x86/asm/head: Rename 'stack_start' -> 'initial_stack'

The 'stack_start' variable is similar in usage to 'initial_code' and
'initial_gs': they're all stored in head_64.S and they're all updated by
SMP and ACPI suspend before starting a CPU.

Rename it to 'initial_stack' to be consistent with the others.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/87063d773a3212051b77e17b0ee427f6582a5050.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index 3327ffb..230e190 100644 (file)
--- a/arch/x86/include/asm/realmode.h
+++ b/arch/x86/include/asm/realmode.h
@@ -46,6 +46,7 @@ extern unsigned char real_mode_blob_end[];
 
 extern unsigned long initial_code;
 extern unsigned long initial_gs;
+extern unsigned long initial_stack;
 
 extern unsigned char real_mode_blob[];
 extern unsigned char real_mode_relocs[];

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index ebd0c16..19980b3 100644 (file)
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -39,9 +39,6 @@ DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid);
 DECLARE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid);
 #endif
 
-/* Static state in head.S used to set up a CPU */
-extern unsigned long stack_start; /* Initial stack pointer address */
-
 struct task_struct;
 
 struct smp_ops {

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index adb3eaf..4858733 100644 (file)
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -99,7 +99,7 @@ int x86_acpi_suspend_lowlevel(void)
        saved_magic = 0x12345678;
 #else /* CONFIG_64BIT */
 #ifdef CONFIG_SMP
-       stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
+       initial_stack = (unsigned long)temp_stack + sizeof(temp_stack);
        early_gdt_descr.address =
                        (unsigned long)get_cpu_gdt_table(smp_processor_id());
        initial_gs = per_cpu_offset(smp_processor_id());

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 6f8902b..5f40126 100644 (file)
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -94,7 +94,7 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE)
  */
 __HEAD
 ENTRY(startup_32)
-       movl pa(stack_start),%ecx
+       movl pa(initial_stack),%ecx
        
        /* test KEEP_SEGMENTS flag to see if the bootloader is asking
                us to not reload segments */
@@ -286,7 +286,7 @@ num_subarch_entries = (. - subarch_entries) / 4
  * start_secondary().
  */
 ENTRY(start_cpu0)
-       movl stack_start, %ecx
+       movl initial_stack, %ecx
        movl %ecx, %esp
        jmp  *(initial_code)
 ENDPROC(start_cpu0)
@@ -307,7 +307,7 @@ ENTRY(startup_32_smp)
        movl %eax,%es
        movl %eax,%fs
        movl %eax,%gs
-       movl pa(stack_start),%ecx
+       movl pa(initial_stack),%ecx
        movl %eax,%ss
        leal -__PAGE_OFFSET(%ecx),%esp
 
@@ -703,7 +703,7 @@ ENTRY(initial_page_table)
 
 .data
 .balign 4
-ENTRY(stack_start)
+ENTRY(initial_stack)
        .long init_thread_union+THREAD_SIZE
 
 __INITRODATA

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 9f8efc9..e048142 100644 (file)
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -66,7 +66,7 @@ startup_64:
         */
 
        /*
-        * Setup stack for verify_cpu(). "-8" because stack_start is defined
+        * Setup stack for verify_cpu(). "-8" because initial_stack is defined
         * this way, see below. Our best guess is a NULL ptr for stack
         * termination heuristics and we don't want to break anything which
         * might depend on it (kgdb, ...).
@@ -226,7 +226,7 @@ ENTRY(secondary_startup_64)
        movq    %rax, %cr0
 
        /* Setup a boot time stack */
-       movq stack_start(%rip), %rsp
+       movq initial_stack(%rip), %rsp
 
        /* zero EFLAGS after setting rsp */
        pushq $0
@@ -310,7 +310,7 @@ ENDPROC(secondary_startup_64)
  * start_secondary().
  */
 ENTRY(start_cpu0)
-       movq stack_start(%rip),%rsp
+       movq initial_stack(%rip),%rsp
        movq    initial_code(%rip),%rax
        pushq   $0              # fake return address to stop unwinder
        pushq   $__KERNEL_CS    # set correct cs
@@ -319,15 +319,14 @@ ENTRY(start_cpu0)
 ENDPROC(start_cpu0)
 #endif
 
-       /* SMP bootup changes these two */
+       /* Both SMP bootup and ACPI suspend change these variables */
        __REFDATA
        .balign 8
        GLOBAL(initial_code)
        .quad   x86_64_start_kernel
        GLOBAL(initial_gs)
        .quad   INIT_PER_CPU_VAR(irq_stack_union)
-
-       GLOBAL(stack_start)
+       GLOBAL(initial_stack)
        .quad  init_thread_union+THREAD_SIZE-8
        .word  0
        __FINITDATA

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 4296beb..c85d2c6 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -969,7 +969,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
 
        early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
        initial_code = (unsigned long)start_secondary;
-       stack_start  = idle->thread.sp;
+       initial_stack  = idle->thread.sp;
 
        /*
         * Enable the espfix hack for this CPU