kernel/fiasco/src/kern/ppc32/context-ppc32.cpp

   1 IMPLEMENTATION [ppc32]:
   2
   3 /** Note: TCB pointer is located in sprg1 */
   4
   5 /*
   6 #include <cassert>
   7 #include <cstdio>
   8
   9 #include "l4_types.h"
  10 #include "cpu_lock.h"
  11 #include "lock_guard.h"
  12 #include "space.h"
  13 #include "thread_state.h"
  14 */
  15
  16 #include "kmem.h"
  17 #include "utcb_support.h"
  18
  19 IMPLEMENT inline
  20 void
  21 Context::spill_user_state()
  22 {}
  23
  24 IMPLEMENT inline
  25 void
  26 Context::fill_user_state()
  27 {}
  28
  29 IMPLEMENT inline
  30 void
  31 Context::switch_cpu(Context *t)
  32 {
  33   unsigned long dummy1, dummy2, dummy3;
  34
  35 //  printf("Switch %p -> %p (sp %p -> %p)\n", this, t, _kernel_sp, t->_kernel_sp);
  36 #warning FIXIT: switchin_context_label needs a Context* parameter (old Context *)
  37   asm volatile (" lis    %%r5, 1f@ha                \n"
  38                 " addi   %%r5, %%r5, 1f@l           \n"
  39
  40                 //save return addr
  41                 " stw    %%r5, 0(%%r1)              \n"
  42                 " stw    %%r1, 0(%[kernel_sp])      \n"
  43
  44                 //switch stack
  45                 " mr     %%r1, %[new_sp]            \n"
  46                 " mr     %%r3, %[new_thread]        \n"
  47
  48                 //address space switch
  49                 " bl     switchin_context_label     \n"
  50                 " lwz    %%r5, 0(%%r1)              \n"
  51                 " mtctr  %%r5                       \n"
  52                 " bctr                              \n"
  53                 "1:                                 \n"
  54                 : [new_thread]"=r" (dummy1),
  55                   [kernel_sp] "=r" (dummy2),
  56                   [new_sp]    "=r" (dummy3)
  57                 : "0" (t),
  58                   "1" (&_kernel_sp),
  59                   "2" (t->_kernel_sp)
  60                 : "r0",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
  61                   "r8",  "r9",  "r13", "r14", "r15", "r16", "r17",
  62                   "r18", "r19", "r20", "r21", "r22", "r23", "r24",
  63                   "r25", "r26", "r27", "r28", "r29", "r30", "r31",
  64                   "ctr", "lr",  "cr2", "cr3", "cr4", "xer", "memory"
  65                   );
  66 }
  67
  68 /** Thread context switchin.  Called on every re-activation of a
  69     thread (switch_exec()).  This method is public only because it is
  70     called by an ``extern "C"'' function that is called
  71     from assembly code (call_switchin_context).
  72  */
  73
  74 IMPLEMENT
  75 void Context::switchin_context(Context *from)
  76 {
  77   assert(this == current());
  78   assert(state() & Thread_ready);
  79   // Set kernel-esp in case we want to return to the user.
  80   // kmem::kernel_esp() returns a pointer to the kernel SP (in the
  81   // TSS) the CPU uses when next switching from user to kernel mode.
  82   // regs() + 1 returns a pointer to the end of our kernel stack.
  83   Kmem::kernel_sp( reinterpret_cast<Mword*>(regs() + 1) );
  84 #if 0
  85   printf("switch in address space: %p\n",_space);
  86 #endif
  87
  88   // switch to our page directory if nessecary
  89   vcpu_aware_space()->switchin_context(from->vcpu_aware_space());
  90
  91   Utcb_support::current(utcb().usr());
  92 }