xref: /freebsd/sys/powerpc/powermac/ata_dbdma.c (revision f126890a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright 2008 by Nathan Whitehorn. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Common routines for the DMA engine on both the Apple Kauai and MacIO
32  * ATA controllers.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/bus.h>
40 #include <sys/malloc.h>
41 #include <sys/sema.h>
42 #include <sys/taskqueue.h>
43 #include <vm/uma.h>
44 #include <machine/stdarg.h>
45 #include <machine/resource.h>
46 #include <machine/bus.h>
47 #include <sys/rman.h>
48 #include <sys/ata.h>
49 #include <dev/ata/ata-all.h>
50 #include <dev/ata/ata-pci.h>
51 #include <ata_if.h>
52 
53 #include "ata_dbdma.h"
54 
55 struct ata_dbdma_dmaload_args {
56 	struct ata_dbdma_channel *sc;
57 
58 	int write;
59 	int nsegs;
60 };
61 
62 static void
63 ata_dbdma_setprd(void *xarg, bus_dma_segment_t *segs, int nsegs, int error)
64 {
65 	struct ata_dbdma_dmaload_args *arg = xarg;
66 	struct ata_dbdma_channel *sc = arg->sc;
67 	int branch_type, command;
68 	int prev_stop;
69 	int i;
70 
71 	mtx_lock(&sc->dbdma_mtx);
72 
73 	prev_stop = sc->next_dma_slot-1;
74 	if (prev_stop < 0)
75 		prev_stop = 0xff;
76 
77 	for (i = 0; i < nsegs; i++) {
78 		/* Loop back to the beginning if this is our last slot */
79 		if (sc->next_dma_slot == 0xff)
80 			branch_type = DBDMA_ALWAYS;
81 		else
82 			branch_type = DBDMA_NEVER;
83 
84 		if (arg->write) {
85 			command = (i + 1 < nsegs) ? DBDMA_OUTPUT_MORE :
86 			    DBDMA_OUTPUT_LAST;
87 		} else {
88 			command = (i + 1 < nsegs) ? DBDMA_INPUT_MORE :
89 			    DBDMA_INPUT_LAST;
90 		}
91 
92 		dbdma_insert_command(sc->dbdma, sc->next_dma_slot++,
93 		    command, 0, segs[i].ds_addr, segs[i].ds_len,
94 		    DBDMA_NEVER, branch_type, DBDMA_NEVER, 0);
95 
96 		if (branch_type == DBDMA_ALWAYS)
97 			sc->next_dma_slot = 0;
98 	}
99 
100 	/* We have a corner case where the STOP command is the last slot,
101 	 * but you can't branch in STOP commands. So add a NOP branch here
102 	 * and the STOP in slot 0. */
103 
104 	if (sc->next_dma_slot == 0xff) {
105 		dbdma_insert_branch(sc->dbdma, sc->next_dma_slot, 0);
106 		sc->next_dma_slot = 0;
107 	}
108 
109 #if 0
110 	dbdma_insert_command(sc->dbdma, sc->next_dma_slot++,
111 	    DBDMA_NOP, 0, 0, 0, DBDMA_ALWAYS, DBDMA_NEVER, DBDMA_NEVER, 0);
112 #endif
113 	dbdma_insert_stop(sc->dbdma, sc->next_dma_slot++);
114 	dbdma_insert_nop(sc->dbdma, prev_stop);
115 
116 	dbdma_sync_commands(sc->dbdma, BUS_DMASYNC_PREWRITE);
117 
118 	mtx_unlock(&sc->dbdma_mtx);
119 
120 	arg->nsegs = nsegs;
121 }
122 
123 static int
124 ata_dbdma_status(device_t dev)
125 {
126 	struct ata_dbdma_channel *sc = device_get_softc(dev);
127 	struct ata_channel *ch = device_get_softc(dev);
128 
129 	if (sc->sc_ch.dma.flags & ATA_DMA_ACTIVE) {
130 		return (!(dbdma_get_chan_status(sc->dbdma) &
131 		    DBDMA_STATUS_ACTIVE));
132 	}
133 
134 	if (ATA_IDX_INB(ch, ATA_ALTSTAT) & ATA_S_BUSY) {
135 		DELAY(100);
136 		if (ATA_IDX_INB(ch, ATA_ALTSTAT) & ATA_S_BUSY)
137 			return 0;
138 	}
139 	return 1;
140 }
141 
142 static int
143 ata_dbdma_start(struct ata_request *request)
144 {
145 	struct ata_dbdma_channel *sc = device_get_softc(request->parent);
146 
147 	sc->sc_ch.dma.flags |= ATA_DMA_ACTIVE;
148 	dbdma_wake(sc->dbdma);
149 	return 0;
150 }
151 
152 static void
153 ata_dbdma_reset(device_t dev)
154 {
155 	struct ata_dbdma_channel *sc = device_get_softc(dev);
156 
157 	mtx_lock(&sc->dbdma_mtx);
158 
159 	dbdma_stop(sc->dbdma);
160 	dbdma_insert_stop(sc->dbdma, 0);
161 	sc->next_dma_slot=1;
162 	dbdma_set_current_cmd(sc->dbdma, 0);
163 
164 	sc->sc_ch.dma.flags &= ~ATA_DMA_ACTIVE;
165 
166 	mtx_unlock(&sc->dbdma_mtx);
167 }
168 
169 static int
170 ata_dbdma_stop(struct ata_request *request)
171 {
172 	struct ata_dbdma_channel *sc = device_get_softc(request->parent);
173 
174 	uint16_t status;
175 
176 	status = dbdma_get_chan_status(sc->dbdma);
177 
178 	dbdma_pause(sc->dbdma);
179 	sc->sc_ch.dma.flags &= ~ATA_DMA_ACTIVE;
180 
181 	if (status & DBDMA_STATUS_DEAD) {
182 		device_printf(request->parent,"DBDMA dead, resetting "
183 		    "channel...\n");
184 		ata_dbdma_reset(request->parent);
185 		return ATA_S_ERROR;
186 	}
187 
188 	if (!(status & DBDMA_STATUS_RUN)) {
189 		device_printf(request->parent,"DBDMA confused, stop called "
190 		    "when channel is not running!\n");
191 		return ATA_S_ERROR;
192 	}
193 
194 	if (status & DBDMA_STATUS_ACTIVE) {
195 		device_printf(request->parent,"DBDMA channel stopped "
196 		    "prematurely\n");
197 		return ATA_S_ERROR;
198 	}
199 	return 0;
200 }
201 
202 static int
203 ata_dbdma_load(struct ata_request *request, void *addr, int *entries)
204 {
205 	struct ata_channel *ch = device_get_softc(request->parent);
206 	struct ata_dbdma_dmaload_args args;
207 
208 	int error;
209 
210 	args.sc = device_get_softc(request->parent);
211 	args.write = !(request->flags & ATA_R_READ);
212 
213 	if (!request->bytecount) {
214 		device_printf(request->dev,
215 		    "FAILURE - zero length DMA transfer attempted\n");
216 		return EIO;
217 	}
218 	if (((uintptr_t)(request->data) & (ch->dma.alignment - 1)) ||
219 	    (request->bytecount & (ch->dma.alignment - 1))) {
220 		device_printf(request->dev,
221 		    "FAILURE - non aligned DMA transfer attempted\n");
222 		return EIO;
223 	}
224 	if (request->bytecount > ch->dma.max_iosize) {
225 		device_printf(request->dev,
226 		    "FAILURE - oversized DMA transfer attempt %d > %d\n",
227 		    request->bytecount, ch->dma.max_iosize);
228 		return EIO;
229 	}
230 
231 	request->dma = &ch->dma.slot[0];
232 
233 	if ((error = bus_dmamap_load(request->dma->data_tag,
234 	    request->dma->data_map, request->data, request->bytecount,
235 	    &ata_dbdma_setprd, &args, BUS_DMA_NOWAIT))) {
236 		device_printf(request->dev, "FAILURE - load data\n");
237 		goto error;
238 	}
239 
240 	if (entries)
241 		*entries = args.nsegs;
242 
243 	bus_dmamap_sync(request->dma->sg_tag, request->dma->sg_map,
244 	    BUS_DMASYNC_PREWRITE);
245 	bus_dmamap_sync(request->dma->data_tag, request->dma->data_map,
246 	    (request->flags & ATA_R_READ) ?
247 	    BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
248 
249 	return 0;
250 
251 error:
252 	ch->dma.unload(request);
253 	return EIO;
254 }
255 
256 void
257 ata_dbdma_dmainit(device_t dev)
258 {
259 	struct ata_dbdma_channel *sc = device_get_softc(dev);
260 
261 	dbdma_allocate_channel(sc->dbdma_regs, sc->dbdma_offset,
262 	    bus_get_dma_tag(dev), 256, &sc->dbdma);
263 
264 	dbdma_set_wait_selector(sc->dbdma,1 << 7, 1 << 7);
265 
266 	dbdma_insert_stop(sc->dbdma,0);
267 	sc->next_dma_slot=1;
268 
269 	sc->sc_ch.dma.start = ata_dbdma_start;
270 	sc->sc_ch.dma.stop = ata_dbdma_stop;
271 	sc->sc_ch.dma.load = ata_dbdma_load;
272 	sc->sc_ch.dma.reset = ata_dbdma_reset;
273 
274 	/*
275 	 * DBDMA's field for transfer size is 16 bits. This will overflow
276 	 * if we try to do a 64K transfer, so stop short of 64K.
277 	 */
278 	sc->sc_ch.dma.segsize = 126 * DEV_BSIZE;
279 	ata_dmainit(dev);
280 
281 	sc->sc_ch.hw.status = ata_dbdma_status;
282 
283 	mtx_init(&sc->dbdma_mtx, "ATA DBDMA", NULL, MTX_DEF);
284 }
285