On Wed, 26 Aug 2020 12:17:02 +0100,
Thomas Gleixner <t...@linutronix.de> wrote:
>
> From: Thomas Gleixner <t...@linutronix.de>
>
> 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 <t...@linutronix.de>
> ---
> 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...@kernel.org>
M.
--
Without deviation from the norm, progress is not possible.
