Clean up TODOs in Kernel.

    * Ensure that unhandled SRESET will trigger TI.

Change-Id: I34807bc357ba6908327ede975afc9c6b6b17c098
RTC: 92848
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/8933
Tested-by: Jenkins Server
Reviewed-by: Douglas R. Gilbert <dgilbert@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>

4 files changed, 81 insertions, 73 deletions

diff --git a/src/kernel/block.C b/src/kernel/block.C
index 5b35fb56e..514af2994 100644
--- a/src/kernel/block.C
+++ b/src/kernel/block.C
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* IBM CONFIDENTIAL                                                       */
 /*                                                                        */
-/* COPYRIGHT International Business Machines Corp. 2011,2013              */
+/* COPYRIGHT International Business Machines Corp. 2011,2014              */
 /*                                                                        */
 /* p1                                                                     */
 /*                                                                        */
@@ -174,7 +174,7 @@ bool Block::handlePageFault(task_t* i_task, uint64_t i_addr, bool i_store)
         }
         else
         {
-            return false; //TODO - Swap kernel base block pages for user pages
+            return false;
         }
     }
 
diff --git a/src/kernel/futexmgr.C b/src/kernel/futexmgr.C
index f66452543..b88bcf370 100644
--- a/src/kernel/futexmgr.C
+++ b/src/kernel/futexmgr.C
@@ -1,25 +1,25 @@
-//  IBM_PROLOG_BEGIN_TAG
-//  This is an automatically generated prolog.
-//
-//  $Source: src/kernel/futexmgr.C $
-//
-//  IBM CONFIDENTIAL
-//
-//  COPYRIGHT International Business Machines Corp. 2011
-//
-//  p1
-//
-//  Object Code Only (OCO) source materials
-//  Licensed Internal Code Source Materials
-//  IBM HostBoot Licensed Internal Code
-//
-//  The source code for this program is not published or other-
-//  wise divested of its trade secrets, irrespective of what has
-//  been deposited with the U.S. Copyright Office.
-//
-//  Origin: 30
-//
-//  IBM_PROLOG_END
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/kernel/futexmgr.C $                                       */
+/*                                                                        */
+/* IBM CONFIDENTIAL                                                       */
+/*                                                                        */
+/* COPYRIGHT International Business Machines Corp. 2011,2014              */
+/*                                                                        */
+/* p1                                                                     */
+/*                                                                        */
+/* Object Code Only (OCO) source materials                                */
+/* Licensed Internal Code Source Materials                                */
+/* IBM HostBoot Licensed Internal Code                                    */
+/*                                                                        */
+/* The source code for this program is not published or otherwise         */
+/* divested of its trade secrets, irrespective of what has been           */
+/* deposited with the U.S. Copyright Office.                              */
+/*                                                                        */
+/* Origin: 30                                                             */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
 /**
  * @file futexmgr.C
  * @brief Definition for kernel side futex management
@@ -94,7 +94,7 @@ uint64_t FutexManager::_wake(uint64_t * i_futex1, uint64_t i_count1,
     uint64_t started = 0;
 
     iv_lock.lock();
-    
+
     // First start up to i_count1 task(s)
     while(started < i_count1)
     {
@@ -123,8 +123,9 @@ uint64_t FutexManager::_wake(uint64_t * i_futex1, uint64_t i_count1,
         // Move up to i_count2 tasks to futex2
         while(moved < i_count2)
         {
-            // What if *i_futex2 got modified !!!! TODO
-            // Do we need a safety check here (another val param) ????
+            // Note: i_futex2 could be modified by this point due to tasks
+            //       released from i_count1.  Userspace has to handle this
+            //       appropriately (currently only in sync_cond_wait).
             _FutexWait_t * waiter = iv_list.find(i_futex1);
             if(waiter == NULL)
             {
diff --git a/src/kernel/ptmgr.C b/src/kernel/ptmgr.C
index 878dea807..6b6436d71 100644
--- a/src/kernel/ptmgr.C
+++ b/src/kernel/ptmgr.C
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* IBM CONFIDENTIAL                                                       */
 /*                                                                        */
-/* COPYRIGHT International Business Machines Corp. 2011,2013              */
+/* COPYRIGHT International Business Machines Corp. 2011,2014              */
 /*                                                                        */
 /* p1                                                                     */
 /*                                                                        */
@@ -879,49 +879,49 @@ void PageTableManager::setAccessBits( PageTableEntry* o_pte,
 {
     o_pte->dword1 &= ~PTE_ACCESS_BITS;
 
-/*  Description of the WIMG bits.
-    W1,3 0 - not Write Through Required
-         1 - Write Through Required
-    I3   0 - not Caching Inhibited
-         1 - Caching Inhibited
-    M2   0 - not Memory Coherence Required
-         1 - Memory Coherence Required
-     G   0 - not Guarded
-         1 - Guarded
-*/
+    /*  Description of the WIMG bits.
+        W1,3 0 - not Write Through Required
+        1 - Write Through Required
+        I3   0 - not Caching Inhibited
+        1 - Caching Inhibited
+        M2   0 - not Memory Coherence Required
+        1 - Memory Coherence Required
+        G   0 - not Guarded
+        1 - Guarded
+        */
     if( SegmentManager::CI_ACCESS == i_accessType )
     {
-      o_pte->WIMG = 0b0101; // Cache Inhibited, Guarded
-      o_pte->pp1_2 = 0b10;  // PP=010
-      o_pte->N = 0b1;       // No Execute
+        o_pte->WIMG = 0b0101; // Cache Inhibited, Guarded
+        o_pte->pp1_2 = 0b10;  // PP=010
+        o_pte->N = 0b1;       // No Execute
     }
     else
     {
-      // Only setting that changes WIMG is CI_ACCESSS
-      // All others are set to 0b0010
-      o_pte->WIMG = 0b0010; // Memory Coherency Required
+        // Only setting that changes WIMG is CI_ACCESSS
+        // All others are set to 0b0010
+        o_pte->WIMG = 0b0010; // Memory Coherency Required
 
-	if (i_accessType & READ_ONLY)
-	{
-	  o_pte->pp1_2 = 0b01;  // PP=001
-	  o_pte->N = 0b1;       // No Execute
-	}
+        if (i_accessType & READ_ONLY)
+        {
+            o_pte->pp1_2 = 0b01;  // PP=001
+            o_pte->N = 0b1;       // No Execute
+        }
         // if writable (implied readable)
-	else if (i_accessType & WRITABLE)
-	{
-	  o_pte->pp1_2 = 0b10;  // PP=010
-	  o_pte->N = 0b1;       // No Execute
-	}
+        else if (i_accessType & WRITABLE)
+        {
+            o_pte->pp1_2 = 0b10;  // PP=010
+            o_pte->N = 0b1;       // No Execute
+        }
         // if executable (implied readable)
-	else if (i_accessType & EXECUTABLE)
-	{
-	  o_pte->pp1_2 = 0b01;  // PP=001
-	  o_pte->N = 0b0;       // Execute
-	}
-	else {
-	  //@fixme - add RO_EXE_ACCESS
-	    Eprintk( "** unrecognized access=%ld\n", i_accessType );
-	}
+        else if (i_accessType & EXECUTABLE)
+        {
+            o_pte->pp1_2 = 0b01;  // PP=001
+            o_pte->N = 0b0;       // Execute
+        }
+        else
+        {
+            Eprintk( "** unrecognized access=%ld\n", i_accessType );
+        }
     }
 }
 
diff --git a/src/kernel/start.S b/src/kernel/start.S
index c9f2663ed..790281305 100644
--- a/src/kernel/start.S
+++ b/src/kernel/start.S
@@ -5,7 +5,7 @@
 #
 # IBM CONFIDENTIAL
 #
-# COPYRIGHT International Business Machines Corp. 2010,2013
+# COPYRIGHT International Business Machines Corp. 2010,2014
 #
 # p1
 #
@@ -172,13 +172,7 @@ STD_INTERRUPT_STUB(system_reset, 0x100)
 intvect_inst_start:
     b _start
 
-    /* TODO: Eventually we likely need specific code for machine check
-     *       interrupts because they can happen at any time, including
-     *       while we're already in an interrupt path.  (Don't want to
-     *       save kernel state over top of a user-space task structure).
-     */
 STD_INTERRUPT(machine_check, 0x200)
-
 STD_INTERRUPT(data_storage, 0x300)
 STD_INTERRUPT(data_segment, 0x380)
 STD_INTERRUPT(inst_storage, 0x400)
@@ -628,9 +622,22 @@ intvect_system_reset:
     beq+ intvect_system_reset_external
     ;// Check for HMI (bits = 101).
     cmpi cr0, r2, 0x5
-    beq+ 1f ;// TODO: need to handle HMIs?
-1:  ;// Unknown reason.
-    b 1b
+    beq+ 1f ;// Unable to handle HMI, jump to 'unknown reason'.
+
+1:  ;// Unknown reason, call as unhandled_exception.
+    sldi r1, r2, 32     ;// Save 42:44 of SRR1 and
+    ori r1, r1, 0x100   ;// SRESET address to
+    mtsprg2 r1          ;// SPRG2 for unhandled_exception.
+        ;/* Restore R2 and R1 */
+    mfsprg1 r2
+    mfsprg0 r1
+        ;/* Need to load unhandled_exception into SPRG0 for kernel_save_task */
+    mtsprg1 r1  ;/* Save off R1 again. */
+    lis r1, intvect_unhandled_finish_save@h
+    ori r1, r1, intvect_unhandled_finish_save@l
+    mtsprg0 r1;
+    mfsprg1 r1; /* Restore GPR1 */
+    b kernel_save_task ; /* Save current task, call unhandled_exception */
 
     ;// @fn intvect_system_reset_inactive
     ;// Handle SRESET on an inactive processor.