Standalone SRIO Driver for Linux

Standalone SRIO Driver for Linux

[Saravanan S]

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Hi ,
      Iam currently working on the GE make DSP230 board consisting of Quad
PowerPC8640 nodes   interconnected by SRIO with Linux 2.6.34 . However the
only way to access the SRIO is through rionet facility . Our requirement is
to use the SRIO interconnect without the Ethernet overheads. This would
definitely enable higher speeds (though I cant find any throughput figures
for SRIO in Linux on the net ??? ).  My query is that whether any attempt
has been made  to develop a  standalone driver and API to access the
messaging  and doorbell services of SRIO . If no then request you to please
provide inputs on the same. From my study I have the following thoughts for
the driver :

a) Have a character device interface for user .
b) Basically use the rio support functions provided in rio.c like
rio_add_inb_buffer ,  rio_add_outb_message to transfer and receive messages
and add buffers .
c) Maintain a dedicated ring of buffers in the driver and transfer  data to
and from the buffer to user space .


Is this the right direction . Would really appreciate any inputs . thanks
in advance.

Regards,

S.Saravanan

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RE: Standalone SRIO Driver for Linux

[Bounine, Alexandre]

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This should work. We use similar approach to test our mport HW drivers.

Alex.

From: Linuxppc-dev [mailto:linuxppc-dev-bounces+alexandre.bounine=idt.com@lists.ozlabs.org] On Behalf Of Saravanan S
Sent: Friday, July 13, 2012 2:16 AM
To: linuxppc-dev@lists.ozlabs.org
Subject: Standalone SRIO Driver for Linux

Hi ,
      Iam currently working on the GE make DSP230 board consisting of Quad PowerPC8640 nodes   interconnected by SRIO with Linux 2.6.34 . However the only way to access the SRIO is through rionet facility . Our requirement is to use the SRIO interconnect without the Ethernet overheads. This would definitely enable higher speeds (though I cant find any throughput figures for SRIO in Linux on the net ??? ).  My query is that whether any attempt has been made  to develop a  standalone driver and API to access the messaging  and doorbell services of SRIO . If no then request you to please provide inputs on the same. From my study I have the following thoughts for the driver :

a) Have a character device interface for user .
b) Basically use the rio support functions provided in rio.c like  rio_add_inb_buffer ,  rio_add_outb_message to transfer and receive messages and add buffers .
c) Maintain a dedicated ring of buffers in the driver and transfer  data to and from the buffer to user space .


Is this the right direction . Would really appreciate any inputs . thanks in advance.

Regards,

S.Saravanan

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Re: Standalone SRIO Driver for Linux

[Saravanan S]

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Hi ,
     Thanks for the reply . i will try to share some of my code later .
Looking forward to ur ideas.

Regards,

S.Saravanan

On Fri, Jul 13, 2012 at 6:18 PM, Bounine, Alexandre <
Alexandre.Bounine@idt.com> wrote:

>  This should work. We use similar approach to test our mport HW drivers.**
> **
>
> ** **
>
> Alex.****
>
> ** **
>
> *From:* Linuxppc-dev [mailto:linuxppc-dev-bounces+alexandre.bounine=
> idt.com@lists.ozlabs.org] *On Behalf Of *Saravanan S
> *Sent:* Friday, July 13, 2012 2:16 AM
> *To:* linuxppc-dev@lists.ozlabs.org
> *Subject:* Standalone SRIO Driver for Linux****
>
> ** **
>
> Hi ,
>
>       Iam currently working on the GE make DSP230 board consisting of Quad
> PowerPC8640 nodes   interconnected by SRIO with Linux 2.6.34 . However the
> only way to access the SRIO is through rionet facility . Our requirement is
> to use the SRIO interconnect without the Ethernet overheads. This would
> definitely enable higher speeds (though I cant find any throughput figures
> for SRIO in Linux on the net ??? ).  My query is that whether any attempt
> has been made  to develop a  standalone driver and API to access the
> messaging  and doorbell services of SRIO . If no then request you to please
> provide inputs on the same. From my study I have the following thoughts for
> the driver :
>
> a) Have a character device interface for user .
> b) Basically use the rio support functions provided in rio.c like
> rio_add_inb_buffer ,  rio_add_outb_message to transfer and receive messages
> and add buffers .
> c) Maintain a dedicated ring of buffers in the driver and transfer  data
> to and from the buffer to user space .
>
>
> Is this the right direction . Would really appreciate any inputs . thanks
> in advance.
>
> Regards,
>
> S.Saravanan****
>
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>

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RE: Standalone SRIO Driver for Linux

[Bounine, Alexandre]

Hi,

With current way of device reporting in RapidIO subsystem you will need
to have at least one SRIO device (switch or EP) attached to your mport
to be able to find a reference to that mport device object. Like in the cod=
e fragment below:

static int rioport_init_module(void)
{
	int ret, i;
	dev_t dev =3D 0;
	struct rio_mport *mport;
	struct rio_net *net;
	struct rio_dev *rdev =3D NULL;
	struct rio_mport *port;

... skip ...

	rdev =3D rio_get_device(RIO_ANY_ID, RIO_ANY_ID, rdev);
	if (NULL =3D=3D rdev)
		return -ENODEV;

	mport =3D rdev->net->hport;
	net =3D rdev->net;
... skip ...
}

I would like to mention that 2.6.34 kernel is quite behind on rapidio suppo=
rt updates.
There are multiple changes/updates added added since 2.6.34.
You may consider backporting these updates to your kernel version
if you are unable to use one of the latest kernel versions.

Alex.


From: Saravanan S [mailto:sarans1987@gmail.com]=20
Sent: Saturday, July 14, 2012 2:25 AM
To: Bounine, Alexandre
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: Standalone SRIO Driver for Linux

Hi ,
=A0 =A0 =A0Thanks for the reply . i will try to share some of my code later=
 . Looking forward to ur ideas.=A0

Regards,

S.Saravanan
On Fri, Jul 13, 2012 at 6:18 PM, Bounine, Alexandre <Alexandre.Bounine@idt.=
com> wrote:
This should work. We use similar approach to test our mport HW drivers.
=A0
Alex.
=A0
From: Linuxppc-dev [mailto:linuxppc-dev-bounces+alexandre.bounine=3Didt.com=
@lists.ozlabs.org] On Behalf Of Saravanan S
Sent: Friday, July 13, 2012 2:16 AM
To: linuxppc-dev@lists.ozlabs.org
Subject: Standalone SRIO Driver for Linux
=A0
Hi ,

=A0=A0=A0=A0=A0 Iam currently working on the GE make DSP230 board consistin=
g of Quad PowerPC8640 nodes =A0 interconnected by SRIO with Linux 2.6.34 . =
However the only way to access the SRIO is through rionet facility . Our re=
quirement is to use the SRIO interconnect without the Ethernet overheads. T=
his would definitely enable higher speeds (though I cant find any throughpu=
t figures for SRIO in Linux on the net ??? ).=A0 My query is that whether a=
ny attempt has been made=A0 to develop a=A0 standalone driver and API to ac=
cess the messaging=A0 and doorbell services of SRIO . If no then request yo=
u to please provide inputs on the same. From my study I have the following =
thoughts for the driver :

a) Have a character device interface for user .
b) Basically use the rio support functions provided in rio.c like=A0 rio_ad=
d_inb_buffer ,=A0 rio_add_outb_message to transfer and receive messages and=
 add buffers .
c) Maintain a dedicated ring of buffers in the driver and transfer=A0 data =
to and from the buffer to user space .


Is this the right direction . Would really appreciate any inputs . thanks i=
n advance.

Regards,

S.Saravanan

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