SMP support for Raspberry Pi 2

[Joel Sherrill]

On 7/31/2015 8:11 AM, Rohini Kulkarni wrote:
> Hi,
>
> How is the number of processors to be used for an application specified?
> The used count minimum of that supported in hardware and that configured. How to specify the latter?

https://docs.rtems.org/doc-current/share/rtems/html/c_user/Configuring-a-System-SMP-Specific-Configuration-Parameters.html#Configuring-a-System-SMP-Specific-Configuration-Parameters

and see the smptests. Many of which do specify the maximum.

> Thanks.
>
> On 29 Jul 2015 15:29, "Sebastian Huber" <sebastian.huber at embedded-brains.de <mailto:sebastian.huber at embedded-brains.de>> wrote:
>
>
>
>     On 29/07/15 11:52, Rohini Kulkarni wrote:
>
>
>
>         On Tue, Jul 28, 2015 at 12:24 PM, Sebastian Huber <sebastian.huber at embedded-brains.de <mailto:sebastian.huber at embedded-brains.de> <mailto:sebastian.huber at embedded-brains.de <mailto:sebastian.huber at embedded-brains.de>>> wrote:
>
>              Hello Rohini,
>
>              please use the devel list.
>
>              On 28/07/15 07:41, Rohini Kulkarni wrote:
>
>                  Hi,
>
>                  I wish to understand where the interprocessor interrupts are
>                  used during the boot process. During final initialization of
>                  SMP I can see
>
>                  rtems_interrupt_handler_install(
>                        ARM_GIC_IRQ_SGI_0,
>                        "IPI",
>                        RTEMS_INTERRUPT_UNIQUE,
>                        bsp_inter_processor_interrupt,
>                        NULL
>                      );
>
>                  Raspberry Pi 2 does not have the generic interrupt controller.
>                  Interrupt routing will have to be handled differently. So I
>                  wish to understand how/ where it is used. I suppose this might
>                  be the problem.
>
>
>              Sorry, that the documentation is so scattered.  I think we should
>              move everything into the CPU Architecture Supplement. It would be
>              nice if you can help to improve the documentation since you have a
>              different view point.
>
>              You must install the IPI during the system initialization. It is
>              raised via the _CPU_SMP_Send_interrupt() function, for an example
>              see arm-a9mpcore-smp.c.
>
>         I could locate the function in  arm-a9mpcore-smp.c. but it would be helpful if I can know where this being called from, a deeper call hierarchy, so that I can ascertain this is a problem. I can see a Send_messgae function call this. But don't know where the send message is being called from.
>
>
>     You can run one of the SMP tests on the realview_pbx_a9_qemu_smp BSP on Qemu and set a break point to _CPU_SMP_Send_interrupt() if you want to know how it is used.
>
>     --
>     Sebastian Huber, embedded brains GmbH
>
>     Address : Dornierstr. 4, D-82178 Puchheim, Germany
>     Phone   : +49 89 189 47 41-16
>     Fax     : +49 89 189 47 41-09
>     E-Mail  : sebastian.huber at embedded-brains.de <mailto:sebastian.huber at embedded-brains.de>
>     PGP     : Public key available on request.
>
>     Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
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