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

1 files changed, 16 insertions, 0 deletions

diff --git a/target/arm/internals.h b/target/arm/internals.h
index 24c0444c8d..2495681435 100644
--- a/target/arm/internals.h
+++ b/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