Debug Cortex-M3 interrupts

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1787 42af7a65-404d-4744-a932-0658087f49c3

9 files changed, 67 insertions, 19 deletions

diff --git a/nuttx/arch/arm/src/common/up_blocktask.c b/nuttx/arch/arm/src/common/up_blocktask.c
index 819208a2c..2590597f8 100644
--- a/nuttx/arch/arm/src/common/up_blocktask.c
+++ b/nuttx/arch/arm/src/common/up_blocktask.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/common/up_blocktask.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -39,9 +39,12 @@
 
 #include <nuttx/config.h>
 #include <sys/types.h>
+
 #include <sched.h>
 #include <debug.h>
+
 #include <nuttx/arch.h>
+
 #include "os_internal.h"
 #include "up_internal.h"
 
@@ -129,7 +132,7 @@ void up_block_task(_TCB *tcb, tstate_t task_state)
                * Just copy the current_regs into the OLD rtcb.
                */
 
-               up_copystate(rtcb->xcp.regs, current_regs);
+               up_savestate(rtcb->xcp.regs);
 
               /* Restore the exception context of the rtcb at the (new) head 
                * of the g_readytorun task list.
@@ -139,7 +142,7 @@ void up_block_task(_TCB *tcb, tstate_t task_state)
 
               /* Then switch contexts */
 
-              up_copystate(current_regs, rtcb->xcp.regs);
+              up_restorestate(rtcb->xcp.regs);
             }
 
           /* Copy the user C context into the TCB at the (old) head of the
diff --git a/nuttx/arch/arm/src/common/up_copystate.c b/nuttx/arch/arm/src/common/up_copystate.c
index 1c4cb42ec..b73c6c95c 100644
--- a/nuttx/arch/arm/src/common/up_copystate.c
+++ b/nuttx/arch/arm/src/common/up_copystate.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/common/up_copystate.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -69,9 +69,22 @@
 void up_copystate(uint32 *dest, uint32 *src)
 {
   int i;
-  for (i = 0; i < XCPTCONTEXT_REGS; i++)
+
+  /* In the current ARM model, the state is always copied to and from the
+   * stack and TCB.  In the Cortex-M3 model, the state is copied from the
+   * stack to the TCB, but only a referenced is passed to get the the state
+   * from the TCB.  So the following check makes sense only for the Cortex-M3
+   * model:
+   */
+
+#ifdef __thumb2__
+  if (src != dest)
+#endif
     {
-      *dest++ = *src++;
+      for (i = 0; i < XCPTCONTEXT_REGS; i++)
+        {
+          *dest++ = *src++;
+        }
     }
 }
 
diff --git a/nuttx/arch/arm/src/common/up_doirq.c b/nuttx/arch/arm/src/common/up_doirq.c
index b863ec0c5..861f5f3d8 100644
--- a/nuttx/arch/arm/src/common/up_doirq.c
+++ b/nuttx/arch/arm/src/common/up_doirq.c
@@ -66,7 +66,11 @@
  * Public Functions
  ****************************************************************************/
 
-uint32 *up_doirq(int irq, uint32* regs)
+#ifdef __thumb2__
+uint32 *up_doirq(int irq, uint32 *regs)
+#else
+void up_doirq(int irq, uint32 *regs)
+#endif
 {
   up_ledon(LED_INIRQ);
 #ifdef CONFIG_SUPPRESS_INTERRUPTS
@@ -94,8 +98,9 @@ uint32 *up_doirq(int irq, uint32* regs)
         * of context switching for te particular chip.
         */
 
+#ifdef __thumb2__
        regs = current_regs;
-
+#endif
        /* Indicate that we are no long in an interrupt handler */
 
        current_regs = NULL;
@@ -108,5 +113,7 @@ uint32 *up_doirq(int irq, uint32* regs)
     }
   up_ledoff(LED_INIRQ);
 #endif
+#ifdef __thumb2__
   return regs;
+#endif
 }
diff --git a/nuttx/arch/arm/src/common/up_internal.h b/nuttx/arch/arm/src/common/up_internal.h
index 430631853..34a7918e1 100644
--- a/nuttx/arch/arm/src/common/up_internal.h
+++ b/nuttx/arch/arm/src/common/up_internal.h
@@ -71,6 +71,20 @@
 # define CONFIG_ARCH_INTERRUPTSTACK 0
 #endif
 
+/* Macros to handle saving and restore interrupt state.  In the current ARM
+ * model, the state is always copied to and from the stack and TCB.  In the
+ * Cortex-M3 model, the state is copied from the stack to the TCB, but only
+ * a referenced is passed to get the the state from the TCB.
+ */
+
+#ifdef __thumb2__
+#  define up_savestate(regs)    up_copystate(regs, current_regs)
+#  define up_restorestate(regs) (current_regs = regs)
+#else
+#  define up_savestate(regs)    up_copystate(regs, current_regs)
+#  define up_restorestate(regs) up_copystate(current_regs, regs)
+#endif
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/
@@ -122,7 +136,11 @@ extern void up_boot(void);
 extern void up_copystate(uint32 *dest, uint32 *src);
 extern void up_dataabort(uint32 *regs);
 extern void up_decodeirq(uint32 *regs);
+#ifdef __thumb2__
 extern uint32 *up_doirq(int irq, uint32 *regs);
+#else
+extern void up_doirq(int irq, uint32 *regs);
+#endif
 extern void up_fullcontextrestore(uint32 *regs) __attribute__ ((noreturn));
 extern void up_irqinitialize(void);
 extern void up_prefetchabort(uint32 *regs);
diff --git a/nuttx/arch/arm/src/common/up_releasepending.c b/nuttx/arch/arm/src/common/up_releasepending.c
index d62fb25c2..d81479e87 100644
--- a/nuttx/arch/arm/src/common/up_releasepending.c
+++ b/nuttx/arch/arm/src/common/up_releasepending.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  *  arch/arm/src/common/up_releasepending.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -94,7 +94,7 @@ void up_release_pending(void)
            * Just copy the current_regs into the OLD rtcb.
            */
 
-           up_copystate(rtcb->xcp.regs, current_regs);
+           up_savestate(rtcb->xcp.regs);
 
           /* Restore the exception context of the rtcb at the (new) head 
            * of the g_readytorun task list.
@@ -105,7 +105,7 @@ void up_release_pending(void)
 
           /* Then switch contexts */
 
-          up_copystate(current_regs, rtcb->xcp.regs);
+          up_restorestate(rtcb->xcp.regs);
         }
 
       /* Copy the exception context into the TCB of the task that
diff --git a/nuttx/arch/arm/src/common/up_reprioritizertr.c b/nuttx/arch/arm/src/common/up_reprioritizertr.c
index 41aa0d5e2..684ff7f43 100644
--- a/nuttx/arch/arm/src/common/up_reprioritizertr.c
+++ b/nuttx/arch/arm/src/common/up_reprioritizertr.c
@@ -142,7 +142,7 @@ void up_reprioritize_rtr(_TCB *tcb, ubyte priority)
                * Just copy the current_regs into the OLD rtcb.
                */
 
-               up_copystate(rtcb->xcp.regs, current_regs);
+               up_savestate(rtcb->xcp.regs);
 
               /* Restore the exception context of the rtcb at the (new) head 
                * of the g_readytorun task list.
@@ -153,7 +153,7 @@ void up_reprioritize_rtr(_TCB *tcb, ubyte priority)
 
               /* Then switch contexts */
 
-              up_copystate(current_regs, rtcb->xcp.regs);
+              up_restorestate(rtcb->xcp.regs);
             }
 
           /* Copy the exception context into the TCB at the (old) head of the
diff --git a/nuttx/arch/arm/src/common/up_schedulesigaction.c b/nuttx/arch/arm/src/common/up_schedulesigaction.c
index fb6798468..a4ae20953 100644
--- a/nuttx/arch/arm/src/common/up_schedulesigaction.c
+++ b/nuttx/arch/arm/src/common/up_schedulesigaction.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * common/up_schedulesigaction.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -137,6 +137,12 @@ void up_schedule_sigaction(_TCB *tcb, sig_deliver_t sigdeliver)
            * interrupted task is the same as the one that
            * must receive the signal, then we will have to modify
            * the return state as well as the state in the TCB.
+           *
+           * Hmmm... there looks like a latent bug here: The following
+           * logic would fail in the strange case where we are in an
+           * interrupt handler, the thread is signalling itself, but
+           * a context switch to another task has occurred so that
+           * current_regs does not refer to the thread at g_readytorun.head!
            */
 
           else
@@ -171,7 +177,7 @@ void up_schedule_sigaction(_TCB *tcb, sig_deliver_t sigdeliver)
                * is the same as the interrupt return context.
                */
 
-              up_copystate(tcb->xcp.regs, current_regs);
+              up_savestate(tcb->xcp.regs);
             }
         }
 
diff --git a/nuttx/arch/arm/src/common/up_sigdeliver.c b/nuttx/arch/arm/src/common/up_sigdeliver.c
index bf5661696..aff743884 100644
--- a/nuttx/arch/arm/src/common/up_sigdeliver.c
+++ b/nuttx/arch/arm/src/common/up_sigdeliver.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * common/up_sigdeliver.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -109,6 +109,7 @@ void up_sigdeliver(void)
 #else
   regs[REG_CPSR]       = rtcb->xcp.saved_cpsr;
 #endif
+
   /* Get a local copy of the sigdeliver function pointer.
    * we do this so that we can nullify the sigdeliver
    * function point in the TCB and accept more signal
diff --git a/nuttx/arch/arm/src/common/up_unblocktask.c b/nuttx/arch/arm/src/common/up_unblocktask.c
index a657a1b84..ea64ed1c6 100644
--- a/nuttx/arch/arm/src/common/up_unblocktask.c
+++ b/nuttx/arch/arm/src/common/up_unblocktask.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  *  arch/arm/src/common/up_unblocktask.c
  *
- *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,7 +121,7 @@ void up_unblock_task(_TCB *tcb)
                * Just copy the current_regs into the OLD rtcb.
                */
 
-               up_copystate(rtcb->xcp.regs, current_regs);
+               up_savestate(rtcb->xcp.regs);
 
               /* Restore the exception context of the rtcb at the (new) head 
                * of the g_readytorun task list.
@@ -131,7 +131,7 @@ void up_unblock_task(_TCB *tcb)
 
               /* Then switch contexts */
 
-              up_copystate(current_regs, rtcb->xcp.regs);
+              up_restorestate(rtcb->xcp.regs);
             }
 
           /* We are not in an interrupt handler.  Copy the user C context