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int_bus_dma.c revision 1.1
      1 /*	$NetBSD: int_bus_dma.c,v 1.1 2001/10/27 16:17:51 rearnsha Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1996, 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  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the NetBSD
     22  *	Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 /*
     40  * The integrator board has memory steering hardware that means that
     41  * the normal physical addresses used by the processor cannot be used
     42  * for DMA.  Instead we have to use the "core module alias mapping
     43  * addresses".  We don't use these for normal processor accesses since
     44  * they are much slower than the direct addresses when accessing
     45  * memory on the local board.
     46  */
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/kernel.h>
     51 #include <sys/map.h>
     52 #include <sys/proc.h>
     53 #include <sys/buf.h>
     54 #include <sys/reboot.h>
     55 #include <sys/conf.h>
     56 #include <sys/file.h>
     57 #include <sys/malloc.h>
     58 #include <sys/mbuf.h>
     59 #include <sys/vnode.h>
     60 #include <sys/device.h>
     61 
     62 #include <uvm/uvm_extern.h>
     63 
     64 #define _ARM32_BUS_DMA_PRIVATE
     65 #include <evbarm/integrator/int_bus_dma.h>
     66 
     67 #include <machine/cpu.h>
     68 #include <machine/cpufunc.h>
     69 #include <machine/psl.h>
     70 
     71 static int	integrator_bus_dmamap_load_buffer __P((bus_dma_tag_t,
     72 		    bus_dmamap_t, void *, bus_size_t, struct proc *, int,
     73 		    vm_offset_t *, int *, int));
     74 static int	integrator_bus_dma_inrange __P((bus_dma_segment_t *, int,
     75 		    bus_addr_t));
     76 
     77 /*
     78  * Common function for loading a DMA map with a linear buffer.  May
     79  * be called by bus-specific DMA map load functions.
     80  */
     81 int
     82 integrator_bus_dmamap_load(t, map, buf, buflen, p, flags)
     83 	bus_dma_tag_t t;
     84 	bus_dmamap_t map;
     85 	void *buf;
     86 	bus_size_t buflen;
     87 	struct proc *p;
     88 	int flags;
     89 {
     90 	vm_offset_t lastaddr;
     91 	int seg, error;
     92 
     93 #ifdef DEBUG_DMA
     94 	printf("dmamap_load: t=%p map=%p buf=%p len=%lx p=%p f=%d\n",
     95 	    t, map, buf, buflen, p, flags);
     96 #endif	/* DEBUG_DMA */
     97 
     98 	/*
     99 	 * Make sure that on error condition we return "no valid mappings".
    100 	 */
    101 	map->dm_mapsize = 0;
    102 	map->dm_nsegs = 0;
    103 
    104 	if (buflen > map->_dm_size)
    105 		return (EINVAL);
    106 
    107 	seg = 0;
    108 	error = integrator_bus_dmamap_load_buffer(t, map, buf, buflen, p, flags,
    109 	    &lastaddr, &seg, 1);
    110 	if (error == 0) {
    111 		map->dm_mapsize = buflen;
    112 		map->dm_nsegs = seg + 1;
    113 	}
    114 #ifdef DEBUG_DMA
    115 	printf("dmamap_load: error=%d\n", error);
    116 #endif	/* DEBUG_DMA */
    117 	return (error);
    118 }
    119 
    120 /*
    121  * Like _bus_dmamap_load(), but for mbufs.
    122  */
    123 int
    124 integrator_bus_dmamap_load_mbuf(t, map, m0, flags)
    125 	bus_dma_tag_t t;
    126 	bus_dmamap_t map;
    127 	struct mbuf *m0;
    128 	int flags;
    129 {
    130 	vm_offset_t lastaddr;
    131 	int seg, error, first;
    132 	struct mbuf *m;
    133 
    134 #ifdef DEBUG_DMA
    135 	printf("dmamap_load_mbuf: t=%p map=%p m0=%p f=%d\n",
    136 	    t, map, m0, flags);
    137 #endif	/* DEBUG_DMA */
    138 
    139 	/*
    140 	 * Make sure that on error condition we return "no valid mappings."
    141 	 */
    142 	map->dm_mapsize = 0;
    143 	map->dm_nsegs = 0;
    144 
    145 #ifdef DIAGNOSTIC
    146 	if ((m0->m_flags & M_PKTHDR) == 0)
    147 		panic("integrator_bus_dmamap_load_mbuf: no packet header");
    148 #endif	/* DIAGNOSTIC */
    149 
    150 	if (m0->m_pkthdr.len > map->_dm_size)
    151 		return (EINVAL);
    152 
    153 	first = 1;
    154 	seg = 0;
    155 	error = 0;
    156 	for (m = m0; m != NULL && error == 0; m = m->m_next) {
    157 		error = integrator_bus_dmamap_load_buffer(t, map, m->m_data,
    158 		    m->m_len, NULL, flags, &lastaddr, &seg, first);
    159 		first = 0;
    160 	}
    161 	if (error == 0) {
    162 		map->dm_mapsize = m0->m_pkthdr.len;
    163 		map->dm_nsegs = seg + 1;
    164 	}
    165 #ifdef DEBUG_DMA
    166 	printf("dmamap_load_mbuf: error=%d\n", error);
    167 #endif	/* DEBUG_DMA */
    168 	return (error);
    169 }
    170 
    171 /*
    172  * Like _bus_dmamap_load(), but for uios.
    173  */
    174 int
    175 integrator_bus_dmamap_load_uio(t, map, uio, flags)
    176 	bus_dma_tag_t t;
    177 	bus_dmamap_t map;
    178 	struct uio *uio;
    179 	int flags;
    180 {
    181 	vm_offset_t lastaddr;
    182 	int seg, i, error, first;
    183 	bus_size_t minlen, resid;
    184 	struct proc *p = NULL;
    185 	struct iovec *iov;
    186 	caddr_t addr;
    187 
    188 	/*
    189 	 * Make sure that on error condition we return "no valid mappings."
    190 	 */
    191 	map->dm_mapsize = 0;
    192 	map->dm_nsegs = 0;
    193 
    194 	resid = uio->uio_resid;
    195 	iov = uio->uio_iov;
    196 
    197 	if (uio->uio_segflg == UIO_USERSPACE) {
    198 		p = uio->uio_procp;
    199 #ifdef DIAGNOSTIC
    200 		if (p == NULL)
    201 			panic("integrator_bus_dmamap_load_uio: USERSPACE but no proc");
    202 #endif
    203 	}
    204 
    205 	first = 1;
    206 	seg = 0;
    207 	error = 0;
    208 	for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
    209 		/*
    210 		 * Now at the first iovec to load.  Load each iovec
    211 		 * until we have exhausted the residual count.
    212 		 */
    213 		minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
    214 		addr = (caddr_t)iov[i].iov_base;
    215 
    216 		error = integrator_bus_dmamap_load_buffer(t, map, addr, minlen,
    217 		    p, flags, &lastaddr, &seg, first);
    218 		first = 0;
    219 
    220 		resid -= minlen;
    221 	}
    222 	if (error == 0) {
    223 		map->dm_mapsize = uio->uio_resid;
    224 		map->dm_nsegs = seg + 1;
    225 	}
    226 	return (error);
    227 }
    228 
    229 /*
    230  * Common function for DMA-safe memory allocation.  May be called
    231  * by bus-specific DMA memory allocation functions.
    232  */
    233 
    234 extern vm_offset_t physical_start;
    235 extern vm_offset_t physical_freestart;
    236 extern vm_offset_t physical_freeend;
    237 extern vm_offset_t physical_end;
    238 
    239 int
    240 integrator_bus_dmamem_alloc(t, size, alignment, boundary, segs, nsegs, rsegs, flags)
    241 	bus_dma_tag_t t;
    242 	bus_size_t size, alignment, boundary;
    243 	bus_dma_segment_t *segs;
    244 	int nsegs;
    245 	int *rsegs;
    246 	int flags;
    247 {
    248 	int error;
    249 #ifdef DEBUG_DMA
    250 	printf("dmamem_alloc t=%p size=%lx align=%lx boundary=%lx segs=%p nsegs=%x rsegs=%p flags=%x\n",
    251 	    t, size, alignment, boundary, segs, nsegs, rsegs, flags);
    252 #endif	/* DEBUG_DMA */
    253 	error =  (integrator_bus_dmamem_alloc_range(t, size, alignment, boundary,
    254 	    segs, nsegs, rsegs, flags, trunc_page(physical_start), trunc_page(physical_end)));
    255 #ifdef DEBUG_DMA
    256 	printf("dmamem_alloc: =%d\n", error);
    257 #endif	/* DEBUG_DMA */
    258 	return(error);
    259 }
    260 
    261 /*
    262  * Common function for freeing DMA-safe memory.  May be called by
    263  * bus-specific DMA memory free functions.
    264  */
    265 void
    266 integrator_bus_dmamem_free(t, segs, nsegs)
    267 	bus_dma_tag_t t;
    268 	bus_dma_segment_t *segs;
    269 	int nsegs;
    270 {
    271 	struct vm_page *m;
    272 	bus_addr_t addr;
    273 	struct pglist mlist;
    274 	int curseg;
    275 
    276 #ifdef DEBUG_DMA
    277 	printf("dmamem_free: t=%p segs=%p nsegs=%x\n", t, segs, nsegs);
    278 #endif	/* DEBUG_DMA */
    279 
    280 	/*
    281 	 * Build a list of pages to free back to the VM system.
    282 	 */
    283 	TAILQ_INIT(&mlist);
    284 	for (curseg = 0; curseg < nsegs; curseg++) {
    285 		for (addr = segs[curseg].ds_addr;
    286 		    addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
    287 		    addr += PAGE_SIZE) {
    288 			m = PHYS_TO_VM_PAGE(CM_ALIAS_TO_LOCAL(addr));
    289 			TAILQ_INSERT_TAIL(&mlist, m, pageq);
    290 		}
    291 	}
    292 	uvm_pglistfree(&mlist);
    293 }
    294 
    295 /*
    296  * Common function for mapping DMA-safe memory.  May be called by
    297  * bus-specific DMA memory map functions.
    298  */
    299 int
    300 integrator_bus_dmamem_map(t, segs, nsegs, size, kvap, flags)
    301 	bus_dma_tag_t t;
    302 	bus_dma_segment_t *segs;
    303 	int nsegs;
    304 	size_t size;
    305 	caddr_t *kvap;
    306 	int flags;
    307 {
    308 	vm_offset_t va;
    309 	bus_addr_t addr;
    310 	int curseg;
    311 	pt_entry_t *ptep/*, pte*/;
    312 
    313 #ifdef DEBUG_DMA
    314 	printf("dmamem_map: t=%p segs=%p nsegs=%x size=%lx flags=%x\n", t,
    315 	    segs, nsegs, (unsigned long)size, flags);
    316 #endif	/* DEBUG_DMA */
    317 
    318 	size = round_page(size);
    319 	va = uvm_km_valloc(kernel_map, size);
    320 
    321 	if (va == 0)
    322 		return (ENOMEM);
    323 
    324 	*kvap = (caddr_t)va;
    325 
    326 	for (curseg = 0; curseg < nsegs; curseg++) {
    327 		for (addr = segs[curseg].ds_addr;
    328 		    addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
    329 		    addr += NBPG, va += NBPG, size -= NBPG) {
    330 #ifdef DEBUG_DMA
    331 			printf("wiring p%lx to v%lx", CM_ALIAS_TO_LOCAL(addr),
    332 			    va);
    333 #endif	/* DEBUG_DMA */
    334 			if (size == 0)
    335 				panic("integrator_bus_dmamem_map: size botch");
    336 			pmap_enter(pmap_kernel(), va, CM_ALIAS_TO_LOCAL(addr),
    337 			    VM_PROT_READ | VM_PROT_WRITE,
    338 			    VM_PROT_READ | VM_PROT_WRITE | PMAP_WIRED);
    339 			/*
    340 			 * If the memory must remain coherent with the
    341 			 * cache then we must make the memory uncacheable
    342 			 * in order to maintain virtual cache coherency.
    343 			 * We must also guarentee the cache does not already
    344 			 * contain the virtal addresses we are making
    345 			 * uncacheable.
    346 			 */
    347 			if (flags & BUS_DMA_COHERENT) {
    348 				cpu_cache_purgeD_rng(va, NBPG);
    349 				cpu_drain_writebuf();
    350 				ptep = vtopte(va);
    351 				*ptep = ((*ptep) & (~PT_C | PT_B));
    352 				tlb_flush();
    353 			}
    354 #ifdef DEBUG_DMA
    355 			ptep = vtopte(va);
    356 			printf(" pte=v%p *pte=%x\n", ptep, *ptep);
    357 #endif	/* DEBUG_DMA */
    358 		}
    359 	}
    360 	pmap_update(pmap_kernel());
    361 #ifdef DEBUG_DMA
    362 	printf("dmamem_map: =%p\n", *kvap);
    363 #endif	/* DEBUG_DMA */
    364 	return (0);
    365 }
    366 
    367 /*
    368  * Common functin for mmap(2)'ing DMA-safe memory.  May be called by
    369  * bus-specific DMA mmap(2)'ing functions.
    370  */
    371 paddr_t
    372 integrator_bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
    373 	bus_dma_tag_t t;
    374 	bus_dma_segment_t *segs;
    375 	int nsegs;
    376 	off_t off;
    377 	int prot, flags;
    378 {
    379 	int i;
    380 
    381 	for (i = 0; i < nsegs; i++) {
    382 #ifdef DIAGNOSTIC
    383 		if (off & PGOFSET)
    384 			panic("integrator_bus_dmamem_mmap: offset unaligned");
    385 		if (segs[i].ds_addr & PGOFSET)
    386 			panic("integrator_bus_dmamem_mmap: segment unaligned");
    387 		if (segs[i].ds_len & PGOFSET)
    388 			panic("integrator_bus_dmamem_mmap: segment size not multiple"
    389 			    " of page size");
    390 #endif	/* DIAGNOSTIC */
    391 		if (off >= segs[i].ds_len) {
    392 			off -= segs[i].ds_len;
    393 			continue;
    394 		}
    395 
    396 		return arm_byte_to_page((u_long)CM_ALIAS_TO_LOCAL(segs[i].ds_addr) + off);
    397 	}
    398 
    399 	/* Page not found. */
    400 	return -1;
    401 }
    402 
    403 /**********************************************************************
    404  * DMA utility functions
    405  **********************************************************************/
    406 
    407 /*
    408  * Utility function to load a linear buffer.  lastaddrp holds state
    409  * between invocations (for multiple-buffer loads).  segp contains
    410  * the starting segment on entrace, and the ending segment on exit.
    411  * first indicates if this is the first invocation of this function.
    412  */
    413 static int
    414 integrator_bus_dmamap_load_buffer(t, map, buf, buflen, p, flags, lastaddrp,
    415     segp, first)
    416 	bus_dma_tag_t t;
    417 	bus_dmamap_t map;
    418 	void *buf;
    419 	bus_size_t buflen;
    420 	struct proc *p;
    421 	int flags;
    422 	vm_offset_t *lastaddrp;
    423 	int *segp;
    424 	int first;
    425 {
    426 	bus_size_t sgsize;
    427 	bus_addr_t curaddr, lastaddr, baddr, bmask;
    428 	vm_offset_t vaddr = (vm_offset_t)buf;
    429 	int seg;
    430 	pmap_t pmap;
    431 
    432 #ifdef DEBUG_DMA
    433 	printf("integrator_bus_dmamem_load_buffer(buf=%p, len=%lx, flags=%d, 1st=%d)\n",
    434 	    buf, buflen, flags, first);
    435 #endif	/* DEBUG_DMA */
    436 
    437 	if (p != NULL)
    438 		pmap = p->p_vmspace->vm_map.pmap;
    439 	else
    440 		pmap = pmap_kernel();
    441 
    442 	lastaddr = *lastaddrp;
    443 	bmask  = ~(map->_dm_boundary - 1);
    444 
    445 	for (seg = *segp; buflen > 0; ) {
    446 		/*
    447 		 * Get the physical address for this segment.
    448 		 */
    449 		(void) pmap_extract(pmap, (vaddr_t)vaddr, &curaddr);
    450 
    451 		/*
    452 		 * Make sure we're in an allowed DMA range.
    453 		 */
    454 		if (t->_ranges != NULL &&
    455 		    integrator_bus_dma_inrange(t->_ranges, t->_nranges, curaddr) == 0)
    456 			return (EINVAL);
    457 
    458 		/*
    459 		 * Compute the segment size, and adjust counts.
    460 		 */
    461 		sgsize = NBPG - ((u_long)vaddr & PGOFSET);
    462 		if (buflen < sgsize)
    463 			sgsize = buflen;
    464 
    465 		/*
    466 		 * Make sure we don't cross any boundaries.
    467 		 */
    468 		if (map->_dm_boundary > 0) {
    469 			baddr = (curaddr + map->_dm_boundary) & bmask;
    470 			if (sgsize > (baddr - curaddr))
    471 				sgsize = (baddr - curaddr);
    472 		}
    473 
    474 		/*
    475 		 * Insert chunk into a segment, coalescing with
    476 		 * previous segment if possible.
    477 		 */
    478 		if (first) {
    479 			map->dm_segs[seg].ds_addr = LOCAL_TO_CM_ALIAS(curaddr);
    480 			map->dm_segs[seg].ds_len = sgsize;
    481 			map->dm_segs[seg]._ds_vaddr = vaddr;
    482 			first = 0;
    483 		} else {
    484 			if (curaddr == lastaddr &&
    485 			    (map->dm_segs[seg].ds_len + sgsize) <=
    486 			     map->_dm_maxsegsz &&
    487 			    (map->_dm_boundary == 0 ||
    488 			     (map->dm_segs[seg].ds_addr & bmask) ==
    489 			     (LOCAL_TO_CM_ALIAS(curaddr) & bmask)))
    490 				map->dm_segs[seg].ds_len += sgsize;
    491 			else {
    492 				if (++seg >= map->_dm_segcnt)
    493 					break;
    494 				map->dm_segs[seg].ds_addr = LOCAL_TO_CM_ALIAS(curaddr);
    495 				map->dm_segs[seg].ds_len = sgsize;
    496 				map->dm_segs[seg]._ds_vaddr = vaddr;
    497 			}
    498 		}
    499 
    500 		lastaddr = curaddr + sgsize;
    501 		vaddr += sgsize;
    502 		buflen -= sgsize;
    503 	}
    504 
    505 	*segp = seg;
    506 	*lastaddrp = lastaddr;
    507 
    508 	/*
    509 	 * Did we fit?
    510 	 */
    511 	if (buflen != 0)
    512 		return (EFBIG);		/* XXX better return value here? */
    513 	return (0);
    514 }
    515 
    516 /*
    517  * Check to see if the specified page is in an allowed DMA range.
    518  */
    519 static int
    520 integrator_bus_dma_inrange(ranges, nranges, curaddr)
    521 	bus_dma_segment_t *ranges;
    522 	int nranges;
    523 	bus_addr_t curaddr;
    524 {
    525 	bus_dma_segment_t *ds;
    526 	int i;
    527 
    528 	for (i = 0, ds = ranges; i < nranges; i++, ds++) {
    529 		if (curaddr >= CM_ALIAS_TO_LOCAL(ds->ds_addr) &&
    530 		    round_page(curaddr) <= (CM_ALIAS_TO_LOCAL(ds->ds_addr) + ds->ds_len))
    531 			return (1);
    532 	}
    533 
    534 	return (0);
    535 }
    536 
    537 /*
    538  * Allocate physical memory from the given physical address range.
    539  * Called by DMA-safe memory allocation methods.
    540  */
    541 int
    542 integrator_bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs,
    543     flags, low, high)
    544 	bus_dma_tag_t t;
    545 	bus_size_t size, alignment, boundary;
    546 	bus_dma_segment_t *segs;
    547 	int nsegs;
    548 	int *rsegs;
    549 	int flags;
    550 	vm_offset_t low;
    551 	vm_offset_t high;
    552 {
    553 	vm_offset_t curaddr, lastaddr;
    554 	struct vm_page *m;
    555 	struct pglist mlist;
    556 	int curseg, error;
    557 
    558 #ifdef DEBUG_DMA
    559 	printf("alloc_range: t=%p size=%lx align=%lx boundary=%lx segs=%p nsegs=%x rsegs=%p flags=%x lo=%lx hi=%lx\n",
    560 	    t, size, alignment, boundary, segs, nsegs, rsegs, flags, low, high);
    561 #endif	/* DEBUG_DMA */
    562 
    563 	/* Always round the size. */
    564 	size = round_page(size);
    565 
    566 	/*
    567 	 * Allocate pages from the VM system.
    568 	 */
    569 	TAILQ_INIT(&mlist);
    570 	error = uvm_pglistalloc(size, low, high, alignment, boundary,
    571 	    &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
    572 	if (error)
    573 		return (error);
    574 
    575 	/*
    576 	 * Compute the location, size, and number of segments actually
    577 	 * returned by the VM code.
    578 	 */
    579 	m = mlist.tqh_first;
    580 	curseg = 0;
    581 	lastaddr = VM_PAGE_TO_PHYS(m);
    582 	segs[curseg].ds_addr = LOCAL_TO_CM_ALIAS(lastaddr);
    583 	segs[curseg].ds_len = PAGE_SIZE;
    584 #ifdef DEBUG_DMA
    585 		printf("alloc: page %lx\n", lastaddr);
    586 #endif	/* DEBUG_DMA */
    587 	m = m->pageq.tqe_next;
    588 
    589 	for (; m != NULL; m = m->pageq.tqe_next) {
    590 		curaddr = VM_PAGE_TO_PHYS(m);
    591 #ifdef DIAGNOSTIC
    592 		if (curaddr < low || curaddr >= high) {
    593 			printf("uvm_pglistalloc returned non-sensical"
    594 			    " address 0x%lx\n", curaddr);
    595 			panic("integrator_bus_dmamem_alloc_range");
    596 		}
    597 #endif	/* DIAGNOSTIC */
    598 #ifdef DEBUG_DMA
    599 		printf("alloc: page %lx\n", curaddr);
    600 #endif	/* DEBUG_DMA */
    601 		if (curaddr == (lastaddr + PAGE_SIZE))
    602 			segs[curseg].ds_len += PAGE_SIZE;
    603 		else {
    604 			curseg++;
    605 			segs[curseg].ds_addr = LOCAL_TO_CM_ALIAS(curaddr);
    606 			segs[curseg].ds_len = PAGE_SIZE;
    607 		}
    608 		lastaddr = curaddr;
    609 	}
    610 
    611 	*rsegs = curseg + 1;
    612 
    613 	return (0);
    614 }
    615