| Message ID | 20210929033646.39630-1-nixiaoming@huawei.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | powerpc:85xx: fix timebase sync issue when CONFIG_HOTPLUG_CPU=n | expand |
On Wed, 29 Sep 2021 11:36:44 +0800, Xiaoming Ni wrote: > When CONFIG_SMP=y, timebase synchronization is required for mpc8572 when > the second kernel is started > arch/powerpc/kernel/smp.c: > int __cpu_up(unsigned int cpu, struct task_struct *tidle) > { > ... > if (smp_ops->give_timebase) > smp_ops->give_timebase(); > ... > } > > [...] Applied to powerpc/next. [1/2] powerpc:85xx:Fix oops when mpc85xx_smp_guts_ids node cannot be found https://git.kernel.org/powerpc/c/3c2172c1c47b4079c29f0e6637d764a99355ebcd [2/2] powerpc:85xx: fix timebase sync issue when CONFIG_HOTPLUG_CPU=n https://git.kernel.org/powerpc/c/c45361abb9185b1e172bd75eff51ad5f601ccae4 cheers
When CONFIG_SMP=y, timebase synchronization is required for mpc8572 when the second kernel is started arch/powerpc/kernel/smp.c: int __cpu_up(unsigned int cpu, struct task_struct *tidle) { ... if (smp_ops->give_timebase) smp_ops->give_timebase(); ... } void start_secondary(void *unused) { ... if (smp_ops->take_timebase) smp_ops->take_timebase(); ... } When CONFIG_HOTPLUG_CPU=n and CONFIG_KEXEC_CORE=n, smp_85xx_ops.give_timebase is NULL, smp_85xx_ops.take_timebase is NULL, As a result, the timebase is not synchronized. test code: for i in $(seq 1 3); do taskset 1 date; taskset 2 date; sleep 1; echo;done log: Sat Sep 25 18:50:00 CST 2021 Sat Sep 25 19:07:47 CST 2021 Sat Sep 25 18:50:01 CST 2021 Sat Sep 25 19:07:48 CST 2021 Sat Sep 25 18:50:02 CST 2021 Sat Sep 25 19:07:49 CST 2021 Code snippet about give_timebase and take_timebase assignments: arch/powerpc/platforms/85xx/smp.c: #ifdef CONFIG_HOTPLUG_CPU #ifdef CONFIG_FSL_CORENET_RCPM fsl_rcpm_init(); #endif #ifdef CONFIG_FSL_PMC mpc85xx_setup_pmc(); #endif if (qoriq_pm_ops) { smp_85xx_ops.give_timebase = mpc85xx_give_timebase; smp_85xx_ops.take_timebase = mpc85xx_take_timebase; config dependency: FSL_CORENET_RCPM depends on the PPC_E500MC. FSL_PMC depends on SUSPEND. SUSPEND depends on ARCH_SUSPEND_POSSIBLE. ARCH_SUSPEND_POSSIBLE depends on !PPC_E500MC. CONFIG_HOTPLUG_CPU and CONFIG_FSL_PMC require the timebase function, but the timebase should not depend on CONFIG_HOTPLUG_CPU and CONFIG_FSL_PMC. Therefore, adjust the macro control range. Ensure that the corresponding timebase hook function is not empty when the dtsi node is configured. ----- changes in v2: 1. add new patch: "powerpc:85xx:Fix oops when mpc85xx_smp_guts_ids node cannot be found" 2. Using !CONFIG_FSL_CORENET_RCPM to manage the timebase code of !PPC_E500MC v1: https://lore.kernel.org/lkml/20210926025144.55674-1-nixiaoming@huawei.com ------ Xiaoming Ni (2): powerpc:85xx:Fix oops when mpc85xx_smp_guts_ids node cannot be found powerpc:85xx: fix timebase sync issue when CONFIG_HOTPLUG_CPU=n arch/powerpc/platforms/85xx/Makefile | 4 +++- arch/powerpc/platforms/85xx/mpc85xx_pm_ops.c | 7 +++++-- arch/powerpc/platforms/85xx/smp.c | 12 ++++++------ 3 files changed, 14 insertions(+), 9 deletions(-)