1/*	$NetBSD: pxa2x0_dmac.c,v 1.14 2018/09/03 16:29:24 riastradh Exp $	*/
2
3/*
4 * Copyright (c) 2003, 2005 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Steve C. Woodford 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 "opt_pxa2x0_dmac.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/device.h>
43#include <sys/kernel.h>
44#include <sys/kmem.h>
45#include <sys/queue.h>
46
47#include <uvm/uvm_param.h>	/* For PAGE_SIZE */
48
49#include <machine/intr.h>
50#include <sys/bus.h>
51
52#include <dev/dmover/dmovervar.h>
53
54#include <arm/xscale/pxa2x0reg.h>
55#include <arm/xscale/pxa2x0var.h>
56#include <arm/xscale/pxa2x0cpu.h>
57
58#include <arm/xscale/pxa2x0_dmac.h>
59
60#include "locators.h"
61
62#undef DMAC_N_PRIORITIES
63#ifndef PXA2X0_DMAC_FIXED_PRIORITY
64#define DMAC_N_PRIORITIES 3
65#define DMAC_PRI(p)   (p)
66#else
67#define DMAC_N_PRIORITIES 1
68#define DMAC_PRI(p)   (0)
69#endif
70
71struct dmac_desc {
72	SLIST_ENTRY(dmac_desc) d_link;
73	struct pxa2x0_dma_desc *d_desc;
74	paddr_t d_desc_pa;
75};
76
77/*
78 * This is used to maintain state for an in-progress transfer.
79 * It tracks the current DMA segment, and offset within the segment
80 * in the case where we had to split a request into several DMA
81 * operations due to a shortage of DMAC descriptors.
82 */
83struct dmac_desc_segs {
84	bus_dma_segment_t *ds_curseg;		/* Current segment */
85	u_int ds_nsegs;				/* Remaining segments */
86	bus_size_t ds_offset;			/* Offset within current seg */
87};
88
89SIMPLEQ_HEAD(dmac_xfer_state_head, dmac_xfer_state);
90
91struct dmac_xfer_state {
92	struct dmac_xfer dxs_xfer;
93#define	dxs_cookie	dxs_xfer.dx_cookie
94#define	dxs_done	dxs_xfer.dx_done
95#define	dxs_priority	dxs_xfer.dx_priority
96#define	dxs_peripheral	dxs_xfer.dx_peripheral
97#define	dxs_flow	dxs_xfer.dx_flow
98#define	dxs_dev_width	dxs_xfer.dx_dev_width
99#define	dxs_burst_size	dxs_xfer.dx_burst_size
100#define	dxs_loop_notify	dxs_xfer.dx_loop_notify
101#define	dxs_desc	dxs_xfer.dx_desc
102	SIMPLEQ_ENTRY(dmac_xfer_state) dxs_link;
103	SLIST_HEAD(, dmac_desc) dxs_descs;
104	struct dmac_xfer_state_head *dxs_queue;
105	u_int dxs_channel;
106#define	DMAC_NO_CHANNEL	(~0)
107	uint32_t dxs_dcmd;
108	struct dmac_desc_segs dxs_segs[2];
109	bool dxs_misaligned_flag;
110};
111
112
113#if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
114/*
115 * This structure is used to maintain state for the dmover(9) backend
116 * part of the driver. We can have a number of concurrent dmover
117 * requests in progress at any given time. The exact number is given
118 * by the PXA2X0_DMAC_DMOVER_CONCURRENCY compile-time constant. One of
119 * these structures is allocated for each concurrent request.
120 */
121struct dmac_dmover_state {
122	LIST_ENTRY(dmac_dmover_state) ds_link;	/* List of idle dmover chans */
123	struct pxadmac_softc *ds_sc;		/* Uplink to pxadmac softc */
124	struct dmover_request *ds_current;	/* Current dmover request */
125	struct dmac_xfer_state ds_xfer;
126	bus_dmamap_t ds_src_dmap;
127	bus_dmamap_t ds_dst_dmap;
128/*
129 * There is no inherent size limit in the DMA engine.
130 * The following limit is somewhat arbitrary.
131 */
132#define	DMAC_DMOVER_MAX_XFER	(8*1024*1024)
133#if 0
134/* This would require 16KB * 2 just for segments... */
135#define DMAC_DMOVER_NSEGS	((DMAC_DMOVER_MAX_XFER / PAGE_SIZE) + 1)
136#else
137#define DMAC_DMOVER_NSEGS	512		/* XXX: Only enough for 2MB */
138#endif
139	bus_dma_segment_t ds_zero_seg;		/* Used for zero-fill ops */
140	void *ds_zero_va;
141	bus_dma_segment_t ds_fill_seg;		/* Used for fill8 ops */
142	void *ds_fill_va;
143
144#define	ds_src_addr_hold	ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_addr_hold
145#define	ds_dst_addr_hold	ds_xfer.dxs_desc[DMAC_DESC_DST].xd_addr_hold
146#define	ds_src_burst		ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_burst_size
147#define	ds_dst_burst		ds_xfer.dxs_desc[DMAC_DESC_DST].xd_burst_size
148#define	ds_src_dma_segs		ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_dma_segs
149#define	ds_dst_dma_segs		ds_xfer.dxs_desc[DMAC_DESC_DST].xd_dma_segs
150#define	ds_src_nsegs		ds_xfer.dxs_desc[DMAC_DESC_SRC].xd_nsegs
151#define	ds_dst_nsegs		ds_xfer.dxs_desc[DMAC_DESC_DST].xd_nsegs
152};
153
154/*
155 * Overall dmover(9) backend state
156 */
157struct dmac_dmover {
158	struct dmover_backend dd_backend;
159	int dd_busy;
160	LIST_HEAD(, dmac_dmover_state) dd_free;
161	struct dmac_dmover_state dd_state[PXA2X0_DMAC_DMOVER_CONCURRENCY];
162};
163#endif
164
165struct pxadmac_softc {
166	device_t sc_dev;
167	bus_space_tag_t sc_bust;
168	bus_dma_tag_t sc_dmat;
169	bus_space_handle_t sc_bush;
170	void *sc_irqcookie;
171
172	/*
173	 * Queue of pending requests, per priority
174	 */
175	struct dmac_xfer_state_head sc_queue[DMAC_N_PRIORITIES];
176
177	/*
178	 * Queue of pending requests, per peripheral
179	 */
180	struct {
181		struct dmac_xfer_state_head sp_queue;
182		u_int sp_busy;
183	} sc_periph[DMAC_N_PERIPH];
184
185	/*
186	 * Active requests, per channel.
187	 */
188	struct dmac_xfer_state *sc_active[DMAC_N_CHANNELS];
189
190	/*
191	 * Channel Priority Allocation
192	 */
193	struct {
194		uint8_t p_first;
195		uint8_t p_pri[DMAC_N_CHANNELS];
196	} sc_prio[DMAC_N_PRIORITIES];
197#define	DMAC_PRIO_END		(~0)
198	uint8_t sc_channel_priority[DMAC_N_CHANNELS];
199
200	/*
201	 * DMA descriptor management
202	 */
203	bus_dmamap_t sc_desc_map;
204	bus_dma_segment_t sc_segs;
205#define	DMAC_N_DESCS	((PAGE_SIZE * 2) / sizeof(struct pxa2x0_dma_desc))
206#define	DMAC_DESCS_SIZE	(DMAC_N_DESCS * sizeof(struct pxa2x0_dma_desc))
207	struct dmac_desc sc_all_descs[DMAC_N_DESCS];
208	u_int sc_free_descs;
209	SLIST_HEAD(, dmac_desc) sc_descs;
210
211#if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
212	/*
213	 * dmover(9) backend state
214	 */
215	struct dmac_dmover sc_dmover;
216#endif
217};
218
219static int	pxadmac_match(device_t, cfdata_t, void *);
220static void	pxadmac_attach(device_t, device_t, void *);
221
222CFATTACH_DECL_NEW(pxadmac, sizeof(struct pxadmac_softc),
223    pxadmac_match, pxadmac_attach, NULL, NULL);
224
225static struct pxadmac_softc *pxadmac_sc;
226
227static void dmac_start(struct pxadmac_softc *, dmac_priority_t);
228static int dmac_continue_xfer(struct pxadmac_softc *, struct dmac_xfer_state *);
229static u_int dmac_channel_intr(struct pxadmac_softc *, u_int);
230static int dmac_intr(void *);
231
232#if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
233static void dmac_dmover_attach(struct pxadmac_softc *);
234static void dmac_dmover_process(struct dmover_backend *);
235static void dmac_dmover_run(struct dmover_backend *);
236static void dmac_dmover_done(struct dmac_xfer *, int);
237#endif
238
239static inline uint32_t
240dmac_reg_read(struct pxadmac_softc *sc, int reg)
241{
242
243	return (bus_space_read_4(sc->sc_bust, sc->sc_bush, reg));
244}
245
246static inline void
247dmac_reg_write(struct pxadmac_softc *sc, int reg, uint32_t val)
248{
249
250	bus_space_write_4(sc->sc_bust, sc->sc_bush, reg, val);
251}
252
253static inline int
254dmac_allocate_channel(struct pxadmac_softc *sc, dmac_priority_t priority,
255    u_int *chanp)
256{
257	u_int channel;
258
259	KDASSERT((u_int)priority < DMAC_N_PRIORITIES);
260
261	if ((channel = sc->sc_prio[priority].p_first) == DMAC_PRIO_END)
262		return (-1);
263	sc->sc_prio[priority].p_first = sc->sc_prio[priority].p_pri[channel];
264
265	*chanp = channel;
266	return (0);
267}
268
269static inline void
270dmac_free_channel(struct pxadmac_softc *sc, dmac_priority_t priority,
271    u_int channel)
272{
273
274	KDASSERT((u_int)priority < DMAC_N_PRIORITIES);
275
276	sc->sc_prio[priority].p_pri[channel] = sc->sc_prio[priority].p_first;
277	sc->sc_prio[priority].p_first = channel;
278}
279
280static int
281pxadmac_match(device_t parent, cfdata_t cf, void *aux)
282{
283	struct pxaip_attach_args *pxa = aux;
284
285	if (pxadmac_sc || pxa->pxa_addr != PXA2X0_DMAC_BASE ||
286	    pxa->pxa_intr != PXA2X0_INT_DMA)
287		return (0);
288
289	pxa->pxa_size = PXA2X0_DMAC_SIZE;
290
291	return (1);
292}
293
294static void
295pxadmac_attach(device_t parent, device_t self, void *aux)
296{
297	struct pxadmac_softc *sc = device_private(self);
298	struct pxaip_attach_args *pxa = aux;
299	struct pxa2x0_dma_desc *dd;
300	int i, nsegs;
301
302	sc->sc_dev = self;
303	sc->sc_bust = pxa->pxa_iot;
304	sc->sc_dmat = pxa->pxa_dmat;
305
306	aprint_normal(": DMA Controller\n");
307
308	if (bus_space_map(sc->sc_bust, pxa->pxa_addr, pxa->pxa_size, 0,
309	    &sc->sc_bush)) {
310		aprint_error_dev(self, "Can't map registers!\n");
311		return;
312	}
313
314	pxadmac_sc = sc;
315
316	/*
317	 * Make sure the DMAC is quiescent
318	 */
319	for (i = 0; i < DMAC_N_CHANNELS; i++) {
320		dmac_reg_write(sc, DMAC_DCSR(i), 0);
321		dmac_reg_write(sc, DMAC_DRCMR(i), 0);
322		sc->sc_active[i] = NULL;
323	}
324	if (!CPU_IS_PXA270)
325		dmac_reg_write(sc, DMAC_DINT,
326		    dmac_reg_read(sc, DMAC_DINT) & DMAC_DINT_MASK);
327
328	/*
329	 * Initialise the request queues
330	 */
331	for (i = 0; i < DMAC_N_PRIORITIES; i++)
332		SIMPLEQ_INIT(&sc->sc_queue[i]);
333
334	/*
335	 * Initialise the request queues
336	 */
337	for (i = 0; i < DMAC_N_PERIPH; i++) {
338		sc->sc_periph[i].sp_busy = 0;
339		SIMPLEQ_INIT(&sc->sc_periph[i].sp_queue);
340	}
341
342	/*
343	 * Initialise the channel priority metadata
344	 */
345	memset(sc->sc_prio, DMAC_PRIO_END, sizeof(sc->sc_prio));
346	for (i = 0; i < DMAC_N_CHANNELS; i++) {
347#if (DMAC_N_PRIORITIES > 1)
348		if (i <= 3)
349			dmac_free_channel(sc, DMAC_PRIORITY_HIGH, i);
350		else
351		if (i <= 7)
352			dmac_free_channel(sc, DMAC_PRIORITY_MED, i);
353		else
354			dmac_free_channel(sc, DMAC_PRIORITY_LOW, i);
355#else
356		dmac_free_channel(sc, DMAC_PRIORITY_NORMAL, i);
357#endif
358	}
359
360	/*
361	 * Initialise DMA descriptors and associated metadata
362	 */
363	if (bus_dmamem_alloc(sc->sc_dmat, DMAC_DESCS_SIZE, DMAC_DESCS_SIZE, 0,
364	    &sc->sc_segs, 1, &nsegs, BUS_DMA_NOWAIT))
365		panic("dmac_pxaip_attach: bus_dmamem_alloc failed");
366
367	if (bus_dmamem_map(sc->sc_dmat, &sc->sc_segs, 1, DMAC_DESCS_SIZE,
368	    (void *)&dd, BUS_DMA_COHERENT|BUS_DMA_NOCACHE))
369		panic("dmac_pxaip_attach: bus_dmamem_map failed");
370
371	if (bus_dmamap_create(sc->sc_dmat, DMAC_DESCS_SIZE, 1,
372	    DMAC_DESCS_SIZE, 0, BUS_DMA_NOWAIT, &sc->sc_desc_map))
373		panic("dmac_pxaip_attach: bus_dmamap_create failed");
374
375	if (bus_dmamap_load(sc->sc_dmat, sc->sc_desc_map, (void *)dd,
376	    DMAC_DESCS_SIZE, NULL, BUS_DMA_NOWAIT))
377		panic("dmac_pxaip_attach: bus_dmamap_load failed");
378
379	SLIST_INIT(&sc->sc_descs);
380	sc->sc_free_descs = DMAC_N_DESCS;
381	for (i = 0; i < DMAC_N_DESCS; i++, dd++) {
382		SLIST_INSERT_HEAD(&sc->sc_descs, &sc->sc_all_descs[i], d_link);
383		sc->sc_all_descs[i].d_desc = dd;
384		sc->sc_all_descs[i].d_desc_pa =
385		    sc->sc_segs.ds_addr + (sizeof(struct pxa2x0_dma_desc) * i);
386	}
387
388	sc->sc_irqcookie = pxa2x0_intr_establish(pxa->pxa_intr, IPL_BIO,
389	    dmac_intr, sc);
390	KASSERT(sc->sc_irqcookie != NULL);
391
392#if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
393	dmac_dmover_attach(sc);
394#endif
395}
396
397#if (PXA2X0_DMAC_DMOVER_CONCURRENCY > 0)
398/*
399 * We support the following dmover(9) operations
400 */
401static const struct dmover_algdesc dmac_dmover_algdescs[] = {
402	{DMOVER_FUNC_ZERO, NULL, 0},	/* Zero-fill */
403	{DMOVER_FUNC_FILL8, NULL, 0},	/* Fill with 8-bit immediate value */
404	{DMOVER_FUNC_COPY, NULL, 1}	/* Copy */
405};
406#define	DMAC_DMOVER_ALGDESC_COUNT \
407	(sizeof(dmac_dmover_algdescs) / sizeof(dmac_dmover_algdescs[0]))
408
409static void
410dmac_dmover_attach(struct pxadmac_softc *sc)
411{
412	struct dmac_dmover *dd = &sc->sc_dmover;
413	struct dmac_dmover_state *ds;
414	int i, dummy;
415
416	/*
417	 * Describe ourselves to the dmover(9) code
418	 */
419	dd->dd_backend.dmb_name = "pxadmac";
420	dd->dd_backend.dmb_speed = 100*1024*1024;	/* XXX */
421	dd->dd_backend.dmb_cookie = sc;
422	dd->dd_backend.dmb_algdescs = dmac_dmover_algdescs;
423	dd->dd_backend.dmb_nalgdescs = DMAC_DMOVER_ALGDESC_COUNT;
424	dd->dd_backend.dmb_process = dmac_dmover_process;
425	dd->dd_busy = 0;
426	LIST_INIT(&dd->dd_free);
427
428	for (i = 0; i < PXA2X0_DMAC_DMOVER_CONCURRENCY; i++) {
429		ds = &dd->dd_state[i];
430		ds->ds_sc = sc;
431		ds->ds_current = NULL;
432		ds->ds_xfer.dxs_cookie = ds;
433		ds->ds_xfer.dxs_done = dmac_dmover_done;
434		ds->ds_xfer.dxs_priority = DMAC_PRIORITY_NORMAL;
435		ds->ds_xfer.dxs_peripheral = DMAC_PERIPH_NONE;
436		ds->ds_xfer.dxs_flow = DMAC_FLOW_CTRL_NONE;
437		ds->ds_xfer.dxs_dev_width = DMAC_DEV_WIDTH_DEFAULT;
438		ds->ds_xfer.dxs_burst_size = DMAC_BURST_SIZE_8;	/* XXX */
439		ds->ds_xfer.dxs_loop_notify = DMAC_DONT_LOOP;
440		ds->ds_src_addr_hold = false;
441		ds->ds_dst_addr_hold = false;
442		ds->ds_src_nsegs = 0;
443		ds->ds_dst_nsegs = 0;
444		LIST_INSERT_HEAD(&dd->dd_free, ds, ds_link);
445
446		/*
447		 * Create dma maps for both source and destination buffers.
448		 */
449		if (bus_dmamap_create(sc->sc_dmat, DMAC_DMOVER_MAX_XFER,
450				DMAC_DMOVER_NSEGS, DMAC_DMOVER_MAX_XFER,
451				0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
452				&ds->ds_src_dmap) ||
453		    bus_dmamap_create(sc->sc_dmat, DMAC_DMOVER_MAX_XFER,
454				DMAC_DMOVER_NSEGS, DMAC_DMOVER_MAX_XFER,
455				0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
456				&ds->ds_dst_dmap)) {
457			panic("dmac_dmover_attach: bus_dmamap_create failed");
458		}
459
460		/*
461		 * Allocate some dma memory to be used as source buffers
462		 * for the zero-fill and fill-8 operations. We only need
463		 * small buffers here, since we set up the DMAC source
464		 * descriptor with 'ds_addr_hold' set to true.
465		 */
466		if (bus_dmamem_alloc(sc->sc_dmat, arm_pcache.dcache_line_size,
467				arm_pcache.dcache_line_size, 0,
468				&ds->ds_zero_seg, 1, &dummy, BUS_DMA_NOWAIT) ||
469		    bus_dmamem_alloc(sc->sc_dmat, arm_pcache.dcache_line_size,
470				arm_pcache.dcache_line_size, 0,
471				&ds->ds_fill_seg, 1, &dummy, BUS_DMA_NOWAIT)) {
472			panic("dmac_dmover_attach: bus_dmamem_alloc failed");
473		}
474
475		if (bus_dmamem_map(sc->sc_dmat, &ds->ds_zero_seg, 1,
476				arm_pcache.dcache_line_size, &ds->ds_zero_va,
477				BUS_DMA_NOWAIT) ||
478		    bus_dmamem_map(sc->sc_dmat, &ds->ds_fill_seg, 1,
479				arm_pcache.dcache_line_size, &ds->ds_fill_va,
480				BUS_DMA_NOWAIT)) {
481			panic("dmac_dmover_attach: bus_dmamem_map failed");
482		}
483
484		/*
485		 * Make sure the zero-fill source buffer really is zero filled
486		 */
487		memset(ds->ds_zero_va, 0, arm_pcache.dcache_line_size);
488	}
489
490	dmover_backend_register(&sc->sc_dmover.dd_backend);
491}
492
493static void
494dmac_dmover_process(struct dmover_backend *dmb)
495{
496	struct pxadmac_softc *sc = dmb->dmb_cookie;
497	int s = splbio();
498
499	/*
500	 * If the backend is currently idle, go process the queue.
501	 */
502	if (sc->sc_dmover.dd_busy == 0)
503		dmac_dmover_run(&sc->sc_dmover.dd_backend);
504	splx(s);
505}
506
507static void
508dmac_dmover_run(struct dmover_backend *dmb)
509{
510	struct dmover_request *dreq;
511	struct pxadmac_softc *sc;
512	struct dmac_dmover *dd;
513	struct dmac_dmover_state *ds;
514	size_t len_src, len_dst;
515	int rv;
516
517	sc = dmb->dmb_cookie;
518	dd = &sc->sc_dmover;
519	sc->sc_dmover.dd_busy = 1;
520
521	/*
522	 * As long as we can queue up dmover requests...
523	 */
524	while ((dreq = TAILQ_FIRST(&dmb->dmb_pendreqs)) != NULL &&
525	    (ds = LIST_FIRST(&dd->dd_free)) != NULL) {
526		/*
527		 * Pull the request off the queue, mark it 'running',
528		 * and make it 'current'.
529		 */
530		dmover_backend_remque(dmb, dreq);
531		dreq->dreq_flags |= DMOVER_REQ_RUNNING;
532		LIST_REMOVE(ds, ds_link);
533		ds->ds_current = dreq;
534
535		switch (dreq->dreq_outbuf_type) {
536		case DMOVER_BUF_LINEAR:
537			len_dst = dreq->dreq_outbuf.dmbuf_linear.l_len;
538			break;
539		case DMOVER_BUF_UIO:
540			len_dst = dreq->dreq_outbuf.dmbuf_uio->uio_resid;
541			break;
542		default:
543			goto error;
544		}
545
546		/*
547		 * Fix up the appropriate DMA 'source' buffer
548		 */
549		if (dreq->dreq_assignment->das_algdesc->dad_ninputs) {
550			struct uio *uio;
551			/*
552			 * This is a 'copy' operation.
553			 * Load up the specified source buffer
554			 */
555			switch (dreq->dreq_inbuf_type) {
556			case DMOVER_BUF_LINEAR:
557				len_src= dreq->dreq_inbuf[0].dmbuf_linear.l_len;
558				if (len_src != len_dst)
559					goto error;
560				if (bus_dmamap_load(sc->sc_dmat,ds->ds_src_dmap,
561				    dreq->dreq_inbuf[0].dmbuf_linear.l_addr,
562				    len_src, NULL,
563				    BUS_DMA_NOWAIT | BUS_DMA_STREAMING |
564				    BUS_DMA_READ))
565					goto error;
566				break;
567
568			case DMOVER_BUF_UIO:
569				uio = dreq->dreq_inbuf[0].dmbuf_uio;
570				len_src = uio->uio_resid;
571				if (uio->uio_rw != UIO_WRITE ||
572				    len_src != len_dst)
573					goto error;
574				if (bus_dmamap_load_uio(sc->sc_dmat,
575				    ds->ds_src_dmap, uio,
576				    BUS_DMA_NOWAIT | BUS_DMA_STREAMING |
577				    BUS_DMA_READ))
578					goto error;
579				break;
580
581			default:
582				goto error;
583			}
584
585			ds->ds_src_addr_hold = false;
586		} else
587		if (dreq->dreq_assignment->das_algdesc->dad_name ==
588		    DMOVER_FUNC_ZERO) {
589			/*
590			 * Zero-fill operation.
591			 * Simply load up the pre-zeroed source buffer
592			 */
593			if (bus_dmamap_load(sc->sc_dmat, ds->ds_src_dmap,
594			    ds->ds_zero_va, arm_pcache.dcache_line_size, NULL,
595			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_READ))
596				goto error;
597
598			ds->ds_src_addr_hold = true;
599		} else
600		if (dreq->dreq_assignment->das_algdesc->dad_name ==
601		    DMOVER_FUNC_FILL8) {
602			/*
603			 * Fill-8 operation.
604			 * Initialise our fill-8 buffer, and load it up.
605			 *
606			 * XXX: Experiment with exactly how much of the
607			 * source buffer needs to be filled. Particularly WRT
608			 * burst size (which is hardcoded to 8 for dmover).
609			 */
610			memset(ds->ds_fill_va, dreq->dreq_immediate[0],
611			    arm_pcache.dcache_line_size);
612
613			if (bus_dmamap_load(sc->sc_dmat, ds->ds_src_dmap,
614			    ds->ds_fill_va, arm_pcache.dcache_line_size, NULL,
615			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_READ))
616				goto error;
617
618			ds->ds_src_addr_hold = true;
619		} else {
620			goto error;
621		}
622
623		/*
624		 * Now do the same for the destination buffer
625		 */
626		switch (dreq->dreq_outbuf_type) {
627		case DMOVER_BUF_LINEAR:
628			if (bus_dmamap_load(sc->sc_dmat, ds->ds_dst_dmap,
629			    dreq->dreq_outbuf.dmbuf_linear.l_addr,
630			    len_dst, NULL,
631			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_WRITE))
632				goto error_unload_src;
633			break;
634
635		case DMOVER_BUF_UIO:
636			if (dreq->dreq_outbuf.dmbuf_uio->uio_rw != UIO_READ)
637				goto error_unload_src;
638			if (bus_dmamap_load_uio(sc->sc_dmat, ds->ds_dst_dmap,
639			    dreq->dreq_outbuf.dmbuf_uio,
640			    BUS_DMA_NOWAIT | BUS_DMA_STREAMING | BUS_DMA_WRITE))
641				goto error_unload_src;
642			break;
643
644		default:
645		error_unload_src:
646			bus_dmamap_unload(sc->sc_dmat, ds->ds_src_dmap);
647		error:
648			dreq->dreq_error = EINVAL;
649			dreq->dreq_flags |= DMOVER_REQ_ERROR;
650			ds->ds_current = NULL;
651			LIST_INSERT_HEAD(&dd->dd_free, ds, ds_link);
652			dmover_done(dreq);
653			continue;
654		}
655
656		/*
657		 * The last step before shipping the request off to the
658		 * DMAC driver is to sync the dma maps.
659		 */
660		bus_dmamap_sync(sc->sc_dmat, ds->ds_src_dmap, 0,
661		    ds->ds_src_dmap->dm_mapsize, BUS_DMASYNC_PREWRITE);
662		ds->ds_src_dma_segs = ds->ds_src_dmap->dm_segs;
663		ds->ds_src_nsegs = ds->ds_src_dmap->dm_nsegs;
664
665		bus_dmamap_sync(sc->sc_dmat, ds->ds_dst_dmap, 0,
666		    ds->ds_dst_dmap->dm_mapsize, BUS_DMASYNC_PREREAD);
667		ds->ds_dst_dma_segs = ds->ds_dst_dmap->dm_segs;
668		ds->ds_dst_nsegs = ds->ds_dst_dmap->dm_nsegs;
669
670		/*
671		 * Hand the request over to the dmac section of the driver.
672		 */
673		if ((rv = pxa2x0_dmac_start_xfer(&ds->ds_xfer.dxs_xfer)) != 0) {
674			bus_dmamap_unload(sc->sc_dmat, ds->ds_src_dmap);
675			bus_dmamap_unload(sc->sc_dmat, ds->ds_dst_dmap);
676			dreq->dreq_error = rv;
677			dreq->dreq_flags |= DMOVER_REQ_ERROR;
678			ds->ds_current = NULL;
679			LIST_INSERT_HEAD(&dd->dd_free, ds, ds_link);
680			dmover_done(dreq);
681		}
682	}
683
684	/* All done */
685	sc->sc_dmover.dd_busy = 0;
686}
687
688static void
689dmac_dmover_done(struct dmac_xfer *dx, int error)
690{
691	struct dmac_dmover_state *ds = dx->dx_cookie;
692	struct pxadmac_softc *sc = ds->ds_sc;
693	struct dmover_request *dreq = ds->ds_current;
694
695	/*
696	 * A dmover(9) request has just completed.
697	 */
698
699	KDASSERT(dreq != NULL);
700
701	/*
702	 * Sync and unload the DMA maps
703	 */
704	bus_dmamap_sync(sc->sc_dmat, ds->ds_src_dmap, 0,
705	    ds->ds_src_dmap->dm_mapsize, BUS_DMASYNC_POSTREAD);
706	bus_dmamap_sync(sc->sc_dmat, ds->ds_dst_dmap, 0,
707	    ds->ds_dst_dmap->dm_mapsize, BUS_DMASYNC_POSTWRITE);
708
709	bus_dmamap_unload(sc->sc_dmat, ds->ds_src_dmap);
710	bus_dmamap_unload(sc->sc_dmat, ds->ds_dst_dmap);
711
712	ds->ds_current = NULL;
713	LIST_INSERT_HEAD(&sc->sc_dmover.dd_free, ds, ds_link);
714
715	/*
716	 * Record the completion status of the transfer
717	 */
718	if (error) {
719		dreq->dreq_error = error;
720		dreq->dreq_flags |= DMOVER_REQ_ERROR;
721	} else {
722		if (dreq->dreq_outbuf_type == DMOVER_BUF_UIO)
723			dreq->dreq_outbuf.dmbuf_uio->uio_resid = 0;
724		if (dreq->dreq_assignment->das_algdesc->dad_ninputs &&
725		    dreq->dreq_inbuf_type == DMOVER_BUF_UIO)
726			dreq->dreq_inbuf[0].dmbuf_uio->uio_resid = 0;
727	}
728
729	/*
730	 * Done!
731	 */
732	dmover_done(dreq);
733
734	/*
735	 * See if we can start some more dmover(9) requests.
736	 *
737	 * Note: We're already at splbio() here.
738	 */
739	if (sc->sc_dmover.dd_busy == 0)
740		dmac_dmover_run(&sc->sc_dmover.dd_backend);
741}
742#endif
743
744struct dmac_xfer *
745pxa2x0_dmac_allocate_xfer(void)
746{
747	struct dmac_xfer_state *dxs;
748
749	dxs = kmem_alloc(sizeof(*dxs), KM_SLEEP);
750
751	return ((struct dmac_xfer *)dxs);
752}
753
754void
755pxa2x0_dmac_free_xfer(struct dmac_xfer *dx)
756{
757	struct dmac_xfer_state *dxs = (struct dmac_xfer_state *)dx;
758
759	/*
760	 * XXX: Should verify the DMAC is not actively using this
761	 * structure before freeing...
762	 */
763	kmem_free(dxs, sizeof(*dxs));
764}
765
766static inline int
767dmac_validate_desc(struct dmac_xfer_desc *xd, size_t *psize,
768    bool *misaligned_flag)
769{
770	bus_dma_segment_t *dma_segs = xd->xd_dma_segs;
771	bus_addr_t periph_end;
772	bus_size_t align;
773	size_t size;
774	int i, nsegs = xd->xd_nsegs;
775
776	/*
777	 * Make sure the transfer parameters are acceptable.
778	 */
779
780	if (xd->xd_addr_hold &&
781	    (nsegs != 1 || dma_segs[0].ds_len == 0))
782		return (EINVAL);
783
784	periph_end = CPU_IS_PXA270 ? PXA270_PERIPH_END : PXA250_PERIPH_END;
785	for (i = 0, size = 0; i < nsegs; i++) {
786		if (dma_segs[i].ds_addr >= PXA2X0_PERIPH_START &&
787		    dma_segs[i].ds_addr + dma_segs[i].ds_len < periph_end)
788			/* Internal Peripherals. */
789			align = 0x03;
790		else /* Companion-Chip/External Peripherals/External Memory. */
791			align = 0x07;
792		/*
793		 * XXXX:
794		 * Also PXA27x has more constraints by pairs Source/Target.
795		 */
796
797		if (dma_segs[i].ds_addr & align) {
798			if (!CPU_IS_PXA270)
799				return (EFAULT);
800			*misaligned_flag = true;
801		}
802		size += dma_segs[i].ds_len;
803	}
804
805	*psize = size;
806	return (0);
807}
808
809static inline int
810dmac_init_desc(struct dmac_desc_segs *ds, struct dmac_xfer_desc *xd,
811    size_t *psize, bool *misaligned_flag)
812{
813	int err;
814
815	if ((err = dmac_validate_desc(xd, psize, misaligned_flag)))
816		return (err);
817
818	ds->ds_curseg = xd->xd_dma_segs;
819	ds->ds_nsegs = xd->xd_nsegs;
820	ds->ds_offset = 0;
821	return (0);
822}
823
824int
825pxa2x0_dmac_start_xfer(struct dmac_xfer *dx)
826{
827	struct pxadmac_softc *sc = pxadmac_sc;
828	struct dmac_xfer_state *dxs = (struct dmac_xfer_state *)dx;
829	struct dmac_xfer_desc *src, *dst;
830	size_t size;
831	int err, s;
832
833	if (dxs->dxs_peripheral != DMAC_PERIPH_NONE &&
834	    dxs->dxs_peripheral >= DMAC_N_PERIPH)
835		return (EINVAL);
836
837	src = &dxs->dxs_desc[DMAC_DESC_SRC];
838	dst = &dxs->dxs_desc[DMAC_DESC_DST];
839
840	dxs->dxs_misaligned_flag = false;
841
842	if ((err = dmac_init_desc(&dxs->dxs_segs[DMAC_DESC_SRC], src, &size,
843	    &dxs->dxs_misaligned_flag)))
844		return (err);
845	if (src->xd_addr_hold == false &&
846	    dxs->dxs_loop_notify != DMAC_DONT_LOOP &&
847	    (size % dxs->dxs_loop_notify) != 0)
848		return (EINVAL);
849
850	if ((err = dmac_init_desc(&dxs->dxs_segs[DMAC_DESC_DST], dst, &size,
851	    &dxs->dxs_misaligned_flag)))
852		return (err);
853	if (dst->xd_addr_hold == false &&
854	    dxs->dxs_loop_notify != DMAC_DONT_LOOP &&
855	    (size % dxs->dxs_loop_notify) != 0)
856		return (EINVAL);
857
858	SLIST_INIT(&dxs->dxs_descs);
859	dxs->dxs_channel = DMAC_NO_CHANNEL;
860	dxs->dxs_dcmd = (((uint32_t)dxs->dxs_dev_width) << DCMD_WIDTH_SHIFT) |
861	    (((uint32_t)dxs->dxs_burst_size) << DCMD_SIZE_SHIFT);
862
863	switch (dxs->dxs_flow) {
864	case DMAC_FLOW_CTRL_NONE:
865		break;
866	case DMAC_FLOW_CTRL_SRC:
867		dxs->dxs_dcmd |= DCMD_FLOWSRC;
868		break;
869	case DMAC_FLOW_CTRL_DEST:
870		dxs->dxs_dcmd |= DCMD_FLOWTRG;
871		break;
872	}
873
874	if (src->xd_addr_hold == false)
875		dxs->dxs_dcmd |= DCMD_INCSRCADDR;
876	if (dst->xd_addr_hold == false)
877		dxs->dxs_dcmd |= DCMD_INCTRGADDR;
878
879	s = splbio();
880	if (dxs->dxs_peripheral == DMAC_PERIPH_NONE ||
881	    sc->sc_periph[dxs->dxs_peripheral].sp_busy == 0) {
882		dxs->dxs_queue = &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)];
883		SIMPLEQ_INSERT_TAIL(dxs->dxs_queue, dxs, dxs_link);
884		if (dxs->dxs_peripheral != DMAC_PERIPH_NONE)
885			sc->sc_periph[dxs->dxs_peripheral].sp_busy++;
886		dmac_start(sc, DMAC_PRI(dxs->dxs_priority));
887	} else {
888		dxs->dxs_queue = &sc->sc_periph[dxs->dxs_peripheral].sp_queue;
889		SIMPLEQ_INSERT_TAIL(dxs->dxs_queue, dxs, dxs_link);
890		sc->sc_periph[dxs->dxs_peripheral].sp_busy++;
891	}
892	splx(s);
893
894	return (0);
895}
896
897void
898pxa2x0_dmac_abort_xfer(struct dmac_xfer *dx)
899{
900	struct pxadmac_softc *sc = pxadmac_sc;
901	struct dmac_xfer_state *ndxs, *dxs = (struct dmac_xfer_state *)dx;
902	struct dmac_desc *desc, *ndesc;
903	struct dmac_xfer_state_head *queue;
904	uint32_t rv;
905	int s, timeout, need_start = 0;
906
907	s = splbio();
908
909	queue = dxs->dxs_queue;
910
911	if (dxs->dxs_channel == DMAC_NO_CHANNEL) {
912		/*
913		 * The request has not yet started, or it has already
914		 * completed. If the request is not on a queue, just
915		 * return.
916		 */
917		if (queue == NULL) {
918			splx(s);
919			return;
920		}
921
922		dxs->dxs_queue = NULL;
923		SIMPLEQ_REMOVE(queue, dxs, dmac_xfer_state, dxs_link);
924	} else {
925		/*
926		 * The request is in progress. This is a bit trickier.
927		 */
928		dmac_reg_write(sc, DMAC_DCSR(dxs->dxs_channel), 0);
929
930		for (timeout = 5000; timeout; timeout--) {
931			rv = dmac_reg_read(sc, DMAC_DCSR(dxs->dxs_channel));
932			if (rv & DCSR_STOPSTATE)
933				break;
934			delay(1);
935		}
936
937		if ((rv & DCSR_STOPSTATE) == 0)
938			panic(
939			   "pxa2x0_dmac_abort_xfer: channel %d failed to abort",
940			    dxs->dxs_channel);
941
942		/*
943		 * Free resources allocated to the request
944		 */
945		for (desc = SLIST_FIRST(&dxs->dxs_descs); desc; desc = ndesc) {
946			ndesc = SLIST_NEXT(desc, d_link);
947			SLIST_INSERT_HEAD(&sc->sc_descs, desc, d_link);
948			sc->sc_free_descs++;
949		}
950
951		sc->sc_active[dxs->dxs_channel] = NULL;
952		dmac_free_channel(sc, DMAC_PRI(dxs->dxs_priority),
953		    dxs->dxs_channel);
954
955		if (dxs->dxs_peripheral != DMAC_PERIPH_NONE)
956			dmac_reg_write(sc, DMAC_DRCMR(dxs->dxs_peripheral), 0);
957
958		need_start = 1;
959		dxs->dxs_queue = NULL;
960	}
961
962	if (dxs->dxs_peripheral == DMAC_PERIPH_NONE ||
963	    sc->sc_periph[dxs->dxs_peripheral].sp_busy-- == 1 ||
964	    queue == &sc->sc_periph[dxs->dxs_peripheral].sp_queue)
965		goto out;
966
967	/*
968	 * We've just removed the current item for this
969	 * peripheral, and there is at least one more
970	 * pending item waiting. Make it current.
971	 */
972	ndxs = SIMPLEQ_FIRST(&sc->sc_periph[dxs->dxs_peripheral].sp_queue);
973	dxs = ndxs;
974	KDASSERT(dxs != NULL);
975	SIMPLEQ_REMOVE_HEAD(&sc->sc_periph[dxs->dxs_peripheral].sp_queue,
976	    dxs_link);
977
978	dxs->dxs_queue = &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)];
979	SIMPLEQ_INSERT_TAIL(dxs->dxs_queue, dxs, dxs_link);
980	need_start = 1;
981
982	/*
983	 * Try to start any pending requests with the same
984	 * priority.
985	 */
986out:
987	if (need_start)
988		dmac_start(sc, DMAC_PRI(dxs->dxs_priority));
989	splx(s);
990}
991
992static void
993dmac_start(struct pxadmac_softc *sc, dmac_priority_t priority)
994{
995	struct dmac_xfer_state *dxs;
996	u_int channel;
997
998	while (sc->sc_free_descs &&
999	    (dxs = SIMPLEQ_FIRST(&sc->sc_queue[priority])) != NULL &&
1000	    dmac_allocate_channel(sc, priority, &channel) == 0) {
1001		/*
1002		 * Yay, got some descriptors, a transfer request, and
1003		 * an available DMA channel.
1004		 */
1005		KDASSERT(sc->sc_active[channel] == NULL);
1006		SIMPLEQ_REMOVE_HEAD(&sc->sc_queue[priority], dxs_link);
1007
1008		/* set DMA alignment register */
1009		if (CPU_IS_PXA270) {
1010			uint32_t dalgn;
1011
1012			dalgn = dmac_reg_read(sc, DMAC_DALGN);
1013			dalgn &= ~(1U << channel);
1014			if (dxs->dxs_misaligned_flag)
1015				dalgn |= (1U << channel);
1016			dmac_reg_write(sc, DMAC_DALGN, dalgn);
1017		}
1018
1019		dxs->dxs_channel = channel;
1020		sc->sc_active[channel] = dxs;
1021		(void) dmac_continue_xfer(sc, dxs);
1022		/*
1023		 * XXX: Deal with descriptor allocation failure for loops
1024		 */
1025	}
1026}
1027
1028static int
1029dmac_continue_xfer(struct pxadmac_softc *sc, struct dmac_xfer_state *dxs)
1030{
1031	struct dmac_desc *desc, *prev_desc;
1032	struct pxa2x0_dma_desc *dd;
1033	struct dmac_desc_segs *src_ds, *dst_ds;
1034	struct dmac_xfer_desc *src_xd, *dst_xd;
1035	bus_dma_segment_t *src_seg, *dst_seg;
1036	bus_addr_t src_mem_addr, dst_mem_addr;
1037	bus_size_t src_size, dst_size, this_size;
1038
1039	desc = NULL;
1040	prev_desc = NULL;
1041	dd = NULL;
1042	src_ds = &dxs->dxs_segs[DMAC_DESC_SRC];
1043	dst_ds = &dxs->dxs_segs[DMAC_DESC_DST];
1044	src_xd = &dxs->dxs_desc[DMAC_DESC_SRC];
1045	dst_xd = &dxs->dxs_desc[DMAC_DESC_DST];
1046	SLIST_INIT(&dxs->dxs_descs);
1047
1048	/*
1049	 * As long as the source/destination buffers have DMA segments,
1050	 * and we have free descriptors, build a DMA chain.
1051	 */
1052	while (src_ds->ds_nsegs && dst_ds->ds_nsegs && sc->sc_free_descs) {
1053		src_seg = src_ds->ds_curseg;
1054		src_mem_addr = src_seg->ds_addr + src_ds->ds_offset;
1055		if (src_xd->xd_addr_hold == false &&
1056		    dxs->dxs_loop_notify != DMAC_DONT_LOOP)
1057			src_size = dxs->dxs_loop_notify;
1058		else
1059			src_size = src_seg->ds_len - src_ds->ds_offset;
1060
1061		dst_seg = dst_ds->ds_curseg;
1062		dst_mem_addr = dst_seg->ds_addr + dst_ds->ds_offset;
1063		if (dst_xd->xd_addr_hold == false &&
1064		    dxs->dxs_loop_notify != DMAC_DONT_LOOP)
1065			dst_size = dxs->dxs_loop_notify;
1066		else
1067			dst_size = dst_seg->ds_len - dst_ds->ds_offset;
1068
1069		/*
1070		 * We may need to split a source or destination segment
1071		 * across two or more DMAC descriptors.
1072		 */
1073		while (src_size && dst_size &&
1074		    (desc = SLIST_FIRST(&sc->sc_descs)) != NULL) {
1075			SLIST_REMOVE_HEAD(&sc->sc_descs, d_link);
1076			sc->sc_free_descs--;
1077
1078			/*
1079			 * Decide how much data we're going to transfer
1080			 * using this DMAC descriptor.
1081			 */
1082			if (src_xd->xd_addr_hold)
1083				this_size = dst_size;
1084			else
1085			if (dst_xd->xd_addr_hold)
1086				this_size = src_size;
1087			else
1088				this_size = uimin(dst_size, src_size);
1089
1090			/*
1091			 * But clamp the transfer size to the DMAC
1092			 * descriptor's maximum.
1093			 */
1094			this_size = uimin(this_size, DCMD_LENGTH_MASK & ~0x1f);
1095
1096			/*
1097			 * Fill in the DMAC descriptor
1098			 */
1099			dd = desc->d_desc;
1100			dd->dd_dsadr = src_mem_addr;
1101			dd->dd_dtadr = dst_mem_addr;
1102			dd->dd_dcmd = dxs->dxs_dcmd | this_size;
1103
1104			/*
1105			 * Link it into the chain
1106			 */
1107			if (prev_desc) {
1108				SLIST_INSERT_AFTER(prev_desc, desc, d_link);
1109				prev_desc->d_desc->dd_ddadr = desc->d_desc_pa;
1110			} else {
1111				SLIST_INSERT_HEAD(&dxs->dxs_descs, desc,
1112				    d_link);
1113			}
1114			prev_desc = desc;
1115
1116			/*
1117			 * Update the source/destination pointers
1118			 */
1119			if (src_xd->xd_addr_hold == false) {
1120				src_size -= this_size;
1121				src_ds->ds_offset += this_size;
1122				if (src_ds->ds_offset == src_seg->ds_len) {
1123					KDASSERT(src_size == 0);
1124					src_ds->ds_curseg = ++src_seg;
1125					src_ds->ds_offset = 0;
1126					src_ds->ds_nsegs--;
1127				} else
1128					src_mem_addr += this_size;
1129			}
1130
1131			if (dst_xd->xd_addr_hold == false) {
1132				dst_size -= this_size;
1133				dst_ds->ds_offset += this_size;
1134				if (dst_ds->ds_offset == dst_seg->ds_len) {
1135					KDASSERT(dst_size == 0);
1136					dst_ds->ds_curseg = ++dst_seg;
1137					dst_ds->ds_offset = 0;
1138					dst_ds->ds_nsegs--;
1139				} else
1140					dst_mem_addr += this_size;
1141			}
1142		}
1143
1144		if (dxs->dxs_loop_notify != DMAC_DONT_LOOP) {
1145			/*
1146			 * We must be able to allocate descriptors for the
1147			 * entire loop. Otherwise, return them to the pool
1148			 * and bail.
1149			 */
1150			if (desc == NULL) {
1151				struct dmac_desc *ndesc;
1152				for (desc = SLIST_FIRST(&dxs->dxs_descs);
1153				    desc; desc = ndesc) {
1154					ndesc = SLIST_NEXT(desc, d_link);
1155					SLIST_INSERT_HEAD(&sc->sc_descs, desc,
1156					    d_link);
1157					sc->sc_free_descs++;
1158				}
1159
1160				return (0);
1161			}
1162
1163			KASSERT(dd != NULL);
1164			dd->dd_dcmd |= DCMD_ENDIRQEN;
1165		}
1166	}
1167
1168	/*
1169	 * Did we manage to build a chain?
1170	 * If not, just return.
1171	 */
1172	if (dd == NULL)
1173		return (0);
1174
1175	if (dxs->dxs_loop_notify == DMAC_DONT_LOOP) {
1176		dd->dd_dcmd |= DCMD_ENDIRQEN;
1177		dd->dd_ddadr = DMAC_DESC_LAST;
1178	} else
1179		dd->dd_ddadr = SLIST_FIRST(&dxs->dxs_descs)->d_desc_pa;
1180
1181	if (dxs->dxs_peripheral != DMAC_PERIPH_NONE) {
1182		dmac_reg_write(sc, DMAC_DRCMR(dxs->dxs_peripheral),
1183		    dxs->dxs_channel | DRCMR_MAPVLD);
1184	}
1185	dmac_reg_write(sc, DMAC_DDADR(dxs->dxs_channel),
1186	    SLIST_FIRST(&dxs->dxs_descs)->d_desc_pa);
1187	dmac_reg_write(sc, DMAC_DCSR(dxs->dxs_channel),
1188	    DCSR_ENDINTR | DCSR_RUN);
1189
1190	return (1);
1191}
1192
1193static u_int
1194dmac_channel_intr(struct pxadmac_softc *sc, u_int channel)
1195{
1196	struct dmac_xfer_state *dxs;
1197	struct dmac_desc *desc, *ndesc;
1198	uint32_t dcsr;
1199	u_int rv = 0;
1200
1201	dcsr = dmac_reg_read(sc, DMAC_DCSR(channel));
1202	dmac_reg_write(sc, DMAC_DCSR(channel), dcsr);
1203	if (dmac_reg_read(sc, DMAC_DCSR(channel)) & DCSR_STOPSTATE)
1204		dmac_reg_write(sc, DMAC_DCSR(channel), dcsr & ~DCSR_RUN);
1205
1206	if ((dxs = sc->sc_active[channel]) == NULL) {
1207		aprint_error_dev(sc->sc_dev,
1208		    "Stray DMAC interrupt for unallocated channel %d\n",
1209		    channel);
1210		return (0);
1211	}
1212
1213	/*
1214	 * Clear down the interrupt in the DMA Interrupt Register
1215	 */
1216	if (!CPU_IS_PXA270)
1217		dmac_reg_write(sc, DMAC_DINT, (1u << channel));
1218
1219	/*
1220	 * If this is a looping request, invoke the 'done' callback and
1221	 * return immediately.
1222	 */
1223	if (dxs->dxs_loop_notify != DMAC_DONT_LOOP &&
1224	    (dcsr & DCSR_BUSERRINTR) == 0) {
1225		(dxs->dxs_done)(&dxs->dxs_xfer, 0);
1226		return (0);
1227	}
1228
1229	/*
1230	 * Free the descriptors allocated to the completed transfer
1231	 *
1232	 * XXX: If there is more data to transfer in this request,
1233	 * we could simply reuse some or all of the descriptors
1234	 * already allocated for the transfer which just completed.
1235	 */
1236	for (desc = SLIST_FIRST(&dxs->dxs_descs); desc; desc = ndesc) {
1237		ndesc = SLIST_NEXT(desc, d_link);
1238		SLIST_INSERT_HEAD(&sc->sc_descs, desc, d_link);
1239		sc->sc_free_descs++;
1240	}
1241
1242	if ((dcsr & DCSR_BUSERRINTR) || dmac_continue_xfer(sc, dxs) == 0) {
1243		/*
1244		 * The transfer completed (possibly due to an error),
1245		 * -OR- we were unable to continue any remaining
1246		 * segment of the transfer due to a lack of descriptors.
1247		 *
1248		 * In either case, we have to free up DMAC resources
1249		 * allocated to the request.
1250		 */
1251		sc->sc_active[channel] = NULL;
1252		dmac_free_channel(sc, DMAC_PRI(dxs->dxs_priority), channel);
1253		dxs->dxs_channel = DMAC_NO_CHANNEL;
1254		if (dxs->dxs_peripheral != DMAC_PERIPH_NONE)
1255			dmac_reg_write(sc, DMAC_DRCMR(dxs->dxs_peripheral), 0);
1256
1257		if (dxs->dxs_segs[DMAC_DESC_SRC].ds_nsegs == 0 ||
1258		    dxs->dxs_segs[DMAC_DESC_DST].ds_nsegs == 0 ||
1259		    (dcsr & DCSR_BUSERRINTR)) {
1260
1261			/*
1262			 * The transfer is complete.
1263			 */
1264			dxs->dxs_queue = NULL;
1265			rv = 1u << DMAC_PRI(dxs->dxs_priority);
1266
1267			if (dxs->dxs_peripheral != DMAC_PERIPH_NONE &&
1268			    --sc->sc_periph[dxs->dxs_peripheral].sp_busy != 0) {
1269				struct dmac_xfer_state *ndxs;
1270				/*
1271				 * We've just removed the current item for this
1272				 * peripheral, and there is at least one more
1273				 * pending item waiting. Make it current.
1274				 */
1275				ndxs = SIMPLEQ_FIRST(
1276				  &sc->sc_periph[dxs->dxs_peripheral].sp_queue);
1277				KDASSERT(ndxs != NULL);
1278				SIMPLEQ_REMOVE_HEAD(
1279				   &sc->sc_periph[dxs->dxs_peripheral].sp_queue,
1280				    dxs_link);
1281
1282				ndxs->dxs_queue =
1283				    &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)];
1284				SIMPLEQ_INSERT_TAIL(ndxs->dxs_queue, ndxs,
1285				    dxs_link);
1286			}
1287
1288			(dxs->dxs_done)(&dxs->dxs_xfer,
1289			    (dcsr & DCSR_BUSERRINTR) ? EFAULT : 0);
1290		} else {
1291			/*
1292			 * The request is not yet complete, but we were unable
1293			 * to make any headway at this time because there are
1294			 * no free descriptors. Put the request back at the
1295			 * head of the appropriate priority queue. It'll be
1296			 * dealt with as other in-progress transfers complete.
1297			 */
1298			SIMPLEQ_INSERT_HEAD(
1299			    &sc->sc_queue[DMAC_PRI(dxs->dxs_priority)], dxs,
1300			    dxs_link);
1301		}
1302	}
1303
1304	return (rv);
1305}
1306
1307static int
1308dmac_intr(void *arg)
1309{
1310	struct pxadmac_softc *sc = arg;
1311	uint32_t rv, mask;
1312	u_int chan, pri;
1313
1314	rv = dmac_reg_read(sc, DMAC_DINT);
1315	if ((rv & DMAC_DINT_MASK) == 0)
1316		return (0);
1317
1318	/*
1319	 * Deal with completed transfers
1320	 */
1321	for (chan = 0, mask = 1u, pri = 0;
1322	    chan < DMAC_N_CHANNELS; chan++, mask <<= 1) {
1323		if (rv & mask)
1324			pri |= dmac_channel_intr(sc, chan);
1325	}
1326
1327	/*
1328	 * Now try to start any queued transfers
1329	 */
1330#if (DMAC_N_PRIORITIES > 1)
1331	if (pri & (1u << DMAC_PRIORITY_HIGH))
1332		dmac_start(sc, DMAC_PRIORITY_HIGH);
1333	if (pri & (1u << DMAC_PRIORITY_MED))
1334		dmac_start(sc, DMAC_PRIORITY_MED);
1335	if (pri & (1u << DMAC_PRIORITY_LOW))
1336		dmac_start(sc, DMAC_PRIORITY_LOW);
1337#else
1338	if (pri)
1339		dmac_start(sc, DMAC_PRIORITY_NORMAL);
1340#endif
1341
1342	return (1);
1343}
1344