2007-12-08 Till Straumann <strauman@slac.stanford.edu>

	* new-exceptions/bspsupport/, new-exceptions/bspsupport/ppc_exc.S,
	new-exceptions/bspsupport/ppc_exc_test.c,
	new-exceptions/bspsupport/vectors.h,
	new-exceptions/bspsupport/vectors_init.c,
	new-exceptions/bspsupport/irq.c,
	new-exceptions/bspsupport/ppc_exc_bspsupp.h,
	new-exceptions/bspsupport/ppc_exc_hdl.c,
	new-exceptions/bspsupport/ppc_exc_asm_macros.h,
	new-exceptions/bspsupport/nested_irq_test.c:
	New files. Added 'middleware' code for helping BSPs implement
	exception and interrupt handling and implementing the 'new'
	RTEMS IRQ API (which I personally dislike).

1 files changed, 374 insertions, 0 deletions

diff --git a/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/irq.c b/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/irq.c
new file mode 100644
index 0000000000..01d96a2a3b
--- /dev/null
+++ b/c/src/lib/libcpu/powerpc/new-exceptions/bspsupport/irq.c
@@ -0,0 +1,374 @@
+/*
+ *
+ *  This file contains the PIC-independent implementation of the functions described in irq.h
+ *
+ *  Copyright (C) 1998, 1999 valette@crf.canon.fr
+ *
+ *  The license and distribution terms for this file may be
+ *  found in found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#include <stdlib.h>
+
+#include <rtems.h>
+#include "irq_supp.h"
+#include <rtems/score/apiext.h>  /* for post ISR signal processing */
+#include <libcpu/raw_exception.h>
+#include <libcpu/cpuIdent.h>
+#include "vectors.h"
+#include <stdlib.h>
+#include <rtems/bspIo.h> /* for printk */
+#include <libcpu/spr.h>
+
+/*
+ * default handler connected on each irq after bsp initialization
+ */
+static rtems_irq_connect_data	default_rtems_entry;
+
+/*
+ * location used to store initial tables used for interrupt
+ * management.
+ */
+static rtems_irq_global_settings* 	internal_config;
+static rtems_irq_connect_data*		rtems_hdl_tbl;
+
+
+SPR_RW(BOOKE_TSR)
+
+/* legacy mode for bookE DEC exception;
+ * to avoid the double layer of function calls
+ * (dec_handler_bookE -> C_dispatch_irq_handler -> user handler)
+ * it is preferrable for the user to hook the DEC 
+ * exception directly.
+ * However, the legacy mode works with less modifications
+ * of user code.
+ */
+void C_dispatch_dec_handler_bookE (BSP_Exception_frame *frame, unsigned int excNum)
+{
+	/* clear interrupt; we must do this
+	 * before C_dispatch_irq_handler()
+	 * re-enables MSR_EE.
+	 */
+	_write_BOOKE_TSR( BOOKE_TSR_DIS );
+	C_dispatch_irq_handler(frame, ASM_DEC_VECTOR);	
+}
+
+/*
+ * ------------------------ RTEMS Irq helper functions ----------------
+ */
+
+/*
+ * This function check that the value given for the irq line
+ * is valid.
+ */
+
+static int isValidInterrupt(int irq)
+{
+  if ( (irq < internal_config->irqBase) || (irq >= internal_config->irqBase + internal_config->irqNb))
+    return 0;
+  return 1;
+}
+
+/*
+ * ------------------------ RTEMS Shared Irq Handler Mngt Routines ----------------
+ */
+int BSP_install_rtems_shared_irq_handler  (const rtems_irq_connect_data* irq)
+{
+    rtems_interrupt_level   level;
+    rtems_irq_connect_data* vchain;
+
+    if (!isValidInterrupt(irq->name)) {
+      printk("Invalid interrupt vector %d\n",irq->name);
+      return 0;
+    }
+
+    rtems_interrupt_disable(level);
+
+    if ( (int)rtems_hdl_tbl[irq->name].next_handler  == -1 ) {
+      rtems_interrupt_enable(level);
+      printk("IRQ vector %d already connected to an unshared handler\n",irq->name);
+      return 0;
+    }
+
+     vchain = (rtems_irq_connect_data*)malloc(sizeof(rtems_irq_connect_data));
+
+    /* save off topmost handler */
+    vchain[0]= rtems_hdl_tbl[irq->name];
+
+    /*
+     * store the data provided by user
+     */
+    rtems_hdl_tbl[irq->name] = *irq;
+
+    /* link chain to new topmost handler */
+    rtems_hdl_tbl[irq->name].next_handler = (void *)vchain;
+
+	/*
+	 * enable_irq_at_pic is supposed to ignore
+	 * requests to disable interrupts outside
+	 * of the range handled by the PIC
+	 */
+	BSP_enable_irq_at_pic(irq->name);
+
+    /*
+     * Enable interrupt on device
+     */
+	if (irq->on)
+    	irq->on(irq);
+
+    rtems_interrupt_enable(level);
+
+    return 1;
+}
+
+/*
+ * ------------------------ RTEMS Single Irq Handler Mngt Routines ----------------
+ */
+
+int BSP_install_rtems_irq_handler  (const rtems_irq_connect_data* irq)
+{
+    rtems_interrupt_level  level;
+
+    if (!isValidInterrupt(irq->name)) {
+      printk("Invalid interrupt vector %d\n",irq->name);
+      return 0;
+    }
+    /*
+     * Check if default handler is actually connected. If not issue an error.
+     * You must first get the current handler via i386_get_current_idt_entry
+     * and then disconnect it using i386_delete_idt_entry.
+     * RATIONALE : to always have the same transition by forcing the user
+     * to get the previous handler before accepting to disconnect.
+     */
+    rtems_interrupt_disable(level);
+    if (rtems_hdl_tbl[irq->name].hdl != default_rtems_entry.hdl) {
+      rtems_interrupt_enable(level);
+      printk("IRQ vector %d already connected\n",irq->name);
+      return 0;
+    }
+
+    /*
+     * store the data provided by user
+     */
+    rtems_hdl_tbl[irq->name] = *irq;
+    rtems_hdl_tbl[irq->name].next_handler = (void *)-1;
+
+	/*
+	 * enable_irq_at_pic is supposed to ignore
+	 * requests to disable interrupts outside
+	 * of the range handled by the PIC
+	 */
+	BSP_enable_irq_at_pic(irq->name);
+
+    /*
+     * Enable interrupt on device
+     */
+	if (irq->on)
+    	irq->on(irq);
+
+    rtems_interrupt_enable(level);
+
+    return 1;
+}
+
+int BSP_get_current_rtems_irq_handler	(rtems_irq_connect_data* irq)
+{
+    rtems_interrupt_level       level;
+
+    if (!isValidInterrupt(irq->name)) {
+      return 0;
+    }
+    rtems_interrupt_disable(level);
+      *irq = rtems_hdl_tbl[irq->name];
+    rtems_interrupt_enable(level);
+    return 1;
+}
+
+int BSP_remove_rtems_irq_handler  (const rtems_irq_connect_data* irq)
+{
+    rtems_irq_connect_data *pchain= NULL, *vchain = NULL;
+    rtems_interrupt_level   level;
+
+    if (!isValidInterrupt(irq->name)) {
+      return 0;
+    }
+    /*
+     * Check if default handler is actually connected. If not issue an error.
+     * You must first get the current handler via i386_get_current_idt_entry
+     * and then disconnect it using i386_delete_idt_entry.
+     * RATIONALE : to always have the same transition by forcing the user
+     * to get the previous handler before accepting to disconnect.
+     */
+    rtems_interrupt_disable(level);
+    if (rtems_hdl_tbl[irq->name].hdl != irq->hdl) {
+      rtems_interrupt_enable(level);
+      return 0;
+    }
+
+    if( (int)rtems_hdl_tbl[irq->name].next_handler != -1 )
+    {
+       int found = 0;
+
+       for( (pchain= NULL, vchain = &rtems_hdl_tbl[irq->name]);
+            (vchain->hdl != default_rtems_entry.hdl);
+            (pchain= vchain, vchain = (rtems_irq_connect_data*)vchain->next_handler) )
+       {
+          if( vchain->hdl == irq->hdl )
+          {
+             found= -1; break;
+          }
+       }
+
+       if( !found )
+       {
+          rtems_interrupt_enable(level);
+          return 0;
+       }
+    }
+    else
+    {
+       if (rtems_hdl_tbl[irq->name].hdl != irq->hdl)
+       {
+          rtems_interrupt_enable(level);
+         return 0;
+       }
+    }
+
+	/*
+	 * disable_irq_at_pic is supposed to ignore
+	 * requests to disable interrupts outside
+	 * of the range handled by the PIC
+	 */
+	BSP_disable_irq_at_pic(irq->name);
+
+    /*
+     * Disable interrupt on device
+     */
+	if (irq->off)
+    	irq->off(irq);
+
+    /*
+     * restore the default irq value
+     */
+    if( !vchain )
+    {
+       /* single handler vector... */
+       rtems_hdl_tbl[irq->name] = default_rtems_entry;
+    }
+    else
+    {
+       if( pchain )
+       {
+          /* non-first handler being removed */
+          pchain->next_handler = vchain->next_handler;
+       }
+       else
+       {
+          /* first handler isn't malloc'ed, so just overwrite it.  Since
+          the contents of vchain are being struct copied, vchain itself
+          goes away */
+          vchain = vchain->next_handler;
+          rtems_hdl_tbl[irq->name]= *vchain;
+       }
+       free(vchain);
+    }
+
+    rtems_interrupt_enable(level);
+
+    return 1;
+}
+
+/*
+ * Less cumbersome, alternate entry points;
+ * RETURNS: more traditional, 0 on success, nonzero on error
+ */
+
+static int doit(
+	int (*p)(const rtems_irq_connect_data*),
+	rtems_irq_number n,
+	rtems_irq_hdl hdl,
+	rtems_irq_hdl_param prm)
+{
+rtems_irq_connect_data 	xx;
+	xx.name   = n;
+	xx.hdl    = hdl;
+	xx.handle = prm;
+	xx.on     = 0;
+	xx.off    = 0;
+	xx.isOn   = 0;
+	return ! p(&xx);
+}
+
+int BSP_rtems_int_connect(rtems_irq_number n, rtems_irq_hdl hdl, rtems_irq_hdl_param p)
+{
+	return doit(BSP_install_rtems_shared_irq_handler, n, hdl, p);
+}
+
+int BSP_rtems_int_disconnect(rtems_irq_number n, rtems_irq_hdl hdl, rtems_irq_hdl_param p)
+{
+	return doit(BSP_remove_rtems_irq_handler, n, hdl, p);
+}
+
+
+/*
+ * RTEMS Global Interrupt Handler Management Routines
+ */
+
+int BSP_rtems_irq_mngt_set(rtems_irq_global_settings* config)
+{
+    int                           i;
+    rtems_interrupt_level         level;
+    rtems_irq_connect_data*       vchain;
+
+    /*
+     * Store various code accelerators
+     */
+    internal_config 		= config;
+    default_rtems_entry 	= config->defaultEntry;
+    rtems_hdl_tbl 		= config->irqHdlTbl;
+
+    rtems_interrupt_disable(level);
+
+	if ( !BSP_setup_the_pic(config) ) {
+		printk("PIC setup failed; leaving IRQs OFF\n");
+		return 0;
+	}
+
+	for ( i = config->irqBase; i < config->irqBase + config->irqNb; i++ ) {
+		for( vchain = &rtems_hdl_tbl[i];
+		     ((int)vchain != -1 && vchain->hdl != default_rtems_entry.hdl); 
+		     vchain = (rtems_irq_connect_data*)vchain->next_handler )
+		{
+			if (vchain->on)
+              vchain->on(vchain);
+		}
+	}
+
+    rtems_interrupt_enable(level);
+
+	{
+			ppc_exc_set_handler(ASM_EXT_VECTOR, C_dispatch_irq_handler);
+
+			if ( ppc_cpu_is_bookE() ) { 
+				/* bookE decrementer interrupt needs to be cleared BEFORE
+				 * dispatching the user ISR (because the user ISR is called
+				 * with EE enabled)
+				 * We do this so that existing DEC handlers can be used
+				 * with minor modifications.
+				 */
+				ppc_exc_set_handler(ASM_BOOKE_PIT_VECTOR, C_dispatch_dec_handler_bookE);
+			} else {
+				ppc_exc_set_handler(ASM_DEC_VECTOR, C_dispatch_irq_handler);
+			}
+	}
+    return 1;
+}
+
+int BSP_rtems_irq_mngt_get(rtems_irq_global_settings** config)
+{
+    *config = internal_config;
+    return 0;
+}