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

From: Scott Branden
Date: Fri Jun 22 2018 - 01:08:42 EST




On 18-06-21 09:54 AM, Lorenzo Pieralisi wrote:
On Wed, Jun 20, 2018 at 10:07:33AM +0200, Jan Kiszka wrote:
On 2018-06-19 13:21, 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/20180612170229.GA10141@xxxxxxxxxxxx
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Scott Branden <scott.branden@xxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Ley Foon Tan <lftan@xxxxxxxxxx>
---
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.

Acked-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Thanks a lot. Scott, Ley Foon, does it work for you ? I would like
to ask Bjorn to send it asap since the build on sparc is still broken.
Change will have to be made for arm64 for ARCH_BCM_IPROC as well.

Thanks,
Lorenzo