Execute 'doze' in idle loop.

Change-Id: Ifd611129c2d7173b5e0dec36c870e06a4d851009
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/1384
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>

10 files changed, 256 insertions, 132 deletions

diff --git a/src/build/debug/Hostboot/Ps.pm b/src/build/debug/Hostboot/Ps.pm
index a5a56ba02..e8a238c11 100755
--- a/src/build/debug/Hostboot/Ps.pm
+++ b/src/build/debug/Hostboot/Ps.pm
@@ -6,7 +6,7 @@
 #
 #  IBM CONFIDENTIAL
 #
-#  COPYRIGHT International Business Machines Corp. 2011
+#  COPYRIGHT International Business Machines Corp. 2011-2012
 #
 #  p1
 #
@@ -20,8 +20,7 @@
 #
 #  Origin: 30
 #
-#  IBM_PROLOG_END
-
+#  IBM_PROLOG_END_TAG
 use strict;
 
 package Hostboot::Ps;
@@ -47,7 +46,7 @@ use constant PS_TRACKER_RETVAL_OFFSET => 8 + PS_TRACKER_STATUS_OFFSET;
 use constant PS_TRACKER_WAITINFO_OFFSET => 8 + PS_TRACKER_RETVAL_OFFSET;
 use constant PS_TRACKER_ENTRYPOINT_OFFSET => 8 + PS_TRACKER_WAITINFO_OFFSET;
 
-use constant PS_TASK_STATE_OFFSET => 8*42;
+use constant PS_TASK_STATE_OFFSET => 8*43;
 use constant PS_TASK_STATEEXTRA_OFFSET => 8 + PS_TASK_STATE_OFFSET;
 
 sub main
diff --git a/src/include/kernel/cpumgr.H b/src/include/kernel/cpumgr.H
index bbd16fcd8..8cf6d0fc3 100644
--- a/src/include/kernel/cpumgr.H
+++ b/src/include/kernel/cpumgr.H
@@ -111,10 +111,11 @@ class CpuManager
         /** Desired value for LPCR after wakeup.
          *
          *  bit 49 - Wake-up from external interrupt.
+         *  bit 50 - Wake-up from decrementer.
          *  bit 51 - Wake-up from machine check.
          *  bit 60, 61 - LPES(0,1) = 1 (see ISA).
          */
-        static const uint64_t WAKEUP_LPCR_VALUE =   0x000000000000500C;
+        static const uint64_t WAKEUP_LPCR_VALUE =   0x000000000000700C;
 
     protected:
         CpuManager();
diff --git a/src/include/kernel/ppcconsts.S b/src/include/kernel/ppcconsts.S
index 89a52a008..1568bb911 100644
--- a/src/include/kernel/ppcconsts.S
+++ b/src/include/kernel/ppcconsts.S
@@ -1,25 +1,25 @@
 #   IBM_PROLOG_BEGIN_TAG
 #   This is an automatically generated prolog.
-#
+# 
 #   $Source: src/include/kernel/ppcconsts.S $
-#
+# 
 #   IBM CONFIDENTIAL
-#
-#   COPYRIGHT International Business Machines Corp. 2010 - 2011
-#
+# 
+#   COPYRIGHT International Business Machines Corp. 2010-2012
+# 
 #   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_END_TAG
 #*--------------------------------------------------------------------*#
 #*  Register Constants                                                *#
 #*--------------------------------------------------------------------*#
@@ -206,8 +206,9 @@
 .set TASK_CR, TASK_LR+8
 .set TASK_CTR, TASK_CR+8
 .set TASK_XER, TASK_CTR+8
+.set TASK_MSR_MASK, TASK_XER+8
 
-.set TASK_FP_CONTEXT, TASK_XER+8
+.set TASK_FP_CONTEXT, TASK_MSR_MASK+8
 .set TASK_FPR_0, 0
 .set TASK_FPR_1, TASK_FPR_0+8
 .set TASK_FPR_2, TASK_FPR_1+8
diff --git a/src/include/kernel/syscalls.H b/src/include/kernel/syscalls.H
index 28e13628c..5523fc158 100644
--- a/src/include/kernel/syscalls.H
+++ b/src/include/kernel/syscalls.H
@@ -92,6 +92,8 @@ namespace Systemcalls
         MISC_CPUSTARTCORE,
             /** cpu_spr_value() */
         MISC_CPUSPRVALUE,
+            /** cpu_doze() - Hidden syscall */
+        MISC_CPUDOZE,
 
             /** mm_alloc_block() */
         MM_ALLOC_BLOCK,
diff --git a/src/include/kernel/task.H b/src/include/kernel/task.H
index 9ff0401ba..f9ceab994 100644
--- a/src/include/kernel/task.H
+++ b/src/include/kernel/task.H
@@ -1,25 +1,26 @@
-//  IBM_PROLOG_BEGIN_TAG
-//  This is an automatically generated prolog.
-//
-//  $Source: src/include/kernel/task.H $
-//
-//  IBM CONFIDENTIAL
-//
-//  COPYRIGHT International Business Machines Corp. 2010 - 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/include/kernel/task.H $
+ *
+ *  IBM CONFIDENTIAL
+ *
+ *  COPYRIGHT International Business Machines Corp. 2010-2012
+ *
+ *  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_TAG
+ */
 /** @file task.H
  *  @brief Defines kernel information about tasks.
  */
@@ -42,6 +43,7 @@ struct context_t
     uint64_t cr;
     uint64_t ctr;
     uint64_t xer;
+    uint64_t msr_mask; // XOR mask applied to MSR.
 };
 
 /** @struct context_fp_t
diff --git a/src/kernel/exception.C b/src/kernel/exception.C
index 6115b5bd8..0d63d0a73 100644
--- a/src/kernel/exception.C
+++ b/src/kernel/exception.C
@@ -1,25 +1,26 @@
-//  IBM_PROLOG_BEGIN_TAG
-//  This is an automatically generated prolog.
-//
-//  $Source: src/kernel/exception.C $
-//
-//  IBM CONFIDENTIAL
-//
-//  COPYRIGHT International Business Machines Corp. 2010 - 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/exception.C $
+ *
+ *  IBM CONFIDENTIAL
+ *
+ *  COPYRIGHT International Business Machines Corp. 2010-2012
+ *
+ *  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_TAG
+ */
 #include <assert.h>
 #include <kernel/types.h>
 #include <kernel/console.H>
@@ -29,14 +30,16 @@
 #include <kernel/vmmmgr.H>
 #include <kernel/cpuid.H>
 #include <kernel/intmsghandler.H>
+#include <errno.h>
+#include <kernel/vmmmgr.H>
 
 namespace ExceptionHandles
 {
-    bool HvEmulation(task_t*);
+    bool PrivInstr(task_t*);
 }
 
 const uint64_t EXCEPTION_SRR1_MASK 	= 0x00000000783F0000;
-const uint64_t EXCEPTION_SRR1_HVEMUL	= 0x0000000000080000;
+const uint64_t EXCEPTION_SRR1_PRIVINS   = 0x0000000000040000;
 
 extern "C"
 void kernel_execute_prog_ex()
@@ -47,9 +50,9 @@ void kernel_execute_prog_ex()
     bool handled = false;
     switch(exception)
     {
-	case EXCEPTION_SRR1_HVEMUL:
-	    handled = ExceptionHandles::HvEmulation(t);
-	    break;
+        case EXCEPTION_SRR1_PRIVINS:
+            handled = ExceptionHandles::PrivInstr(t);
+            break;
     }
     if (!handled)
     {
@@ -157,22 +160,26 @@ void kernel_execute_hype_emu_assist()
 
 namespace ExceptionHandles
 {
-    bool HvEmulation(task_t* t)
+    bool PrivInstr(task_t* t)
     {
-	/*printk("NIP = %lx : Inst = %x\n",
-	       t->context.nip,
-	       (*(uint32_t*)t->context.nip));*/
-
-	uint32_t instruction = *(uint32_t*)t->context.nip;
-
-	    // check for mfsprg3
-	if ((instruction & 0xfc1fffff) == 0x7c1342a6)
-	{
-	    t->context.gprs[(instruction & 0x03E00000) >> 21] =
-		    (uint64_t) t;
-	    t->context.nip = (void*) (((uint64_t)t->context.nip)+4);
-	    return true;
-	}
+        uint64_t phys_addr = VmmManager::findPhysicalAddress(
+                reinterpret_cast<uint64_t>(t->context.nip));
+
+        if (-EFAULT != static_cast<int64_t>(phys_addr))
+        {
+            uint32_t* instruction = reinterpret_cast<uint32_t*>(phys_addr);
+
+            // Check for 'doze' and skip over.  This avoids a task-crash
+            // if for some reason we entered back into the task without
+            // priviledge raised.
+            if (*instruction == 0x4c000324)
+            {
+                printk("Error: Doze executed with lowered permissions on %d\n",
+                       t->tid);
+                t->context.nip = static_cast<void*>(instruction + 1);
+                return true;
+            }
+        }
 
 	return false;
     }
diff --git a/src/kernel/misc.C b/src/kernel/misc.C
index 74be12de1..a29aaea21 100644
--- a/src/kernel/misc.C
+++ b/src/kernel/misc.C
@@ -1,25 +1,26 @@
-//  IBM_PROLOG_BEGIN_TAG
-//  This is an automatically generated prolog.
-//
-//  $Source: src/kernel/misc.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/misc.C $
+ *
+ *  IBM CONFIDENTIAL
+ *
+ *  COPYRIGHT International Business Machines Corp. 2011-2012
+ *
+ *  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_TAG
+ */
 #include <kernel/misc.H>
 #include <kernel/cpumgr.H>
 #include <kernel/cpuid.H>
@@ -84,6 +85,9 @@ namespace KernelMisc
                 printk("No payload... doze'ing all threads.\n");
             }
 
+            // Clear LPCR values that wakes up from doze.  LPCR[49, 50, 51]
+            setLPCR(getLPCR() & (~0x0000000000007000));
+
             while(1)
             {
                 doze();
diff --git a/src/kernel/start.S b/src/kernel/start.S
index 2e4cd1784..7d2d77845 100644
--- a/src/kernel/start.S
+++ b/src/kernel/start.S
@@ -146,11 +146,41 @@ finished_relocate:
 
 .org _start + 0x100
 intvect_system_reset:
-    b _start
+    /* TODO: Add handling for SRESET from winkle for master. */
+    ;// Need to identify reason for SRESET and then perform appropriate
+    ;// action.
+    ;// Current support:
+    ;//         - Decrementer wake-up from doze.
+    ;//         - External interrupt (also wake-up from doze).
+    ;//         - IPI wake-up from winkle of slave core.
+
+    ;// Free up two registers temporarily.
+    mtsprg0 r1
+    mtsprg1 r2
+
+    ;// Save CR.
+    mfcr r1
+
+    ;// Find bit 42:44 of SRR1 (reason for SRESET).
+    mfsrr1 r2
+    extrdi r2, r2, 3, 42
+    ;// Check for decrementer (bits = 011).
+    cmpi cr0, r2, 0x3
+    beq+ intvect_system_reset_decrementer
+    ;// Check for external interrupt (bits = 010).
+    cmpi cr0, r2, 0x4
+    beq+ intvect_system_reset_external
+    ;// Check for HMI (bits = 101).
+    cmpi cr0, r2, 0x5
+    beq+ _start
+    ;// Check for bits 000, which is probably a Simics bug right now.
+    cmpi cr0, r2, 0x0
+    beq+ _start
+1:  ;// Unknown reason.
+    b 1b
 
-.org _start + 0x17C
-hbi_pre_phyp_breakpoint:
-    attn;   /* TODO: Add actual breakpoint attention. */
+.org _start + 0x180
+intvect_inst_start:
     b _start
 
     /* TODO: Eventually we likely need specific code for machine check
@@ -436,10 +466,10 @@ kernel_dispatch_task:
 
     mfmsr r2		;// Get current MSR
     ori r2,r2, 0xC030	;// Enable MSR[EE,PR,IR,DR].
-    rldicl r2,r2,1,1	;// Clear ...
-    rotldi r2,r2,63	;// 	MSR[TA]
     rldicl r2,r2,50,1   ;// Clear ...
     rotldi r2,r2,14     ;//     MSR[FP]
+    ld r3, TASK_MSR_MASK(r1) ;// Load MSR mask.
+    xor r2, r2, r3      ;// Apply MSR mask (XOR).
     mtsrr1 r2		;// Set task MSR (SRR1)
 
     ld r2, TASK_NIP(r1)	;// Load NIP from context.
@@ -544,7 +574,44 @@ kernel_dispatch_task:
 
     b 2b
 
+    ;// @fn intvect_system_reset_decrementer
+    ;// Handle SRESET due to decrementer wake-up.
+    ;//     This is a wake-up from 'doze'.  Clear priviledge escalation and
+    ;//     perform decrementer.
+intvect_system_reset_decrementer:
+    ;// Restore CR.
+    mtcr r1
+
+    ;// Clear MSR mask, since privilaged instruction was now executed (doze).
+    mfsprg3 r1  ;// Load task structure to r1.
+    li r2, 0    ;// Zero r2.
+    std r2, TASK_MSR_MASK(r1) ;// Zero msr_mask.
+
+    ;// Advance saved NIA (past doze).
+    mfsrr0 r1
+    addi r1, r1, 4
+    mtsrr0 r1
+
+    ;// Restore save registers.
+    mfsprg0 r1
+    mfsprg1 r2
+
+    b intvect_decrementer
+
+    ;// @fn intvect_system_reset_external
+    ;// Handle SRESET due to wake-up from external interrupt.
+    ;//     This is a wake-up from 'doze', but not due to the decrementer
+    ;//     itself firing.  Therefore, leave 'doze' process state alone
+    ;//     including NIA and handle the external interrupt.
+intvect_system_reset_external:
+    ;// Restore CR.
+    mtcr r1
+
+    ;// Restore save registers.
+    mfsprg0 r1
+    mfsprg1 r2
 
+    b intvect_external
 
     ;// @fn system_call_fast_path
     ;// Handle fast path system calls.
diff --git a/src/kernel/syscall.C b/src/kernel/syscall.C
index 061971f96..6dcbe0c25 100644
--- a/src/kernel/syscall.C
+++ b/src/kernel/syscall.C
@@ -98,6 +98,7 @@ namespace Systemcalls
     void CpuDDLevel(task_t *t);
     void CpuStartCore(task_t *t);
     void CpuSprValue(task_t *t);
+    void CpuDoze(task_t *t);
     void MmAllocBlock(task_t *t);
     void MmRemovePages(task_t *t);
     void MmSetPermission(task_t *t);
@@ -133,6 +134,7 @@ namespace Systemcalls
         &CpuDDLevel,  // MISC_CPUDDLEVEL
         &CpuStartCore, // MISC_CPUSTARTCORE
         &CpuSprValue, // MISC_CPUSPRVALUE
+        &CpuDoze, // MISC_CPUDOZE
 
         &MmAllocBlock, // MM_ALLOC_BLOCK
         &MmRemovePages, // MM_REMOVE_PAGES
@@ -668,6 +670,34 @@ namespace Systemcalls
     };
 
     /**
+     *  Allow a task to request priviledge escalation to execute the 'doze'
+     *  instruction.
+     *
+     *  Verifies the instruction to execute is, in fact, doze and then sets
+     *  an MSR mask in the task structure to allow escalation on next
+     *  execution.
+     *
+     *  When 'doze' is executed the processor will eventually issue an
+     *  SRESET exception with flags in srr1 to indication that the
+     *  decrementer caused the wake-up.  The kernel will then need to
+     *  advance the task to the instruction after the doze and remove
+     *  priviledge escalation.
+     *
+     */
+    void CpuDoze(task_t *t)
+    {
+
+        uint32_t* instruction = static_cast<uint32_t*>(t->context.nip);
+        if (0x4c000324 == (*instruction)) // Verify 'doze' instruction,
+                                          // otherwise just return.
+        {
+            // Disable PR, IR, DR so 'doze' can be executed.
+            //     (which means to stay in HV state)
+            t->context.msr_mask = 0x4030;
+        }
+    };
+
+    /**
      * Allocate a block of virtual memory within the base segment
      * @param[in] t: The task used to allocate a block in the base segment
      */
diff --git a/src/sys/prof/idletask.C b/src/sys/prof/idletask.C
index 843f26628..da568f955 100644
--- a/src/sys/prof/idletask.C
+++ b/src/sys/prof/idletask.C
@@ -1,26 +1,26 @@
-//  IBM_PROLOG_BEGIN_TAG
-//  This is an automatically generated prolog.
-//
-//  $Source: src/sys/prof/idletask.C $
-//
-//  IBM CONFIDENTIAL
-//
-//  COPYRIGHT International Business Machines Corp. 2012
-//
-//  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/sys/prof/idletask.C $
+ *
+ *  IBM CONFIDENTIAL
+ *
+ *  COPYRIGHT International Business Machines Corp. 2012
+ *
+ *  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_TAG
+ */
 /** @file idletask.C
  *  @brief Code for the kernel idle-loop.
  *
@@ -31,11 +31,22 @@
 
 #include <kernel/taskmgr.H>
 #include <arch/ppc.H>
+#include <sys/syscall.h>
+
+using namespace Systemcalls;
 
 void TaskManager::idleTaskLoop(void* unused)
 {
     while(1)
     {
-	setThreadPriorityLow();
+	// Lower priority (and yield simics thread).
+        setThreadPriorityLow();
+
+        // Request privilege escalation for doze.
+        register uint64_t syscall = MISC_CPUDOZE;
+        asm volatile("or 3, %0, %0; sc" :: "r" (syscall) : "r3");
+
+        // Execute doze.
+        doze();
     }
 }