x86-64: Move kernelstack from PDA to per-cpu.
Also clean up PER_CPU_VAR usage in xen-asm_64.S
tj: * remove now unused stack_thread_info()
* s/kernelstack/kernel_stack/
* added FIXME comment in xen-asm_64.S
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index 4f7a210..cafff5f 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -49,7 +49,6 @@
BLANK();
#undef ENTRY
#define ENTRY(entry) DEFINE(pda_ ## entry, offsetof(struct x8664_pda, entry))
- ENTRY(kernelstack);
ENTRY(oldrsp);
ENTRY(irqcount);
DEFINE(pda_size, sizeof(struct x8664_pda));
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index b50e38d1..06b6290 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -889,6 +889,10 @@
per_cpu_var(irq_stack) + IRQ_STACK_SIZE - 64;
#endif
+DEFINE_PER_CPU(unsigned long, kernel_stack) =
+ (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;
+EXPORT_PER_CPU_SYMBOL(kernel_stack);
+
void __cpuinit pda_init(int cpu)
{
struct x8664_pda *pda = cpu_pda(cpu);
@@ -900,8 +904,6 @@
load_pda_offset(cpu);
pda->irqcount = -1;
- pda->kernelstack = (unsigned long)stack_thread_info() -
- PDA_STACKOFFSET + THREAD_SIZE;
if (cpu != 0) {
if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index d22677a..0dd4585 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -468,7 +468,7 @@
ENTRY(system_call)
CFI_STARTPROC simple
CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,PDA_STACKOFFSET
+ CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET
CFI_REGISTER rip,rcx
/*CFI_REGISTER rflags,r11*/
SWAPGS_UNSAFE_STACK
@@ -480,7 +480,7 @@
ENTRY(system_call_after_swapgs)
movq %rsp,%gs:pda_oldrsp
- movq %gs:pda_kernelstack,%rsp
+ movq PER_CPU_VAR(kernel_stack),%rsp
/*
* No need to follow this irqs off/on section - it's straight
* and short:
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index e00c31a..6c5f576 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -620,9 +620,9 @@
write_pda(oldrsp, next->usersp);
percpu_write(current_task, next_p);
- write_pda(kernelstack,
+ percpu_write(kernel_stack,
(unsigned long)task_stack_page(next_p) +
- THREAD_SIZE - PDA_STACKOFFSET);
+ THREAD_SIZE - KERNEL_STACK_OFFSET);
#ifdef CONFIG_CC_STACKPROTECTOR
write_pda(stack_canary, next_p->stack_canary);
/*
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5854be0..869b988 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -798,6 +798,9 @@
#else
clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
initial_gs = per_cpu_offset(cpu);
+ per_cpu(kernel_stack, cpu) =
+ (unsigned long)task_stack_page(c_idle.idle) -
+ KERNEL_STACK_OFFSET + THREAD_SIZE;
#endif
early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
initial_code = (unsigned long)start_secondary;