osfmk/ppc/io_map.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  *
  25  */
  26
  27 #include <debug.h>
  28 #include <mach/vm_param.h>
  29 #include <vm/vm_kern.h>
  30 #include <vm/vm_map.h>
  31 #include <vm/vm_page.h>
  32 #include <ppc/pmap.h>
  33 #include <ppc/io_map_entries.h>
  34 #include <ppc/Firmware.h>
  35 #include <ppc/mappings.h>
  36 #include <ppc/proc_reg.h>
  37
  38 extern vm_offset_t      virtual_avail;
  39
  40 /*
  41  * Allocate and map memory for devices that may need to be mapped
  42  * outside the usual physical memory. If phys_addr is NULL then
  43  * steal the appropriate number of physical pages from the vm
  44  * system and map them.
  45  */
  46 vm_offset_t
  47 io_map(phys_addr, size)
  48         vm_offset_t     phys_addr;
  49         vm_size_t       size;
  50 {
  51         vm_offset_t     start;
  52         int             i;
  53         unsigned int j;
  54         vm_page_t       m;
  55
  56
  57 #if DEBUG
  58         assert (kernel_map != VM_MAP_NULL);                     /* VM must be initialised */
  59 #endif
  60
  61         if (phys_addr != 0) {
  62                 /* make sure we map full contents of all the pages concerned */
  63                 size = round_page(size + (phys_addr & PAGE_MASK));
  64
  65                 /* Steal some free virtual addresses */
  66
  67                 (void) kmem_alloc_pageable(kernel_map, &start, size);
  68
  69                 pmap_map_block(kernel_pmap, start, phys_addr, size,
  70                    VM_PROT_READ|VM_PROT_WRITE, PTE_WIMG_IO, 0); /* Set up a block mapped area */
  71
  72                 return (start + (phys_addr & PAGE_MASK));
  73
  74         } else {
  75
  76                 /* Steal some free virtual addresses */
  77                 (void) kmem_alloc_pageable(kernel_map, &start, size);
  78
  79                 mapping_prealloc(size);                                 /* Make sure there are enough free mappings */
  80                 /* Steal some physical pages and map them one by one */
  81                 for (i = 0; i < size ; i += PAGE_SIZE) {
  82                         m = VM_PAGE_NULL;
  83                         while ((m = vm_page_grab()) == VM_PAGE_NULL)
  84                                 VM_PAGE_WAIT();
  85                         vm_page_gobble(m);
  86                         (void) pmap_map_bd(start + i,
  87                                            m->phys_addr,
  88                                            m->phys_addr + PAGE_SIZE,
  89                                            VM_PROT_READ|VM_PROT_WRITE);
  90                 }
  91
  92                 mapping_relpre();                                               /* Allow mapping release */
  93                 return start;
  94         }
  95 }