kernel/system/do_umap.c

   1 /* The kernel call implemented in this file:
   2  *   m_type:    SYS_UMAP
   3  *
   4  * The parameters for this kernel call are:
   5  *    m5_i1:    CP_SRC_PROC_NR  (process number)
   6  *    m5_c1:    CP_SRC_SPACE    (segment where address is: T, D, or S)
   7  *    m5_l1:    CP_SRC_ADDR     (virtual address)
   8  *    m5_l2:    CP_DST_ADDR     (returns physical address)
   9  *    m5_l3:    CP_NR_BYTES     (size of datastructure)
  10  */
  11
  12 #include "../system.h"
  13
  14 #if USE_UMAP
  15
  16 /*==========================================================================*
  17  *                              do_umap                                     *
  18  *==========================================================================*/
  19 PUBLIC int do_umap(m_ptr)
  20 register message *m_ptr;        /* pointer to request message */
  21 {
  22 /* Map virtual address to physical, for non-kernel processes. */
  23   int seg_type = m_ptr->CP_SRC_SPACE & SEGMENT_TYPE;
  24   int seg_index = m_ptr->CP_SRC_SPACE & SEGMENT_INDEX;
  25   vir_bytes offset = m_ptr->CP_SRC_ADDR;
  26   int count = m_ptr->CP_NR_BYTES;
  27   int endpt = (int) m_ptr->CP_SRC_ENDPT;
  28   int proc_nr;
  29   phys_bytes phys_addr;
  30
  31   /* Verify process number. */
  32   if (endpt == SELF)
  33         proc_nr = who_p;
  34   else
  35         if (! isokendpt(endpt, &proc_nr))
  36                 return(EINVAL);
  37
  38   /* See which mapping should be made. */
  39   switch(seg_type) {
  40   case LOCAL_SEG:
  41       phys_addr = umap_local(proc_addr(proc_nr), seg_index, offset, count);
  42       break;
  43   case REMOTE_SEG:
  44       phys_addr = umap_remote(proc_addr(proc_nr), seg_index, offset, count);
  45       break;
  46 #if _MINIX_CHIP == _CHIP_INTEL
  47   case BIOS_SEG:
  48       phys_addr = umap_bios(proc_addr(proc_nr), offset, count);
  49       break;
  50 #endif
  51   case GRANT_SEG:
  52       phys_addr = umap_grant(proc_addr(proc_nr), offset, count);
  53       break;
  54   default:
  55       return(EINVAL);
  56   }
  57   m_ptr->CP_DST_ADDR = phys_addr;
  58   return (phys_addr == 0) ? EFAULT: OK;
  59 }
  60
  61 #endif /* USE_UMAP */