x86/asm/entry: Move the 'thunk' functions to arch/x86/entry/

These are all calling x86 entry code functions, so move them close
to other entry code.

Change lib-y to obj-y: there's no real difference between the two
as we don't really drop any of them during the linking stage, and
obj-y is the more common approach for core kernel object code.

Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 112 insertions, 2 deletions

diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile
index c97532492ef5..9df72c8a0ac2 100644
--- a/arch/x86/entry/Makefile
+++ b/arch/x86/entry/Makefile
@@ -1,8 +1,7 @@
 #
 # Makefile for the x86 low level entry code
 #
-obj-y				:= entry_$(BITS).o
-
+obj-y				:= entry_$(BITS).o thunk_$(BITS).o
 obj-y				+= vdso/
 
 obj-$(CONFIG_IA32_EMULATION)	+= ia32entry.o
diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S
new file mode 100644
index 000000000000..e9acf5f4fc92
--- /dev/null
+++ b/arch/x86/entry/thunk_32.S
@@ -0,0 +1,42 @@
+/*
+ * Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash)
+ * Copyright 2008 by Steven Rostedt, Red Hat, Inc
+ *  (inspired by Andi Kleen's thunk_64.S)
+ * Subject to the GNU public license, v.2. No warranty of any kind.
+ */
+	#include <linux/linkage.h>
+	#include <asm/asm.h>
+
+	/* put return address in eax (arg1) */
+	.macro THUNK name, func, put_ret_addr_in_eax=0
+	.globl \name
+\name:
+	pushl %eax
+	pushl %ecx
+	pushl %edx
+
+	.if \put_ret_addr_in_eax
+	/* Place EIP in the arg1 */
+	movl 3*4(%esp), %eax
+	.endif
+
+	call \func
+	popl %edx
+	popl %ecx
+	popl %eax
+	ret
+	_ASM_NOKPROBE(\name)
+	.endm
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+	THUNK trace_hardirqs_on_thunk,trace_hardirqs_on_caller,1
+	THUNK trace_hardirqs_off_thunk,trace_hardirqs_off_caller,1
+#endif
+
+#ifdef CONFIG_PREEMPT
+	THUNK ___preempt_schedule, preempt_schedule
+#ifdef CONFIG_CONTEXT_TRACKING
+	THUNK ___preempt_schedule_context, preempt_schedule_context
+#endif
+#endif
+
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
new file mode 100644
index 000000000000..10f555e435e1
--- /dev/null
+++ b/arch/x86/entry/thunk_64.S
@@ -0,0 +1,69 @@
+/*
+ * Save registers before calling assembly functions. This avoids
+ * disturbance of register allocation in some inline assembly constructs.
+ * Copyright 2001,2002 by Andi Kleen, SuSE Labs.
+ * Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc.
+ * Subject to the GNU public license, v.2. No warranty of any kind.
+ */
+#include <linux/linkage.h>
+#include <asm/calling.h>
+#include <asm/asm.h>
+
+	/* rdi:	arg1 ... normal C conventions. rax is saved/restored. */
+	.macro THUNK name, func, put_ret_addr_in_rdi=0
+	.globl \name
+\name:
+
+	/* this one pushes 9 elems, the next one would be %rIP */
+	pushq %rdi
+	pushq %rsi
+	pushq %rdx
+	pushq %rcx
+	pushq %rax
+	pushq %r8
+	pushq %r9
+	pushq %r10
+	pushq %r11
+
+	.if \put_ret_addr_in_rdi
+	/* 9*8(%rsp) is return addr on stack */
+	movq 9*8(%rsp), %rdi
+	.endif
+
+	call \func
+	jmp  restore
+	_ASM_NOKPROBE(\name)
+	.endm
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+	THUNK trace_hardirqs_on_thunk,trace_hardirqs_on_caller,1
+	THUNK trace_hardirqs_off_thunk,trace_hardirqs_off_caller,1
+#endif
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	THUNK lockdep_sys_exit_thunk,lockdep_sys_exit
+#endif
+
+#ifdef CONFIG_PREEMPT
+	THUNK ___preempt_schedule, preempt_schedule
+#ifdef CONFIG_CONTEXT_TRACKING
+	THUNK ___preempt_schedule_context, preempt_schedule_context
+#endif
+#endif
+
+#if defined(CONFIG_TRACE_IRQFLAGS) \
+ || defined(CONFIG_DEBUG_LOCK_ALLOC) \
+ || defined(CONFIG_PREEMPT)
+restore:
+	popq %r11
+	popq %r10
+	popq %r9
+	popq %r8
+	popq %rax
+	popq %rcx
+	popq %rdx
+	popq %rsi
+	popq %rdi
+	ret
+	_ASM_NOKPROBE(restore)
+#endif