[PATCH v3 03/51] x86/asm/head: rename 'stack_start' -> 'initial_stack'

From: Josh Poimboeuf
Date: Fri Aug 12 2016 - 10:44:07 EST


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@xxxxxxxxxx>
---
arch/x86/include/asm/realmode.h | 1 +
arch/x86/include/asm/smp.h | 3 ---
arch/x86/kernel/acpi/sleep.c | 2 +-
arch/x86/kernel/head_32.S | 8 ++++----
arch/x86/kernel/head_64.S | 11 +++++------
arch/x86/kernel/smpboot.c | 2 +-
6 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index 3327ffb..230e190 100644
--- 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
--- 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
--- 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
--- 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
--- 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 067de61..d9d3d67 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -962,7 +962,7 @@ 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
--
2.7.4