From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Tue, 18 Oct 2011 13:39:00 +0100 Subject: [PATCH v4 0/4] genirq: handling GIC per-cpu interrupts In-Reply-To: <20111013181415.GM21648@n2100.arm.linux.org.uk> References: <1317661446-2876-1-git-send-email-marc.zyngier@arm.com> <20111013181415.GM21648@n2100.arm.linux.org.uk> Message-ID: <4E9D7364.2020209@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 13/10/11 19:14, Russell King - ARM Linux wrote: > On Mon, Oct 03, 2011 at 06:04:02PM +0100, Marc Zyngier wrote: >> The current GIC per-cpu interrupts (aka PPIs) suffer from a number of >> problems: >> >> - They use a completely separate scheme to handle the interrupts, >> mostly because the PPI concept doesn't really match the kernel view >> of an interrupt. >> - PPIs can only be used by the timer code, unless we add more low-level >> assembly code. >> - The local timer code can only be used by devices generating PPIs, >> and not SPIs. >> - At least one platform (msm) has started implementing its own >> alternative scheme. >> - Some low-level code gets duplicated, as usual... >> >> The proposed solution is to handle the PPIs using the same path as >> SPIs. A new core API is added to deal with per-cpu interrupts in a >> less awkward way. The local timer code is updated to reflect these >> changes. >> >> The core API changes are based on an initial idea by Thomas Gleixner. >> >> Tested on ARM Versatile Express (Cortex A15), ARM RealView PB11MP, >> OMAP4 (Panda) and Tegra (Harmony). Patch series against next-20110930. >> >> The two first patches can also be found in Thomas' tree: >> >> git://tesla.tglx.de/git/linux-2.6-tip irq/core > > So, how do we deal with merging this without ending up with some > problematical inter-tree dependencies? > > It looks like I'll see conflicts with: > arch/arm/common/gic.c > arch/arm/kernel/smp.c > arch/arm/include/asm/localtimer.h > > and possibly: > arch/arm/include/asm/smp.h > arch/arm/kernel/irq.c > > as well. I've not checked with patch 4, so there may be some more too. > > Some of this is probably because of 7123/1 and 7124/1. I've set up a branch based on your "smp" branch, resolving the above conflicts: git://github.com/mzyngier/arm-platforms.git ppi-for-rmk M. -- Jazz is not dead. It just smells funny...