diff mbox series

[V4,05/26] agp: nvidia: deprecate pci_get_bus_and_slot()

Message ID 1513661883-28662-6-git-send-email-okaya@codeaurora.org
State Accepted
Headers show
Series PCI: deprecate pci_get_bus_and_slot() | expand

Commit Message

Sinan Kaya Dec. 19, 2017, 5:37 a.m. UTC
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().

Replace pci_get_bus_and_slot() with pci_get_domain_bus_and_slot()
and extract the domain number from struct pci_dev.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/char/agp/nvidia-agp.c | 12 +++++++++---
 drivers/char/agp/sworks-agp.c |  3 ++-
 2 files changed, 11 insertions(+), 4 deletions(-)

Comments

Sinan Kaya Jan. 3, 2018, 12:44 p.m. UTC | #1
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().
> 
> Replace pci_get_bus_and_slot() with pci_get_domain_bus_and_slot()
> and extract the domain number from struct pci_dev.
> 
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/char/agp/nvidia-agp.c | 12 +++++++++---
>  drivers/char/agp/sworks-agp.c |  3 ++-
>  2 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c
> index 828b344..623205b 100644
> --- a/drivers/char/agp/nvidia-agp.c
> +++ b/drivers/char/agp/nvidia-agp.c
> @@ -340,11 +340,17 @@ static int agp_nvidia_probe(struct pci_dev *pdev,
>  	u8 cap_ptr;
>  
>  	nvidia_private.dev_1 =
> -		pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 1));
> +		pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> +					    (unsigned int)pdev->bus->number,
> +					    PCI_DEVFN(0, 1));
>  	nvidia_private.dev_2 =
> -		pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 2));
> +		pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> +					    (unsigned int)pdev->bus->number,
> +					    PCI_DEVFN(0, 2));
>  	nvidia_private.dev_3 =
> -		pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(30, 0));
> +		pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> +					    (unsigned int)pdev->bus->number,
> +					    PCI_DEVFN(30, 0));
>  
>  	if (!nvidia_private.dev_1 || !nvidia_private.dev_2 || !nvidia_private.dev_3) {
>  		printk(KERN_INFO PFX "Detected an NVIDIA nForce/nForce2 "
> diff --git a/drivers/char/agp/sworks-agp.c b/drivers/char/agp/sworks-agp.c
> index 03be4ac..4dbdd3b 100644
> --- a/drivers/char/agp/sworks-agp.c
> +++ b/drivers/char/agp/sworks-agp.c
> @@ -474,7 +474,8 @@ static int agp_serverworks_probe(struct pci_dev *pdev,
>  	}
>  
>  	/* Everything is on func 1 here so we are hardcoding function one */
> -	bridge_dev = pci_get_bus_and_slot((unsigned int)pdev->bus->number,
> +	bridge_dev = pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> +			(unsigned int)pdev->bus->number,
>  			PCI_DEVFN(0, 1));
>  	if (!bridge_dev) {
>  		dev_info(&pdev->dev, "can't find secondary device\n");
> 

Any feedback here? most of the remaining patches have the ACK except these.
Dave Airlie Jan. 29, 2018, 9:43 p.m. UTC | #2
On 3 January 2018 at 22:44, Sinan Kaya <okaya@codeaurora.org> 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.

So not a major problem, but it would be pretty much impossible for either
of these agp drivers to be used in any other domain ever.

What does this buy us, maybe just rename pci_get_bus_and_slot to
pci_get_domain0_bus_and_slot as a helper, or just pass the pdev in
and have it do the right thing always.

Dave.

>>
>> Getting ready to remove pci_get_bus_and_slot() function in favor of
>> pci_get_domain_bus_and_slot().
>>
>> Replace pci_get_bus_and_slot() with pci_get_domain_bus_and_slot()
>> and extract the domain number from struct pci_dev.
>>
>> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
>> ---
>>  drivers/char/agp/nvidia-agp.c | 12 +++++++++---
>>  drivers/char/agp/sworks-agp.c |  3 ++-
>>  2 files changed, 11 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c
>> index 828b344..623205b 100644
>> --- a/drivers/char/agp/nvidia-agp.c
>> +++ b/drivers/char/agp/nvidia-agp.c
>> @@ -340,11 +340,17 @@ static int agp_nvidia_probe(struct pci_dev *pdev,
>>       u8 cap_ptr;
>>
>>       nvidia_private.dev_1 =
>> -             pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 1));
>> +             pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
>> +                                         (unsigned int)pdev->bus->number,
>> +                                         PCI_DEVFN(0, 1));
>>       nvidia_private.dev_2 =
>> -             pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 2));
>> +             pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
>> +                                         (unsigned int)pdev->bus->number,
>> +                                         PCI_DEVFN(0, 2));
>>       nvidia_private.dev_3 =
>> -             pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(30, 0));
>> +             pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
>> +                                         (unsigned int)pdev->bus->number,
>> +                                         PCI_DEVFN(30, 0));
>>
>>       if (!nvidia_private.dev_1 || !nvidia_private.dev_2 || !nvidia_private.dev_3) {
>>               printk(KERN_INFO PFX "Detected an NVIDIA nForce/nForce2 "
>> diff --git a/drivers/char/agp/sworks-agp.c b/drivers/char/agp/sworks-agp.c
>> index 03be4ac..4dbdd3b 100644
>> --- a/drivers/char/agp/sworks-agp.c
>> +++ b/drivers/char/agp/sworks-agp.c
>> @@ -474,7 +474,8 @@ static int agp_serverworks_probe(struct pci_dev *pdev,
>>       }
>>
>>       /* Everything is on func 1 here so we are hardcoding function one */
>> -     bridge_dev = pci_get_bus_and_slot((unsigned int)pdev->bus->number,
>> +     bridge_dev = pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
>> +                     (unsigned int)pdev->bus->number,
>>                       PCI_DEVFN(0, 1));
>>       if (!bridge_dev) {
>>               dev_info(&pdev->dev, "can't find secondary device\n");
>>
>
> Any feedback here? most of the remaining patches have the ACK except these.
>
>
> --
> 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.
Sinan Kaya Jan. 29, 2018, 10:01 p.m. UTC | #3
On 1/29/2018 4:43 PM, Dave Airlie wrote:
>>  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.
> So not a major problem, but it would be pretty much impossible for either
> of these agp drivers to be used in any other domain ever.
> 
> What does this buy us, maybe just rename pci_get_bus_and_slot to
> pci_get_domain0_bus_and_slot as a helper, or just pass the pdev in
> and have it do the right thing always.

There is nothing wrong with doing all three. Since nobody replied until
patch v4, I did the heavy-lifting and converted code to use pci_domain_nr()
as much as I can rather than hard-coding a 0 while calling
pci_get_domain_bus_and_slot().

From PCI coding perspective, pci_domain_nr() call is the right thing. It is
guaranteed to work no matter what your domain number is. 

People look at other code for examples on how to write a PCI driver
in general. You want to minimize the exceptions as much as possible.

Some discussion here about the benefits:

https://lkml.org/lkml/2017/12/19/349
Bjorn Helgaas Jan. 29, 2018, 10:38 p.m. UTC | #4
On Tue, Jan 30, 2018 at 07:43:21AM +1000, Dave Airlie wrote:
> On 3 January 2018 at 22:44, Sinan Kaya <okaya@codeaurora.org> 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.
> 
> So not a major problem, but it would be pretty much impossible for either
> of these agp drivers to be used in any other domain ever.
> 
> What does this buy us, maybe just rename pci_get_bus_and_slot to
> pci_get_domain0_bus_and_slot as a helper, or just pass the pdev in
> and have it do the right thing always.

I already have this patch on my "next" branch, planned for the v4.16
merge window, so it's done unless you have a major objection.

> >> Getting ready to remove pci_get_bus_and_slot() function in favor of
> >> pci_get_domain_bus_and_slot().
> >>
> >> Replace pci_get_bus_and_slot() with pci_get_domain_bus_and_slot()
> >> and extract the domain number from struct pci_dev.
> >>
> >> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> >> ---
> >>  drivers/char/agp/nvidia-agp.c | 12 +++++++++---
> >>  drivers/char/agp/sworks-agp.c |  3 ++-
> >>  2 files changed, 11 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c
> >> index 828b344..623205b 100644
> >> --- a/drivers/char/agp/nvidia-agp.c
> >> +++ b/drivers/char/agp/nvidia-agp.c
> >> @@ -340,11 +340,17 @@ static int agp_nvidia_probe(struct pci_dev *pdev,
> >>       u8 cap_ptr;
> >>
> >>       nvidia_private.dev_1 =
> >> -             pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 1));
> >> +             pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> >> +                                         (unsigned int)pdev->bus->number,
> >> +                                         PCI_DEVFN(0, 1));
> >>       nvidia_private.dev_2 =
> >> -             pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 2));
> >> +             pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> >> +                                         (unsigned int)pdev->bus->number,
> >> +                                         PCI_DEVFN(0, 2));
> >>       nvidia_private.dev_3 =
> >> -             pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(30, 0));
> >> +             pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> >> +                                         (unsigned int)pdev->bus->number,
> >> +                                         PCI_DEVFN(30, 0));
> >>
> >>       if (!nvidia_private.dev_1 || !nvidia_private.dev_2 || !nvidia_private.dev_3) {
> >>               printk(KERN_INFO PFX "Detected an NVIDIA nForce/nForce2 "
> >> diff --git a/drivers/char/agp/sworks-agp.c b/drivers/char/agp/sworks-agp.c
> >> index 03be4ac..4dbdd3b 100644
> >> --- a/drivers/char/agp/sworks-agp.c
> >> +++ b/drivers/char/agp/sworks-agp.c
> >> @@ -474,7 +474,8 @@ static int agp_serverworks_probe(struct pci_dev *pdev,
> >>       }
> >>
> >>       /* Everything is on func 1 here so we are hardcoding function one */
> >> -     bridge_dev = pci_get_bus_and_slot((unsigned int)pdev->bus->number,
> >> +     bridge_dev = pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
> >> +                     (unsigned int)pdev->bus->number,
> >>                       PCI_DEVFN(0, 1));
> >>       if (!bridge_dev) {
> >>               dev_info(&pdev->dev, "can't find secondary device\n");
> >>
> >
> > Any feedback here? most of the remaining patches have the ACK except these.
> >
> >
> > --
> > 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.
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Dave Airlie Jan. 29, 2018, 10:43 p.m. UTC | #5
On 30 January 2018 at 08:38, Bjorn Helgaas <helgaas@kernel.org> wrote:
> On Tue, Jan 30, 2018 at 07:43:21AM +1000, Dave Airlie wrote:
>> On 3 January 2018 at 22:44, Sinan Kaya <okaya@codeaurora.org> 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.
>>
>> So not a major problem, but it would be pretty much impossible for either
>> of these agp drivers to be used in any other domain ever.
>>
>> What does this buy us, maybe just rename pci_get_bus_and_slot to
>> pci_get_domain0_bus_and_slot as a helper, or just pass the pdev in
>> and have it do the right thing always.
>
> I already have this patch on my "next" branch, planned for the v4.16
> merge window, so it's done unless you have a major objection.

Yeah I don't really care either way, I just can't seen the point in changing
agp drivers that definitely will never see a domain, but if it gets
rid of a dumb API,
so be it.

Dave.
diff mbox series

Patch

diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c
index 828b344..623205b 100644
--- a/drivers/char/agp/nvidia-agp.c
+++ b/drivers/char/agp/nvidia-agp.c
@@ -340,11 +340,17 @@  static int agp_nvidia_probe(struct pci_dev *pdev,
 	u8 cap_ptr;
 
 	nvidia_private.dev_1 =
-		pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 1));
+		pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+					    (unsigned int)pdev->bus->number,
+					    PCI_DEVFN(0, 1));
 	nvidia_private.dev_2 =
-		pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(0, 2));
+		pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+					    (unsigned int)pdev->bus->number,
+					    PCI_DEVFN(0, 2));
 	nvidia_private.dev_3 =
-		pci_get_bus_and_slot((unsigned int)pdev->bus->number, PCI_DEVFN(30, 0));
+		pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+					    (unsigned int)pdev->bus->number,
+					    PCI_DEVFN(30, 0));
 
 	if (!nvidia_private.dev_1 || !nvidia_private.dev_2 || !nvidia_private.dev_3) {
 		printk(KERN_INFO PFX "Detected an NVIDIA nForce/nForce2 "
diff --git a/drivers/char/agp/sworks-agp.c b/drivers/char/agp/sworks-agp.c
index 03be4ac..4dbdd3b 100644
--- a/drivers/char/agp/sworks-agp.c
+++ b/drivers/char/agp/sworks-agp.c
@@ -474,7 +474,8 @@  static int agp_serverworks_probe(struct pci_dev *pdev,
 	}
 
 	/* Everything is on func 1 here so we are hardcoding function one */
-	bridge_dev = pci_get_bus_and_slot((unsigned int)pdev->bus->number,
+	bridge_dev = pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+			(unsigned int)pdev->bus->number,
 			PCI_DEVFN(0, 1));
 	if (!bridge_dev) {
 		dev_info(&pdev->dev, "can't find secondary device\n");