[RFC,2/4] ARM: SRAM: Add macro for generating SRAM resume trampoline

Commit Message

Russ Dill Sept. 3, 2013, 4:44 p.m. UTC

Add a helper that generates a short snippet of code that loads
the stack pointer and calls a c (or asm) function. The code gets
placed into a SRAM section for loading into SRAM.

Signed-off-by: Russ Dill <[e-mail]>
---
 arch/arm/include/asm/suspend.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Patch

diff --git a/arch/arm/include/asm/suspend.h b/arch/arm/include/asm/suspend.h
index cd20029..d23d004 100644
--- a/arch/arm/include/asm/suspend.h
+++ b/arch/arm/include/asm/suspend.h
@@ -9,4 +9,18 @@  struct sleep_save_sp {
 extern void cpu_resume(void);
 extern int cpu_suspend(unsigned long, int (*)(unsigned long));
 
+/*
+ * Generate a SRAM trampoline for resume.
+ * @proc: SoC, should match argument used with SRAM_SECTIONS().
+ * @func: C or asm function to call at resume.
+ * @stack: Stack to use before calling func.
+ */
+#define ARM_SRAM_RESUME(proc, func, stack)				\
+void __naked __noreturn __sram_##proc proc##_resume_trampoline(void)	\
+{									\
+	__asm__ __volatile__("mov sp, %0" : : "r"((stack)) : "sp");	\
+	func();								\
+}
+
+
 #endif