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>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index d22677a66438..0dd45859a7a8 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -468,7 +468,7 @@ END(ret_from_fork)
 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)
 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: