From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey.Brodkin@synopsys.com (Alexey Brodkin) Date: Thu, 25 May 2017 11:14:59 +0000 Subject: [PATCH 10/10] ARC: [plat-eznps] Handle memory error as an exception In-Reply-To: <1495679660-9598-11-git-send-email-noamca@mellanox.com> References: <1495679660-9598-1-git-send-email-noamca@mellanox.com> <1495679660-9598-11-git-send-email-noamca@mellanox.com> List-ID: Message-ID: <1495710896.5393.32.camel@synopsys.com> To: linux-snps-arc@lists.infradead.org Hi Noam, On Thu, 2017-05-25@05:34 +0300, Noam Camus wrote: > From: Noam Camus > > 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. > > Signed-off-by: Elad Kanfi > Signed-off-by: Noam Camus > --- > ?arch/arc/kernel/entry-compact.S |???11 +++++++++++ > ?arch/arc/plat-eznps/Kconfig?????|???11 +++++++++++ > ?2 files changed, 22 insertions(+), 0 deletions(-) > > diff --git a/arch/arc/kernel/entry-compact.S b/arch/arc/kernel/entry-compact.S > index f285dbb..d152d36 100644 > --- a/arch/arc/kernel/entry-compact.S > +++ b/arch/arc/kernel/entry-compact.S > @@ -203,6 +203,17 @@ END(handle_interrupt_level2) > ?; --------------------------------------------- > ?ENTRY(mem_service) > ? > +#if defined(CONFIG_EZNPS_MEM_ERROR) > +????????; 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 I'm not really buying that. Why don't you just make simulator behaving exactly as your real chip? Adding those stubs for some corner-cases here and there complicate code, affect maintainability etc. -Alexey