong@hisilicon.com
State New
Headers show
Series Add support for HiSilicon PCIe Tune and Trace device | expand

Commit Message

Yicong Yang April 7, 2022, 12:58 p.m. UTC
The DMA operations of HiSilicon PTT device can only work properly with
identical mappings. So add a quirk for the device to force the domain
as passthrough.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Will Deacon May 10, 2022, 11:23 a.m. UTC | #1
On Thu, Apr 07, 2022 at 08:58:35PM +0800, Yicong Yang wrote:
> The DMA operations of HiSilicon PTT device can only work properly with
> identical mappings. So add a quirk for the device to force the domain
> as passthrough.
> 
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)

I still don't like this being part of the SMMU driver, but given that
(a) Robin doesn't seem to agree with the objection and (b) you've been
refreshing the patch series:

Acked-by: Will Deacon <will@kernel.org>

If you do respin, then:

> 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..5ec15ae2a9b1 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2839,6 +2839,21 @@ static int arm_smmu_dev_disable_feature(struct device *dev,
>  	}
>  }

It might be worth adding a brief comment here to explain what this device is
and why it needs an identity mapping.

> +#define IS_HISI_PTT_DEVICE(pdev)	((pdev)->vendor == PCI_VENDOR_ID_HUAWEI && \
> +					 (pdev)->device == 0xa12e)

Will
Yicong Yang May 10, 2022, 12:43 p.m. UTC | #2
On 2022/5/10 19:23, Will Deacon wrote:
> On Thu, Apr 07, 2022 at 08:58:35PM +0800, Yicong Yang wrote:
>> The DMA operations of HiSilicon PTT device can only work properly with
>> identical mappings. So add a quirk for the device to force the domain
>> as passthrough.
>>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
>> ---
>>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 ++++++++++++++++
>>  1 file changed, 16 insertions(+)
> 
> I still don't like this being part of the SMMU driver, but given that
> (a) Robin doesn't seem to agree with the objection and (b) you've been
> refreshing the patch series:
> 
> Acked-by: Will Deacon <will@kernel.org>
> 
> If you do respin, then:
> 
>> 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..5ec15ae2a9b1 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> @@ -2839,6 +2839,21 @@ static int arm_smmu_dev_disable_feature(struct device *dev,
>>  	}
>>  }
> 
> It might be worth adding a brief comment here to explain what this device is
> and why it needs an identity mapping.
> 
>> +#define IS_HISI_PTT_DEVICE(pdev)	((pdev)->vendor == PCI_VENDOR_ID_HUAWEI && \
>> +					 (pdev)->device == 0xa12e)
> 

Will add a brief comment here in next version.

Thanks,
Yicong
John Garry May 11, 2022, 11:42 a.m. UTC | #3
On 07/04/2022 13:58, Yicong Yang wrote:
> The DMA operations of HiSilicon PTT device can only work properly with
> identical mappings. So add a quirk for the device to force the domain

I'm not sure if you meant to write "identity mappings".

> as passthrough.
> 
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>

FWIW,

Reviewed-by: John Garry <john.garry@huawei.com>

> ---
>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> 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..5ec15ae2a9b1 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2839,6 +2839,21 @@ static int arm_smmu_dev_disable_feature(struct device *dev,
>   	}
>   }
>   
> +#define IS_HISI_PTT_DEVICE(pdev)	((pdev)->vendor == PCI_VENDOR_ID_HUAWEI && \
> +					 (pdev)->device == 0xa12e)
> +
> +static int arm_smmu_def_domain_type(struct device *dev)
> +{
> +	if (dev_is_pci(dev)) {
> +		struct pci_dev *pdev = to_pci_dev(dev);
> +
> +		if (IS_HISI_PTT_DEVICE(pdev))
> +			return IOMMU_DOMAIN_IDENTITY;
> +	}
> +
> +	return 0;
> +}
> +
>   static struct iommu_ops arm_smmu_ops = {
>   	.capable		= arm_smmu_capable,
>   	.domain_alloc		= arm_smmu_domain_alloc,
> @@ -2856,6 +2871,7 @@ static struct iommu_ops arm_smmu_ops = {
>   	.sva_unbind		= arm_smmu_sva_unbind,
>   	.sva_get_pasid		= arm_smmu_sva_get_pasid,
>   	.page_response		= arm_smmu_page_response,
> +	.def_domain_type	= arm_smmu_def_domain_type,
>   	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
>   	.owner			= THIS_MODULE,
>   	.default_domain_ops = &(const struct iommu_domain_ops) {
diff mbox series

Patch

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..5ec15ae2a9b1 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2839,6 +2839,21 @@  static int arm_smmu_dev_disable_feature(struct device *dev,
 	}
 }
 
+#define IS_HISI_PTT_DEVICE(pdev)	((pdev)->vendor == PCI_VENDOR_ID_HUAWEI && \
+					 (pdev)->device == 0xa12e)
+
+static int arm_smmu_def_domain_type(struct device *dev)
+{
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		if (IS_HISI_PTT_DEVICE(pdev))
+			return IOMMU_DOMAIN_IDENTITY;
+	}
+
+	return 0;
+}
+
 static struct iommu_ops arm_smmu_ops = {
 	.capable		= arm_smmu_capable,
 	.domain_alloc		= arm_smmu_domain_alloc,
@@ -2856,6 +2871,7 @@  static struct iommu_ops arm_smmu_ops = {
 	.sva_unbind		= arm_smmu_sva_unbind,
 	.sva_get_pasid		= arm_smmu_sva_get_pasid,
 	.page_response		= arm_smmu_page_response,
+	.def_domain_type	= arm_smmu_def_domain_type,
 	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
 	.owner			= THIS_MODULE,
 	.default_domain_ops = &(const struct iommu_domain_ops) {