arch/x86_64-pc/kernel/kernel_cpu.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <exec/lists.h>
   7 #include <exec/tasks.h>
   8 #include <exec/execbase.h>
   9 #include <hardware/intbits.h>
  10 #include <proto/exec.h>
  11
  12 #include "kernel_base.h"
  13 #include "kernel_intern.h"
  14 #include "kernel_intr.h"
  15 #include "kernel_scheduler.h"
  16
  17 void cpu_Dispatch(struct ExceptionContext *regs)
  18 {
  19     struct Task *task;
  20     struct ExceptionContext *ctx;
  21
  22     /*
  23      * Is the list of ready tasks empty? Well, increment the idle switch cound and halt CPU.
  24      * It should be extended by some plugin mechanism which would put CPU and whole machine
  25      * into some more sophisticated sleep states (ACPI?)
  26      */
  27     while (!(task = core_Dispatch()))
  28     {
  29         /* Sleep almost forever ;) */
  30         __asm__ __volatile__("sti; hlt; cli");
  31
  32         if (SysBase->SysFlags & SFF_SoftInt)
  33             core_Cause(INTB_SOFTINT, 1l << INTB_SOFTINT);
  34     }
  35
  36     /* TODO: Handle exception
  37     if (task->tc_Flags & TF_EXCEPT)
  38         Exception(); */
  39
  40     /* Get task's context */
  41     ctx = task->tc_UnionETask.tc_ETask->et_RegFrame;
  42
  43     /*
  44      * Restore the fpu, mmx, xmm state
  45      * TODO: Change to the lazy saving of the XMM state!!!!
  46      */
  47     if (ctx->Flags & ECF_FPX)
  48         asm volatile("fxrstor (%0)"::"r"(ctx->FXData));
  49
  50     /*
  51      * Leave interrupt and jump to the new task.
  52      * We will restore CPU state right from this buffer,
  53      * so no need to copy anything.
  54      */
  55     core_LeaveInterrupt(ctx);
  56 }
  57
  58 void cpu_Switch(struct ExceptionContext *regs)
  59 {
  60     struct Task *task = SysBase->ThisTask;
  61     struct ExceptionContext *ctx = task->tc_UnionETask.tc_ETask->et_RegFrame;
  62
  63     /*
  64      * Copy current task's context into the ETask structure. Note that context on stack
  65      * misses SSE data pointer.
  66      */
  67     CopyMemQuick(regs, ctx, sizeof(struct ExceptionContext) - sizeof(struct FPXContext *));
  68
  69     /*
  70      * Copy the fpu, mmx, xmm state
  71      * TODO: Change to the lazy saving of the XMM state!!!!
  72      */
  73     asm volatile("fxsave (%0)"::"r"(ctx->FXData));
  74
  75     /* We have the complete data now */
  76     ctx->Flags = ECF_SEGMENTS | ECF_FPX;
  77
  78     /* Set task's tc_SPReg */
  79     task->tc_SPReg = (APTR)regs->rsp;
  80
  81     core_Switch();
  82 }