Hi Heng, Even if we don't support 1 to N model in gem5, it is not strictly true that all SPIs are handled by cpu0. In fact this is managed at software level.
SPIs are handled at the Distributor level (GICD): All SPIs (from 32 to 1019) have a personal GICD_IROUTER register selecting to which the PE (cpu) the interrupt will be routed by the GIC. https://developer.arm.com/docs/ddi0601/b/external-system-registers/gicd_irouterne The register has a set of fields (Affinity numbers) tagging a PE in your cluster configuration. In gem5 core0 will have an affinity value of 0.0.0.0; core1 will have 0.0.0.1 (Anyway have a look at the MPIDR register value in the arm reference manual for more info) So if you want to deliver an interrupt to core1 you should write 0.0.0.1 to the specific GICD_IROUTER register. How can you do that? I have never tested it, but I think this is doable via the procfs: Change the value of: /proc/irq/<irq>/smp_affinity and double check if this constitutes a write to IROUTER. Then test the interrupt and let us know if it worked. if you read /proc/interrupts, it should tell you to which CPU an interrupt has been delivered Regards Giacomo ________________________________ From: gem5-users <gem5-users-boun...@gem5.org> on behalf of HENG ZHUO <hzh...@wisc.edu> Sent: 25 February 2020 21:15 To: gem5-users@gem5.org <gem5-users@gem5.org> Subject: [gem5-users] ARM SPI interrupt 1 to N model support Dear all, I noticed that in ARM multi core fs simulation, SPI (shared processor interrupts, Ethernet interrupt for instance) is all handled by cpu0. I was looking for mechanisms letting all cpu involved in handling interrupts. After some literature research and code digging, seems like 1-N (in gic v2) or 1 of N (in gic v3) features is not supported. Am I missing something here or is this actually some features that are not supported now? Any help is appreciated! Thanks. Best, Heng _______________________________________________ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
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