NetBSD-5.0.2/sys/arch/powerpc/powerpc/bus_dma.c
/* $NetBSD: bus_dma.c,v 1.33 2008/06/04 12:41:41 ad Exp $ */
/*-
* Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.33 2008/06/04 12:41:41 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <uvm/uvm_extern.h>
#define _POWERPC_BUS_DMA_PRIVATE
#include <machine/bus.h>
#include <machine/intr.h>
int _bus_dmamap_load_buffer (bus_dma_tag_t, bus_dmamap_t, void *,
bus_size_t, struct vmspace *, int, paddr_t *, int *, int);
static inline void
dcbst(paddr_t pa, long len, int dcache_line_size)
{
paddr_t epa;
for (epa = pa + len; pa < epa; pa += dcache_line_size)
__asm volatile("dcbst 0,%0" :: "r"(pa));
}
static inline void
dcbi(paddr_t pa, long len, int dcache_line_size)
{
paddr_t epa;
for (epa = pa + len; pa < epa; pa += dcache_line_size)
__asm volatile("dcbi 0,%0" :: "r"(pa));
}
static inline void
dcbf(paddr_t pa, long len, int dcache_line_size)
{
paddr_t epa;
for (epa = pa + len; pa < epa; pa += dcache_line_size)
__asm volatile("dcbf 0,%0" :: "r"(pa));
}
/*
* Common function for DMA map creation. May be called by bus-specific
* DMA map creation functions.
*/
int
_bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, flags, dmamp)
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;
{
struct powerpc_bus_dmamap *map;
void *mapstore;
size_t mapsize;
/*
* Allocate and initialize the DMA map. The end of the map
* is a variable-sized array of segments, so we allocate enough
* room for them in one shot.
*
* Note we don't preserve the WAITOK or NOWAIT flags. Preservation
* of ALLOCNOW notifies others that we've reserved these resources,
* and they are not to be freed.
*
* The bus_dmamap_t includes one bus_dma_segment_t, hence
* the (nsegments - 1).
*/
mapsize = sizeof(struct powerpc_bus_dmamap) +
(sizeof(bus_dma_segment_t) * (nsegments - 1));
if ((mapstore = malloc(mapsize, M_DMAMAP,
(flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL)
return (ENOMEM);
memset(mapstore, 0, mapsize);
map = (struct powerpc_bus_dmamap *)mapstore;
map->_dm_size = size;
map->_dm_segcnt = nsegments;
map->_dm_maxmaxsegsz = maxsegsz;
map->_dm_boundary = boundary;
map->_dm_bounce_thresh = t->_bounce_thresh;
map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
map->dm_maxsegsz = maxsegsz;
map->dm_mapsize = 0; /* no valid mappings */
map->dm_nsegs = 0;
*dmamp = map;
return (0);
}
/*
* Common function for DMA map destruction. May be called by bus-specific
* DMA map destruction functions.
*/
void
_bus_dmamap_destroy(t, map)
bus_dma_tag_t t;
bus_dmamap_t map;
{
free(map, M_DMAMAP);
}
/*
* Utility function to load a linear buffer. lastaddrp holds state
* between invocations (for multiple-buffer loads). segp contains
* the starting segment on entrance, and the ending segment on exit.
* first indicates if this is the first invocation of this function.
*/
int
_bus_dmamap_load_buffer(t, map, buf, buflen, vm, flags, lastaddrp, segp, first)
bus_dma_tag_t t;
bus_dmamap_t map;
void *buf;
bus_size_t buflen;
struct vmspace *vm;
int flags;
paddr_t *lastaddrp;
int *segp;
int first;
{
bus_size_t sgsize;
bus_addr_t curaddr, lastaddr, baddr, bmask;
vaddr_t vaddr = (vaddr_t)buf;
int seg;
lastaddr = *lastaddrp;
bmask = ~(map->_dm_boundary - 1);
for (seg = *segp; buflen > 0 ; ) {
/*
* Get the physical address for this segment.
*/
if (!VMSPACE_IS_KERNEL_P(vm))
(void) pmap_extract(vm_map_pmap(&vm->vm_map),
vaddr, (void *)&curaddr);
else
curaddr = vtophys(vaddr);
/*
* If we're beyond the bounce threshold, notify
* the caller.
*/
if (map->_dm_bounce_thresh != 0 &&
curaddr >= map->_dm_bounce_thresh)
return (EINVAL);
/*
* Compute the segment size, and adjust counts.
*/
sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET);
if (buflen < sgsize)
sgsize = buflen;
sgsize = min(sgsize, map->dm_maxsegsz);
/*
* Make sure we don't cross any boundaries.
*/
if (map->_dm_boundary > 0) {
baddr = (curaddr + map->_dm_boundary) & bmask;
if (sgsize > (baddr - curaddr))
sgsize = (baddr - curaddr);
}
/*
* Insert chunk into a segment, coalescing with
* the previous segment if possible.
*/
if (first) {
map->dm_segs[seg].ds_addr = PHYS_TO_BUS_MEM(t, curaddr);
map->dm_segs[seg].ds_len = sgsize;
first = 0;
} else {
if (curaddr == lastaddr &&
(map->dm_segs[seg].ds_len + sgsize) <=
map->dm_maxsegsz &&
(map->_dm_boundary == 0 ||
(map->dm_segs[seg].ds_addr & bmask) ==
(PHYS_TO_BUS_MEM(t, curaddr) & bmask)))
map->dm_segs[seg].ds_len += sgsize;
else {
if (++seg >= map->_dm_segcnt)
break;
map->dm_segs[seg].ds_addr =
PHYS_TO_BUS_MEM(t, curaddr);
map->dm_segs[seg].ds_len = sgsize;
}
}
lastaddr = curaddr + sgsize;
vaddr += sgsize;
buflen -= sgsize;
}
*segp = seg;
*lastaddrp = lastaddr;
/*
* Did we fit?
*/
if (buflen != 0)
return (EFBIG); /* XXX better return value here? */
return (0);
}
/*
* Common function for loading a DMA map with a linear buffer. May
* be called by bus-specific DMA map load functions.
*/
int
_bus_dmamap_load(t, map, buf, buflen, p, flags)
bus_dma_tag_t t;
bus_dmamap_t map;
void *buf;
bus_size_t buflen;
struct proc *p;
int flags;
{
paddr_t lastaddr = 0;
int seg, error;
struct vmspace *vm;
/*
* Make sure that on error condition we return "no valid mappings".
*/
map->dm_mapsize = 0;
map->dm_nsegs = 0;
KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
if (buflen > map->_dm_size)
return (EINVAL);
if (p != NULL) {
vm = p->p_vmspace;
} else {
vm = vmspace_kernel();
}
seg = 0;
error = _bus_dmamap_load_buffer(t, map, buf, buflen, vm, flags,
&lastaddr, &seg, 1);
if (error == 0) {
map->dm_mapsize = buflen;
map->dm_nsegs = seg + 1;
}
return (error);
}
/*
* Like _bus_dmamap_load(), but for mbufs.
*/
int
_bus_dmamap_load_mbuf(t, map, m0, flags)
bus_dma_tag_t t;
bus_dmamap_t map;
struct mbuf *m0;
int flags;
{
paddr_t lastaddr = 0;
int seg, error, first;
struct mbuf *m;
/*
* Make sure that on error condition we return "no valid mappings."
*/
map->dm_mapsize = 0;
map->dm_nsegs = 0;
KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
#ifdef DIAGNOSTIC
if ((m0->m_flags & M_PKTHDR) == 0)
panic("_bus_dmamap_load_mbuf: no packet header");
#endif
if (m0->m_pkthdr.len > map->_dm_size)
return (EINVAL);
first = 1;
seg = 0;
error = 0;
for (m = m0; m != NULL && error == 0; m = m->m_next, first = 0) {
if (m->m_len == 0)
continue;
#ifdef POOL_VTOPHYS
/* XXX Could be better about coalescing. */
/* XXX Doesn't check boundaries. */
switch (m->m_flags & (M_EXT|M_CLUSTER)) {
case M_EXT|M_CLUSTER:
/* XXX KDASSERT */
KASSERT(m->m_ext.ext_paddr != M_PADDR_INVALID);
lastaddr = m->m_ext.ext_paddr +
(m->m_data - m->m_ext.ext_buf);
have_addr:
if (first == 0 && ++seg >= map->_dm_segcnt) {
error = EFBIG;
continue;
}
map->dm_segs[seg].ds_addr =
PHYS_TO_BUS_MEM(t, lastaddr);
map->dm_segs[seg].ds_len = m->m_len;
lastaddr += m->m_len;
continue;
case 0:
lastaddr = m->m_paddr + M_BUFOFFSET(m) +
(m->m_data - M_BUFADDR(m));
goto have_addr;
default:
break;
}
#endif
error = _bus_dmamap_load_buffer(t, map, m->m_data,
m->m_len, vmspace_kernel(), flags, &lastaddr, &seg, first);
}
if (error == 0) {
map->dm_mapsize = m0->m_pkthdr.len;
map->dm_nsegs = seg + 1;
}
return (error);
}
/*
* Like _bus_dmamap_load(), but for uios.
*/
int
_bus_dmamap_load_uio(t, map, uio, flags)
bus_dma_tag_t t;
bus_dmamap_t map;
struct uio *uio;
int flags;
{
paddr_t lastaddr = 0;
int seg, i, error, first;
bus_size_t minlen, resid;
struct iovec *iov;
void *addr;
/*
* Make sure that on error condition we return "no valid mappings."
*/
map->dm_mapsize = 0;
map->dm_nsegs = 0;
KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
resid = uio->uio_resid;
iov = uio->uio_iov;
first = 1;
seg = 0;
error = 0;
for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
/*
* Now at the first iovec to load. Load each iovec
* until we have exhausted the residual count.
*/
minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
addr = (void *)iov[i].iov_base;
error = _bus_dmamap_load_buffer(t, map, addr, minlen,
uio->uio_vmspace, flags, &lastaddr, &seg, first);
first = 0;
resid -= minlen;
}
if (error == 0) {
map->dm_mapsize = uio->uio_resid;
map->dm_nsegs = seg + 1;
}
return (error);
}
/*
* Like _bus_dmamap_load(), but for raw memory allocated with
* bus_dmamem_alloc().
*/
int
_bus_dmamap_load_raw(t, map, segs, nsegs, size, flags)
bus_dma_tag_t t;
bus_dmamap_t map;
bus_dma_segment_t *segs;
int nsegs;
bus_size_t size;
int flags;
{
panic("_bus_dmamap_load_raw: not implemented");
}
/*
* Common function for unloading a DMA map. May be called by
* chipset-specific DMA map unload functions.
*/
void
_bus_dmamap_unload(t, map)
bus_dma_tag_t t;
bus_dmamap_t map;
{
/*
* No resources to free; just mark the mappings as
* invalid.
*/
map->dm_maxsegsz = map->_dm_maxmaxsegsz;
map->dm_mapsize = 0;
map->dm_nsegs = 0;
}
/*
* Common function for DMA map synchronization. May be called
* by chipset-specific DMA map synchronization functions.
*/
void
_bus_dmamap_sync(t, map, offset, len, ops)
bus_dma_tag_t t;
bus_dmamap_t map;
bus_addr_t offset;
bus_size_t len;
int ops;
{
const int dcache_line_size = curcpu()->ci_ci.dcache_line_size;
const bus_dma_segment_t *ds = map->dm_segs;
if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 &&
(ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0)
panic("_bus_dmamap_sync: invalid ops %#x", ops);
#ifdef DIAGNOSTIC
if (offset + len > map->dm_mapsize)
panic("_bus_dmamap_sync: bad offset and/or length");
#endif
/*
* Skip leading amount
*/
while (offset >= ds->ds_len) {
offset -= ds->ds_len;
ds++;
}
__asm volatile("eieio");
for (; len > 0; ds++, offset = 0) {
bus_size_t seglen = ds->ds_len - offset;
bus_addr_t addr = BUS_MEM_TO_PHYS(t, ds->ds_addr) + offset;
if (seglen > len)
seglen = len;
len -= seglen;
KASSERT(ds < &map->dm_segs[map->dm_nsegs]);
/*
* Readjust things to start on cacheline boundarys
*/
offset = (addr & (dcache_line_size-1));
seglen += offset;
addr -= offset;
/*
* Now do the appropriate thing.
*/
switch (ops) {
case BUS_DMASYNC_PREWRITE:
/*
* Make sure cache contents are in memory for the DMA.
*/
dcbst(addr, seglen, dcache_line_size);
break;
case BUS_DMASYNC_PREREAD:
/*
* If the region to be invalidated doesn't fall on
* cacheline boundary, flush that cacheline so we
* preserve the leading content.
*/
if (offset) {
dcbf(addr, 1, 1);
/*
* If we are doing <= one cache line, stop now.
*/
if (seglen <= dcache_line_size)
break;
/*
* Advance one cache line since we've flushed
* this one.
*/
addr += dcache_line_size;
seglen -= dcache_line_size;
}
/*
* If the byte after the region to be invalidated
* doesn't fall on cacheline boundary, flush that
* cacheline so we preserve the trailing content.
*/
if (seglen & (dcache_line_size-1)) {
dcbf(addr + seglen, 1, 1);
if (seglen <= dcache_line_size)
break;
/*
* Truncate the length to a multiple of a
* dcache line size. No reason to flush
* the last entry again.
*/
seglen &= ~(dcache_line_size - 1);
}
__asm volatile("sync; eieio"); /* is this needed? */
/* FALLTHROUGH */
case BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE:
case BUS_DMASYNC_POSTREAD:
/*
* The contents will have changed, make sure to remove
* them from the cache. Note: some implementation
* implement dcbi identically to dcbf. Thus if the
* cacheline has data, it will be written to memory.
* If the DMA is updating the same cacheline at the
* time, bad things can happen.
*/
dcbi(addr, seglen, dcache_line_size);
break;
case BUS_DMASYNC_POSTWRITE:
/*
* Do nothing.
*/
break;
case BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE:
/*
* Force it to memory and remove from cache.
*/
dcbf(addr, seglen, dcache_line_size);
break;
}
}
__asm volatile("sync");
}
/*
* Common function for DMA-safe memory allocation. May be called
* by bus-specific DMA memory allocation functions.
*/
int
_bus_dmamem_alloc(t, size, alignment, boundary, segs, nsegs, rsegs, flags)
bus_dma_tag_t t;
bus_size_t size, alignment, boundary;
bus_dma_segment_t *segs;
int nsegs;
int *rsegs;
int flags;
{
paddr_t avail_start = 0xffffffff, avail_end = 0;
int bank;
for (bank = 0; bank < vm_nphysseg; bank++) {
if (avail_start > vm_physmem[bank].avail_start << PGSHIFT)
avail_start = vm_physmem[bank].avail_start << PGSHIFT;
if (avail_end < vm_physmem[bank].avail_end << PGSHIFT)
avail_end = vm_physmem[bank].avail_end << PGSHIFT;
}
return _bus_dmamem_alloc_range(t, size, alignment, boundary, segs,
nsegs, rsegs, flags, avail_start, avail_end - PAGE_SIZE);
}
/*
* Common function for freeing DMA-safe memory. May be called by
* bus-specific DMA memory free functions.
*/
void
_bus_dmamem_free(t, segs, nsegs)
bus_dma_tag_t t;
bus_dma_segment_t *segs;
int nsegs;
{
struct vm_page *m;
bus_addr_t addr;
struct pglist mlist;
int curseg;
/*
* Build a list of pages to free back to the VM system.
*/
TAILQ_INIT(&mlist);
for (curseg = 0; curseg < nsegs; curseg++) {
for (addr = BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr);
addr < (BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr)
+ segs[curseg].ds_len);
addr += PAGE_SIZE) {
m = PHYS_TO_VM_PAGE(addr);
TAILQ_INSERT_TAIL(&mlist, m, pageq.queue);
}
}
uvm_pglistfree(&mlist);
}
/*
* Common function for mapping DMA-safe memory. May be called by
* bus-specific DMA memory map functions.
*/
int
_bus_dmamem_map(t, segs, nsegs, size, kvap, flags)
bus_dma_tag_t t;
bus_dma_segment_t *segs;
int nsegs;
size_t size;
void **kvap;
int flags;
{
vaddr_t va;
bus_addr_t addr;
int curseg;
const uvm_flag_t kmflags =
(flags & BUS_DMA_NOWAIT) != 0 ? UVM_KMF_NOWAIT : 0;
size = round_page(size);
va = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY | kmflags);
if (va == 0)
return (ENOMEM);
*kvap = (void *)va;
for (curseg = 0; curseg < nsegs; curseg++) {
for (addr = BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr);
addr < (BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr)
+ segs[curseg].ds_len);
addr += PAGE_SIZE, va += PAGE_SIZE, size -= PAGE_SIZE) {
if (size == 0)
panic("_bus_dmamem_map: size botch");
/*
* If we are mapping nocache, flush the page from
* cache before we map it.
*/
if (flags & BUS_DMA_NOCACHE)
dcbf(addr, PAGE_SIZE,
curcpu()->ci_ci.dcache_line_size);
pmap_kenter_pa(va, addr,
VM_PROT_READ | VM_PROT_WRITE |
PMAP_WIRED |
((flags & BUS_DMA_NOCACHE) ? PMAP_NC : 0));
}
}
return (0);
}
/*
* Common function for unmapping DMA-safe memory. May be called by
* bus-specific DMA memory unmapping functions.
*/
void
_bus_dmamem_unmap(t, kva, size)
bus_dma_tag_t t;
void *kva;
size_t size;
{
#ifdef DIAGNOSTIC
if ((u_long)kva & PGOFSET)
panic("_bus_dmamem_unmap");
#endif
size = round_page(size);
pmap_kremove((vaddr_t)kva, size);
uvm_km_free(kernel_map, (vaddr_t)kva, size, UVM_KMF_VAONLY);
}
/*
* Common functin for mmap(2)'ing DMA-safe memory. May be called by
* bus-specific DMA mmap(2)'ing functions.
*/
paddr_t
_bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
bus_dma_tag_t t;
bus_dma_segment_t *segs;
int nsegs;
off_t off;
int prot, flags;
{
int i;
for (i = 0; i < nsegs; i++) {
#ifdef DIAGNOSTIC
if (off & PGOFSET)
panic("_bus_dmamem_mmap: offset unaligned");
if (BUS_MEM_TO_PHYS(t, segs[i].ds_addr) & PGOFSET)
panic("_bus_dmamem_mmap: segment unaligned");
if (segs[i].ds_len & PGOFSET)
panic("_bus_dmamem_mmap: segment size not multiple"
" of page size");
#endif
if (off >= segs[i].ds_len) {
off -= segs[i].ds_len;
continue;
}
return (BUS_MEM_TO_PHYS(t, segs[i].ds_addr) + off);
}
/* Page not found. */
return (-1);
}
/*
* Allocate physical memory from the given physical address range.
* Called by DMA-safe memory allocation methods.
*/
int
_bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs,
flags, low, high)
bus_dma_tag_t t;
bus_size_t size, alignment, boundary;
bus_dma_segment_t *segs;
int nsegs;
int *rsegs;
int flags;
paddr_t low;
paddr_t high;
{
paddr_t curaddr, lastaddr;
struct vm_page *m;
struct pglist mlist;
int curseg, error;
/* Always round the size. */
size = round_page(size);
/*
* Allocate pages from the VM system.
*/
error = uvm_pglistalloc(size, low, high, alignment, boundary,
&mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
if (error)
return (error);
/*
* Compute the location, size, and number of segments actually
* returned by the VM code.
*/
m = mlist.tqh_first;
curseg = 0;
lastaddr = VM_PAGE_TO_PHYS(m);
segs[curseg].ds_addr = PHYS_TO_BUS_MEM(t, lastaddr);
segs[curseg].ds_len = PAGE_SIZE;
m = m->pageq.queue.tqe_next;
for (; m != NULL; m = m->pageq.queue.tqe_next) {
curaddr = VM_PAGE_TO_PHYS(m);
#ifdef DIAGNOSTIC
if (curaddr < low || curaddr >= high) {
printf("vm_page_alloc_memory returned non-sensical"
" address 0x%lx\n", curaddr);
panic("_bus_dmamem_alloc_range");
}
#endif
if (curaddr == (lastaddr + PAGE_SIZE))
segs[curseg].ds_len += PAGE_SIZE;
else {
curseg++;
segs[curseg].ds_addr = PHYS_TO_BUS_MEM(t, curaddr);
segs[curseg].ds_len = PAGE_SIZE;
}
lastaddr = curaddr;
}
*rsegs = curseg + 1;
return (0);
}
/*
* Generic form of PHYS_TO_BUS_MEM().
*/
bus_addr_t
_bus_dma_phys_to_bus_mem_generic(t, addr)
bus_dma_tag_t t;
bus_addr_t addr;
{
return (addr);
}
/*
* Generic form of BUS_MEM_TO_PHYS().
*/
bus_addr_t
_bus_dma_bus_mem_to_phys_generic(t, addr)
bus_dma_tag_t t;
bus_addr_t addr;
{
return (addr);
}