[PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[Sinan Kaya]

pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
where a PCI device is present. This restricts the device drivers to be
reused for other domain numbers.

Getting ready to remove pci_get_bus_and_slot() function in favor of
pci_get_domain_bus_and_slot().

Hard-code the domain number as 0 for the AMD IOMMU driver.

Signed-off-by: Sinan Kaya <okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/iommu/amd_iommu.c      | 3 ++-
 drivers/iommu/amd_iommu_init.c | 9 +++++----
 drivers/iommu/amd_iommu_v2.c   | 3 ++-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 7d5eb00..821547b 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -527,7 +527,8 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
 	struct iommu_dev_data *dev_data = NULL;
 	struct pci_dev *pdev;
 
-	pdev = pci_get_bus_and_slot(PCI_BUS_NUM(devid), devid & 0xff);
+	pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
+					   devid & 0xff);
 	if (pdev)
 		dev_data = get_dev_data(&pdev->dev);
 
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 6fe2d03..4e4a615 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1697,8 +1697,8 @@ static int iommu_init_pci(struct amd_iommu *iommu)
 	u32 range, misc, low, high;
 	int ret;
 
-	iommu->dev = pci_get_bus_and_slot(PCI_BUS_NUM(iommu->devid),
-					  iommu->devid & 0xff);
+	iommu->dev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(iommu->devid),
+						 iommu->devid & 0xff);
 	if (!iommu->dev)
 		return -ENODEV;
 
@@ -1764,8 +1764,9 @@ static int iommu_init_pci(struct amd_iommu *iommu)
 	if (is_rd890_iommu(iommu->dev)) {
 		int i, j;
 
-		iommu->root_pdev = pci_get_bus_and_slot(iommu->dev->bus->number,
-				PCI_DEVFN(0, 0));
+		iommu->root_pdev =
+			pci_get_domain_bus_and_slot(0, iommu->dev->bus->number,
+						    PCI_DEVFN(0, 0));
 
 		/*
 		 * Some rd890 systems may not be fully reconfigured by the
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 7d94e1d..8696382 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -564,7 +564,8 @@ static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data)
 	finish      = (iommu_fault->tag >> 9) & 1;
 
 	devid = iommu_fault->device_id;
-	pdev = pci_get_bus_and_slot(PCI_BUS_NUM(devid), devid & 0xff);
+	pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
+					   devid & 0xff);
 	if (!pdev)
 		return -ENODEV;
 	dev_data = get_dev_data(&pdev->dev);
-- 
1.9.1

Re: [PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[Sinan Kaya]

On 12/19/2017 12:37 AM, Sinan Kaya wrote:
> pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
> where a PCI device is present. This restricts the device drivers to be
> reused for other domain numbers.
> 
> Getting ready to remove pci_get_bus_and_slot() function in favor of
> pci_get_domain_bus_and_slot().
> 
> Hard-code the domain number as 0 for the AMD IOMMU driver.
> 
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/iommu/amd_iommu.c      | 3 ++-
>  drivers/iommu/amd_iommu_init.c | 9 +++++----
>  drivers/iommu/amd_iommu_v2.c   | 3 ++-
>  3 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index 7d5eb00..821547b 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -527,7 +527,8 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
>  	struct iommu_dev_data *dev_data = NULL;
>  	struct pci_dev *pdev;
>  
> -	pdev = pci_get_bus_and_slot(PCI_BUS_NUM(devid), devid & 0xff);
> +	pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
> +					   devid & 0xff);
>  	if (pdev)
>  		dev_data = get_dev_data(&pdev->dev);
>  
> diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
> index 6fe2d03..4e4a615 100644
> --- a/drivers/iommu/amd_iommu_init.c
> +++ b/drivers/iommu/amd_iommu_init.c
> @@ -1697,8 +1697,8 @@ static int iommu_init_pci(struct amd_iommu *iommu)
>  	u32 range, misc, low, high;
>  	int ret;
>  
> -	iommu->dev = pci_get_bus_and_slot(PCI_BUS_NUM(iommu->devid),
> -					  iommu->devid & 0xff);
> +	iommu->dev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(iommu->devid),
> +						 iommu->devid & 0xff);
>  	if (!iommu->dev)
>  		return -ENODEV;
>  
> @@ -1764,8 +1764,9 @@ static int iommu_init_pci(struct amd_iommu *iommu)
>  	if (is_rd890_iommu(iommu->dev)) {
>  		int i, j;
>  
> -		iommu->root_pdev = pci_get_bus_and_slot(iommu->dev->bus->number,
> -				PCI_DEVFN(0, 0));
> +		iommu->root_pdev =
> +			pci_get_domain_bus_and_slot(0, iommu->dev->bus->number,
> +						    PCI_DEVFN(0, 0));
>  
>  		/*
>  		 * Some rd890 systems may not be fully reconfigured by the
> diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
> index 7d94e1d..8696382 100644
> --- a/drivers/iommu/amd_iommu_v2.c
> +++ b/drivers/iommu/amd_iommu_v2.c
> @@ -564,7 +564,8 @@ static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data)
>  	finish      = (iommu_fault->tag >> 9) & 1;
>  
>  	devid = iommu_fault->device_id;
> -	pdev = pci_get_bus_and_slot(PCI_BUS_NUM(devid), devid & 0xff);
> +	pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
> +					   devid & 0xff);
>  	if (!pdev)
>  		return -ENODEV;
>  	dev_data = get_dev_data(&pdev->dev);
> 

Any comments from the IOMMU people?

-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[Gary R Hook]

On 01/04/2018 06:25 AM, Sinan Kaya wrote:
> On 12/19/2017 12:37 AM, Sinan Kaya wrote:
>> pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
>> where a PCI device is present. This restricts the device drivers to be
>> reused for other domain numbers.
>>
>> Getting ready to remove pci_get_bus_and_slot() function in favor of
>> pci_get_domain_bus_and_slot().
>>
>> Hard-code the domain number as 0 for the AMD IOMMU driver.

<snip>

 >
 > Any comments from the IOMMU people?
 >

pci_get_bus_and_slot() appears to (now) be a convenience function that 
wraps pci_get_domain_bus_and_slot() while using a 0 for the domain 
value. Exactly what you are doing here, albeit in a more overt way.

How is this patch advantageous? Seems to me that if other domains need 
to be enabled, that driver could be changed if and when that requirement 
arises.

But perhaps I'm missing a nuance here.

Re: [PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[Sinan Kaya]

On 1/4/2018 11:28 AM, Gary R Hook wrote:
> On 01/04/2018 06:25 AM, Sinan Kaya wrote:
>> On 12/19/2017 12:37 AM, Sinan Kaya wrote:
>>> pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
>>> where a PCI device is present. This restricts the device drivers to be
>>> reused for other domain numbers.
>>>
>>> Getting ready to remove pci_get_bus_and_slot() function in favor of
>>> pci_get_domain_bus_and_slot().
>>>
>>> Hard-code the domain number as 0 for the AMD IOMMU driver.
> 
> <snip>
> 
>>
>> Any comments from the IOMMU people?
>>
> 
> pci_get_bus_and_slot() appears to (now) be a convenience function that wraps pci_get_domain_bus_and_slot() while using a 0 for the domain value. Exactly what you are doing here, albeit in a more overt way.
> 
> How is this patch advantageous? Seems to me that if other domains need to be enabled, that driver could be changed if and when that requirement arises.
> 
> But perhaps I'm missing a nuance here.
> 
> 

The benefit of the change was discussed here:

https://lkml.org/lkml/2017/12/19/349

I hope it helps.


-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[Gary R Hook]

On 01/04/2018 10:32 AM, Sinan Kaya wrote:
> On 1/4/2018 11:28 AM, Gary R Hook wrote:
>> On 01/04/2018 06:25 AM, Sinan Kaya wrote:
>>> On 12/19/2017 12:37 AM, Sinan Kaya wrote:
>>>> pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
>>>> where a PCI device is present. This restricts the device drivers to be
>>>> reused for other domain numbers.
>>>>
>>>> Getting ready to remove pci_get_bus_and_slot() function in favor of
>>>> pci_get_domain_bus_and_slot().
>>>>
>>>> Hard-code the domain number as 0 for the AMD IOMMU driver.
>>
>> <snip>
>>
>>>
>>> Any comments from the IOMMU people?
>>>
>>
>> pci_get_bus_and_slot() appears to (now) be a convenience function that wraps pci_get_domain_bus_and_slot() while using a 0 for the domain value. Exactly what you are doing here, albeit in a more overt way.
>>
>> How is this patch advantageous? Seems to me that if other domains need to be enabled, that driver could be changed if and when that requirement arises.
>>
>> But perhaps I'm missing a nuance here.
>>
>>
> 
> The benefit of the change was discussed here:
> 
> https://lkml.org/lkml/2017/12/19/349
> 
> I hope it helps.
> 
> 

Thank you for pointing out that thread directly. I read through it and 
thought further about this change.

I am not the maintainer, but as an AMD developer, this is fine change. I 
can't ACK but I can agree.

Gary

Re: [PATCH V4 11/26] iommu/amd: deprecate pci_get_bus_and_slot()

[Joerg Roedel]

On Tue, Dec 19, 2017 at 12:37:47AM -0500, Sinan Kaya wrote:
> pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
> where a PCI device is present. This restricts the device drivers to be
> reused for other domain numbers.
> 
> Getting ready to remove pci_get_bus_and_slot() function in favor of
> pci_get_domain_bus_and_slot().
> 
> Hard-code the domain number as 0 for the AMD IOMMU driver.
> 
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/iommu/amd_iommu.c      | 3 ++-
>  drivers/iommu/amd_iommu_init.c | 9 +++++----
>  drivers/iommu/amd_iommu_v2.c   | 3 ++-
>  3 files changed, 9 insertions(+), 6 deletions(-)

Acked-by: Joerg Roedel <jroedel@suse.de>