lib/libarch/alpha/alpha_pci_mem.c

   1 /*      $NetBSD: alpha_pci_mem.c,v 1.4 2002/07/19 22:03:39 mycroft Exp $        */
   2
   3 /*-
   4  * Copyright (c) 2000 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Jason R. Thorpe.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Support for mapping PCI/EISA/ISA memory space.  This is currently used
  34  * to provide such support for XFree86.  In a perfect world, this would go
  35  * away in favor of a real bus space mapping framework.
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/mman.h>
  40
  41 #include <machine/sysarch.h>
  42
  43 #include <fcntl.h>
  44 #include <paths.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48
  49 struct alpha_bus_window *alpha_pci_mem_windows;
  50 int alpha_pci_mem_window_count;
  51
  52 void *
  53 alpha_pci_mem_map(bus_addr_t memaddr, bus_size_t memsize, int flags,
  54     struct alpha_bus_space_translation *rabst)
  55 {
  56         struct alpha_bus_window *abw;
  57         void *addr;
  58         int prefetchable = flags & BUS_SPACE_MAP_PREFETCHABLE;
  59         int linear = flags & BUS_SPACE_MAP_LINEAR;
  60         bus_size_t offset;
  61         int i, fd;
  62
  63         /*
  64          * Can't have linear without prefetchable.
  65          */
  66         if (linear && !prefetchable)
  67                 return (MAP_FAILED);
  68
  69         if (alpha_pci_mem_windows == NULL) {
  70                 i = alpha_bus_getwindows(ALPHA_BUS_TYPE_PCI_MEM, &abw);
  71                 if (i <= 0)
  72                         return (MAP_FAILED);
  73
  74                 alpha_pci_mem_windows = abw;
  75                 alpha_pci_mem_window_count = i;
  76         }
  77
  78         for (i = 0; i < alpha_pci_mem_window_count; i++) {
  79                 abw = &alpha_pci_mem_windows[i];
  80                 if (memaddr < abw->abw_abst.abst_bus_start ||
  81                     (memaddr + (memsize - 1)) > abw->abw_abst.abst_bus_end)
  82                         continue;
  83
  84                 /*
  85                  * Prefetchable memory must be mapped in dense space;
  86                  * otherwise use sparse space.
  87                  */
  88                 if (prefetchable &&
  89                     (abw->abw_abst.abst_flags & ABST_DENSE) == 0)
  90                         continue;
  91                 if (!prefetchable &&
  92                     (abw->abw_abst.abst_flags & ABST_DENSE) != 0)
  93                         continue;
  94
  95                 /* Looks like we have a winner! */
  96                 goto found;
  97         }
  98
  99         /* Not found in any of the windows. */
 100         return (MAP_FAILED);
 101
 102  found:
 103         fd = open(_PATH_MEM, O_RDWR, 0600);
 104         if (fd == -1)
 105                 return (MAP_FAILED);
 106
 107         if (prefetchable)
 108                 abw->abw_abst.abst_addr_shift = 0;
 109         memsize <<= abw->abw_abst.abst_addr_shift;
 110         offset = (memaddr - abw->abw_abst.abst_bus_start) <<
 111             abw->abw_abst.abst_addr_shift;
 112
 113         addr = mmap(NULL, memsize, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
 114             fd, (off_t) (abw->abw_abst.abst_sys_start + offset));
 115
 116         (void) close(fd);
 117
 118         if (addr != MAP_FAILED) {
 119                 /*
 120                  * Make a copy of the space translation so that the caller
 121                  * can do the correct access.
 122                  */
 123                 *rabst = abw->abw_abst;
 124         }
 125         return (addr);
 126 }
 127
 128 void
 129 alpha_pci_mem_unmap(struct alpha_bus_space_translation *abst, void *addr,
 130     bus_size_t size)
 131 {
 132
 133         (void) munmap(addr, size << abst->abst_addr_shift);
 134 }