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 <dzhu@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
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

1 files 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)