/*
* Copyright (c) 1997 Justin T. Gibbs.
* All rights reserved.
*
* 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,
* without modification, immediately at the beginning of the file.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
#include <sys/proc.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <machine/atomic.h>
#include <machine/bus.h>
#include <machine/md_var.h>
#define MAX_BPAGES 128
struct bus_dma_tag {
bus_dma_tag_t parent;
bus_size_t alignment;
bus_size_t boundary;
bus_addr_t lowaddr;
bus_addr_t highaddr;
bus_dma_filter_t *filter;
void *filterarg;
bus_size_t maxsize;
u_int nsegments;
bus_size_t maxsegsz;
int flags;
int ref_count;
int map_count;
bus_dma_lock_t *lockfunc;
void *lockfuncarg;
};
struct bounce_page {
vm_offset_t vaddr; /* kva of bounce buffer */
bus_addr_t busaddr; /* Physical address */
vm_offset_t datavaddr; /* kva of client data */
bus_size_t datacount; /* client data count */
STAILQ_ENTRY(bounce_page) links;
};
int busdma_swi_pending;
static struct mtx bounce_lock;
static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
static int free_bpages;
static int reserved_bpages;
static int active_bpages;
static int total_bpages;
static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
struct bus_dmamap {
struct bp_list bpages;
int pagesneeded;
int pagesreserved;
bus_dma_tag_t dmat;
void *buf; /* unmapped buffer pointer */
bus_size_t buflen; /* unmapped buffer length */
vm_offset_t busaddress; /* address in bus space */
bus_dmamap_callback_t *callback;
void *callback_arg;
void *sgmaphandle; /* handle into sgmap */
STAILQ_ENTRY(bus_dmamap) links;
};
static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
static struct bus_dmamap nobounce_dmamap;
static void init_bounce_pages(void *dummy);
static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
int commit);
static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
vm_offset_t vaddr, bus_size_t size);
static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
/*
* Return true if a match is made.
*
* To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
*
* If paddr is within the bounds of the dma tag then call the filter callback
* to check for a match, if there is no filter callback then assume a match.
*/
static __inline int
run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
{
int retval;
retval = 0;
do {
if (paddr > dmat->lowaddr
&& paddr <= dmat->highaddr
&& (dmat->filter == NULL
|| (*dmat->filter)(dmat->filterarg, paddr) != 0))
retval = 1;
dmat = dmat->parent;
} while (retval == 0 && dmat != NULL);
return (retval);
}
/*
* Convenience function for manipulating driver locks from busdma (during
* busdma_swi, for example). Drivers that don't provide their own locks
* should specify &Giant to dmat->lockfuncarg. Drivers that use their own
* non-mutex locking scheme don't have to use this at all.
*/
void
busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
{
struct mtx *dmtx;
dmtx = (struct mtx *)arg;
switch (op) {
case BUS_DMA_LOCK:
mtx_lock(dmtx);
break;
case BUS_DMA_UNLOCK:
mtx_unlock(dmtx);
break;
default:
panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
}
}
/*
* dflt_lock should never get called. It gets put into the dma tag when
* lockfunc == NULL, which is only valid if the maps that are associated
* with the tag are meant to never be defered.
* XXX Should have a way to identify which driver is responsible here.
*/
static void
dflt_lock(void *arg, bus_dma_lock_op_t op)
{
#ifdef INVARIANTS
panic("driver error: busdma dflt_lock called");
#else
printf("DRIVER_ERROR: busdma dflt_lock called\n");
#endif
}
#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
/*
* Allocate a device specific dma_tag.
*/
int
bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
bus_size_t boundary, bus_addr_t lowaddr,
bus_addr_t highaddr, bus_dma_filter_t *filter,
void *filterarg, bus_size_t maxsize, int nsegments,
bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
void *lockfuncarg, bus_dma_tag_t *dmat)
{
bus_dma_tag_t newtag;
int error = 0;
/* Return a NULL tag on failure */
*dmat = NULL;
newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
if (newtag == NULL)
return (ENOMEM);
newtag->parent = parent;
newtag->alignment = alignment;
newtag->boundary = boundary;
newtag->lowaddr = trunc_page(lowaddr) + (PAGE_SIZE - 1);
newtag->highaddr = trunc_page(highaddr) + (PAGE_SIZE - 1);
newtag->filter = filter;
newtag->filterarg = filterarg;
newtag->maxsize = maxsize;
newtag->nsegments = nsegments;
newtag->maxsegsz = maxsegsz;
newtag->flags = flags;
newtag->ref_count = 1; /* Count ourself */
newtag->map_count = 0;
if (lockfunc != NULL) {
newtag->lockfunc = lockfunc;
newtag->lockfuncarg = lockfuncarg;
} else {
newtag->lockfunc = dflt_lock;
newtag->lockfuncarg = NULL;
}
/* Take into account any restrictions imposed by our parent tag */
if (parent != NULL) {
newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
/*
* XXX Not really correct??? Probably need to honor boundary
* all the way up the inheritence chain.
*/
newtag->boundary = MAX(parent->boundary, newtag->boundary);
if (newtag->filter == NULL) {
/*
* Short circuit looking at our parent directly
* since we have encapsulated all of its information
*/
newtag->filter = parent->filter;
newtag->filterarg = parent->filterarg;
newtag->parent = parent->parent;
}
if (newtag->parent != NULL)
atomic_add_int(&parent->ref_count, 1);
}
if (newtag->lowaddr < ptoa(Maxmem) && (flags & BUS_DMA_ALLOCNOW) != 0) {
/* Must bounce */
if (lowaddr > bounce_lowaddr) {
/*
* Go through the pool and kill any pages
* that don't reside below lowaddr.
*/
panic("bus_dma_tag_create: page reallocation "
"not implemented");
}
if (ptoa(total_bpages) < maxsize) {
int pages;
pages = atop(maxsize) - total_bpages;
/* Add pages to our bounce pool */
if (alloc_bounce_pages(newtag, pages) < pages)
error = ENOMEM;
}
/* Performed initial allocation */
newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
}
if (error != 0) {
free(newtag, M_DEVBUF);
} else {
*dmat = newtag;
}
return (error);
}
int
bus_dma_tag_destroy(bus_dma_tag_t dmat)
{
if (dmat != NULL) {
if (dmat->map_count != 0)
return (EBUSY);
while (dmat != NULL) {
bus_dma_tag_t parent;
parent = dmat->parent;
atomic_subtract_int(&dmat->ref_count, 1);
if (dmat->ref_count == 0) {
free(dmat, M_DEVBUF);
/*
* Last reference count, so
* release our reference
* count on our parent.
*/
dmat = parent;
} else
dmat = NULL;
}
}
return (0);
}
/*
* Allocate a handle for mapping from kva/uva/physical
* address space into bus device space.
*/
int
bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
{
int error;
error = 0;
if (dmat->flags & BUS_DMA_ISA) {
bus_dmamap_t map;
map = (bus_dmamap_t)malloc(sizeof(*map), M_DEVBUF,
M_NOWAIT | M_ZERO);
if (map == NULL)
return (ENOMEM);
#if 0
map->busaddress =
sgmap_alloc_region(chipset.sgmap,
dmat->maxsize,
dmat->boundary,
&map->sgmaphandle);
#endif
dmat->map_count++;
*mapp = map;
return (0);
}
if (dmat->lowaddr < ptoa(Maxmem)) {
/* Must bounce */
int maxpages;
*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
M_NOWAIT | M_ZERO);
if (*mapp == NULL)
return (ENOMEM);
/* Initialize the new map */
STAILQ_INIT(&((*mapp)->bpages));
/*
* Attempt to add pages to our pool on a per-instance
* basis up to a sane limit.
*/
maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
|| (dmat->map_count > 0
&& total_bpages < maxpages)) {
int pages;
if (dmat->lowaddr > bounce_lowaddr) {
/*
* Go through the pool and kill any pages
* that don't reside below lowaddr.
*/
panic("bus_dmamap_create: page reallocation "
"not implemented");
}
pages = atop(dmat->maxsize);
pages = MIN(maxpages - total_bpages, pages);
error = alloc_bounce_pages(dmat, pages);
if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
if (error == 0)
dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
} else {
error = 0;
}
}
} else {
*mapp = &nobounce_dmamap;
}
if (error == 0)
dmat->map_count++;
return (error);
}
/*
* Destroy a handle for mapping from kva/uva/physical
* address space into bus device space.
*/
int
bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
{
if (dmat->flags & BUS_DMA_ISA) {
#if 0
sgmap_free_region(chipset.sgmap, map->sgmaphandle);
#endif
}
if (map != NULL && map != &nobounce_dmamap) {
if (STAILQ_FIRST(&map->bpages) != NULL)
return (EBUSY);
free(map, M_DEVBUF);
}
dmat->map_count--;
return (0);
}
/*
* Allocate a piece of memory that can be efficiently mapped into
* bus device space based on the constraints lited in the dma tag.
* A dmamap to for use with dmamap_load is also allocated.
*/
int
bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
bus_dmamap_t *mapp)
{
int mflags;
if (flags & BUS_DMA_NOWAIT)
mflags = M_NOWAIT;
else
mflags = M_WAITOK;
if (flags & BUS_DMA_ZERO)
mflags |= M_ZERO;
/* If we succeed, no mapping/bouncing will be required */
*mapp = &nobounce_dmamap;
if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) {
*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
} else {
/*
* XXX Use Contigmalloc until it is merged into this facility
* and handles multi-seg allocations. Nobody is doing
* multi-seg allocations yet though.
*/
*vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
dmat->boundary);
}
if (*vaddr == NULL)
return (ENOMEM);
return (0);
}
/*
* Free a piece of memory and it's allociated dmamap, that was allocated
* via bus_dmamem_alloc. Make the same choice for free/contigfree.
*/
void
bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
{
/*
* dmamem does not need to be bounced, so the map should be
* NULL
*/
if (map != &nobounce_dmamap)
panic("bus_dmamem_free: Invalid map freed\n");
if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem))
free(vaddr, M_DEVBUF);
else {
contigfree(vaddr, dmat->maxsize, M_DEVBUF);
}
}
#define BUS_DMAMAP_NSEGS ((64 * 1024 / PAGE_SIZE) + 1)
/*
* Map the buffer buf into bus space using the dmamap map.
*/
int
bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
bus_size_t buflen, bus_dmamap_callback_t *callback,
void *callback_arg, int flags)
{
vm_offset_t vaddr;
vm_offset_t paddr;
#ifdef __GNUC__
bus_dma_segment_t dm_segments[dmat->nsegments];
#else
bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
#endif
bus_dma_segment_t *sg;
int seg;
int error;
vm_offset_t nextpaddr;
error = 0;
if (dmat->flags & BUS_DMA_ISA) {
/*
* For ISA dma, we use the chipset's scatter-gather
* map to map the tranfer into the ISA reachable range
* of the bus address space.
*/
vaddr = trunc_page((vm_offset_t) buf);
dm_segments[0].ds_addr =
map->busaddress + (vm_offset_t) buf - vaddr;
dm_segments[0].ds_len = buflen;
buflen = round_page((vm_offset_t) buf + buflen) - vaddr;
#if 0
sgmap_load_region(chipset.sgmap,
map->busaddress,
vaddr,
buflen);
#endif
map->buflen = buflen;
(*callback)(callback_arg, dm_segments, 1, error);
return (0);
}
/*
* If we are being called during a callback, pagesneeded will
* be non-zero, so we can avoid doing the work twice.
*/
if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
vm_offset_t vendaddr;
/*
* Count the number of bounce pages
* needed in order to complete this transfer
*/
vaddr = trunc_page(buf);
vendaddr = (vm_offset_t)buf + buflen;
while (vaddr < vendaddr) {
paddr = pmap_kextract(vaddr);
if (run_filter(dmat, paddr) != 0) {
map->pagesneeded++;
}
vaddr += PAGE_SIZE;
}
}
/* Reserve Necessary Bounce Pages */
if (map->pagesneeded != 0) {
mtx_lock(&bounce_lock);
if (flags & BUS_DMA_NOWAIT) {
if (reserve_bounce_pages(dmat, map, 0) != 0) {
mtx_unlock(&bounce_lock);
return (ENOMEM);
}
} else {
if (reserve_bounce_pages(dmat, map, 1) != 0) {
/* Queue us for resources */
map->dmat = dmat;
map->buf = buf;
map->buflen = buflen;
map->callback = callback;
map->callback_arg = callback_arg;
STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
map, links);
mtx_unlock(&bounce_lock);
return (EINPROGRESS);
}
}
mtx_unlock(&bounce_lock);
}
vaddr = (vm_offset_t)buf;
sg = &dm_segments[0];
seg = 1;
sg->ds_len = 0;
nextpaddr = 0;
do {
bus_size_t size;
paddr = pmap_kextract(vaddr);
size = PAGE_SIZE - (paddr & PAGE_MASK);
if (size > buflen)
size = buflen;
if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
paddr = add_bounce_page(dmat, map, vaddr, size);
}
if (sg->ds_len == 0) {
sg->ds_addr = paddr;
sg->ds_len = size;
} else if (paddr == nextpaddr) {
sg->ds_len += size;
} else {
/* Go to the next segment */
sg++;
seg++;
if (seg > dmat->nsegments)
break;
sg->ds_addr = paddr;
sg->ds_len = size;
}
vaddr += size;
nextpaddr = paddr + size;
buflen -= size;
} while (buflen > 0);
if (buflen != 0) {
printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
buflen);
error = EFBIG;
}
(*callback)(callback_arg, dm_segments, seg, error);
return (0);
}
/*
* Utility function to load a linear buffer. lastaddrp holds state
* between invocations (for multiple-buffer loads). segp contains
* the starting segment on entrace, and the ending segment on exit.
* first indicates if this is the first invocation of this function.
*/
static int
_bus_dmamap_load_buffer(bus_dma_tag_t dmat,
bus_dma_segment_t segs[],
void *buf, bus_size_t buflen,
struct thread *td,
int flags,
vm_offset_t *lastaddrp,
int *segp,
int first)
{
bus_size_t sgsize;
bus_addr_t curaddr, lastaddr, baddr, bmask;
vm_offset_t vaddr = (vm_offset_t)buf;
int seg;
pmap_t pmap;
if (td != NULL)
pmap = vmspace_pmap(td->td_proc->p_vmspace);
else
pmap = NULL;
lastaddr = *lastaddrp;
bmask = ~(dmat->boundary - 1);
for (seg = *segp; buflen > 0 ; ) {
/*
* Get the physical address for this segment.
*/
if (pmap)
curaddr = pmap_extract(pmap, vaddr);
else
curaddr = pmap_kextract(vaddr);
/*
* Compute the segment size, and adjust counts.
*/
sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
if (buflen < sgsize)
sgsize = buflen;
/*
* Make sure we don't cross any boundaries.
*/
if (dmat->boundary > 0) {
baddr = (curaddr + dmat->boundary) & bmask;
if (sgsize > (baddr - curaddr))
sgsize = (baddr - curaddr);
}
/*
* Insert chunk into a segment, coalescing with
* previous segment if possible.
*/
if (first) {
segs[seg].ds_addr = curaddr;
segs[seg].ds_len = sgsize;
first = 0;
} else {
if (curaddr == lastaddr &&
(segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
(dmat->boundary == 0 ||
(segs[seg].ds_addr & bmask) == (curaddr & bmask)))
segs[seg].ds_len += sgsize;
else {
if (++seg >= dmat->nsegments)
break;
segs[seg].ds_addr = curaddr;
segs[seg].ds_len = sgsize;
}
}
lastaddr = curaddr + sgsize;
vaddr += sgsize;
buflen -= sgsize;
}
*segp = seg;
*lastaddrp = lastaddr;
/*
* Did we fit?
*/
return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
}
/*
* Like _bus_dmamap_load(), but for mbufs.
*/
int
bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
struct mbuf *m0,
bus_dmamap_callback2_t *callback, void *callback_arg,
int flags)
{
#ifdef __GNUC__
bus_dma_segment_t dm_segments[dmat->nsegments];
#else
bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
#endif
int nsegs, error;
KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
("bus_dmamap_load_mbuf: No support for bounce pages!"));
M_ASSERTPKTHDR(m0);
nsegs = 0;
error = 0;
if (m0->m_pkthdr.len <= dmat->maxsize) {
int first = 1;
bus_addr_t lastaddr = 0;
struct mbuf *m;
for (m = m0; m != NULL && error == 0; m = m->m_next) {
if (m->m_len > 0) {
error = _bus_dmamap_load_buffer(dmat,
dm_segments,
m->m_data, m->m_len,
NULL, flags, &lastaddr,
&nsegs, first);
first = 0;
}
}
} else {
error = EINVAL;
}
if (error) {
/* force "no valid mappings" in callback */
(*callback)(callback_arg, dm_segments, 0, 0, error);
} else {
(*callback)(callback_arg, dm_segments,
nsegs+1, m0->m_pkthdr.len, error);
}
return (error);
}
/*
* Like _bus_dmamap_load(), but for uios.
*/
int
bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
struct uio *uio,
bus_dmamap_callback2_t *callback, void *callback_arg,
int flags)
{
bus_addr_t lastaddr;
#ifdef __GNUC__
bus_dma_segment_t dm_segments[dmat->nsegments];
#else
bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
#endif
int nsegs, error, first, i;
bus_size_t resid;
struct iovec *iov;
struct thread *td = NULL;
KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
("bus_dmamap_load_uio: No support for bounce pages!"));
resid = uio->uio_resid;
iov = uio->uio_iov;
if (uio->uio_segflg == UIO_USERSPACE) {
td = uio->uio_td;
KASSERT(td != NULL,
("bus_dmamap_load_uio: USERSPACE but no proc"));
}
nsegs = 0;
error = 0;
first = 1;
for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
/*
* Now at the first iovec to load. Load each iovec
* until we have exhausted the residual count.
*/
bus_size_t minlen =
resid < iov[i].iov_len ? resid : iov[i].iov_len;
caddr_t addr = (caddr_t) iov[i].iov_base;
if (minlen > 0) {
error = _bus_dmamap_load_buffer(dmat,
dm_segments,
addr, minlen,
td, flags, &lastaddr, &nsegs, first);
first = 0;
resid -= minlen;
}
}
if (error) {
/* force "no valid mappings" in callback */
(*callback)(callback_arg, dm_segments, 0, 0, error);
} else {
(*callback)(callback_arg, dm_segments,
nsegs+1, uio->uio_resid, error);
}
return (error);
}
/*
* Release the mapping held by map.
*/
void
_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
{
struct bounce_page *bpage;
if (dmat->flags & BUS_DMA_ISA) {
#if 0
sgmap_unload_region(chipset.sgmap,
map->busaddress,
map->buflen);
#endif
return;
}
while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
STAILQ_REMOVE_HEAD(&map->bpages, links);
free_bounce_page(dmat, bpage);
}
}
void
_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
{
struct bounce_page *bpage;
if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
/*
* Handle data bouncing. We might also
* want to add support for invalidating
* the caches on broken hardware
*/
if (op & BUS_DMASYNC_PREWRITE) {
while (bpage != NULL) {
bcopy((void *)bpage->datavaddr,
(void *)bpage->vaddr,
bpage->datacount);
bpage = STAILQ_NEXT(bpage, links);
}
}
if (op & BUS_DMASYNC_POSTREAD) {
while (bpage != NULL) {
bcopy((void *)bpage->vaddr,
(void *)bpage->datavaddr,
bpage->datacount);
bpage = STAILQ_NEXT(bpage, links);
}
}
}
}
static void
init_bounce_pages(void *dummy __unused)
{
free_bpages = 0;
reserved_bpages = 0;
active_bpages = 0;
total_bpages = 0;
STAILQ_INIT(&bounce_page_list);
STAILQ_INIT(&bounce_map_waitinglist);
STAILQ_INIT(&bounce_map_callbacklist);
mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
}
SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
static int
alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
{
int count;
count = 0;
while (numpages > 0) {
struct bounce_page *bpage;
bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
M_NOWAIT | M_ZERO);
if (bpage == NULL)
break;
bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
M_NOWAIT, 0ul,
dmat->lowaddr,
PAGE_SIZE,
dmat->boundary);
if (bpage->vaddr == 0) {
free(bpage, M_DEVBUF);
break;
}
bpage->busaddr = pmap_kextract(bpage->vaddr);
mtx_lock(&bounce_lock);
STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
total_bpages++;
free_bpages++;
mtx_unlock(&bounce_lock);
count++;
numpages--;
}
return (count);
}
static int
reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
{
int pages;
mtx_assert(&bounce_lock, MA_OWNED);
pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
return (map->pagesneeded - (map->pagesreserved + pages));
free_bpages -= pages;
reserved_bpages += pages;
map->pagesreserved += pages;
pages = map->pagesneeded - map->pagesreserved;
return (pages);
}
static bus_addr_t
add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
bus_size_t size)
{
struct bounce_page *bpage;
if (map->pagesneeded == 0)
panic("add_bounce_page: map doesn't need any pages");
map->pagesneeded--;
if (map->pagesreserved == 0)
panic("add_bounce_page: map doesn't need any pages");
map->pagesreserved--;
mtx_lock(&bounce_lock);
bpage = STAILQ_FIRST(&bounce_page_list);
if (bpage == NULL)
panic("add_bounce_page: free page list is empty");
STAILQ_REMOVE_HEAD(&bounce_page_list, links);
reserved_bpages--;
active_bpages++;
mtx_unlock(&bounce_lock);
bpage->datavaddr = vaddr;
bpage->datacount = size;
STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
return (bpage->busaddr);
}
static void
free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
{
struct bus_dmamap *map;
bpage->datavaddr = 0;
bpage->datacount = 0;
mtx_lock(&bounce_lock);
STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
free_bpages++;
active_bpages--;
if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
map, links);
busdma_swi_pending = 1;
swi_sched(vm_ih, 0);
}
}
mtx_unlock(&bounce_lock);
}
void
busdma_swi(void)
{
bus_dma_tag_t dmat;
struct bus_dmamap *map;
mtx_lock(&bounce_lock);
while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
mtx_unlock(&bounce_lock);
dmat = map->dmat;
(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
map->callback, map->callback_arg, /*flags*/0);
(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
mtx_lock(&bounce_lock);
}
mtx_unlock(&bounce_lock);
}
