osfmk/ppc/io_map.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  *
  28  */
  29
  30 #include <debug.h>
  31 #include <mach/vm_param.h>
  32 #include <vm/vm_kern.h>
  33 #include <vm/vm_map.h>
  34 #include <vm/vm_page.h>
  35 #include <ppc/pmap.h>
  36 #include <ppc/io_map_entries.h>
  37 #include <ppc/Firmware.h>
  38 #include <ppc/mappings.h>
  39 #include <ppc/proc_reg.h>
  40
  41 extern vm_offset_t      virtual_avail;
  42
  43 /*
  44  * Allocate and map memory for devices that may need to be mapped
  45  * outside the usual physical memory. If phys_addr is NULL then
  46  * steal the appropriate number of physical pages from the vm
  47  * system and map them.
  48  */
  49 vm_offset_t
  50 io_map(phys_addr, size)
  51         vm_offset_t     phys_addr;
  52         vm_size_t       size;
  53 {
  54         vm_offset_t     start;
  55         int             i;
  56         unsigned int j;
  57         vm_page_t       m;
  58
  59
  60 #if DEBUG
  61         assert (kernel_map != VM_MAP_NULL);                     /* VM must be initialised */
  62 #endif
  63
  64         if (phys_addr != 0) {
  65                 /* make sure we map full contents of all the pages concerned */
  66                 size = round_page(size + (phys_addr & PAGE_MASK));
  67
  68                 /* Steal some free virtual addresses */
  69
  70                 (void) kmem_alloc_pageable(kernel_map, &start, size);
  71
  72                 pmap_map_block(kernel_pmap, start, phys_addr, size,
  73                    VM_PROT_READ|VM_PROT_WRITE, PTE_WIMG_IO, 0); /* Set up a block mapped area */
  74
  75                 return (start + (phys_addr & PAGE_MASK));
  76
  77         } else {
  78
  79                 /* Steal some free virtual addresses */
  80                 (void) kmem_alloc_pageable(kernel_map, &start, size);
  81
  82                 mapping_prealloc(size);                                 /* Make sure there are enough free mappings */
  83                 /* Steal some physical pages and map them one by one */
  84                 for (i = 0; i < size ; i += PAGE_SIZE) {
  85                         m = VM_PAGE_NULL;
  86                         while ((m = vm_page_grab()) == VM_PAGE_NULL)
  87                                 VM_PAGE_WAIT();
  88                         vm_page_gobble(m);
  89                         (void) pmap_map_bd(start + i,
  90                                            m->phys_addr,
  91                                            m->phys_addr + PAGE_SIZE,
  92                                            VM_PROT_READ|VM_PROT_WRITE);
  93                 }
  94
  95                 mapping_relpre();                                               /* Allow mapping release */
  96                 return start;
  97         }
  98 }