current_regs should be volatile; add support for nested interrupts; enable interrupts during syscall processing

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3475 42af7a65-404d-4744-a932-0658087f49c3

6 files changed, 47 insertions, 26 deletions

diff --git a/nuttx/arch/z80/src/common/up_doirq.c b/nuttx/arch/z80/src/common/up_doirq.c
index 2c4c9e113..828806a49 100644
--- a/nuttx/arch/z80/src/common/up_doirq.c
+++ b/nuttx/arch/z80/src/common/up_doirq.c
@@ -84,6 +84,8 @@ FAR chipreg_t *up_doirq(uint8_t irq, FAR chipreg_t *regs)
 #else
   if (irq < NR_IRQS)
     {
+       FAR chipreg_t *savestate;
+
        /* Indicate that we have entered IRQ processing logic */
 
        IRQ_ENTER(irq, regs);
diff --git a/nuttx/arch/z80/src/ez80/ez80_irq.c b/nuttx/arch/z80/src/ez80/ez80_irq.c
index 38a51c9c4..d89bff859 100644
--- a/nuttx/arch/z80/src/ez80/ez80_irq.c
+++ b/nuttx/arch/z80/src/ez80/ez80_irq.c
@@ -57,7 +57,7 @@
  * structure.  If is non-NULL only during interrupt processing.
  */
 
-chipreg_t *current_regs;
+volatile chipreg_t *current_regs;
 
 /****************************************************************************
  * Private Data
diff --git a/nuttx/arch/z80/src/ez80/switch.h b/nuttx/arch/z80/src/ez80/switch.h
index b1d71669b..3b7f1bd95 100644
--- a/nuttx/arch/z80/src/ez80/switch.h
+++ b/nuttx/arch/z80/src/ez80/switch.h
@@ -2,7 +2,7 @@
  * arch/z80/src/ez80/switch.h
  * arch/z80/src/chip/switch.h
  *
- *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -61,7 +61,7 @@
 
 #define INIT_IRQCONTEXT()        current_regs = NULL
 
-/* IN_INTERRUPT returns true if the system is current operating in the interrupt
+/* IN_INTERRUPT returns true if the system is currently operating in the interrupt
  * context.  IN_INTERRUPT is the inline equivalent of up_interrupt_context().
  */
 
@@ -69,11 +69,15 @@
 
 /* The following macro is used when the system enters interrupt handling logic */
 
-#define IRQ_ENTER(irq, regs)     current_regs = (regs)
+#define IRQ_ENTER(irq, regs) \
+  do { \
+    savestate    = (FAR chipreg_t *)current_regs; \
+    current_regs = (regs); \
+  } while (0)
 
 /* The following macro is used when the system exits interrupt handling logic */
 
-#define IRQ_LEAVE(irq)           current_regs = NULL
+#define IRQ_LEAVE(irq)           current_regs = savestate
 
 /* The following macro is used to sample the interrupt state (as a opaque handle) */
 
@@ -81,11 +85,11 @@
 
 /* Save the current IRQ context in the specified TCB */
 
-#define SAVE_IRQCONTEXT(tcb)     ez80_copystate((tcb)->xcp.regs, current_regs)
+#define SAVE_IRQCONTEXT(tcb)     ez80_copystate((tcb)->xcp.regs, (FAR chipreg_t*)current_regs)
 
 /* Set the current IRQ context to the state specified in the TCB */
 
-#define SET_IRQCONTEXT(tcb)      ez80_copystate(current_regs, (tcb)->xcp.regs)
+#define SET_IRQCONTEXT(tcb)      ez80_copystate((FAR chipreg_t*)current_regs, (tcb)->xcp.regs)
 
 /* Save the user context in the specified TCB.  User context saves can be simpler
  * because only those registers normally saved in a C called need be stored.
@@ -116,7 +120,7 @@
  * If is non-NULL only during interrupt processing.
  */
 
-extern chipreg_t *current_regs;
+extern volatile chipreg_t *current_regs;
 #endif
 
 /************************************************************************************
@@ -133,19 +137,19 @@ extern "C" {
 
 /* Defined in ez80_copystate.c */
 
-EXTERN void ez80_copystate(chipreg_t *dest, const chipreg_t *src);
+EXTERN void ez80_copystate(FAR chipreg_t *dest, FAR const chipreg_t *src);
 
 /* Defined in ez80_saveusercontext.asm */
 
-EXTERN int ez80_saveusercontext(chipreg_t *regs);
+EXTERN int ez80_saveusercontext(FAR chipreg_t *regs);
 
 /* Defined in ez80_restorecontext.asm */
 
-EXTERN void ez80_restorecontext(chipreg_t *regs);
+EXTERN void ez80_restorecontext(FAR chipreg_t *regs);
 
 /* Defined in ez80_sigsetup.c */
 
-EXTERN void ez80_sigsetup(_TCB *tcb, sig_deliver_t sigdeliver, chipreg_t *regs);
+EXTERN void ez80_sigsetup(FAR _TCB *tcb, sig_deliver_t sigdeliver, chipreg_t *regs);
 
 /* Defined in ez80_registerdump.c */
 
diff --git a/nuttx/arch/z80/src/z8/switch.h b/nuttx/arch/z80/src/z8/switch.h
index 69e766cf6..c37d7bcd0 100644
--- a/nuttx/arch/z80/src/z8/switch.h
+++ b/nuttx/arch/z80/src/z8/switch.h
@@ -2,7 +2,7 @@
  * arch/z80/src/z8/switch.h
  * arch/z80/src/chip/switch.h
  *
- *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -105,7 +105,7 @@
     g_z8irqstate.state = Z8_IRQSTATE_NONE; \
   } while (0)
 
-/* IN_INTERRUPT returns true if the system is current operating in the interrupt
+/* IN_INTERRUPT returns true if the system is currently operating in the interrupt
  * context.  IN_INTERRUPT is the inline equivalent of up_interrupt_context().
  */
 
@@ -114,8 +114,15 @@
 
 /* The following macro is used when the system enters interrupt handling logic */
 
+#define IRQ_SAVE(irq, regs)      savestate    = (FAR chipreg_t *)current_regs;
+#define IRQ_ENTER(irq, regs)     current_regs = (regs)
+
+/* The following macro is used when the system exits interrupt handling logic */
+
 #define IRQ_ENTER(irq, regs) \
   do { \
+    savestate.state    = g_z8irqstate.state; \
+    savestate.regs     = g_z8irqstate.regs; \
     g_z8irqstate.state = Z8_IRQSTATE_ENTRY; \
     g_z8irqstate.regs  = (regs); \
     up_maskack_irq(irq); \
@@ -125,7 +132,8 @@
 
 #define IRQ_LEAVE(irq) \
   do { \
-    g_z8irqstate.state = Z8_IRQSTATE_NONE; \
+    g_z8irqstate.state = savestate.state; \
+    g_z8irqstate.regs  = savestate.regs; \
     up_enable_irq(irq); \
   } while (0)
 
diff --git a/nuttx/arch/z80/src/z80/switch.h b/nuttx/arch/z80/src/z80/switch.h
index f30f41b9c..1b54ada5e 100644
--- a/nuttx/arch/z80/src/z80/switch.h
+++ b/nuttx/arch/z80/src/z80/switch.h
@@ -2,7 +2,7 @@
  * arch/z80/src/z80/switch.h
  * arch/z80/src/chip/switch.h
  *
- *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -68,11 +68,15 @@
 
 /* The following macro is used when the system enters interrupt handling logic */
 
-#define IRQ_ENTER(irq, regs)     current_regs = (regs)
+#define IRQ_ENTER(irq, regs) \
+  do { \
+    savestate    = (FAR chipreg_t *)current_regs; \
+    current_regs = (regs); \
+  } while (0)
 
 /* The following macro is used when the system exits interrupt handling logic */
 
-#define IRQ_LEAVE(irq)           current_regs = NULL
+#define IRQ_LEAVE(irq)           current_regs = savestate
 
 /* The following macro is used to sample the interrupt state (as a opaque handle) */
 
@@ -80,11 +84,11 @@
 
 /* Save the current IRQ context in the specified TCB */
 
-#define SAVE_IRQCONTEXT(tcb)     z80_copystate((tcb)->xcp.regs, current_regs)
+#define SAVE_IRQCONTEXT(tcb)     z80_copystate((tcb)->xcp.regs, (FAR chipreg_t*)current_regs)
 
 /* Set the current IRQ context to the state specified in the TCB */
 
-#define SET_IRQCONTEXT(tcb)      z80_copystate(current_regs, (tcb)->xcp.regs)
+#define SET_IRQCONTEXT(tcb)      z80_copystate((FAR chipreg_t*)current_regs, (tcb)->xcp.regs)
 
 /* Save the user context in the specified TCB.  User context saves can be simpler
  * because only those registers normally saved in a C called need be stored.
@@ -103,16 +107,19 @@
 #define _REGISTER_DUMP()         z80_registerdump()
 
 /************************************************************************************
+ * Public Types
+ ************************************************************************************/
+
+/************************************************************************************
  * Public Variables
  ************************************************************************************/
 
 #ifndef __ASSEMBLY__
-/* This holds a references to the current interrupt level
- * register storage structure.  If is non-NULL only during
- * interrupt processing.
+/* This holds a references to the current interrupt level register storage structure.
+ * If is non-NULL only during interrupt processing.
  */
 
-extern chipreg_t *current_regs;
+extern volatile chipreg_t *current_regs;
 #endif
 
 /************************************************************************************
diff --git a/nuttx/arch/z80/src/z80/z80_irq.c b/nuttx/arch/z80/src/z80/z80_irq.c
index 8b46acc40..5efd36b9f 100644
--- a/nuttx/arch/z80/src/z80/z80_irq.c
+++ b/nuttx/arch/z80/src/z80/z80_irq.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/z80/src/z80/z80_irq.c
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -56,7 +56,7 @@
  * structure.  If is non-NULL only during interrupt processing.
  */
 
-chipreg_t *current_regs;
+volatile chipreg_t *current_regs;
 
 /****************************************************************************
  * Private Data