From 1447864bee4cd9ea96fe793ea8fb49a8ea784412 Mon Sep 17 00:00:00 2001 From: Dengcheng Zhu Date: Tue, 11 Sep 2018 14:49:22 -0700 Subject: [PATCH] MIPS: kexec: CPS systems to halt nonboot CPUs Share code between play_dead() and cps_kexec_nonboot_cpu(). Register the latter to mp_ops for kexec. Signed-off-by: Dengcheng Zhu Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/20567/ Cc: pburton@wavecomp.com Cc: ralf@linux-mips.org Cc: linux-mips@linux-mips.org Cc: rachel.mozes@intel.com --- arch/mips/kernel/smp-cps.c | 80 ++++++++++++++++++++++++++------------ 1 file changed, 55 insertions(+), 25 deletions(-) diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index 03f1026ad148..faccfa4b280b 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -398,6 +398,55 @@ static void cps_smp_finish(void) local_irq_enable(); } +#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_KEXEC) + +enum cpu_death { + CPU_DEATH_HALT, + CPU_DEATH_POWER, +}; + +static void cps_shutdown_this_cpu(enum cpu_death death) +{ + unsigned int cpu, core, vpe_id; + + cpu = smp_processor_id(); + core = cpu_core(&cpu_data[cpu]); + + if (death == CPU_DEATH_HALT) { + vpe_id = cpu_vpe_id(&cpu_data[cpu]); + + pr_debug("Halting core %d VP%d\n", core, vpe_id); + if (cpu_has_mipsmt) { + /* Halt this TC */ + write_c0_tchalt(TCHALT_H); + instruction_hazard(); + } else if (cpu_has_vp) { + write_cpc_cl_vp_stop(1 << vpe_id); + + /* Ensure that the VP_STOP register is written */ + wmb(); + } + } else { + pr_debug("Gating power to core %d\n", core); + /* Power down the core */ + cps_pm_enter_state(CPS_PM_POWER_GATED); + } +} + +#ifdef CONFIG_KEXEC + +static void cps_kexec_nonboot_cpu(void) +{ + if (cpu_has_mipsmt || cpu_has_vp) + cps_shutdown_this_cpu(CPU_DEATH_HALT); + else + cps_shutdown_this_cpu(CPU_DEATH_POWER); +} + +#endif /* CONFIG_KEXEC */ + +#endif /* CONFIG_HOTPLUG_CPU || CONFIG_KEXEC */ + #ifdef CONFIG_HOTPLUG_CPU static int cps_cpu_disable(void) @@ -421,19 +470,15 @@ static int cps_cpu_disable(void) } static unsigned cpu_death_sibling; -static enum { - CPU_DEATH_HALT, - CPU_DEATH_POWER, -} cpu_death; +static enum cpu_death cpu_death; void play_dead(void) { - unsigned int cpu, core, vpe_id; + unsigned int cpu; local_irq_disable(); idle_task_exit(); cpu = smp_processor_id(); - core = cpu_core(&cpu_data[cpu]); cpu_death = CPU_DEATH_POWER; pr_debug("CPU%d going offline\n", cpu); @@ -456,25 +501,7 @@ void play_dead(void) /* This CPU has chosen its way out */ (void)cpu_report_death(); - if (cpu_death == CPU_DEATH_HALT) { - vpe_id = cpu_vpe_id(&cpu_data[cpu]); - - pr_debug("Halting core %d VP%d\n", core, vpe_id); - if (cpu_has_mipsmt) { - /* Halt this TC */ - write_c0_tchalt(TCHALT_H); - instruction_hazard(); - } else if (cpu_has_vp) { - write_cpc_cl_vp_stop(1 << vpe_id); - - /* Ensure that the VP_STOP register is written */ - wmb(); - } - } else { - pr_debug("Gating power to core %d\n", core); - /* Power down the core */ - cps_pm_enter_state(CPS_PM_POWER_GATED); - } + cps_shutdown_this_cpu(cpu_death); /* This should never be reached */ panic("Failed to offline CPU %u", cpu); @@ -593,6 +620,9 @@ static const struct plat_smp_ops cps_smp_ops = { .cpu_disable = cps_cpu_disable, .cpu_die = cps_cpu_die, #endif +#ifdef CONFIG_KEXEC + .kexec_nonboot_cpu = cps_kexec_nonboot_cpu, +#endif }; bool mips_cps_smp_in_use(void)