by Bjorn Helgaas

[permalink] [raw]

Subject: Re: [PATCH v2] PCI: controller: Move PCI_DOMAINS selection to arch Kconfig

On Tue, Jun 19, 2018 at 12:21:05PM +0100, Lorenzo Pieralisi wrote:
> Commit 51bc085d6454 ("PCI: Improve host drivers compile test coverage")
> added configuration options to allow PCI host controller drivers to be
> compile tested on all architectures.
>
> Some host controller drivers (eg PCIE_ALTERA) config entries select
> the PCI_DOMAINS config option to enable PCI domains management in
> the kernel. Now that host controller drivers can be compiled on
> all architectures, this triggers build regressions on arches that
> do not implement the PCI_DOMAINS required API (ie pci_domain_nr()):
>
> drivers/ata/pata_ali.c: In function 'ali_init_chipset':
> drivers/ata/pata_ali.c:469:38: error:
> implicit declaration of function 'pci_domain_nr';
> did you mean 'pci_iomap_wc'?
>
> Furthemore, some software configurations (ie Jailhouse) require a
> PCI_DOMAINS enabled kernel to configure multiple host controllers
> without having an explicit dependency on the ARM platform on which
> they run.
>
> Make PCI_DOMAINS a visible configuration option on ARM so that software
> configurations that need it can manually select it and move the
> PCI_DOMAINS selection from PCI controllers configuration file to ARM
> sub-arch config entries that currently require it, fixing the issue.
>
> Fixes: 51bc085d6454 ("PCI: Improve host drivers compile test coverage")
> Link: https://lkml.kernel.org/r/[email protected]
> Reported-by: Guenter Roeck <[email protected]>
> Signed-off-by: Lorenzo Pieralisi <[email protected]>
> Cc: Scott Branden <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Bjorn Helgaas <[email protected]>
> Cc: Rob Herring <[email protected]>
> Cc: Russell King <[email protected]>
> Cc: Jan Kiszka <[email protected]>
> Cc: Guenter Roeck <[email protected]>
> Cc: Ley Foon Tan <[email protected]>

I applied this to for-linus for v4.18, with acks from Jan, Ley Foon, and
Rob. Thanks!

> ---
> v1 -> v2
> - Removed ARCH_VIRT PCI_DOMAINS selection
> - Added PCI_DOMAINS visible config option
>
> v1: https://marc.info/?l=linux-pci&m=152932092612352&w=2
>
> arch/arm/Kconfig | 8 +++++++-
> arch/arm/mach-bcm/Kconfig | 1 +
> arch/arm/mach-socfpga/Kconfig | 1 +
> drivers/pci/controller/Kconfig | 3 ---
> 4 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 54eeb8d00bc6..843edfd000be 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1245,8 +1245,14 @@ config PCI
> VESA. If you have PCI, say Y, otherwise N.
>
> config PCI_DOMAINS
> - bool
> + bool "Support for multiple PCI domains"
> depends on PCI
> + help
> + Enable PCI domains kernel management. Say Y if your machine
> + has a PCI bus hierarchy that requires more than one PCI
> + domain (aka segment) to be correctly managed. Say N otherwise.
> +
> + If you don't know what to do here, say N.
>
> config PCI_DOMAINS_GENERIC
> def_bool PCI_DOMAINS
> diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
> index c46a728df44e..25aac6ee2ab1 100644
> --- a/arch/arm/mach-bcm/Kconfig
> +++ b/arch/arm/mach-bcm/Kconfig
> @@ -20,6 +20,7 @@ config ARCH_BCM_IPROC
> select GPIOLIB
> select ARM_AMBA
> select PINCTRL
> + select PCI_DOMAINS if PCI
> help
> This enables support for systems based on Broadcom IPROC architected SoCs.
> The IPROC complex contains one or more ARM CPUs along with common
> diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
> index d0f62eacf59d..4adb901dd5eb 100644
> --- a/arch/arm/mach-socfpga/Kconfig
> +++ b/arch/arm/mach-socfpga/Kconfig
> @@ -10,6 +10,7 @@ menuconfig ARCH_SOCFPGA
> select HAVE_ARM_SCU
> select HAVE_ARM_TWD if SMP
> select MFD_SYSCON
> + select PCI_DOMAINS if PCI
>
> if ARCH_SOCFPGA
> config SOCFPGA_SUSPEND
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index 18fa09b3ac8f..cc9fa02d32a0 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -96,7 +96,6 @@ config PCI_HOST_GENERIC
> depends on OF
> select PCI_HOST_COMMON
> select IRQ_DOMAIN
> - select PCI_DOMAINS
> help
> Say Y here if you want to support a simple generic PCI host
> controller, such as the one emulated by kvmtool.
> @@ -138,7 +137,6 @@ config PCI_VERSATILE
>
> config PCIE_IPROC
> tristate
> - select PCI_DOMAINS
> help
> This enables the iProc PCIe core controller support for Broadcom's
> iProc family of SoCs. An appropriate bus interface driver needs
> @@ -176,7 +174,6 @@ config PCIE_IPROC_MSI
> config PCIE_ALTERA
> bool "Altera PCIe controller"
> depends on ARM || NIOS2 || COMPILE_TEST
> - select PCI_DOMAINS
> help
> Say Y here if you want to enable PCIe controller support on Altera
> FPGA.
> --
> 2.15.0
>