Add standard context switching functions for m9s12

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3301 42af7a65-404d-4744-a932-0658087f49c3

arch/hc/src/common/up_blocktask.c

+/****************************************************************************
+ * arch/hc/src/common/up_blocktask.c
+ *
+ *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <stdbool.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+
+#include "os_internal.h"
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_block_task
+ *
+ * Description:
+ *   The currently executing task at the head of
+ *   the ready to run list must be stopped.  Save its context
+ *   and move it to the inactive list specified by task_state.
+ *
+ * Inputs:
+ *   tcb: Refers to a task in the ready-to-run list (normally
+ *     the task at the head of the list).  It most be
+ *     stopped, its context saved and moved into one of the
+ *     waiting task lists.  It it was the task at the head
+ *     of the ready-to-run list, then a context to the new
+ *     ready to run task must be performed.
+ *   task_state: Specifies which waiting task list should be
+ *     hold the blocked task TCB.
+ *
+ ****************************************************************************/
+
+void up_block_task(_TCB *tcb, tstate_t task_state)
+{
+  /* Verify that the context switch can be performed */
+
+  if ((tcb->task_state < FIRST_READY_TO_RUN_STATE) ||
+      (tcb->task_state > LAST_READY_TO_RUN_STATE))
+    {
+      PANIC(OSERR_BADBLOCKSTATE);
+    }
+  else
+    {
+      _TCB *rtcb = (_TCB*)g_readytorun.head;
+      bool switch_needed;
+
+      /* Remove the tcb task from the ready-to-run list.  If we
+       * are blocking the task at the head of the task list (the
+       * most likely case), then a context switch to the next
+       * ready-to-run task is needed. In this case, it should
+       * also be true that rtcb == tcb.
+       */
+
+      switch_needed = sched_removereadytorun(tcb);
+
+      /* Add the task to the specified blocked task list */
+
+      sched_addblocked(tcb, (tstate_t)task_state);
+
+      /* If there are any pending tasks, then add them to the g_readytorun
+       * task list now
+       */
+
+      if (g_pendingtasks.head)
+        {
+          switch_needed |= sched_mergepending();
+        }
+
+      /* Now, perform the context switch if one is needed */
+
+      if (switch_needed)
+        {
+          /* Are we in an interrupt handler? */
+
+          if (current_regs)
+            {
+              /* Yes, then we have to do things differently.
+               * Just copy the current_regs into the OLD rtcb.
+               */
+
+               up_savestate(rtcb->xcp.regs);
+
+              /* Restore the exception context of the rtcb at the (new) head 
+               * of the g_readytorun task list.
+               */
+
+              rtcb = (_TCB*)g_readytorun.head;
+
+              /* Then switch contexts */
+
+              up_restorestate(rtcb->xcp.regs);
+            }
+
+          /* Copy the user C context into the TCB at the (old) head of the
+           * g_readytorun Task list. if up_saveusercontext returns a non-zero
+           * value, then this is really the previously running task restarting!
+           */
+
+          else if (!up_saveusercontext(rtcb->xcp.regs))
+            {
+              /* Restore the exception context of the rtcb at the (new) head 
+               * of the g_readytorun task list.
+               */
+
+              rtcb = (_TCB*)g_readytorun.head;
+
+              /* Then switch contexts */
+
+              up_fullcontextrestore(rtcb->xcp.regs);
+            }
+        }
+    }
+}

arch/hc/src/common/up_copystate.c

+/****************************************************************************
+ * arch/hc/src/common/up_copystate.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <stdint.h>
+
+#include "os_internal.h"
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_undefinedinsn
+ ****************************************************************************/
+
+/* A little faster than most memcpy's */
+
+void up_copystate(uint8_t *dest, uint8_t *src)
+{
+  int i;
+
+  /* In the current ARM model, the state is always copied to and from the
+   * stack and TCB.
+   */
+
+  for (i = 0; i < XCPTCONTEXT_REGS; i++)
+    {
+      *dest++ = *src++;
+    }
+}
+

arch/hc/src/common/up_internal.h

@@ -130,12 +130,12 @@ extern void up_boot(void);
 
 /* Context switching functions */
 
-extern void up_copystate(uint32_t *dest, uint32_t *src);
-extern void up_decodeirq(uint32_t *regs);
+extern void up_copystate(uint8_t *dest, uint8_t *src);
+extern void up_decodeirq(uint8_t *regs);
 extern void up_irqinitialize(void);
-extern int  up_saveusercontext(uint32_t *saveregs);
-extern void up_fullcontextrestore(uint32_t *restoreregs) __attribute__ ((noreturn));
-extern void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
+extern int  up_saveusercontext(uint8_t *saveregs);
+extern void up_fullcontextrestore(uint8_t *restoreregs) __attribute__ ((noreturn));
+extern void up_switchcontext(uint8_t *saveregs, uint8_t *restoreregs);
 
 /* Interrupt handling */
 

arch/hc/src/common/up_unblocktask.c

+/****************************************************************************
+ *  arch/hc/src/common/up_unblocktask.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <sched.h>
+#include <debug.h>
+#include <nuttx/arch.h>
+
+#include "os_internal.h"
+#include "clock_internal.h"
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_unblock_task
+ *
+ * Description:
+ *   A task is currently in an inactive task list
+ *   but has been prepped to execute.  Move the TCB to the
+ *   ready-to-run list, restore its context, and start execution.
+ *
+ * Inputs:
+ *   tcb: Refers to the tcb to be unblocked.  This tcb is
+ *     in one of the waiting tasks lists.  It must be moved to
+ *     the ready-to-run list and, if it is the highest priority
+ *     ready to run taks, executed.
+ *
+ ****************************************************************************/
+
+void up_unblock_task(_TCB *tcb)
+{
+  /* Verify that the context switch can be performed */
+
+  if ((tcb->task_state < FIRST_BLOCKED_STATE) ||
+      (tcb->task_state > LAST_BLOCKED_STATE))
+    {
+      PANIC(OSERR_BADUNBLOCKSTATE);
+    }
+  else
+    {
+      _TCB *rtcb = (_TCB*)g_readytorun.head;
+
+      /* Remove the task from the blocked task list */
+
+      sched_removeblocked(tcb);
+
+      /* Reset its timeslice.  This is only meaningful for round
+       * robin tasks but it doesn't here to do it for everything
+       */
+
+#if CONFIG_RR_INTERVAL > 0
+      tcb->timeslice = CONFIG_RR_INTERVAL / MSEC_PER_TICK;
+#endif
+
+      /* Add the task in the correct location in the prioritized
+       * g_readytorun task list
+       */
+
+      if (sched_addreadytorun(tcb))
+        {
+          /* The currently active task has changed! We need to do
+           * a context switch to the new task.
+           *
+           * Are we in an interrupt handler? 
+           */
+
+          if (current_regs)
+            {
+              /* Yes, then we have to do things differently.
+               * Just copy the current_regs into the OLD rtcb.
+               */
+
+               up_savestate(rtcb->xcp.regs);
+
+              /* Restore the exception context of the rtcb at the (new) head 
+               * of the g_readytorun task list.
+               */
+
+              rtcb = (_TCB*)g_readytorun.head;
+
+              /* Then switch contexts */
+
+              up_restorestate(rtcb->xcp.regs);
+            }
+
+          /* We are not in an interrupt handler.  Copy the user C context
+           * into the TCB of the task that was previously active.  if 
+           * up_saveusercontext returns a non-zero value, then this is really the
+           * previously running task restarting!
+           */
+
+          else if (!up_saveusercontext(rtcb->xcp.regs))
+            {
+              /* Restore the exception context of the new task that is ready to
+               * run (probably tcb).  This is the new rtcb at the head of the
+               * g_readytorun task list.
+               */
+
+              rtcb = (_TCB*)g_readytorun.head;
+
+              /* Then switch contexts */
+
+              up_fullcontextrestore(rtcb->xcp.regs);
+            }
+        }
+    }
+}

arch/hc/src/m9s12/Make.defs

@@ -36,10 +36,11 @@
 HEAD_ASRC	= m9s12_vectors.S
 
 CMN_ASRCS	= 
-CMN_CSRCS	= up_allocateheap.c up_createstack.c up_doirq.c up_idle.c up_initialize.c \
-			  up_interruptcontext.c up_mdelay.c up_modifyreg16.c \
-			  up_modifyreg32.c up_modifyreg8.c up_puts.c up_releasestack.c \
-			  up_udelay.c up_usestack.c
+CMN_CSRCS	= up_allocateheap.c up_blocktask.c up_copystate.c up_createstack.c \
+			  up_doirq.c up_idle.c up_initialize.c up_interruptcontext.c \
+			  up_mdelay.c up_modifyreg16.c up_modifyreg32.c up_modifyreg8.c \
+			  up_puts.c up_releasestack.c up_udelay.c up_unblocktask.c \
+			  up_usestack.c
 
 CHIP_ASRCS	= m9s12_start.S m9s12_lowputc.S m9s12_saveusercontext.S
 CHIP_CSRCS	= m9s12_assert.c m9s12_serial.c m9s12_irq.c