xref: /freebsd/sys/arm/arm/bus_space_generic.c (revision 076ad2f8)
1 /*	$NetBSD: obio_space.c,v 1.6 2003/07/15 00:25:05 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001, 2002, 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed for the NetBSD Project by
20  *	Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/bus.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/devmap.h>
47 
48 #include <vm/vm.h>
49 #include <vm/pmap.h>
50 #include <vm/vm_kern.h>
51 #include <vm/vm_extern.h>
52 
53 #include <machine/bus.h>
54 #include <machine/cpufunc.h>
55 
56 void
57 generic_bs_unimplemented(void)
58 {
59 
60 	panic("unimplemented bus_space function called");
61 }
62 
63 /* Prototypes for all the bus_space structure functions */
64 bs_protos(generic);
65 
66 int
67 generic_bs_map(bus_space_tag_t t, bus_addr_t bpa, bus_size_t size, int flags,
68     bus_space_handle_t *bshp)
69 {
70 	void *va;
71 
72 	/*
73 	 * We don't even examine the passed-in flags.  For ARM, the CACHEABLE
74 	 * flag doesn't make sense (we create VM_MEMATTR_DEVICE mappings), and
75 	 * the LINEAR flag is just implied because we use kva_alloc(size).
76 	 */
77 	if ((va = pmap_mapdev(bpa, size)) == NULL)
78 		return (ENOMEM);
79 	*bshp = (bus_space_handle_t)va;
80 	return (0);
81 }
82 
83 int
84 generic_bs_alloc(bus_space_tag_t t, bus_addr_t rstart, bus_addr_t rend, bus_size_t size,
85     bus_size_t alignment, bus_size_t boundary, int flags, bus_addr_t *bpap,
86     bus_space_handle_t *bshp)
87 {
88 
89 	panic("generic_bs_alloc(): not implemented");
90 }
91 
92 
93 void
94 generic_bs_unmap(bus_space_tag_t t, bus_space_handle_t h, bus_size_t size)
95 {
96 
97 	pmap_unmapdev((vm_offset_t)h, size);
98 }
99 
100 void
101 generic_bs_free(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size)
102 {
103 
104 	panic("generic_bs_free(): not implemented");
105 }
106 
107 int
108 generic_bs_subregion(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t offset,
109     bus_size_t size, bus_space_handle_t *nbshp)
110 {
111 
112 	*nbshp = bsh + offset;
113 	return (0);
114 }
115 
116 void
117 generic_bs_barrier(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t offset,
118     bus_size_t len, int flags)
119 {
120 
121 	/*
122 	 * dsb() will drain the L1 write buffer and establish a memory access
123 	 * barrier point on platforms where that has meaning.  On a write we
124 	 * also need to drain the L2 write buffer, because most on-chip memory
125 	 * mapped devices are downstream of the L2 cache.  Note that this needs
126 	 * to be done even for memory mapped as Device type, because while
127 	 * Device memory is not cached, writes to it are still buffered.
128 	 */
129 	dsb();
130 	if (flags & BUS_SPACE_BARRIER_WRITE) {
131 		cpu_l2cache_drain_writebuf();
132 	}
133 }
134