Re: [PATCH 13/19] arm64: cpu_ops: Introduce get_secondary_cpu_ops()

Introduce get_secondary_cpu_ops() to retrieve a pointer to the
'cpu_operations' structure for the non-boot CPUs and use it instead of
get_cpu_ops() where we are dealing with secondary CPUs.

This is a pre-requisite for enabling parallel CPU bring-up.

Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/include/asm/cpu_ops.h |  1 +
 arch/arm64/kernel/cpu_ops.c      |  5 +++++
 arch/arm64/kernel/smp.c          | 19 +++++++------------
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
index a444c8915e88..cd298a8710d8 100644
--- a/arch/arm64/include/asm/cpu_ops.h
+++ b/arch/arm64/include/asm/cpu_ops.h

@@ -48,6 +48,7 @@ struct cpu_operations {
 
 int __init init_cpu_ops(int cpu);
 extern const struct cpu_operations *get_cpu_ops(int cpu);
+extern const struct cpu_operations *get_secondary_cpu_ops(void);
 
 static inline void __init init_bootcpu_ops(void)
 {

diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
index eacfb88a0c0c..7d183ca31dc8 100644
--- a/arch/arm64/kernel/cpu_ops.c
+++ b/arch/arm64/kernel/cpu_ops.c

@@ -127,3 +127,8 @@ const struct cpu_operations *get_cpu_ops(int cpu)
 
 	return NULL;
 }
+
+const struct cpu_operations *get_secondary_cpu_ops(void)
+{
+	return cpu_ops;
+}

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index c5e9d5d5e003..2e98a92eb764 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c

@@ -100,7 +100,7 @@ static inline int op_cpu_kill(unsigned int cpu)
  */
 static int boot_secondary(unsigned int cpu, struct task_struct *idle)
 {
-	const struct cpu_operations *ops = get_cpu_ops(cpu);
+	const struct cpu_operations *ops = get_secondary_cpu_ops();
 
 	if (ops->cpu_boot)
 		return ops->cpu_boot(cpu);

@@ -220,7 +220,7 @@ asmlinkage notrace void secondary_start_kernel(void)
 	 */
 	check_local_cpu_capabilities();
 
-	ops = get_cpu_ops(cpu);
+	ops = get_secondary_cpu_ops();
 	if (ops->cpu_postboot)
 		ops->cpu_postboot();
 

@@ -327,7 +327,7 @@ int __cpu_disable(void)
 
 static int op_cpu_kill(unsigned int cpu)
 {
-	const struct cpu_operations *ops = get_cpu_ops(cpu);
+	const struct cpu_operations *ops = get_secondary_cpu_ops();
 
 	/*
 	 * If we have no means of synchronising with the dying CPU, then assume

@@ -368,7 +368,7 @@ void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
 void __noreturn cpu_die(void)
 {
 	unsigned int cpu = smp_processor_id();
-	const struct cpu_operations *ops = get_cpu_ops(cpu);
+	const struct cpu_operations *ops = get_secondary_cpu_ops();
 
 	idle_task_exit();
 

@@ -492,7 +492,7 @@ static int __init smp_cpu_setup(int cpu)
 	if (init_cpu_ops(cpu))
 		return -ENODEV;
 
-	ops = get_cpu_ops(cpu);
+	ops = get_secondary_cpu_ops();
 	if (ops->cpu_init(cpu))
 		return -ENODEV;
 

@@ -776,7 +776,7 @@ void __init smp_init_cpus(void)
 
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
-	const struct cpu_operations *ops;
+	const struct cpu_operations *ops = get_secondary_cpu_ops();
 	unsigned int cpu;
 	int err;
 

@@ -802,10 +802,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 		if (cpu == 0)
 			continue;
 
-		ops = get_cpu_ops(cpu);
-		if (!ops)
-			continue;
-

 		err = ops->cpu_prepare(cpu);
 		if (err)
 			continue;

@@ -1341,8 +1337,7 @@ bool smp_crash_stop_failed(void)
 static bool have_cpu_die(void)
 {
 #ifdef CONFIG_HOTPLUG_CPU
-	int any_cpu = raw_smp_processor_id();
-	const struct cpu_operations *ops = get_cpu_ops(any_cpu);
+	const struct cpu_operations *ops = get_secondary_cpu_ops();
 
 	if (ops && ops->cpu_die)
 		return true;