target/arm: Move v7m_using_psp() to internals.h

We're going to want v7m_using_psp() in op_helper.c in the
next patch, so move it from helper.c to internals.h.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20181002163556.10279-4-peter.maydell@linaro.org

target/arm/helper.c

@@ -6582,18 +6582,6 @@ static bool v7m_stack_read(ARMCPU *cpu, uint32_t *dest, uint32_t addr,
     return false;
 }
 
-/* Return true if we're using the process stack pointer (not the MSP) */
-static bool v7m_using_psp(CPUARMState *env)
-{
-    /* Handler mode always uses the main stack; for thread mode
-     * the CONTROL.SPSEL bit determines the answer.
-     * Note that in v7M it is not possible to be in Handler mode with
-     * CONTROL.SPSEL non-zero, but in v8M it is, so we must check both.
-     */
-    return !arm_v7m_is_handler_mode(env) &&
-        env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK;
-}
-
 /* Write to v7M CONTROL.SPSEL bit for the specified security bank.
  * This may change the current stack pointer between Main and Process
  * stack pointers if it is done for the CONTROL register for the current

target/arm/internals.h

@@ -801,4 +801,20 @@ static inline uint32_t arm_debug_exception_fsr(CPUARMState *env)
  */
 #define MEMOPIDX_SHIFT  8
 
+/**
+ * v7m_using_psp: Return true if using process stack pointer
+ * Return true if the CPU is currently using the process stack
+ * pointer, or false if it is using the main stack pointer.
+ */
+static inline bool v7m_using_psp(CPUARMState *env)
+{
+    /* Handler mode always uses the main stack; for thread mode
+     * the CONTROL.SPSEL bit determines the answer.
+     * Note that in v7M it is not possible to be in Handler mode with
+     * CONTROL.SPSEL non-zero, but in v8M it is, so we must check both.
+     */
+    return !arm_v7m_is_handler_mode(env) &&
+        env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK;
+}
+
 #endif