Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Simon Glass]

Hi Heinrich,

On Tue, 31 Dec 2019 at 09:59, Heinrich Schuchardt  wrote:
>
> On 12/31/19 4:49 PM, Sughosh Ganu wrote:
> >
> > On Tue, 31 Dec 2019 at 20:38, Heinrich Schuchardt  > > wrote:
> >
> > On 12/31/19 2:31 PM, Sughosh Ganu wrote:
> >  > Scan the pci bus in board_init routine before scanning the virtio
> >  > devices. This enumerates all the virtio devices, including devices
> >  > found on the pci bus.
> >  >
> >  > Signed-off-by: Sughosh Ganu  > >
> >  > ---
> >  >  board/emulation/qemu-arm/qemu-arm.c | 7 +++
> >  >  1 file changed, 7 insertions(+)
> >  >
> >  > diff --git a/board/emulation/qemu-arm/qemu-arm.c
> > b/board/emulation/qemu-arm/qemu-arm.c
> >  > index 4e18733..6c5335c 100644
> >  > --- a/board/emulation/qemu-arm/qemu-arm.c
> >  > +++ b/board/emulation/qemu-arm/qemu-arm.c
> >  > @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
> >  >  int board_init(void)
> >  >  {
> >  >   /*
> >  > +  * Scan the pci bus before calling virtio_init. This
> >  > +  * enumerates all virtio devices, including devices
> >  > +  * on the pci bus.
> >
> > The last sentence is easy to misunderstand. You surely do not mean that
> > pci_init() would enumerate all virtio devices including mmio virtio
> > devices.
> >
> > I would suggest to rephrase it to "This enumerates all pci devices
> > including virtio devices on the pci bus."
> >
> >
> > Ok.
> >
> >
> > With the patch I no longer need to run `virtio scan` on
> > qemu_arm64_defonfig before using the rng command supplied in patch
> >
> > [PATCH 1/1] cmd: add rng command
> > https://lists.denx.de/pipermail/u-boot/2019-December/394539.html
> >
> > Unfortunately you only considered the ARM architecture. We need a
> > solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).
> >
> >
> > That is fine with me, but currently, only risc-v and arm architectures
> > are calling virtio_init.
> >
> >
> > How about eliminating board_init() for ARM and RISC-V and moving
> > virtio_init() to common/board_r.c after initr_pci?
> >
> >
> > That can be done, but currently, for some reason, initr_pci function
> > calls pci_init only when CONFIG_DM_PCI is not defined. Not sure why that
> > is the case, although initr_pci gets called after initr_dm.
> >
> > -sughosh
>
> This dates back to Simon's commit ff3e077bd23c ("dm: pci: Add a uclass
> for PCI").
>
> I hope that Simon can tell us why he chose not to call pci_init() if
> DM_PCI is defined.

Driver model uses lazy init. We have discussed this before, and
considered using a uclass flag to tell U-Boot that the uclass needs to
be fully probed (i.e. probe all devices in that uclass, recursively).

But I'm not sure we got agreement. If you think it is a good idea you
could send a patch. The only thing is that I think some platforms
don't need PCI to boot so might not want this?

Regards,
Simon

Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Heinrich Schuchardt]

On 12/31/19 4:49 PM, Sughosh Ganu wrote:


On Tue, 31 Dec 2019 at 20:38, Heinrich Schuchardt mailto:xypron.g...@gmx.de>> wrote:

On 12/31/19 2:31 PM, Sughosh Ganu wrote:
 > Scan the pci bus in board_init routine before scanning the virtio
 > devices. This enumerates all the virtio devices, including devices
 > found on the pci bus.
 >
 > Signed-off-by: Sughosh Ganu mailto:sughosh.g...@linaro.org>>
 > ---
 >  board/emulation/qemu-arm/qemu-arm.c | 7 +++
 >  1 file changed, 7 insertions(+)
 >
 > diff --git a/board/emulation/qemu-arm/qemu-arm.c
b/board/emulation/qemu-arm/qemu-arm.c
 > index 4e18733..6c5335c 100644
 > --- a/board/emulation/qemu-arm/qemu-arm.c
 > +++ b/board/emulation/qemu-arm/qemu-arm.c
 > @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
 >  int board_init(void)
 >  {
 >       /*
 > +      * Scan the pci bus before calling virtio_init. This
 > +      * enumerates all virtio devices, including devices
 > +      * on the pci bus.

The last sentence is easy to misunderstand. You surely do not mean that
pci_init() would enumerate all virtio devices including mmio virtio
devices.

I would suggest to rephrase it to "This enumerates all pci devices
including virtio devices on the pci bus."


Ok.


With the patch I no longer need to run `virtio scan` on
qemu_arm64_defonfig before using the rng command supplied in patch

[PATCH 1/1] cmd: add rng command
https://lists.denx.de/pipermail/u-boot/2019-December/394539.html

Unfortunately you only considered the ARM architecture. We need a
solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).


That is fine with me, but currently, only risc-v and arm architectures
are calling virtio_init.


How about eliminating board_init() for ARM and RISC-V and moving
virtio_init() to common/board_r.c after initr_pci?


That can be done, but currently, for some reason, initr_pci function
calls pci_init only when CONFIG_DM_PCI is not defined. Not sure why that
is the case, although initr_pci gets called after initr_dm.

-sughosh


This dates back to Simon's commit ff3e077bd23c ("dm: pci: Add a uclass
for PCI").

I hope that Simon can tell us why he chose not to call pci_init() if
DM_PCI is defined.

Best regards

Heinrich

Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Sughosh Ganu]

On Tue, 31 Dec 2019 at 20:38, Heinrich Schuchardt 
wrote:

> On 12/31/19 2:31 PM, Sughosh Ganu wrote:
> > Scan the pci bus in board_init routine before scanning the virtio
> > devices. This enumerates all the virtio devices, including devices
> > found on the pci bus.
> >
> > Signed-off-by: Sughosh Ganu 
> > ---
> >  board/emulation/qemu-arm/qemu-arm.c | 7 +++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/board/emulation/qemu-arm/qemu-arm.c
> b/board/emulation/qemu-arm/qemu-arm.c
> > index 4e18733..6c5335c 100644
> > --- a/board/emulation/qemu-arm/qemu-arm.c
> > +++ b/board/emulation/qemu-arm/qemu-arm.c
> > @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
> >  int board_init(void)
> >  {
> >   /*
> > +  * Scan the pci bus before calling virtio_init. This
> > +  * enumerates all virtio devices, including devices
> > +  * on the pci bus.
>
> The last sentence is easy to misunderstand. You surely do not mean that
> pci_init() would enumerate all virtio devices including mmio virtio
> devices.
>
> I would suggest to rephrase it to "This enumerates all pci devices
> including virtio devices on the pci bus."
>

Ok.


>
> With the patch I no longer need to run `virtio scan` on
> qemu_arm64_defonfig before using the rng command supplied in patch
>
> [PATCH 1/1] cmd: add rng command
> https://lists.denx.de/pipermail/u-boot/2019-December/394539.html
>
> Unfortunately you only considered the ARM architecture. We need a
> solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).
>

That is fine with me, but currently, only risc-v and arm architectures are
calling virtio_init.


>
> How about eliminating board_init() for ARM and RISC-V and moving
> virtio_init() to common/board_r.c after initr_pci?
>

That can be done, but currently, for some reason, initr_pci function calls
pci_init only when CONFIG_DM_PCI is not defined. Not sure why that is the
case, although initr_pci gets called after initr_dm.

-sughosh

Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Bin Meng]

On Tue, Dec 31, 2019 at 11:18 PM Heinrich Schuchardt  wrote:
>
> CC Bin Meng
>
> On 12/31/19 4:08 PM, Heinrich Schuchardt wrote:
> > On 12/31/19 2:31 PM, Sughosh Ganu wrote:
> >> Scan the pci bus in board_init routine before scanning the virtio
> >> devices. This enumerates all the virtio devices, including devices
> >> found on the pci bus.
> >>
> >> Signed-off-by: Sughosh Ganu 
> >> ---
> >>  board/emulation/qemu-arm/qemu-arm.c | 7 +++
> >>  1 file changed, 7 insertions(+)
> >>
> >> diff --git a/board/emulation/qemu-arm/qemu-arm.c 
> >> b/board/emulation/qemu-arm/qemu-arm.c
> >> index 4e18733..6c5335c 100644
> >> --- a/board/emulation/qemu-arm/qemu-arm.c
> >> +++ b/board/emulation/qemu-arm/qemu-arm.c
> >> @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
> >>  int board_init(void)
> >>  {
> >>  /*
> >> + * Scan the pci bus before calling virtio_init. This
> >> + * enumerates all virtio devices, including devices
> >> + * on the pci bus.
> >
> > The last sentence is easy to misunderstand. You surely do not mean that
> > pci_init() would enumerate all virtio devices including mmio virtio devices.
> >
> > I would suggest to rephrase it to "This enumerates all pci devices
> > including virtio devices on the pci bus."

Sounds good.

> >
> > With the patch I no longer need to run `virtio scan` on
> > qemu_arm64_defonfig before using the rng command supplied in patch
> >
> > [PATCH 1/1] cmd: add rng command
> > https://lists.denx.de/pipermail/u-boot/2019-December/394539.html
> >
> > Unfortunately you only considered the ARM architecture. We need a
> > solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).
> >

Agreed, sorry I missed that. Actually all the board_init() look
similar so we should do the same.

> > How about eliminating board_init() for ARM and RISC-V and moving
> > virtio_init() to common/board_r.c after initr_pci?
> >

Or maybe we introduce a new driver model flag so that uclass drivers
are automatically probed?

Regards,
Bin

Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Heinrich Schuchardt]

CC Bin Meng

On 12/31/19 4:08 PM, Heinrich Schuchardt wrote:
> On 12/31/19 2:31 PM, Sughosh Ganu wrote:
>> Scan the pci bus in board_init routine before scanning the virtio
>> devices. This enumerates all the virtio devices, including devices
>> found on the pci bus.
>>
>> Signed-off-by: Sughosh Ganu 
>> ---
>>  board/emulation/qemu-arm/qemu-arm.c | 7 +++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/board/emulation/qemu-arm/qemu-arm.c 
>> b/board/emulation/qemu-arm/qemu-arm.c
>> index 4e18733..6c5335c 100644
>> --- a/board/emulation/qemu-arm/qemu-arm.c
>> +++ b/board/emulation/qemu-arm/qemu-arm.c
>> @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
>>  int board_init(void)
>>  {
>>  /*
>> + * Scan the pci bus before calling virtio_init. This
>> + * enumerates all virtio devices, including devices
>> + * on the pci bus.
>
> The last sentence is easy to misunderstand. You surely do not mean that
> pci_init() would enumerate all virtio devices including mmio virtio devices.
>
> I would suggest to rephrase it to "This enumerates all pci devices
> including virtio devices on the pci bus."
>
> With the patch I no longer need to run `virtio scan` on
> qemu_arm64_defonfig before using the rng command supplied in patch
>
> [PATCH 1/1] cmd: add rng command
> https://lists.denx.de/pipermail/u-boot/2019-December/394539.html
>
> Unfortunately you only considered the ARM architecture. We need a
> solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).
>
> How about eliminating board_init() for ARM and RISC-V and moving
> virtio_init() to common/board_r.c after initr_pci?
>
> Best regards
>
> Heinrich
>
>> + */
>> +pci_init();
>> +
>> +/*
>>   * Make sure virtio bus is enumerated so that peripherals
>>   * on the virtio bus can be discovered by their drivers
>>   */
>>
>
>

Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Heinrich Schuchardt]

On 12/31/19 2:31 PM, Sughosh Ganu wrote:
> Scan the pci bus in board_init routine before scanning the virtio
> devices. This enumerates all the virtio devices, including devices
> found on the pci bus.
>
> Signed-off-by: Sughosh Ganu 
> ---
>  board/emulation/qemu-arm/qemu-arm.c | 7 +++
>  1 file changed, 7 insertions(+)
>
> diff --git a/board/emulation/qemu-arm/qemu-arm.c 
> b/board/emulation/qemu-arm/qemu-arm.c
> index 4e18733..6c5335c 100644
> --- a/board/emulation/qemu-arm/qemu-arm.c
> +++ b/board/emulation/qemu-arm/qemu-arm.c
> @@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
>  int board_init(void)
>  {
>   /*
> +  * Scan the pci bus before calling virtio_init. This
> +  * enumerates all virtio devices, including devices
> +  * on the pci bus.

The last sentence is easy to misunderstand. You surely do not mean that
pci_init() would enumerate all virtio devices including mmio virtio devices.

I would suggest to rephrase it to "This enumerates all pci devices
including virtio devices on the pci bus."

With the patch I no longer need to run `virtio scan` on
qemu_arm64_defonfig before using the rng command supplied in patch

[PATCH 1/1] cmd: add rng command
https://lists.denx.de/pipermail/u-boot/2019-December/394539.html

Unfortunately you only considered the ARM architecture. We need a
solution that works on all QEMU architectures (MIPS, RISC-V, X86, ARM).

How about eliminating board_init() for ARM and RISC-V and moving
virtio_init() to common/board_r.c after initr_pci?

Best regards

Heinrich

> +  */
> + pci_init();
> +
> + /*
>* Make sure virtio bus is enumerated so that peripherals
>* on the virtio bus can be discovered by their drivers
>*/
>

Re: [PATCH] qemu: arm: Scan the pci bus in board_init

[Bin Meng]

On Tue, Dec 31, 2019 at 9:31 PM Sughosh Ganu  wrote:
>
> Scan the pci bus in board_init routine before scanning the virtio
> devices. This enumerates all the virtio devices, including devices
> found on the pci bus.
>
> Signed-off-by: Sughosh Ganu 
> ---
>  board/emulation/qemu-arm/qemu-arm.c | 7 +++
>  1 file changed, 7 insertions(+)
>

Reviewed-by: Bin Meng 

[PATCH] qemu: arm: Scan the pci bus in board_init

[Sughosh Ganu]

Scan the pci bus in board_init routine before scanning the virtio
devices. This enumerates all the virtio devices, including devices
found on the pci bus.

Signed-off-by: Sughosh Ganu 
---
 board/emulation/qemu-arm/qemu-arm.c | 7 +++
 1 file changed, 7 insertions(+)

diff --git a/board/emulation/qemu-arm/qemu-arm.c 
b/board/emulation/qemu-arm/qemu-arm.c
index 4e18733..6c5335c 100644
--- a/board/emulation/qemu-arm/qemu-arm.c
+++ b/board/emulation/qemu-arm/qemu-arm.c
@@ -63,6 +63,13 @@ struct mm_region *mem_map = qemu_arm64_mem_map;
 int board_init(void)
 {
/*
+* Scan the pci bus before calling virtio_init. This
+* enumerates all virtio devices, including devices
+* on the pci bus.
+*/
+   pci_init();
+
+   /*
 * Make sure virtio bus is enumerated so that peripherals
 * on the virtio bus can be discovered by their drivers
 */
-- 
2.7.4