genirq: Provide real IRQ affinity masks in non-SMP configs

From:		Samuel Holland <samuel-AT-sholland.org>
To:		Marc Zyngier <maz-AT-kernel.org>, Thomas Gleixner <tglx-AT-linutronix.de>
Subject:		[PATCH v3 0/8] genirq: Provide real IRQ affinity masks in non-SMP configs
Date:		Fri, 01 Jul 2022 15:00:48 -0500
Message-ID:		<20220701200056.46555-1-samuel@sholland.org>
Cc:		Samuel Holland <samuel-AT-sholland.org>, Andy Shevchenko <andy.shevchenko-AT-gmail.com>, Bartosz Golaszewski <brgl-AT-bgdev.pl>, Bjorn Helgaas <bhelgaas-AT-google.com>, Boris Ostrovsky <boris.ostrovsky-AT-oracle.com>, Borislav Petkov <bp-AT-alien8.de>, Broadcom internal kernel review list <bcm-kernel-feedback-list-AT-broadcom.com>, Chris Zankel <chris-AT-zankel.net>, Colin Ian King <colin.king-AT-intel.com>, Dave Hansen <dave.hansen-AT-linux.intel.com>, Dexuan Cui <decui-AT-microsoft.com>, Florian Fainelli <f.fainelli-AT-gmail.com>, Guo Ren <guoren-AT-kernel.org>, "H. Peter Anvin" <hpa-AT-zytor.com>, Haiyang Zhang <haiyangz-AT-microsoft.com>, Helge Deller <deller-AT-gmx.de>, Ingo Molnar <mingo-AT-redhat.com>, Ivan Kokshaysky <ink-AT-jurassic.park.msu.ru>, "James E.J. Bottomley" <James.Bottomley-AT-HansenPartnership.com>, Jan Beulich <jbeulich-AT-suse.com>, Joerg Roedel <joro-AT-8bytes.org>, Juergen Gross <jgross-AT-suse.com>, Julia Lawall <Julia.Lawall-AT-inria.fr>, "K. Y. Srinivasan" <kys-AT-microsoft.com>, Kees Cook <keescook-AT-chromium.org>, Krzysztof Wilczyński <kw-AT-linux.com>, Linus Walleij <linus.walleij-AT-linaro.org>, Lorenzo Pieralisi <lpieralisi-AT-kernel.org>, Mark Rutland <mark.rutland-AT-arm.com>, Matt Turner <mattst88-AT-gmail.com>, Max Filippov <jcmvbkbc-AT-gmail.com>, Maximilian Heyne <mheyne-AT-amazon.de>, Oleksandr Tyshchenko <oleksandr_tyshchenko-AT-epam.com>, Rich Felker <dalias-AT-libc.org>, Richard Henderson <rth-AT-twiddle.net>, Rikard Falkeborn <rikard.falkeborn-AT-gmail.com>, Rob Herring <robh-AT-kernel.org>, Russell King <linux-AT-armlinux.org.uk>, Serge Semin <fancer.lancer-AT-gmail.com>, Stefano Stabellini <sstabellini-AT-kernel.org>, Stephen Hemminger <sthemmin-AT-microsoft.com>, Sven Schnelle <svens-AT-stackframe.org>, Thomas Bogendoerfer <tsbogend-AT-alpha.franken.de>, Wei Liu <wei.liu-AT-kernel.org>, Wei Xu <xuwei5-AT-hisilicon.com>, Will Deacon <will-AT-kernel.org>, Yoshinori Sato <ysato-AT-users.sourceforge.jp>, iommu-AT-lists.linux-foundation.org, iommu-AT-lists.linux.dev, linux-alpha-AT-vger.kernel.org, linux-arm-kernel-AT-lists.infradead.org, linux-hyperv-AT-vger.kernel.org, linux-ia64-AT-vger.kernel.org, linux-kernel-AT-vger.kernel.org, linux-mips-AT-vger.kernel.org, linux-parisc-AT-vger.kernel.org, linux-pci-AT-vger.kernel.org, linux-sh-AT-vger.kernel.org, linux-xtensa-AT-linux-xtensa.org, x86-AT-kernel.org, xen-devel-AT-lists.xenproject.org
Archive-link:		Article

This series solves some inconsistency with how IRQ affinity masks are
handled between SMP and non-SMP configurations.

In non-SMP configs, an IRQ's true affinity is always cpumask_of(0), so
irq_{,data_}get_affinity_mask now return that, instead of returning an
uninitialized per-IRQ cpumask. This change makes iterating over the
affinity mask do the right thing in both SMP and non-SMP configurations.

To accomplish that:
 - patches 1-3 disable some library code that was broken anyway on !SMP
 - patches 4-7 refactor the code so that irq_{,data_}get_affinity_mask
   can return a const cpumask, since that is what cpumask_of provides
 - patch 8 drops the per-IRQ cpumask and replaces it with cpumask_of(0)

This series was split from the v2 series here, which uses the new
behavior in the RISC-V PLIC irqchip driver:

https://lore.kernel.org/lkml/20220616064028.57933-1-samue...

Changes in v3:
 - New patch to fix build errors in uniprocessor MIPS configs
 - New patch to drop irq_init_effective_affinity
 - New patch to introduce irq_data_update_affinity
 - New patch to make the returned cpumasks const
 - Use cpumask_of(0) instead of cpu_possible_mask

Changes in v2:
 - New patch to prevent GENERIC_IRQ_IPI from being selected on !SMP

Samuel Holland (8):
  irqchip/mips-gic: Only register IPI domain when SMP is enabled
  genirq: GENERIC_IRQ_IPI depends on SMP
  genirq: GENERIC_IRQ_EFFECTIVE_AFF_MASK depends on SMP
  genirq: Drop redundant irq_init_effective_affinity
  genirq: Refactor accessors to use irq_data_get_affinity_mask
  genirq: Add and use an irq_data_update_affinity helper
  genirq: Return a const cpumask from irq_data_get_affinity_mask
  genirq: Provide an IRQ affinity mask in non-SMP configs

 arch/alpha/kernel/irq.c              |  2 +-
 arch/arm/mach-hisi/Kconfig           |  2 +-
 arch/ia64/kernel/iosapic.c           |  2 +-
 arch/ia64/kernel/irq.c               |  4 +-
 arch/ia64/kernel/msi_ia64.c          |  4 +-
 arch/mips/cavium-octeon/octeon-irq.c |  4 +-
 arch/parisc/kernel/irq.c             |  2 +-
 arch/sh/kernel/irq.c                 |  7 +--
 arch/x86/hyperv/irqdomain.c          |  2 +-
 arch/xtensa/kernel/irq.c             |  7 +--
 drivers/iommu/hyperv-iommu.c         |  2 +-
 drivers/irqchip/Kconfig              | 19 +++----
 drivers/irqchip/irq-bcm6345-l1.c     |  4 +-
 drivers/irqchip/irq-mips-gic.c       | 80 +++++++++++++++++++---------
 drivers/parisc/iosapic.c             |  2 +-
 drivers/pci/controller/pci-hyperv.c  | 10 ++--
 drivers/sh/intc/chip.c               |  2 +-
 drivers/xen/events/events_base.c     |  7 +--
 include/linux/irq.h                  | 34 ++++++++----
 kernel/irq/Kconfig                   |  2 +
 kernel/irq/chip.c                    |  8 +--
 kernel/irq/debugfs.c                 |  2 +-
 kernel/irq/ipi.c                     | 16 +++---
 kernel/irq/manage.c                  | 10 +---
 24 files changed, 140 insertions(+), 94 deletions(-)

-- 
2.35.1