MIPS: SMP: Allow boot_secondary SMP op to return errors

Allow the boot_secondary SMP op to return an error to __cpu_up(), which
will in turn return it to its caller.

This will allow SMP implementations to return errors quickly in cases
they they know have failed, rather than relying upon __cpu_up()
eventually timing out waiting for the cpu_running completion.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17014/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

6 files changed, 17 insertions, 6 deletions

diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index 4ac576c68034..406072e26752 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -179,7 +179,7 @@ static void bmips_prepare_cpus(unsigned int max_cpus)
 /*
  * Tell the hardware to boot CPUx - runs on CPU0
  */
-static void bmips_boot_secondary(int cpu, struct task_struct *idle)
+static int bmips_boot_secondary(int cpu, struct task_struct *idle)
 {
 	bmips_smp_boot_sp = __KSTK_TOS(idle);
 	bmips_smp_boot_gp = (unsigned long)task_thread_info(idle);
@@ -231,6 +231,8 @@ static void bmips_boot_secondary(int cpu, struct task_struct *idle)
 		}
 		cpumask_set_cpu(cpu, &bmips_booted_mask);
 	}
+
+	return 0;
 }
 
 /*
diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c
index 1acffdee88f4..04b21deea4f2 100644
--- a/arch/mips/kernel/smp-cmp.c
+++ b/arch/mips/kernel/smp-cmp.c
@@ -78,7 +78,7 @@ static void cmp_smp_finish(void)
  * __KSTK_TOS(idle) is apparently the stack pointer
  * (unsigned long)idle->thread_info the gp
  */
-static void cmp_boot_secondary(int cpu, struct task_struct *idle)
+static int cmp_boot_secondary(int cpu, struct task_struct *idle)
 {
 	struct thread_info *gp = task_thread_info(idle);
 	unsigned long sp = __KSTK_TOS(idle);
@@ -95,6 +95,7 @@ static void cmp_boot_secondary(int cpu, struct task_struct *idle)
 #endif
 
 	amon_cpu_start(cpu, pc, sp, (unsigned long)gp, a0);
+	return 0;
 }
 
 /*
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index 7aac84ffc2af..4a4a25c722f1 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -288,7 +288,7 @@ static void remote_vpe_boot(void *dummy)
 	mips_cps_boot_vpes(core_cfg, cpu_vpe_id(&current_cpu_data));
 }
 
-static void cps_boot_secondary(int cpu, struct task_struct *idle)
+static int cps_boot_secondary(int cpu, struct task_struct *idle)
 {
 	unsigned core = cpu_core(&cpu_data[cpu]);
 	unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);
@@ -346,6 +346,7 @@ static void cps_boot_secondary(int cpu, struct task_struct *idle)
 	mips_cps_boot_vpes(core_cfg, vpe_id);
 out:
 	preempt_enable();
+	return 0;
 }
 
 static void cps_init_secondary(void)
diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
index 5a7b5857d083..30415a74f312 100644
--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -152,7 +152,7 @@ static void vsmp_smp_finish(void)
  * (unsigned long)idle->thread_info the gp
  * assumes a 1:1 mapping of TC => VPE
  */
-static void vsmp_boot_secondary(int cpu, struct task_struct *idle)
+static int vsmp_boot_secondary(int cpu, struct task_struct *idle)
 {
 	struct thread_info *gp = task_thread_info(idle);
 	dvpe();
@@ -184,6 +184,8 @@ static void vsmp_boot_secondary(int cpu, struct task_struct *idle)
 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
 
 	evpe(EVPE_ENABLE);
+
+	return 0;
 }
 
 /*
diff --git a/arch/mips/kernel/smp-up.c b/arch/mips/kernel/smp-up.c
index 4cf015a624d1..525d3196f793 100644
--- a/arch/mips/kernel/smp-up.c
+++ b/arch/mips/kernel/smp-up.c
@@ -39,8 +39,9 @@ static void up_smp_finish(void)
 /*
  * Firmware CPU startup hook
  */
-static void up_boot_secondary(int cpu, struct task_struct *idle)
+static int up_boot_secondary(int cpu, struct task_struct *idle)
 {
+	return 0;
 }
 
 static void __init up_smp_setup(void)
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 6248a5a3ec9e..a4a59ed0164c 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -439,7 +439,11 @@ void smp_prepare_boot_cpu(void)
 
 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	mp_ops->boot_secondary(cpu, tidle);
+	int err;
+
+	err = mp_ops->boot_secondary(cpu, tidle);
+	if (err)
+		return err;
 
 	/*
 	 * We must check for timeout here, as the CPU will not be marked