From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 26 Aug 2020 22:14:58 +0100 Message-ID: <8736492jot.wl-maz@kernel.org> From: Marc Zyngier Subject: Re: [patch V2 34/46] PCI/MSI: Make arch_.*_msi_irq[s] fallbacks selectable In-Reply-To: <20200826112333.992429909@linutronix.de> References: <20200826111628.794979401@linutronix.de> <20200826112333.992429909@linutronix.de> MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: To: Thomas Gleixner Cc: LKML , x86@kernel.org, Joerg Roedel , iommu@lists.linux-foundation.org, linux-hyperv@vger.kernel.org, Haiyang Zhang , Jon Derrick , Lu Baolu , Wei Liu , "K. Y. Srinivasan" , Stephen Hemminger , Steve Wahl , Dimitri Sivanich , Russ Anderson , linux-pci@vger.kernel.org, Bjorn Helgaas , Lorenzo Pieralisi , Konrad Rzeszutek Wilk , xen-devel@lists.xenproject.org, Juergen Gross , Boris Ostrovsky , Stefano Stabellini , Greg Kroah-Hartman , "Rafael J. Wysocki" , Megha Dey , Jason Gunthorpe , Dave Jiang , Alex Williamson , Jacob Pan , Baolu Lu , Kevin Tian , Dan Williams On Wed, 26 Aug 2020 12:17:02 +0100, Thomas Gleixner wrote: > > From: Thomas Gleixner > > The arch_.*_msi_irq[s] fallbacks are compiled in whether an architecture > requires them or not. Architectures which are fully utilizing hierarchical > irq domains should never call into that code. > > It's not only architectures which depend on that by implementing one or > more of the weak functions, there is also a bunch of drivers which relies > on the weak functions which invoke msi_controller::setup_irq[s] and > msi_controller::teardown_irq. > > Make the architectures and drivers which rely on them select them in Kconfig > and if not selected replace them by stub functions which emit a warning and > fail the PCI/MSI interrupt allocation. > > Signed-off-by: Thomas Gleixner > --- > V2: Make the architectures (and drivers) which need the fallbacks select them > and not the other way round (Bjorn). > --- > arch/ia64/Kconfig | 1 + > arch/mips/Kconfig | 1 + > arch/powerpc/Kconfig | 1 + > arch/s390/Kconfig | 1 + > arch/sparc/Kconfig | 1 + > arch/x86/Kconfig | 1 + > drivers/pci/Kconfig | 3 +++ > drivers/pci/controller/Kconfig | 3 +++ > drivers/pci/msi.c | 3 ++- > include/linux/msi.h | 31 ++++++++++++++++++++++++++----- > 10 files changed, 40 insertions(+), 6 deletions(-) > [...] > --- a/drivers/pci/controller/Kconfig > +++ b/drivers/pci/controller/Kconfig > @@ -41,6 +41,7 @@ config PCI_TEGRA > bool "NVIDIA Tegra PCIe controller" > depends on ARCH_TEGRA || COMPILE_TEST > depends on PCI_MSI_IRQ_DOMAIN > + select PCI_MSI_ARCH_FALLBACKS > help > Say Y here if you want support for the PCIe host controller found > on NVIDIA Tegra SoCs. > @@ -67,6 +68,7 @@ config PCIE_RCAR_HOST > bool "Renesas R-Car PCIe host controller" > depends on ARCH_RENESAS || COMPILE_TEST > depends on PCI_MSI_IRQ_DOMAIN > + select PCI_MSI_ARCH_FALLBACKS > help > Say Y here if you want PCIe controller support on R-Car SoCs in host > mode. > @@ -103,6 +105,7 @@ config PCIE_XILINX_CPM > bool "Xilinx Versal CPM host bridge support" > depends on ARCH_ZYNQMP || COMPILE_TEST > select PCI_HOST_COMMON > + select PCI_MSI_ARCH_FALLBACKS This guy actually doesn't implement MSIs at all (it seems to delegate them to an ITS present in the system, if I read the DT binding correctly). However its older brother from the same silicon dealer seems to need it. The patchlet below should fix it. diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig index 9ad13919bcaa..f56ff049d469 100644 --- a/drivers/pci/controller/Kconfig +++ b/drivers/pci/controller/Kconfig @@ -96,6 +96,7 @@ config PCI_HOST_GENERIC config PCIE_XILINX bool "Xilinx AXI PCIe host bridge support" + select PCI_MSI_ARCH_FALLBACKS depends on OF || COMPILE_TEST help Say 'Y' here if you want kernel to support the Xilinx AXI PCIe @@ -105,7 +106,6 @@ config PCIE_XILINX_CPM bool "Xilinx Versal CPM host bridge support" depends on ARCH_ZYNQMP || COMPILE_TEST select PCI_HOST_COMMON - select PCI_MSI_ARCH_FALLBACKS help Say 'Y' here if you want kernel support for the Xilinx Versal CPM host bridge. With that fixed, Acked-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.