arch/ppc-sam440/kernel/kernel_cpu.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <asm/amcc440.h>
   7 #include <aros/kernel.h>
   8 #include <aros/libcall.h>
   9 #include <exec/execbase.h>
  10 #include <hardware/intbits.h>
  11
  12 #include "etask.h"
  13
  14 #include "kernel_intern.h"
  15 #include "kernel_cpu.h"
  16 #include "kernel_syscall.h"
  17 #include "kernel_scheduler.h"
  18 #include "kernel_intr.h"
  19
  20 #include <strings.h>
  21
  22 /*
  23  * Task dispatcher. Basically it may be the same one no matter what scheduling algorithm is used
  24  */
  25 void cpu_Dispatch(context_t *regs)
  26 {
  27     struct ExecBase *SysBase = getSysBase();
  28     struct Task *task;
  29     uint64_t idle;
  30     extern uint64_t idle_time;
  31
  32     __asm__ __volatile__("wrteei 0;");
  33     idle = mftbu();
  34
  35     while (!(task = core_Dispatch())) {
  36         /*
  37          * Is the list of ready tasks empty? Well, increment the idle switch cound and halt CPU.
  38          * It should be extended by some plugin mechanism which would put CPU and whole machine
  39          * into some more sophisticated sleep states (ACPI?)
  40          */
  41         wrmsr(rdmsr() | MSR_POW | MSR_EE);
  42         __asm__ __volatile__("sync; isync;");
  43         __asm__ __volatile__("wrteei 0");
  44         if (SysBase->SysFlags & SFF_SoftInt)
  45             core_Cause(INTB_SOFTINT, 1l << INTB_SOFTINT);
  46         idle_time += mftbu() - idle;
  47     }
  48
  49     /* Handle tasks's flags */
  50     if (task->tc_Flags & TF_EXCEPT)
  51         Exception();
  52
  53     /* Store the launch time */
  54     GetIntETask(task)->iet_private1 = mftbu();
  55
  56     if (task->tc_Flags & TF_LAUNCH)
  57     {
  58         AROS_UFC1(void, task->tc_Launch,
  59                   AROS_UFCA(struct ExecBase *, SysBase, A6));
  60     }
  61
  62     /* Restore the task's state */
  63     regs = task->tc_UnionETask.tc_ETask->et_RegFrame;
  64
  65     if (SysBase->IDNestCnt < 0)
  66             regs->cpu.srr1 |= MSR_EE;
  67
  68     /* Copy the fpu, mmx, xmm state */
  69 // FIXME: Change to the lazy saving of the FPU state!!!!
  70
  71     regs->cpu.srr1 &= ~MSR_POW;
  72 }
  73
  74 void cpu_Switch(context_t *regs)
  75 {
  76     struct ExecBase *SysBase = getSysBase();
  77     struct Task *task;
  78
  79     /* Disable interrupts for a while */
  80     __asm__ __volatile__("wrteei 0");
  81
  82     task = SysBase->ThisTask;
  83
  84     /* Copy current task's context into the ETask structure */
  85     bcopy(regs, task->tc_UnionETask.tc_ETask->et_RegFrame, sizeof(context_t));
  86
  87     /* Copy the fpu, mmx, xmm state */
  88 // FIXME: Change to the lazy saving of the FPU state!!!!
  89
  90     task->tc_SPReg = (APTR)regs->cpu.gpr[1];
  91
  92     /* And enable interrupts */
  93     __asm__ __volatile__("wrteei 1");
  94
  95     core_Switch();
  96 }