Re: [PATCH v3] s390/pci: fix CPU address in MSI for directed IRQ

Naresh Kamboju
2020-12-09T15:09:46Z

On Thu, 26 Nov 2020 at 22:32, Alexander Gordeev <agordeev@linux.ibm.com> wrote:
>
> The directed MSIs are delivered to CPUs whose address is
> written to the MSI message data. The current code assumes
> that a CPU logical number (as it is seen by the kernel)
> is also that CPU address.
>
> The above assumption is not correct, as the CPU address
> is rather the value returned by STAP instruction. That
> value does not necessarily match the kernel logical CPU
> number.
>
> Fixes: e979ce7bced2 ("s390/pci: provide support for CPU directed interrupts")
> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
> ---
> arch/s390/pci/pci_irq.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
> index 743f257cf2cb..75217fb63d7b 100644
> --- a/arch/s390/pci/pci_irq.c
> +++ b/arch/s390/pci/pci_irq.c
> @@ -103,9 +103,10 @@ static int zpci_set_irq_affinity(struct irq_data *data, const struct cpumask *de
> {
> struct msi_desc *entry = irq_get_msi_desc(data->irq);
> struct msi_msg msg = entry->msg;
> + int cpu_addr = smp_cpu_get_cpu_address(cpumask_first(dest));

While building S390 the following kernel warning / error noticed
on stable -rc 5.4 branch with gcc-8, gcc-9 and gcc-10 and defconfig

make --silent --keep-going --jobs=8
O=/home/tuxbuild/.cache/tuxmake/builds/6/tmp ARCH=s390
CROSS_COMPILE=s390x-linux-gnu- 'CC=sccache s390x-linux-gnu-gcc'
'HOSTCC=sccache gcc' vmlinux
arch/s390/pci/pci_irq.c: In function 'zpci_set_irq_affinity':
arch/s390/pci/pci_irq.c:106:17: error: implicit declaration of
function 'smp_cpu_get_cpu_address'
[-Werror=implicit-function-declaration]
106 | int cpu_addr = smp_cpu_get_cpu_address(cpumask_first(dest));
| ^~~~~~~~~~~~~~~~~~~~~~~

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>

steps to reproduce:
--------------------------
# TuxMake is a command line tool and Python library that provides
# portable and repeatable Linux kernel builds across a variety of
# architectures, toolchains, kernel configurations, and make targets.
#
# TuxMake supports the concept of runtimes.
# See https://docs.tuxmake.org/runtimes/, for that to work it requires
# that you install podman or docker on your system.
#
# To install tuxmake on your system globally:
# sudo pip3 install -U tuxmake
#
# See https://docs.tuxmake.org/ for complete documentation.

tuxmake --runtime docker --target-arch s390 --toolchain gcc-9
--kconfig defconfig

metadata:
git_repo: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc
target_arch: s390
toolchain: gcc-9
git_describe: v5.4.82-36-gc45075765dae
kernel_version: 5.4.83-rc1

full build log link,
https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc/-/jobs/899272224

--
Linaro LKFT