On 05/27/2017 11:52 PM, Noam Camus wrote:
> From: Noam Camus <[email protected]>
>
> This commit adds the configuration CONFIG_EZNPS_MEM_ERROR.
> If set, it will cause the kernel to handle user memory error
> as a machine check exception.
> It is required in order to align the NPS simulator memory
> error handling to the one of the NPS400 real chip behavior.
> We override weak symbole of mem_service to achieve that.
>
> Signed-off-by: Elad Kanfi <[email protected]>
> Signed-off-by: Noam Camus <[email protected]>
> ---
> arch/arc/plat-eznps/Kconfig | 11 +++++++++++
> arch/arc/plat-eznps/entry.S | 14 ++++++++++++++
> 2 files changed, 25 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arc/plat-eznps/Kconfig b/arch/arc/plat-eznps/Kconfig
> index feaa471..c5f946c 100644
> --- a/arch/arc/plat-eznps/Kconfig
> +++ b/arch/arc/plat-eznps/Kconfig
> @@ -32,3 +32,14 @@ config EZNPS_MTM_EXT
> any of them seem like CPU from Linux point of view.
> All threads within same core share the execution unit of the
> core and HW scheduler round robin between them.
> +
> +config EZNPS_MEM_ERROR
> + bool "ARC-EZchip Memory error as an exception"
> + depends on ARC_PLAT_EZNPS
> + default n
So you set default to "n" - thus by default it works for the simulator not silicon ?
> + help
> + On the real chip of the NPS, user memory errors are handled
> + as a machine check exception, whereas on simulator platform
> + for NPS, it handled as an interrupt level 2 (like legacy arc
> + real chip architecture).This configuration will cause the kernel
> + to handle memory error as a machine check exception.
> diff --git a/arch/arc/plat-eznps/entry.S b/arch/arc/plat-eznps/entry.S
> index 328261c..03e2892 100644
> --- a/arch/arc/plat-eznps/entry.S
> +++ b/arch/arc/plat-eznps/entry.S
> @@ -68,3 +68,17 @@ ENTRY(res_service)
>
> j stext
> END(res_service)
> +
> +#if defined(CONFIG_EZNPS_MEM_ERROR)
> +ENTRY(mem_service)
> + ; SW workaround to cover up on a difference between
> + ; NPS real chip and simulator behaviors.
> + ; NPS real chip will activate a machine check exception
> + ; in case of memory error, while the simulator will
> + ; trigger a level 2 interrupt. Therefor this code section
> + ; should be reached only in simulation mode.
> + ; DEAD END: display Regs and HALT
> +
> + j EV_MachineCheck
> +END(mem_service)
> +#endif
>
>From: Vineet Gupta [mailto:[email protected]]
>Sent: Wednesday, June 7, 2017 1:11 AM
...
>> +
>> +config EZNPS_MEM_ERROR
>> + bool "ARC-EZchip Memory error as an exception"
>> + depends on ARC_PLAT_EZNPS
>> + default n
>So you set default to "n" - thus by default it works for the simulator not silicon ?
Correct, this way I "align" Sim environment to react as close as possible to how it work with silicon.
-Noam