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alpha_pci_mem.c revision 1.4
      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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Support for mapping PCI/EISA/ISA memory space.  This is currently used
     41  * to provide such support for XFree86.  In a perfect world, this would go
     42  * away in favor of a real bus space mapping framework.
     43  */
     44 
     45 #include <sys/param.h>
     46 #include <sys/mman.h>
     47 
     48 #include <machine/sysarch.h>
     49 
     50 #include <fcntl.h>
     51 #include <paths.h>
     52 #include <stdlib.h>
     53 #include <string.h>
     54 #include <unistd.h>
     55 
     56 struct alpha_bus_window *alpha_pci_mem_windows;
     57 int alpha_pci_mem_window_count;
     58 
     59 void *
     60 alpha_pci_mem_map(bus_addr_t memaddr, bus_size_t memsize, int flags,
     61     struct alpha_bus_space_translation *rabst)
     62 {
     63 	struct alpha_bus_window *abw;
     64 	void *addr;
     65 	int prefetchable = flags & BUS_SPACE_MAP_PREFETCHABLE;
     66 	int linear = flags & BUS_SPACE_MAP_LINEAR;
     67 	bus_size_t offset;
     68 	int i, fd;
     69 
     70 	/*
     71 	 * Can't have linear without prefetchable.
     72 	 */
     73 	if (linear && !prefetchable)
     74 		return (MAP_FAILED);
     75 
     76 	if (alpha_pci_mem_windows == NULL) {
     77 		i = alpha_bus_getwindows(ALPHA_BUS_TYPE_PCI_MEM, &abw);
     78 		if (i <= 0)
     79 			return (MAP_FAILED);
     80 
     81 		alpha_pci_mem_windows = abw;
     82 		alpha_pci_mem_window_count = i;
     83 	}
     84 
     85 	for (i = 0; i < alpha_pci_mem_window_count; i++) {
     86 		abw = &alpha_pci_mem_windows[i];
     87 		if (memaddr < abw->abw_abst.abst_bus_start ||
     88 		    (memaddr + (memsize - 1)) > abw->abw_abst.abst_bus_end)
     89 			continue;
     90 
     91 		/*
     92 		 * Prefetchable memory must be mapped in dense space;
     93 		 * otherwise use sparse space.
     94 		 */
     95 		if (prefetchable &&
     96 		    (abw->abw_abst.abst_flags & ABST_DENSE) == 0)
     97 			continue;
     98 		if (!prefetchable &&
     99 		    (abw->abw_abst.abst_flags & ABST_DENSE) != 0)
    100 			continue;
    101 
    102 		/* Looks like we have a winner! */
    103 		goto found;
    104 	}
    105 
    106 	/* Not found in any of the windows. */
    107 	return (MAP_FAILED);
    108 
    109  found:
    110 	fd = open(_PATH_MEM, O_RDWR, 0600);
    111 	if (fd == -1)
    112 		return (MAP_FAILED);
    113 
    114 	if (prefetchable)
    115 		abw->abw_abst.abst_addr_shift = 0;
    116 	memsize <<= abw->abw_abst.abst_addr_shift;
    117 	offset = (memaddr - abw->abw_abst.abst_bus_start) <<
    118 	    abw->abw_abst.abst_addr_shift;
    119 
    120 	addr = mmap(NULL, memsize, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
    121 	    fd, (off_t) (abw->abw_abst.abst_sys_start + offset));
    122 
    123 	(void) close(fd);
    124 
    125 	if (addr != MAP_FAILED) {
    126 		/*
    127 		 * Make a copy of the space translation so that the caller
    128 		 * can do the correct access.
    129 		 */
    130 		*rabst = abw->abw_abst;
    131 	}
    132 	return (addr);
    133 }
    134 
    135 void
    136 alpha_pci_mem_unmap(struct alpha_bus_space_translation *abst, void *addr,
    137     bus_size_t size)
    138 {
    139 
    140 	(void) munmap(addr, size << abst->abst_addr_shift);
    141 }
    142