linux-kernel - Affinity for GIC irq line

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 25 Apr 2018 08:53:09 +0530
From:   valmiki <valmikibow@...il.com>
To:     linux-kernel@...r.kernel.org
Cc:     Marc Zyngier <marc.zyngier@....com>, tglx@...utronix.de,
        jason@...edaemon.net, Catalin Marinas <catalin.marinas@....com>
Subject: Affinity for GIC irq line

Hi all,

When an IRQ line is set affinity using irq_set_affinity, which calls 
irq_do_set_affinity, this API copies affinity mask to affinity variable 
in irq_common_data of this irq descriptor.

But as per ARM GICv2 document in order to drive a interrupt to a 
specific CPU we need to program GICD_ITARGETSRn register.

But irq_set_affinity isn't writing to this register.Please correct me if 
I'm wrong i did not find code for this register being updated in 
irq_set_affinity flow.
So how affinity is being set for an IRQ line ?

If affinity was set successfully on what CPU does asm_do_IRQ run ?
For every interrupt this runs on CPU0 and then FIQ/IRQ handling is 
scheduled on different CPU as per affinity ?
How the respective irq line handler is handled on specific CPU core ?

Regards,
Valmiki

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus