x86/realmode: Remove trampoline_status

There is no reader of trampoline_status, it's only written.

It turns out that after commit ce4b1b16502b ("x86/smpboot: Initialize
secondary CPU only if master CPU will wait for it"), trampoline_status is
not needed any more.

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1563266424-3472-1-git-send-email-kernelfans@gmail.com

6 files changed, 0 insertions, 17 deletions

diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index c53682303c9c..09ecc32f6524 100644
--- a/arch/x86/include/asm/realmode.h
+++ b/arch/x86/include/asm/realmode.h
@@ -20,7 +20,6 @@ struct real_mode_header {
         u32     ro_end;
         /* SMP trampoline */
         u32     trampoline_start;
-        u32     trampoline_status;
         u32     trampoline_header;
 #ifdef CONFIG_X86_64
         u32     trampoline_pgd;
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index fdbd47ceb84d..497e9b7077c1 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1023,8 +1023,6 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle)
 static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
                        int *cpu0_nmi_registered)
 {
-        volatile u32 *trampoline_status =
-                (volatile u32 *) __va(real_mode_header->trampoline_status);
         /* start_ip had better be page-aligned! */
         unsigned long start_ip = real_mode_header->trampoline_start;
 
@@ -1116,9 +1114,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
                 }
         }
 
-        /* mark "stuck" area as not stuck */
-        *trampoline_status = 0;
-
         if (x86_platform.legacy.warm_reset) {
                 /*
                  * Cleanup possible dangling ends...
diff --git a/arch/x86/realmode/rm/header.S b/arch/x86/realmode/rm/header.S
index 30b0d30d861a..6363761cc74c 100644
--- a/arch/x86/realmode/rm/header.S
+++ b/arch/x86/realmode/rm/header.S
@@ -19,7 +19,6 @@ GLOBAL(real_mode_header)
         .long   pa_ro_end
         /* SMP trampoline */
         .long   pa_trampoline_start
-        .long   pa_trampoline_status
         .long   pa_trampoline_header
 #ifdef CONFIG_X86_64
         .long   pa_trampoline_pgd;
diff --git a/arch/x86/realmode/rm/trampoline_32.S b/arch/x86/realmode/rm/trampoline_32.S
index 2dd866c9e21e..1868b158480d 100644
--- a/arch/x86/realmode/rm/trampoline_32.S
+++ b/arch/x86/realmode/rm/trampoline_32.S
@@ -41,9 +41,6 @@ ENTRY(trampoline_start)
 
         movl    tr_start, %eax  # where we need to go
 
-        movl    $0xA5A5A5A5, trampoline_status
-                                # write marker for master knows we're running
-
         /*
          * GDT tables in non default location kernel can be beyond 16MB and
          * lgdt will not be able to load the address as in real mode default
diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S
index 24bb7598774e..aee2b45d83b8 100644
--- a/arch/x86/realmode/rm/trampoline_64.S
+++ b/arch/x86/realmode/rm/trampoline_64.S
@@ -49,9 +49,6 @@ ENTRY(trampoline_start)
         mov     %ax, %es
         mov     %ax, %ss
 
-        movl    $0xA5A5A5A5, trampoline_status
-        # write marker for master knows we're running
-
         # Setup stack
         movl    $rm_stack_end, %esp
 
diff --git a/arch/x86/realmode/rm/trampoline_common.S b/arch/x86/realmode/rm/trampoline_common.S
index 7c706772ab59..8d8208dcca24 100644
--- a/arch/x86/realmode/rm/trampoline_common.S
+++ b/arch/x86/realmode/rm/trampoline_common.S
@@ -2,7 +2,3 @@
         .section ".rodata","a"
         .balign 16
 tr_idt: .fill 1, 6, 0
-
-        .bss
-        .balign 4
-GLOBAL(trampoline_status)       .space  4