Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752300AbbGIN5r (ORCPT ); Thu, 9 Jul 2015 09:57:47 -0400 Received: from foss.arm.com ([217.140.101.70]:46412 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751154AbbGIN5j (ORCPT ); Thu, 9 Jul 2015 09:57:39 -0400 Date: Thu, 9 Jul 2015 14:58:09 +0100 From: Lorenzo Pieralisi To: Marc Zyngier Cc: Bjorn Helgaas , Thomas Gleixner , Jiang Liu , Jason Cooper , "linux-arm-kernel@lists.infradead.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Yijing Wang , Ma Jun Subject: Re: [PATCH v3 00/15] Introducing per-device MSI domain Message-ID: <20150709135809.GA5223@red-moon> References: <1436289485-28230-1-git-send-email-marc.zyngier@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436289485-28230-1-git-send-email-marc.zyngier@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6248 Lines: 129 On Tue, Jul 07, 2015 at 06:17:50PM +0100, Marc Zyngier wrote: > [Picking up this series again after sleeping on it for too long, > hopefully still relevant] > > MSI-like interrupts are starting to creep out of the PCI world, and > can now be seen into a number of "platform"-type busses. The > introduction of the MSI domains feature in v3.19 recognised that fact, > and started providing a way to implement this. > > Another problem we have to solve is to identify which MSI domain a > device is "connected" to. Currently, PCI gets away with a mixture of > arch-specific callbacks, and a msi_controller structure that can > optionally carry a pointer to an MSI domain. As we add new bus types > and start dealing with topologies that do not map to what PCI does, > this doesn't scale anymore. > > This patch series tries to address some of it by providing a basic > link between 'struct device' and an MSI domain. It also adds : > > - a way to "tag" domains according to the "type" of interrupt it > provides (PCI/MSI, platform MSI...), allowing a driver for a piece > of HW identified by its device_node to provide several IRQ domains > > - (yet another) way for PCI to propagate the domain pointer through > the PCI device hierarchy, providing a method for OF to kick-start > the propagation process, and finally allowing the PCI/MSI layer to > use that information > > - a similar way to hook an MSI domain to a platform device. > > Hopefully this can serve as a model to implement support for different > but types. > > Additionally, the last few patches use all the above to remove any > trace of the msi_controller structure from the three MSI controllers > we use on arm64, so that they solely rely on the above infrastructure, > leading to some interesting improvements. We take this opportunity to > also kill the domain pointer from the msi_controller structure. > > My hope is to eventually kill msi_controller entirely, and only rely > on the msi_domain contained in the device structure (any help > welcomed). And kill pcibios_msi_controller from arch/arm, which means we have to convert all arm platforms relying on pci_sys_data for the MSI look-up, I only have an iMX6 Sabrelite, so yes, help is welcome here. BTW, is there a reason why _all_ arm host bridges rely on pcibios_msi_controller (so pci_sys_data) instead of initializing the struct pci_bus.msi pointer to carry out the MSI controller look-up ? I do not see any (and I want to get rid of pcibios_msi_controller on arm asap, if we can use the struct pci_bus.msi pointer patch that's trivial). I know that the way forward is by doing it through domains and this patchset, just asking (to understand why pcibios_msi_controller is even needed on arm at present). > This has been tested on arm64 with GICv2m (AMD Seattle) and GICv3 ITS > (FVP model). I tested it on arm64 AMD Seattle too, so FWIW: Tested-by: Lorenzo Pieralisi > Patches are on top of 4.2-rc1 and available at: > > git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git irq/msi_domain > > As always, comments most welcome. > > Marc Zyngier (15): > genirq: irqdomain: Allow irq domain aliasing > PCI: MSI: Register irq domain with specific token > device core: Introduce per-device MSI domain pointer > PCI/MSI: Add hooks to populate the msi_domain field > PCI/MSI: of: Add support for OF-provided msi_domain > PCI/MSI: of: Allow msi_domain lookup using the host bridge node > PCI/MSI: Let pci_msi_get_domain use struct device's msi_domain > platform: of: Assign MSI domain to platform device > irqchip: gicv3-its: Split PCI/MSI code from the core ITS driver > irqchip: gicv3-its: Register irq domain with platform MSI token > irqchip: GICv2m: Get rid of struct msi_controller > irqchip: gicv3-its: Get rid of struct msi_controller > irqchip: gicv3-its: Make the PCI/MSI code standalone > PCI/MSI: pci-xgene-msi: Get rid of struct msi_controller > PCI/MSI: Drop domain field from msi_controller > > arch/powerpc/platforms/512x/mpc5121_ads_cpld.c | 3 +- > arch/powerpc/platforms/cell/interrupt.c | 3 +- > arch/powerpc/platforms/embedded6xx/flipper-pic.c | 3 +- > arch/powerpc/platforms/powermac/pic.c | 3 +- > arch/powerpc/platforms/powernv/opal-irqchip.c | 3 +- > arch/powerpc/platforms/ps3/interrupt.c | 3 +- > arch/powerpc/sysdev/ehv_pic.c | 3 +- > arch/powerpc/sysdev/i8259.c | 3 +- > arch/powerpc/sysdev/ipic.c | 3 +- > arch/powerpc/sysdev/mpic.c | 3 +- > arch/powerpc/sysdev/qe_lib/qe_ic.c | 3 +- > arch/powerpc/sysdev/xics/xics-common.c | 3 +- > drivers/irqchip/Makefile | 2 +- > drivers/irqchip/irq-gic-v2m.c | 27 ++--- > drivers/irqchip/irq-gic-v3-its-pci-msi.c | 135 +++++++++++++++++++++++ > drivers/irqchip/irq-gic-v3-its.c | 130 ++++------------------ > drivers/of/irq.c | 16 +++ > drivers/of/platform.c | 1 + > drivers/pci/host/pci-xgene-msi.c | 41 +++---- > drivers/pci/msi.c | 11 +- > drivers/pci/of.c | 24 ++++ > drivers/pci/probe.c | 31 ++++++ > include/linux/device.h | 20 ++++ > include/linux/irqchip/arm-gic-v3.h | 3 + > include/linux/irqdomain.h | 25 ++++- > include/linux/msi.h | 3 - > include/linux/of_irq.h | 1 + > include/linux/pci.h | 3 + > kernel/irq/irqdomain.c | 18 ++- > 29 files changed, 350 insertions(+), 177 deletions(-) > create mode 100644 drivers/irqchip/irq-gic-v3-its-pci-msi.c > > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/