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 <aros/debug.h>
   7
   8 #include <asm/amcc440.h>
   9 #include <aros/kernel.h>
  10 #include <aros/libcall.h>
  11 #include <exec/execbase.h>
  12 #include <hardware/intbits.h>
  13
  14 #include "etask.h"
  15
  16 #include "kernel_intern.h"
  17 #include "kernel_cpu.h"
  18 #include "kernel_syscall.h"
  19 #include "kernel_scheduler.h"
  20 #include "kernel_intr.h"
  21
  22 #include <strings.h>
  23
  24 /*
  25  * Task dispatcher. Basically it may be the same one no matter what scheduling algorithm is used
  26  */
  27 void cpu_Dispatch(context_t *regs)
  28 {
  29     struct Task *task;
  30     uint64_t idle;
  31     extern uint64_t idle_time;
  32
  33     __asm__ __volatile__("wrteei 0;");
  34     idle = mftbu();
  35
  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
  42     /* Break Disable() if needed */
  43     if (SysBase->IDNestCnt >= 0) {
  44         SysBase->IDNestCnt = -1;
  45         /* Enable selected external interrupts */
  46         wrdcr(UIC0_ER, uic_er[0]);
  47     }
  48
  49     while (!(task = core_Dispatch())) {
  50         wrmsr(rdmsr() | MSR_POW | MSR_EE);
  51         __asm__ __volatile__("sync; isync;");
  52         __asm__ __volatile__("wrteei 0");
  53         idle_time += mftbu() - idle;
  54
  55         if (SysBase->SysFlags & SFF_SoftInt)
  56             core_Cause(INTB_SOFTINT, 1l << INTB_SOFTINT);
  57     }
  58
  59     /* Restore the task's state */
  60     CopyMem(task->tc_UnionETask.tc_ETask->et_RegFrame, regs, sizeof(regs_t));
  61     regs->cpu.gpr[1] = (IPTR)task->tc_SPReg;
  62
  63     /* Handle tasks's flags */
  64     if (task->tc_Flags & TF_EXCEPT)
  65         Exception();
  66
  67     /* Store the launch time */
  68     GetIntETask(task)->iet_private1 = mftbu();
  69
  70     if (task->tc_Flags & TF_LAUNCH)
  71     {
  72         AROS_UFC1(void, task->tc_Launch,
  73                   AROS_UFCA(struct ExecBase *, SysBase, A6));
  74     }
  75
  76     /* Copy the fpu, mmx, xmm state */
  77 // FIXME: Change to the lazy saving of the FPU state!!!!
  78
  79     regs->cpu.srr1 |= MSR_EE;
  80 }
  81
  82 void cpu_Switch(context_t *regs)
  83 {
  84     struct Task *task;
  85
  86     /* Disable interrupts until the task switch */
  87     __asm__ __volatile__("wrteei 0");
  88
  89     task = SysBase->ThisTask;
  90
  91     /* Copy current task's context into the ETask structure */
  92     memmove(task->tc_UnionETask.tc_ETask->et_RegFrame, regs, sizeof(context_t));
  93
  94     /* Copy the fpu, mmx, xmm state */
  95 // FIXME: Change to the lazy saving of the FPU state!!!!
  96
  97     task->tc_SPReg = (APTR)regs->cpu.gpr[1];
  98
  99     core_Switch();
 100 }