[patch 04/37] x86/smpboot: Rename start_cpu0() to soft_restart_cpu()

Thomas Gleixner
2023-04-14T23:44:39Z

This is used in the SEV play_dead() implementation to re-online CPUs. But
that has nothing to do with CPU0.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/include/asm/cpu.h | 2 +-
arch/x86/kernel/callthunks.c | 2 +-
arch/x86/kernel/head_32.S | 10 +++++-----
arch/x86/kernel/head_64.S | 10 +++++-----
arch/x86/kernel/sev.c | 2 +-
5 files changed, 13 insertions(+), 13 deletions(-)

--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -30,7 +30,7 @@ struct x86_cpu {
#ifdef CONFIG_HOTPLUG_CPU
extern int arch_register_cpu(int num);
extern void arch_unregister_cpu(int);
-extern void start_cpu0(void);
+extern void soft_restart_cpu(void);
#ifdef CONFIG_DEBUG_HOTPLUG_CPU0
extern int _debug_hotplug_cpu(int cpu, int action);
#endif
--- a/arch/x86/kernel/callthunks.c
+++ b/arch/x86/kernel/callthunks.c
@@ -134,7 +134,7 @@ static bool skip_addr(void *dest)
if (dest == ret_from_fork)
return true;
#ifdef CONFIG_HOTPLUG_CPU
- if (dest == start_cpu0)
+ if (dest == soft_restart_cpu)
return true;
#endif
#ifdef CONFIG_FUNCTION_TRACER
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -140,16 +140,16 @@ SYM_CODE_END(startup_32)

#ifdef CONFIG_HOTPLUG_CPU
/*
- * Boot CPU0 entry point. It's called from play_dead(). Everything has been set
- * up already except stack. We just set up stack here. Then call
- * start_secondary().
+ * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for
+ * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot
+ * unplug. Everything is set up already except the stack.
*/
-SYM_FUNC_START(start_cpu0)
+SYM_FUNC_START(soft_restart_cpu)
movl initial_stack, %ecx
movl %ecx, %esp
call *(initial_code)
1: jmp 1b
-SYM_FUNC_END(start_cpu0)
+SYM_FUNC_END(soft_restart_cpu)
#endif

/*
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -377,11 +377,11 @@ SYM_CODE_END(secondary_startup_64)

#ifdef CONFIG_HOTPLUG_CPU
/*
- * Boot CPU0 entry point. It's called from play_dead(). Everything has been set
- * up already except stack. We just set up stack here. Then call
- * start_secondary() via .Ljump_to_C_code.
+ * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for
+ * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot
+ * unplug. Everything is set up already except the stack.
*/
-SYM_CODE_START(start_cpu0)
+SYM_CODE_START(soft_restart_cpu)
ANNOTATE_NOENDBR
UNWIND_HINT_EMPTY

@@ -390,7 +390,7 @@ SYM_CODE_START(start_cpu0)
movq TASK_threadsp(%rcx), %rsp

jmp .Ljump_to_C_code
-SYM_CODE_END(start_cpu0)
+SYM_CODE_END(soft_restart_cpu)
#endif

#ifdef CONFIG_AMD_MEM_ENCRYPT
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -1326,7 +1326,7 @@ static void sev_es_play_dead(void)
* If we get here, the VCPU was woken up again. Jump to CPU
* startup code to get it back online.
*/
- start_cpu0();
+ soft_restart_cpu();
}
#else /* CONFIG_HOTPLUG_CPU */
#define sev_es_play_dead native_play_dead