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/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 9878964..b46f8ca 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -194,25 +194,21 @@
#else /* X86_32 */
-#include <asm/pda.h>
+#include <asm/percpu.h>
+#define KERNEL_STACK_OFFSET (5*8)
/*
* macros/functions for gaining access to the thread information structure
* preempt_count needs to be 1 initially, until the scheduler is functional.
*/
#ifndef __ASSEMBLY__
+DECLARE_PER_CPU(unsigned long, kernel_stack);
+
static inline struct thread_info *current_thread_info(void)
{
struct thread_info *ti;
- ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
- return ti;
-}
-
-/* do not use in interrupt context */
-static inline struct thread_info *stack_thread_info(void)
-{
- struct thread_info *ti;
- asm("andq %%rsp,%0; " : "=r" (ti) : "0" (~(THREAD_SIZE - 1)));
+ ti = (void *)(percpu_read(kernel_stack) +
+ KERNEL_STACK_OFFSET - THREAD_SIZE);
return ti;
}
@@ -220,8 +216,8 @@
/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) \
- movq %gs:pda_kernelstack,reg ; \
- subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
+ movq PER_CPU_VAR(kernel_stack),reg ; \
+ subq $(THREAD_SIZE-KERNEL_STACK_OFFSET),reg
#endif