1 /* $NetBSD: bus_dma.c,v 1.74 2022/07/26 20:08:54 andvar Exp $ */
2
3 /*-
4 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
34
35 __KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.74 2022/07/26 20:08:54 andvar Exp $");
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/device.h>
41 #include <sys/kmem.h>
42 #include <sys/proc.h>
43 #include <sys/mbuf.h>
44
45 #include <uvm/uvm_extern.h>
46
47 #define _ALPHA_BUS_DMA_PRIVATE
48 #include <sys/bus.h>
49 #include <machine/intr.h>
50
51 #include <dev/bus_dma/bus_dmamem_common.h>
52
53 static int _bus_dmamap_load_buffer_direct(bus_dma_tag_t,
54 bus_dmamap_t, void *, bus_size_t, struct vmspace *, int,
55 paddr_t *, int *, int);
56
57 extern paddr_t avail_start, avail_end; /* from pmap.c */
58
59 #define DMA_COUNT_DECL(cnt) _DMA_COUNT_DECL(dma_direct, cnt)
60 #define DMA_COUNT(cnt) _DMA_COUNT(dma_direct, cnt)
61
62 static size_t
_bus_dmamap_mapsize(int const nsegments)63 _bus_dmamap_mapsize(int const nsegments)
64 {
65 KASSERT(nsegments > 0);
66 return sizeof(struct alpha_bus_dmamap) +
67 (sizeof(bus_dma_segment_t) * (nsegments - 1));
68 }
69
70 /*
71 * Common function for DMA map creation. May be called by bus-specific
72 * DMA map creation functions.
73 */
74 int
_bus_dmamap_create(bus_dma_tag_t t,bus_size_t size,int nsegments,bus_size_t maxsegsz,bus_size_t boundary,int flags,bus_dmamap_t * dmamp)75 _bus_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments,
76 bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp)
77 {
78 struct alpha_bus_dmamap *map;
79 void *mapstore;
80
81 /*
82 * Allocate and initialize the DMA map. The end of the map
83 * is a variable-sized array of segments, so we allocate enough
84 * room for them in one shot.
85 *
86 * Note we don't preserve the WAITOK or NOWAIT flags. Preservation
87 * of ALLOCNOW notifies others that we've reserved these resources,
88 * and they are not to be freed.
89 *
90 * The bus_dmamap_t includes one bus_dma_segment_t, hence
91 * the (nsegments - 1).
92 */
93 if ((mapstore = kmem_zalloc(_bus_dmamap_mapsize(nsegments),
94 (flags & BUS_DMA_NOWAIT) ? KM_NOSLEEP : KM_SLEEP)) == NULL)
95 return (ENOMEM);
96
97 map = (struct alpha_bus_dmamap *)mapstore;
98 map->_dm_size = size;
99 map->_dm_segcnt = nsegments;
100 map->_dm_maxmaxsegsz = maxsegsz;
101 if (t->_boundary != 0 && t->_boundary < boundary)
102 map->_dm_boundary = t->_boundary;
103 else
104 map->_dm_boundary = boundary;
105 map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
106 map->dm_maxsegsz = maxsegsz;
107 map->dm_mapsize = 0; /* no valid mappings */
108 map->dm_nsegs = 0;
109 map->_dm_window = NULL;
110
111 *dmamp = map;
112 return (0);
113 }
114
115 /*
116 * Common function for DMA map destruction. May be called by bus-specific
117 * DMA map destruction functions.
118 */
119 void
_bus_dmamap_destroy(bus_dma_tag_t t,bus_dmamap_t map)120 _bus_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map)
121 {
122
123 kmem_free(map, _bus_dmamap_mapsize(map->_dm_segcnt));
124 }
125
126 /*
127 * Utility function to load a linear buffer. lastaddrp holds state
128 * between invocations (for multiple-buffer loads). segp contains
129 * the starting segment on entrance, and the ending segment on exit.
130 * first indicates if this is the first invocation of this function.
131 */
132 static int
_bus_dmamap_load_buffer_direct(bus_dma_tag_t t,bus_dmamap_t map,void * buf,size_t buflen,struct vmspace * vm,int flags,paddr_t * lastaddrp,int * segp,int first)133 _bus_dmamap_load_buffer_direct(bus_dma_tag_t t, bus_dmamap_t map,
134 void *buf, size_t buflen, struct vmspace *vm, int flags, paddr_t *lastaddrp,
135 int *segp, int first)
136 {
137 bus_size_t sgsize;
138 bus_addr_t curaddr, lastaddr, baddr, bmask;
139 vaddr_t vaddr = (vaddr_t)buf;
140 int seg;
141 bool address_is_valid __diagused;
142
143 lastaddr = *lastaddrp;
144 bmask = ~(map->_dm_boundary - 1);
145
146 for (seg = *segp; buflen > 0 ; ) {
147 /*
148 * Get the physical address for this segment.
149 */
150 address_is_valid =
151 pmap_extract(vm->vm_map.pmap, vaddr, &curaddr);
152 KASSERT(address_is_valid);
153
154 /*
155 * If we're beyond the current DMA window, indicate
156 * that and try to fall back into SGMAPs.
157 */
158 if (t->_wsize != 0 && curaddr >= t->_wsize)
159 return (EINVAL);
160
161 curaddr |= t->_wbase;
162
163 /*
164 * Compute the segment size, and adjust counts.
165 */
166 sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET);
167 if (buflen < sgsize)
168 sgsize = buflen;
169 if (map->dm_maxsegsz < sgsize)
170 sgsize = map->dm_maxsegsz;
171
172 /*
173 * Make sure we don't cross any boundaries.
174 */
175 if (map->_dm_boundary > 0) {
176 baddr = (curaddr + map->_dm_boundary) & bmask;
177 if (sgsize > (baddr - curaddr))
178 sgsize = (baddr - curaddr);
179 }
180
181 /*
182 * Insert chunk into a segment, coalescing with
183 * the previous segment if possible.
184 */
185 if (first) {
186 map->dm_segs[seg].ds_addr = curaddr;
187 map->dm_segs[seg].ds_len = sgsize;
188 first = 0;
189 } else {
190 if ((map->_dm_flags & DMAMAP_NO_COALESCE) == 0 &&
191 curaddr == lastaddr &&
192 (map->dm_segs[seg].ds_len + sgsize) <=
193 map->dm_maxsegsz &&
194 (map->_dm_boundary == 0 ||
195 (map->dm_segs[seg].ds_addr & bmask) ==
196 (curaddr & bmask)))
197 map->dm_segs[seg].ds_len += sgsize;
198 else {
199 if (++seg >= map->_dm_segcnt)
200 break;
201 map->dm_segs[seg].ds_addr = curaddr;
202 map->dm_segs[seg].ds_len = sgsize;
203 }
204 }
205
206 lastaddr = curaddr + sgsize;
207 vaddr += sgsize;
208 buflen -= sgsize;
209 }
210
211 *segp = seg;
212 *lastaddrp = lastaddr;
213
214 /*
215 * Did we fit?
216 */
217 if (buflen != 0) {
218 /*
219 * If there is a chained window, we will automatically
220 * fall back to it.
221 */
222 return (EFBIG); /* XXX better return value here? */
223 }
224
225 return (0);
226 }
227
228 DMA_COUNT_DECL(load);
229 DMA_COUNT_DECL(load_next_window);
230
231 /*
232 * Common function for loading a direct-mapped DMA map with a linear
233 * buffer. Called by bus-specific DMA map load functions with the
234 * OR value appropriate for indicating "direct-mapped" for that
235 * chipset.
236 */
237 int
_bus_dmamap_load_direct(bus_dma_tag_t t,bus_dmamap_t map,void * buf,bus_size_t buflen,struct proc * p,int flags)238 _bus_dmamap_load_direct(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
239 bus_size_t buflen, struct proc *p, int flags)
240 {
241 paddr_t lastaddr;
242 int seg, error;
243 struct vmspace *vm;
244
245 /*
246 * Make sure that on error condition we return "no valid mappings".
247 */
248 map->dm_mapsize = 0;
249 map->dm_nsegs = 0;
250 KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
251 KASSERT((map->_dm_flags & (BUS_DMA_READ|BUS_DMA_WRITE)) == 0);
252
253 if (buflen > map->_dm_size)
254 return (EINVAL);
255
256 if (p != NULL) {
257 vm = p->p_vmspace;
258 } else {
259 vm = vmspace_kernel();
260 }
261 seg = 0;
262 error = _bus_dmamap_load_buffer_direct(t, map, buf, buflen,
263 vm, flags, &lastaddr, &seg, 1);
264 if (error == 0) {
265 DMA_COUNT(load);
266 map->dm_mapsize = buflen;
267 map->dm_nsegs = seg + 1;
268 map->_dm_window = t;
269 } else if (t->_next_window != NULL) {
270 /*
271 * Give the next window a chance.
272 */
273 DMA_COUNT(load_next_window);
274 error = bus_dmamap_load(t->_next_window, map, buf, buflen,
275 p, flags);
276 }
277 return (error);
278 }
279
280 DMA_COUNT_DECL(load_mbuf);
281 DMA_COUNT_DECL(load_mbuf_next_window);
282
283 /*
284 * Like _bus_dmamap_load_direct(), but for mbufs.
285 */
286 int
_bus_dmamap_load_mbuf_direct(bus_dma_tag_t t,bus_dmamap_t map,struct mbuf * m0,int flags)287 _bus_dmamap_load_mbuf_direct(bus_dma_tag_t t, bus_dmamap_t map,
288 struct mbuf *m0, int flags)
289 {
290 paddr_t lastaddr;
291 int seg, error, first;
292 struct mbuf *m;
293
294 /*
295 * Make sure that on error condition we return "no valid mappings."
296 */
297 map->dm_mapsize = 0;
298 map->dm_nsegs = 0;
299 KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
300 KASSERT((map->_dm_flags & (BUS_DMA_READ|BUS_DMA_WRITE)) == 0);
301
302 #ifdef DIAGNOSTIC
303 if ((m0->m_flags & M_PKTHDR) == 0)
304 panic("_bus_dmamap_load_mbuf_direct: no packet header");
305 #endif
306
307 if (m0->m_pkthdr.len > map->_dm_size)
308 return (EINVAL);
309
310 first = 1;
311 seg = 0;
312 error = 0;
313 for (m = m0; m != NULL && error == 0; m = m->m_next) {
314 if (m->m_len == 0)
315 continue;
316 /* XXX Could be better about coalescing. */
317 /* XXX Doesn't check boundaries. */
318 switch (m->m_flags & (M_EXT|M_EXT_CLUSTER)) {
319 case M_EXT|M_EXT_CLUSTER:
320 /* XXX KDASSERT */
321 KASSERT(m->m_ext.ext_paddr != M_PADDR_INVALID);
322 lastaddr = m->m_ext.ext_paddr +
323 (m->m_data - m->m_ext.ext_buf);
324 have_addr:
325 if (first == 0 &&
326 ++seg >= map->_dm_segcnt) {
327 error = EFBIG;
328 break;
329 }
330
331 /*
332 * If we're beyond the current DMA window, indicate
333 * that and try to fall back into SGMAPs.
334 */
335 if (t->_wsize != 0 && lastaddr >= t->_wsize) {
336 error = EINVAL;
337 break;
338 }
339 lastaddr |= t->_wbase;
340
341 map->dm_segs[seg].ds_addr = lastaddr;
342 map->dm_segs[seg].ds_len = m->m_len;
343 lastaddr += m->m_len;
344 break;
345
346 case 0:
347 lastaddr = m->m_paddr + M_BUFOFFSET(m) +
348 (m->m_data - M_BUFADDR(m));
349 goto have_addr;
350
351 default:
352 error = _bus_dmamap_load_buffer_direct(t, map,
353 m->m_data, m->m_len, vmspace_kernel(), flags,
354 &lastaddr, &seg, first);
355 }
356 first = 0;
357 }
358 if (error == 0) {
359 DMA_COUNT(load_mbuf);
360 map->dm_mapsize = m0->m_pkthdr.len;
361 map->dm_nsegs = seg + 1;
362 map->_dm_window = t;
363 } else if (t->_next_window != NULL) {
364 /*
365 * Give the next window a chance.
366 */
367 DMA_COUNT(load_mbuf_next_window);
368 error = bus_dmamap_load_mbuf(t->_next_window, map, m0, flags);
369 }
370 return (error);
371 }
372
373 DMA_COUNT_DECL(load_uio);
374 DMA_COUNT_DECL(load_uio_next_window);
375
376 /*
377 * Like _bus_dmamap_load_direct(), but for uios.
378 */
379 int
_bus_dmamap_load_uio_direct(bus_dma_tag_t t,bus_dmamap_t map,struct uio * uio,int flags)380 _bus_dmamap_load_uio_direct(bus_dma_tag_t t, bus_dmamap_t map,
381 struct uio *uio, int flags)
382 {
383 paddr_t lastaddr;
384 int seg, i, error, first;
385 bus_size_t minlen, resid;
386 struct vmspace *vm;
387 struct iovec *iov;
388 void *addr;
389
390 /*
391 * Make sure that on error condition we return "no valid mappings."
392 */
393 map->dm_mapsize = 0;
394 map->dm_nsegs = 0;
395 KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
396 KASSERT((map->_dm_flags & (BUS_DMA_READ|BUS_DMA_WRITE)) == 0);
397
398 resid = uio->uio_resid;
399 iov = uio->uio_iov;
400
401 vm = uio->uio_vmspace;
402
403 first = 1;
404 seg = 0;
405 error = 0;
406 for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
407 /*
408 * Now at the first iovec to load. Load each iovec
409 * until we have exhausted the residual count.
410 */
411 minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
412 addr = (void *)iov[i].iov_base;
413
414 error = _bus_dmamap_load_buffer_direct(t, map,
415 addr, minlen, vm, flags, &lastaddr, &seg, first);
416 first = 0;
417
418 resid -= minlen;
419 }
420 if (error == 0) {
421 DMA_COUNT(load_uio);
422 map->dm_mapsize = uio->uio_resid;
423 map->dm_nsegs = seg + 1;
424 map->_dm_window = t;
425 } else if (t->_next_window != NULL) {
426 /*
427 * Give the next window a chance.
428 */
429 DMA_COUNT(load_uio_next_window);
430 error = bus_dmamap_load_uio(t->_next_window, map, uio, flags);
431 }
432 return (error);
433 }
434
435 /*
436 * Like _bus_dmamap_load_direct(), but for raw memory.
437 */
438 int
_bus_dmamap_load_raw_direct(bus_dma_tag_t t,bus_dmamap_t map,bus_dma_segment_t * segs,int nsegs,bus_size_t size,int flags)439 _bus_dmamap_load_raw_direct(bus_dma_tag_t t, bus_dmamap_t map,
440 bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags)
441 {
442
443 panic("_bus_dmamap_load_raw_direct: not implemented");
444 }
445
446 /*
447 * Common function for unloading a DMA map. May be called by
448 * chipset-specific DMA map unload functions.
449 */
450 void
_bus_dmamap_unload_common(bus_dma_tag_t t,bus_dmamap_t map)451 _bus_dmamap_unload_common(bus_dma_tag_t t, bus_dmamap_t map)
452 {
453
454 /*
455 * No resources to free; just mark the mappings as
456 * invalid.
457 */
458 map->dm_maxsegsz = map->_dm_maxmaxsegsz;
459 map->dm_mapsize = 0;
460 map->dm_nsegs = 0;
461 map->_dm_window = NULL;
462 map->_dm_flags &= ~(BUS_DMA_READ|BUS_DMA_WRITE);
463 }
464
465 DMA_COUNT_DECL(unload);
466
467 void
_bus_dmamap_unload(bus_dma_tag_t t,bus_dmamap_t map)468 _bus_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
469 {
470 KASSERT(map->_dm_window == t);
471 DMA_COUNT(unload);
472 _bus_dmamap_unload_common(t, map);
473 }
474
475 /*
476 * Common function for DMA map synchronization. May be called
477 * by chipset-specific DMA map synchronization functions.
478 */
479 void
_bus_dmamap_sync(bus_dma_tag_t t,bus_dmamap_t map,bus_addr_t offset,bus_size_t len,int ops)480 _bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
481 bus_size_t len, int ops)
482 {
483
484 alpha_mb();
485 }
486
487 /*
488 * Common function for DMA-safe memory allocation. May be called
489 * by bus-specific DMA memory allocation functions.
490 */
491 int
_bus_dmamem_alloc(bus_dma_tag_t t,bus_size_t size,bus_size_t alignment,bus_size_t boundary,bus_dma_segment_t * segs,int nsegs,int * rsegs,int flags)492 _bus_dmamem_alloc(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment,
493 bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs,
494 int flags)
495 {
496
497 return (_bus_dmamem_alloc_range(t, size, alignment, boundary,
498 segs, nsegs, rsegs, flags, 0, trunc_page(avail_end)));
499 }
500
501 /*
502 * Allocate physical memory from the given physical address range.
503 * Called by DMA-safe memory allocation methods.
504 */
505 int
_bus_dmamem_alloc_range(bus_dma_tag_t t,bus_size_t size,bus_size_t alignment,bus_size_t boundary,bus_dma_segment_t * segs,int nsegs,int * rsegs,int flags,paddr_t low,paddr_t high)506 _bus_dmamem_alloc_range(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment,
507 bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs,
508 int flags, paddr_t low, paddr_t high)
509 {
510
511 return (_bus_dmamem_alloc_range_common(t, size, alignment, boundary,
512 segs, nsegs, rsegs, flags,
513 low, high));
514 }
515
516 /*
517 * Common function for freeing DMA-safe memory. May be called by
518 * bus-specific DMA memory free functions.
519 */
520 void
_bus_dmamem_free(bus_dma_tag_t t,bus_dma_segment_t * segs,int nsegs)521 _bus_dmamem_free(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs)
522 {
523
524 _bus_dmamem_free_common(t, segs, nsegs);
525 }
526
527 /*
528 * Common function for mapping DMA-safe memory. May be called by
529 * bus-specific DMA memory map functions.
530 */
531 int
_bus_dmamem_map(bus_dma_tag_t t,bus_dma_segment_t * segs,int nsegs,size_t size,void ** kvap,int flags)532 _bus_dmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
533 size_t size, void **kvap, int flags)
534 {
535
536 /*
537 * If we're only mapping 1 segment, use K0SEG, to avoid
538 * TLB thrashing.
539 */
540 if (nsegs == 1) {
541 *kvap = (void *)ALPHA_PHYS_TO_K0SEG(segs[0].ds_addr);
542 return (0);
543 }
544
545 return (_bus_dmamem_map_common(t, segs, nsegs, size, kvap, flags, 0));
546 }
547
548 /*
549 * Common function for unmapping DMA-safe memory. May be called by
550 * bus-specific DMA memory unmapping functions.
551 */
552 void
_bus_dmamem_unmap(bus_dma_tag_t t,void * kva,size_t size)553 _bus_dmamem_unmap(bus_dma_tag_t t, void *kva, size_t size)
554 {
555
556 /*
557 * Nothing to do if we mapped it with K0SEG.
558 */
559 if (kva >= (void *)ALPHA_K0SEG_BASE &&
560 kva <= (void *)ALPHA_K0SEG_END)
561 return;
562
563 _bus_dmamem_unmap_common(t, kva, size);
564 }
565
566 /*
567 * Common function for mmap(2)'ing DMA-safe memory. May be called by
568 * bus-specific DMA mmap(2)'ing functions.
569 */
570 paddr_t
_bus_dmamem_mmap(bus_dma_tag_t t,bus_dma_segment_t * segs,int nsegs,off_t off,int prot,int flags)571 _bus_dmamem_mmap(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
572 off_t off, int prot, int flags)
573 {
574 bus_addr_t rv;
575
576 rv = _bus_dmamem_mmap_common(t, segs, nsegs, off, prot, flags);
577 if (rv == (bus_addr_t)-1)
578 return (-1);
579
580 return (alpha_btop((char *)rv));
581 }
582