1/* $NetBSD: mcadma_machdep.c,v 1.4 2020/11/21 15:52:32 thorpej Exp $ */
2
3/*-
4 * Copyright (c) 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Tim Rightnour
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#include <sys/cdefs.h>
33__KERNEL_RCSID(0, "$NetBSD: mcadma_machdep.c,v 1.4 2020/11/21 15:52:32 thorpej Exp $");
34
35#include <sys/param.h>
36#include <sys/systm.h>
37#include <sys/syslog.h>
38#include <sys/device.h>
39#include <sys/kmem.h>
40#include <sys/proc.h>
41#include <sys/mbuf.h>
42
43#define _POWERPC_BUS_DMA_PRIVATE
44#include <sys/bus.h>
45
46#include <machine/pio.h>
47
48#include <dev/mca/mcavar.h>
49#include <dev/mca/mcareg.h>
50
51struct rs6000_dma_cookie {
52	int	id_flags;
53	uint32_t	bid;		/* the BID of this IOCC */
54	uint32_t	tce_off;	/* offset of the TCE */
55	uint32_t	nroftce;
56	uint32_t	nrofslaves;	/* nrof slave channels */
57	uint32_t	slave_regs;	/* allocation bitmask */
58	uint32_t	dma_regs;	/* allocation bitmask */
59};
60
61/*
62 * Entry points for MCA DMA.  These are mostly wrappers around
63 * the generic functions that understand how to deal with bounce
64 * buffers, if necessary.
65 */
66
67struct powerpc_bus_dma_tag mca_bus_dma_tag = {
68	0,			/* _bounce_thresh */
69	_mca_bus_dmamap_create,
70	_bus_dmamap_destroy,
71	_bus_dmamap_load,
72	_bus_dmamap_load_mbuf,
73	_bus_dmamap_load_uio,
74	_bus_dmamap_load_raw,
75	_bus_dmamap_unload,
76	NULL,			/* _dmamap_sync */
77	_bus_dmamem_alloc,
78	_bus_dmamem_free,
79	_bus_dmamem_map,
80	_bus_dmamem_unmap,
81	_bus_dmamem_mmap,
82};
83
84/*
85 * Allocate a DMA map, and set up DMA channel.
86 */
87static int
88_mca_bus_dmamap_create(bus_dma_tag_t t, bus_size_t size, int flags,
89    bus_dmamap_t *dmamp, int dmach)
90{
91	int error;
92	struct rs6000_dma_cookie *cookie;
93
94#ifdef DEBUG
95	/* Sanity check */
96	if (dmach < 0 || dmach >= MAX_DMA_CHANNELS) {
97		printf("mcadma_create: invalid DMA channel %d\n", dmach);
98		return EINVAL;
99	}
100
101	if (size > 65536) {
102		panic("mca_dmamap_create: dmamap sz %ld > 65536", (long) size);
103	}
104#endif
105
106	/*
107	 * MCA DMA transfer can be maximum 65536 bytes long and must
108 	 * be in one chunk. No specific boundary constraints are present.
109 	 */
110	if ((error = _bus_dmamap_create(t, size, 1, 65536, 0, flags, dmamp)))
111		return error;
112
113	cookie = (struct rs6000_dma_cookie *) (*dmamp)->_dm_cookie;
114
115	if (cookie == NULL) {
116		/*
117 		 * Allocate our cookie if not yet done.
118		 */
119		cookie = kmem_zalloc(sizeof(struct rs6000_dma_cookie),
120		    ((flags & BUS_DMA_NOWAIT) ? KM_NOSLEEP : KM_SLEEP));
121		if (cookie == NULL) {
122
123			return ENOMEM;
124		}
125		(*dmamp)->_dm_cookie = cookie;
126	}
127
128	/* Encode DMA channel */
129	cookie->id_flags &= 0x0f;
130	cookie->id_flags |= dmach << 4;
131
132	/* Mark the dmamap as using DMA controller. Some devices
133	 * drive DMA themselves, and don't need the MCA DMA controller.
134	 * To distinguish the two, use a flag for dmamaps which use the DMA
135	 * controller.
136	 */
137	(*dmamp)->_dm_flags |= _MCABUS_DMA_USEDMACTRL;
138	return 0;
139}
140
141static void
142_mca_bus_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
143{
144	struct rs6000_dma_cookie *cookie = map->_dm_cookie;
145
146	kmem_free(cookie, sizeof(struct rs6000_dma_cookie));
147	_bus_dmamap_destroy(t, map);
148}
149
150/*
151 * Load an MCA DMA map with a linear buffer.
152 */
153static int
154_mca_bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
155    bus_size_t buflen, struct proc *p, int flags)
156{
157	struct rs6000_dma_cookie *cookie = map->_dm_cookie;
158	int error;
159
160	/* Make sure that on error condition we return "no valid mappings." */
161	map->dm_mapsize = 0;
162	map->dm_nsegs = 0;
163
164	error = _bus_dmamap_load(t, map, buf, buflen, p, flags);
165	return error;
166}
167
168/*
169 * Like _mca_bus_dmamap_load(), but for mbufs.
170 */
171static int
172_mca_bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
173    int flags)
174{
175	struct rs6000_dma_cookie *cookie = map->_dm_cookie;
176	int error;
177
178	/* Make sure that on error condition we return "no valid mappings." */
179	map->dm_mapsize = 0;
180	map->dm_nsegs = 0;
181
182#ifdef DIAGNOSTIC
183	if ((m0->m_flags & M_PKTHDR) == 0)
184		panic("_mca_bus_dmamap_load_mbuf: no packet header");
185#endif
186
187	if (m0->m_pkthdr.len > map->_dm_size)
188		return EINVAL;
189
190	error = _bus_dmamap_load_mbuf(t, map, m0, flags);
191	return error;
192}
193
194/*
195 * Like _mca_bus_dmamap_load(), but for uios.
196 */
197static int
198_mca_bus_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio,
199    int flags)
200{
201
202	panic("_mca_bus_dmamap_load_uio: not implemented");
203}
204
205/*
206 * Like _mca_bus_dmamap_load(), but for raw memory allocated with
207 * bus_dmamem_alloc().
208 */
209static int
210_mca_bus_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map,
211    bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags)
212{
213
214	panic("_mca_bus_dmamap_load_raw: not implemented");
215}
216
217/*
218 * Unload an MCA DMA map.
219 */
220static void
221_mca_bus_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
222{
223
224	_bus_dmamap_unload(t, map);
225}
226
227/*
228 * Allocate memory safe for MCA DMA.
229 */
230static int
231_mca_bus_dmamem_alloc(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment,
232    bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs,
233    int flags)
234{
235	paddr_t high;
236
237	high = trunc_page(avail_end);
238
239	return _bus_dmamem_alloc_range(t, size, alignment, boundary,
240	    segs, nsegs, rsegs, flags, 0, high);
241}
242