Add a common ARM implementation of up_tls_info()

2016-03-10 18:10:17 -06:00 · 2016-03-10 18:10:17 -06:00 · 5445a1af83
commit 5445a1af83
parent a9b880a02b
1 changed files with 109 additions and 0 deletions
--- a/arch/arm/src/common/up_tlsinfo.c
+++ b/arch/arm/src/common/up_tlsinfo.c
@ -0,0 +1,109 @@
+/****************************************************************************
+ * arch/arm/src/common/up_tlsinfo.c
+ *
+ *   Copyright (C) 2016 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <nuttx/tls.h>
+#include <nuttx/arch.h>
+
+#ifdef CONFIG_TLS
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_getsp
+ ****************************************************************************/
+
+/* I don't know if the builtin to get SP is enabled */
+
+static inline uint32_t up_getsp(void)
+{
+  uint32_t sp;
+  __asm__
+  (
+    "\tmov %0, sp\n\t"
+    : "=r"(sp)
+  );
+
+  return sp;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_tls_info
+ *
+ * Description:
+ *   Return the TLS information structure for the currently executing thread.
+ *   When TLS is enabled, up_createstack() will align allocated stacks to
+ *   the TLS_STACK_ALIGN value.  An instance of the following structure will
+ *   be implicitly positioned at the "lower" end of the stack.  Assuming a
+ *   "push down" stack, this is at the "far" end of the stack (and can be
+ *   clobbered if the stack overflows).
+ *
+ *   If an MCU has a "push up" then that TLS structure will lie at the top
+ *   of the stack and stack allocation and initialization logic must take
+ *   care to preserve this structure content.
+ *
+ *   The stack memory is fully accessible to user mode threads but will
+ *   contain references to OS internal, private data structures (such as the
+ *   TCB)
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   A pointer to TLS info structure at the beginning of the STACK memory
+ *   allocation.  This is essentially an application of the TLS_INFO(sp)
+ *   macro and has a platform dependency only in the manner in which the
+ *   stack pointer (sp) is obtained and interpreted.
+ *
+ ****************************************************************************/
+
+FAR struct tls_info_s *up_tls_info(void)
+{
+  uintptr_s sp = (uintptr_t)up_getsp();
+  return TLS_INFO(sp);
+}
+
+#endif /* CONFIG_TLS */