busdma_machdep.c revision 112436 
1/*
2 * Copyright (c) 2002 Peter Grehan
3 * Copyright (c) 1997, 1998 Justin T. Gibbs.
4 * 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 *    without modification, immediately at the beginning of the file.
12 * 2. The name of the author may not be used to endorse or promote products
13 *    derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
19 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 *   From i386/busdma_machdep.c,v 1.26 2002/04/19 22:58:09 alfred
28 */
29
30#ifndef lint
31static const char rcsid[] =
32  "$FreeBSD: head/sys/powerpc/powerpc/busdma_machdep.c 112436 2003-03-20 19:45:26Z mux $";
33#endif /* not lint */
34
35/*
36 * MacPPC bus dma support routines
37 */
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/malloc.h>
42#include <sys/bus.h>
43#include <sys/interrupt.h>
44#include <sys/lock.h>
45#include <sys/proc.h>
46#include <sys/mutex.h>
47#include <sys/mbuf.h>
48#include <sys/uio.h>
49
50#include <vm/vm.h>
51#include <vm/vm_page.h>
52#include <vm/vm_map.h>
53
54#include <machine/atomic.h>
55#include <machine/bus.h>
56#include <machine/cpufunc.h>
57
58struct bus_dma_tag {
59	bus_dma_tag_t     parent;
60	bus_size_t        alignment;
61	bus_size_t        boundary;
62	bus_addr_t        lowaddr;
63	bus_addr_t        highaddr;
64	bus_dma_filter_t *filter;
65	void             *filterarg;
66	bus_size_t        maxsize;
67	u_int             nsegments;
68	bus_size_t        maxsegsz;
69	int               flags;
70	int               ref_count;
71	int               map_count;
72};
73
74struct bus_dmamap {
75        bus_dma_tag_t          dmat;
76        void                  *buf;             /* unmapped buffer pointer */
77        bus_size_t             buflen;          /* unmapped buffer length */
78        bus_dmamap_callback_t *callback;
79        void                  *callback_arg;
80};
81
82/*
83 * Allocate a device specific dma_tag.
84 */
85int
86bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
87		   bus_size_t boundary, bus_addr_t lowaddr,
88		   bus_addr_t highaddr, bus_dma_filter_t *filter,
89		   void *filterarg, bus_size_t maxsize, int nsegments,
90		   bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
91{
92	bus_dma_tag_t newtag;
93	int error = 0;
94
95	/* Return a NULL tag on failure */
96	*dmat = NULL;
97
98	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
99	if (newtag == NULL)
100		return (ENOMEM);
101
102	newtag->parent = parent;
103	newtag->alignment = alignment;
104	newtag->boundary = boundary;
105	newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
106	newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
107	newtag->filter = filter;
108	newtag->filterarg = filterarg;
109        newtag->maxsize = maxsize;
110        newtag->nsegments = nsegments;
111	newtag->maxsegsz = maxsegsz;
112	newtag->flags = flags;
113	newtag->ref_count = 1; /* Count ourself */
114	newtag->map_count = 0;
115
116        /*
117	 * Take into account any restrictions imposed by our parent tag
118	 */
119        if (parent != NULL) {
120                newtag->lowaddr = min(parent->lowaddr, newtag->lowaddr);
121                newtag->highaddr = max(parent->highaddr, newtag->highaddr);
122
123                /*
124                 * XXX Not really correct??? Probably need to honor boundary
125                 *     all the way up the inheritence chain.
126                 */
127                newtag->boundary = max(parent->boundary, newtag->boundary);
128                if (newtag->filter == NULL) {
129                        /*
130                         * Short circuit looking at our parent directly
131                         * since we have encapsulated all of its information
132                         */
133                        newtag->filter = parent->filter;
134                        newtag->filterarg = parent->filterarg;
135                        newtag->parent = parent->parent;
136		}
137		if (newtag->parent != NULL)
138			atomic_add_int(&parent->ref_count, 1);
139	}
140
141	*dmat = newtag;
142	return (error);
143}
144
145int
146bus_dma_tag_destroy(bus_dma_tag_t dmat)
147{
148	if (dmat != NULL) {
149
150                if (dmat->map_count != 0)
151                        return (EBUSY);
152
153                while (dmat != NULL) {
154                        bus_dma_tag_t parent;
155
156                        parent = dmat->parent;
157                        atomic_subtract_int(&dmat->ref_count, 1);
158                        if (dmat->ref_count == 0) {
159                                free(dmat, M_DEVBUF);
160                                /*
161                                 * Last reference count, so
162                                 * release our reference
163                                 * count on our parent.
164                                 */
165                                dmat = parent;
166                        } else
167                                dmat = NULL;
168                }
169        }
170        return (0);
171}
172
173/*
174 * Allocate a handle for mapping from kva/uva/physical
175 * address space into bus device space.
176 */
177int
178bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
179{
180	*mapp = NULL;
181	dmat->map_count++;
182
183	return (0);
184}
185
186/*
187 * Destroy a handle for mapping from kva/uva/physical
188 * address space into bus device space.
189 */
190int
191bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
192{
193        if (map != NULL) {
194		panic("dmamap_destroy: NULL?\n");
195        }
196        dmat->map_count--;
197        return (0);
198}
199
200/*
201 * Allocate a piece of memory that can be efficiently mapped into
202 * bus device space based on the constraints lited in the dma tag.
203 * A dmamap to for use with dmamap_load is also allocated.
204 */
205int
206bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
207                 bus_dmamap_t *mapp)
208{
209        *mapp = NULL;
210
211        if (dmat->maxsize <= PAGE_SIZE) {
212                *vaddr = malloc(dmat->maxsize, M_DEVBUF,
213                             (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK);
214        } else {
215                /*
216                 * XXX Use Contigmalloc until it is merged into this facility
217                 *     and handles multi-seg allocations.  Nobody is doing
218                 *     multi-seg allocations yet though.
219                 */
220		mtx_lock(&Giant);
221                *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF,
222                    (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK,
223                    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
224                    dmat->boundary);
225		mtx_unlock(&Giant);
226        }
227
228        if (*vaddr == NULL)
229                return (ENOMEM);
230
231        return (0);
232}
233
234/*
235 * Free a piece of memory and it's allocated dmamap, that was allocated
236 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
237 */
238void
239bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
240{
241        if (map != NULL)
242                panic("bus_dmamem_free: Invalid map freed\n");
243        if (dmat->maxsize <= PAGE_SIZE)
244		free(vaddr, M_DEVBUF);
245        else {
246		mtx_lock(&Giant);
247		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
248		mtx_unlock(&Giant);
249	}
250}
251
252/*
253 * Map the buffer buf into bus space using the dmamap map.
254 */
255int
256bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
257                bus_size_t buflen, bus_dmamap_callback_t *callback,
258                void *callback_arg, int flags)
259{
260        vm_offset_t             vaddr;
261        vm_offset_t             paddr;
262#ifdef __GNUC__
263        bus_dma_segment_t       dm_segments[dmat->nsegments];
264#else
265        bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
266#endif
267        bus_dma_segment_t      *sg;
268        int                     seg;
269        int                     error = 0;
270        vm_offset_t             nextpaddr;
271
272        if (map != NULL)
273		panic("bus_dmamap_load: Invalid map\n");
274
275        vaddr = (vm_offset_t)buf;
276        sg = &dm_segments[0];
277        seg = 1;
278        sg->ds_len = 0;
279        nextpaddr = 0;
280
281        do {
282		bus_size_t      size;
283
284                paddr = pmap_kextract(vaddr);
285                size = PAGE_SIZE - (paddr & PAGE_MASK);
286                if (size > buflen)
287                        size = buflen;
288
289                if (sg->ds_len == 0) {
290                        sg->ds_addr = paddr;
291                        sg->ds_len = size;
292                } else if (paddr == nextpaddr) {
293                        sg->ds_len += size;
294                } else {
295                        /* Go to the next segment */
296                        sg++;
297                        seg++;
298                        if (seg > dmat->nsegments)
299				break;
300                        sg->ds_addr = paddr;
301                        sg->ds_len = size;
302                }
303                vaddr += size;
304                nextpaddr = paddr + size;
305                buflen -= size;
306
307	} while (buflen > 0);
308
309	if (buflen != 0) {
310		printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
311		    (u_long)buflen);
312		error = EFBIG;
313	}
314
315	(*callback)(callback_arg, dm_segments, seg, error);
316
317	return (0);
318}
319
320/*
321 * Utility function to load a linear buffer.  lastaddrp holds state
322 * between invocations (for multiple-buffer loads).  segp contains
323 * the starting segment on entrance, and the ending segment on exit.
324 * first indicates if this is the first invocation of this function.
325 */
326static int
327bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t segs[],
328    void *buf, bus_size_t buflen, struct thread *td,
329    int flags, vm_offset_t *lastaddrp, int *segp,
330    int first)
331{
332	bus_size_t sgsize;
333	bus_addr_t curaddr, lastaddr, baddr, bmask;
334	vm_offset_t vaddr = (vm_offset_t)buf;
335	int seg;
336	pmap_t pmap;
337
338	if (td != NULL)
339		pmap = vmspace_pmap(td->td_proc->p_vmspace);
340	else
341		pmap = NULL;
342
343	lastaddr = *lastaddrp;
344	bmask = ~(dmat->boundary - 1);
345
346	for (seg = *segp; buflen > 0 ; ) {
347		/*
348		 * Get the physical address for this segment.
349		 */
350		if (pmap)
351			curaddr = pmap_extract(pmap, vaddr);
352		else
353			curaddr = pmap_kextract(vaddr);
354
355		/*
356		 * Compute the segment size, and adjust counts.
357		 */
358		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
359		if (buflen < sgsize)
360			sgsize = buflen;
361
362		/*
363		 * Make sure we don't cross any boundaries.
364		 */
365		if (dmat->boundary > 0) {
366			baddr = (curaddr + dmat->boundary) & bmask;
367			if (sgsize > (baddr - curaddr))
368				sgsize = (baddr - curaddr);
369		}
370
371		/*
372		 * Insert chunk into a segment, coalescing with
373		 * the previous segment if possible.
374		 */
375		if (first) {
376			segs[seg].ds_addr = curaddr;
377			segs[seg].ds_len = sgsize;
378			first = 0;
379		} else {
380			if (curaddr == lastaddr &&
381			    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
382			    (dmat->boundary == 0 ||
383			     (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
384				segs[seg].ds_len += sgsize;
385			else {
386				if (++seg >= dmat->nsegments)
387					break;
388				segs[seg].ds_addr = curaddr;
389				segs[seg].ds_len = sgsize;
390			}
391		}
392
393		lastaddr = curaddr + sgsize;
394		vaddr += sgsize;
395		buflen -= sgsize;
396	}
397
398	*segp = seg;
399	*lastaddrp = lastaddr;
400
401	/*
402	 * Did we fit?
403	 */
404	return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
405}
406
407/*
408 * Like bus_dmamap_load(), but for mbufs.
409 */
410int
411bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
412		     bus_dmamap_callback2_t *callback, void *callback_arg,
413		     int flags)
414{
415#ifdef __GNUC__
416	bus_dma_segment_t dm_segments[dmat->nsegments];
417#else
418	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
419#endif
420	int nsegs = 0, error = 0;
421
422	KASSERT(m0->m_flags & M_PKTHDR,
423	    ("bus_dmamap_load_mbuf: no packet header"));
424
425	if (m0->m_pkthdr.len <= dmat->maxsize) {
426		int first = 1;
427		vm_offset_t lastaddr = 0;
428		struct mbuf *m;
429
430		for (m = m0; m != NULL && error == 0; m = m->m_next) {
431			if (m->m_len > 0) {
432				error = bus_dmamap_load_buffer(dmat,
433				    dm_segments, m->m_data, m->m_len, NULL,
434				    flags, &lastaddr, &nsegs, first);
435				first = 0;
436			}
437		}
438	} else {
439		error = EINVAL;
440	}
441
442	if (error) {
443		/*
444		 * force "no valid mappings" on error in callback.
445		 */
446		(*callback)(callback_arg, dm_segments, 0, 0, error);
447	} else {
448		(*callback)(callback_arg, dm_segments, nsegs+1,
449		    m0->m_pkthdr.len, error);
450	}
451	return (error);
452}
453
454/*
455 * Like bus_dmamap_load(), but for uios.
456 */
457int
458bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
459    bus_dmamap_callback2_t *callback, void *callback_arg,
460    int flags)
461{
462	vm_offset_t lastaddr;
463#ifdef __GNUC__
464	bus_dma_segment_t dm_segments[dmat->nsegments];
465#else
466	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
467#endif
468	int nsegs, i, error, first;
469	bus_size_t resid;
470	struct iovec *iov;
471	struct proc *td = NULL;
472
473	resid = uio->uio_resid;
474	iov = uio->uio_iov;
475
476	if (uio->uio_segflg == UIO_USERSPACE) {
477		td = uio->uio_td;
478		KASSERT(td != NULL,
479		    ("bus_dmamap_load_uio: USERSPACE but no proc"));
480	}
481
482	first = 1;
483	nsegs = error = 0;
484	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
485		/*
486		 * Now at the first iovec to load.  Load each iovec
487		 * until we have exhausted the residual count.
488		 */
489		bus_size_t minlen =
490		    resid < iov[i].iov_len ? resid : iov[i].iov_len;
491		caddr_t addr = (caddr_t) iov[i].iov_base;
492
493		if (minlen > 0) {
494			error = bus_dmamap_load_buffer(dmat, dm_segments, addr,
495			    minlen, td, flags, &lastaddr, &nsegs, first);
496
497			first = 0;
498
499			resid -= minlen;
500		}
501	}
502
503	if (error) {
504		/*
505		 * force "no valid mappings" on error in callback.
506		 */
507		(*callback)(callback_arg, dm_segments, 0, 0, error);
508	} else {
509		(*callback)(callback_arg, dm_segments, nsegs+1,
510		    uio->uio_resid, error);
511	}
512
513	return (error);
514}
515
516/*
517 * Release the mapping held by map. A no-op on PowerPC.
518 */
519void
520bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
521{
522
523	return;
524}
525
526void
527bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
528{
529
530	return;
531}
532