d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
freebsd-skq/sys/arm/arm/busdma_machdep.c

1509 lines
42 KiB
C
Raw Blame History

/*-
* Copyright (c) 2012 Ian Lepore
* Copyright (c) 2004 Olivier Houchard
* Copyright (c) 2002 Peter Grehan
* Copyright (c) 1997, 1998 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.
*
* From i386/busdma_machdep.c,v 1.26 2002/04/19 22:58:09 alfred
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* ARM bus dma support routines.
*
* XXX Things to investigate / fix some day...
* - What is the earliest that this API can be called? Could there be any
* fallout from changing the SYSINIT() order from SI_SUB_VM to SI_SUB_KMEM?
* - The manpage mentions the BUS_DMA_NOWAIT flag only in the context of the
* bus_dmamap_load() function. This code has historically (and still does)
* honor it in bus_dmamem_alloc(). If we got rid of that we could lose some
* error checking because some resource management calls would become WAITOK
* and thus "cannot fail."
* - The decisions made by _bus_dma_can_bounce() should be made once, at tag
* creation time, and the result stored in the tag.
* - It should be possible to take some shortcuts when mapping a buffer we know
* came from the uma(9) allocators based on what we know about such buffers
* (aligned, contiguous, etc).
* - The allocation of bounce pages could probably be cleaned up, then we could
* retire arm_remap_nocache().
*/
#define _ARM32_BUS_DMA_PRIVATE
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/bus.h>
#include <sys/busdma_bufalloc.h>
#include <sys/interrupt.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/memdesc.h>
#include <sys/mutex.h>
#include <sys/ktr.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <vm/uma.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <machine/atomic.h>
#include <machine/bus.h>
#include <machine/cpufunc.h>
#include <machine/md_var.h>
#define MAX_BPAGES 64
#define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
struct bounce_zone;
struct bus_dma_tag {
bus_dma_tag_t parent;
bus_size_t alignment;
bus_addr_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;
/*
* DMA range for this tag. If the page doesn't fall within
* one of these ranges, an error is returned. The caller
* may then decide what to do with the transfer. If the
* range pointer is NULL, it is ignored.
*/
struct arm32_dma_range *ranges;
int _nranges;
struct bounce_zone *bounce_zone;
/*
* Most tags need one or two segments, and can use the local tagsegs
* array. For tags with a larger limit, we'll allocate a bigger array
* on first use.
*/
bus_dma_segment_t *segments;
bus_dma_segment_t tagsegs[2];
};
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_addr_t dataaddr; /* client physical address */
bus_size_t datacount; /* client data count */
STAILQ_ENTRY(bounce_page) links;
};
struct sync_list {
vm_offset_t vaddr; /* kva of bounce buffer */
bus_addr_t busaddr; /* Physical address */
bus_size_t datacount; /* client data count */
};
int busdma_swi_pending;
struct bounce_zone {
STAILQ_ENTRY(bounce_zone) links;
STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
int total_bpages;
int free_bpages;
int reserved_bpages;
int active_bpages;
int total_bounced;
int total_deferred;
int map_count;
bus_size_t alignment;
bus_addr_t lowaddr;
char zoneid[8];
char lowaddrid[20];
struct sysctl_ctx_list sysctl_tree;
struct sysctl_oid *sysctl_tree_top;
};
static struct mtx bounce_lock;
static int total_bpages;
static int busdma_zonecount;
static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
"Total bounce pages");
#define DMAMAP_COHERENT 0x8
#define DMAMAP_CACHE_ALIGNED 0x10
struct bus_dmamap {
struct bp_list bpages;
int pagesneeded;
int pagesreserved;
bus_dma_tag_t dmat;
struct memdesc mem;
int flags;
STAILQ_ENTRY(bus_dmamap) links;
bus_dmamap_callback_t *callback;
void *callback_arg;
int sync_count;
struct sync_list *slist;
};
static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
static struct mtx busdma_mtx;
MTX_SYSINIT(busdma_mtx, &busdma_mtx, "busdma lock", MTX_DEF);
static void init_bounce_pages(void *dummy);
static int alloc_bounce_zone(bus_dma_tag_t dmat);
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_addr_t addr,
bus_size_t size);
static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
/* Default tag, as most drivers provide no parent tag. */
bus_dma_tag_t arm_root_dma_tag;
/*
* ----------------------------------------------------------------------------
* Begin block of code useful to transplant to other implementations.
*/
static uma_zone_t dmamap_zone; /* Cache of struct bus_dmamap items */
static busdma_bufalloc_t coherent_allocator; /* Cache of coherent buffers */
static busdma_bufalloc_t standard_allocator; /* Cache of standard buffers */
/*
* This is the ctor function passed to uma_zcreate() for the pool of dma maps.
* It'll need platform-specific changes if this code is copied.
*/
static int
dmamap_ctor(void *mem, int size, void *arg, int flags)
{
bus_dmamap_t map;
bus_dma_tag_t dmat;
map = (bus_dmamap_t)mem;
dmat = (bus_dma_tag_t)arg;
dmat->map_count++;
map->dmat = dmat;
map->flags = 0;
STAILQ_INIT(&map->bpages);
return (0);
}
/*
* This is the dtor function passed to uma_zcreate() for the pool of dma maps.
* It may need platform-specific changes if this code is copied .
*/
static void
dmamap_dtor(void *mem, int size, void *arg)
{
bus_dmamap_t map;
map = (bus_dmamap_t)mem;
map->dmat->map_count--;
}
static void
busdma_init(void *dummy)
{
/* Create a cache of maps for bus_dmamap_create(). */
dmamap_zone = uma_zcreate("dma maps", sizeof(struct bus_dmamap),
dmamap_ctor, dmamap_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
/* Create a cache of buffers in standard (cacheable) memory. */
standard_allocator = busdma_bufalloc_create("buffer",
arm_dcache_align, /* minimum_alignment */
NULL, /* uma_alloc func */
NULL, /* uma_free func */
0); /* uma_zcreate_flags */
/*
* Create a cache of buffers in uncacheable memory, to implement the
* BUS_DMA_COHERENT (and potentially BUS_DMA_NOCACHE) flag.
*/
coherent_allocator = busdma_bufalloc_create("coherent",
arm_dcache_align, /* minimum_alignment */
busdma_bufalloc_alloc_uncacheable,
busdma_bufalloc_free_uncacheable,
0); /* uma_zcreate_flags */
}
/*
* This init historically used SI_SUB_VM, but now the init code requires
* malloc(9) using M_DEVBUF memory, which is set up later than SI_SUB_VM, by
* SI_SUB_KMEM and SI_ORDER_THIRD, so we'll go right after that by using
* SI_SUB_KMEM and SI_ORDER_FOURTH.
*/
SYSINIT(busdma, SI_SUB_KMEM, SI_ORDER_FOURTH, busdma_init, NULL);
/*
* End block of code useful to transplant to other implementations.
* ----------------------------------------------------------------------------
*/
/*
* 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 int
run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
{
int retval;
retval = 0;
do {
if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
|| ((paddr & (dmat->alignment - 1)) != 0))
&& (dmat->filter == NULL
|| (*dmat->filter)(dmat->filterarg, paddr) != 0))
retval = 1;
dmat = dmat->parent;
} while (retval == 0 && dmat != NULL);
return (retval);
}
/*
* This routine checks the exclusion zone constraints from a tag against the
* physical RAM available on the machine. If a tag specifies an exclusion zone
* but there's no RAM in that zone, then we avoid allocating resources to bounce
* a request, and we can use any memory allocator (as opposed to needing
* kmem_alloc_contig() just because it can allocate pages in an address range).
*
* Most tags have BUS_SPACE_MAXADDR or BUS_SPACE_MAXADDR_32BIT (they are the
* same value on 32-bit architectures) as their lowaddr constraint, and we can't
* possibly have RAM at an address higher than the highest address we can
* express, so we take a fast out.
*/
static __inline int
_bus_dma_can_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
{
int i;
if (lowaddr >= BUS_SPACE_MAXADDR)
return (0);
for (i = 0; phys_avail[i] && phys_avail[i + 1]; i += 2) {
if ((lowaddr >= phys_avail[i] && lowaddr <= phys_avail[i + 1])
|| (lowaddr < phys_avail[i] &&
highaddr > phys_avail[i]))
return (1);
}
return (0);
}
static __inline struct arm32_dma_range *
_bus_dma_inrange(struct arm32_dma_range *ranges, int nranges,
bus_addr_t curaddr)
{
struct arm32_dma_range *dr;
int i;
for (i = 0, dr = ranges; i < nranges; i++, dr++) {
if (curaddr >= dr->dr_sysbase &&
round_page(curaddr) <= (dr->dr_sysbase + dr->dr_len))
return (dr);
}
return (NULL);
}
/*
* 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
}
/*
* Allocate a device specific dma_tag.
*/
#define SEG_NB 1024
int
bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
bus_addr_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;
if (!parent)
parent = arm_root_dma_tag;
newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
if (newtag == NULL) {
CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
__func__, newtag, 0, error);
return (ENOMEM);
}
newtag->parent = parent;
newtag->alignment = alignment ? alignment : 1;
newtag->boundary = boundary;
newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
newtag->highaddr = trunc_page((vm_offset_t)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;
newtag->ranges = bus_dma_get_range();
newtag->_nranges = bus_dma_get_range_nb();
if (lockfunc != NULL) {
newtag->lockfunc = lockfunc;
newtag->lockfuncarg = lockfuncarg;
} else {
newtag->lockfunc = dflt_lock;
newtag->lockfuncarg = NULL;
}
/*
* If all the segments we need fit into the local tagsegs array, set the
* pointer now. Otherwise NULL the pointer and an array of segments
* will be allocated later, on first use. We don't pre-allocate now
* because some tags exist just to pass contraints to children in the
* device hierarchy, and they tend to use BUS_SPACE_UNRESTRICTED and we
* sure don't want to try to allocate an array for that.
*/
if (newtag->nsegments <= nitems(newtag->tagsegs))
newtag->segments = newtag->tagsegs;
else
newtag->segments = 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);
if (newtag->boundary == 0)
newtag->boundary = parent->boundary;
else if (parent->boundary != 0)
newtag->boundary = MIN(parent->boundary,
newtag->boundary);
if ((newtag->filter != NULL) ||
((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
newtag->flags |= BUS_DMA_COULD_BOUNCE;
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 (_bus_dma_can_bounce(newtag->lowaddr, newtag->highaddr)
|| newtag->alignment > 1)
newtag->flags |= BUS_DMA_COULD_BOUNCE;
if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
(flags & BUS_DMA_ALLOCNOW) != 0) {
struct bounce_zone *bz;
/* Must bounce */
if ((error = alloc_bounce_zone(newtag)) != 0) {
free(newtag, M_DEVBUF);
return (error);
}
bz = newtag->bounce_zone;
if (ptoa(bz->total_bpages) < maxsize) {
int pages;
pages = atop(maxsize) - bz->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;
} else
newtag->bounce_zone = NULL;
if (error != 0)
free(newtag, M_DEVBUF);
else
*dmat = newtag;
CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
__func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
return (error);
}
int
bus_dma_tag_destroy(bus_dma_tag_t dmat)
{
#ifdef KTR
bus_dma_tag_t dmat_copy = dmat;
#endif
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) {
if (dmat->segments != NULL &&
dmat->segments != dmat->tagsegs)
free(dmat->segments, M_DEVBUF);
free(dmat, M_DEVBUF);
/*
* Last reference count, so
* release our reference
* count on our parent.
*/
dmat = parent;
} else
dmat = NULL;
}
}
CTR2(KTR_BUSDMA, "%s tag %p", __func__, dmat_copy);
return (0);
}
#include <sys/kdb.h>
/*
* 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)
{
struct sync_list *slist;
bus_dmamap_t map;
int error = 0;
slist = malloc(sizeof(*slist) * dmat->nsegments, M_DEVBUF, M_NOWAIT);
if (slist == NULL)
return (ENOMEM);
map = uma_zalloc_arg(dmamap_zone, dmat, M_NOWAIT);
*mapp = map;
if (map == NULL) {
free(slist, M_DEVBUF);
return (ENOMEM);
}
/*
* If the tag's segments haven't been allocated yet we need to do it
* now, because we can't sleep for resources at map load time.
*/
if (dmat->segments == NULL) {
dmat->segments = malloc(dmat->nsegments *
sizeof(*dmat->segments), M_DEVBUF, M_NOWAIT);
if (dmat->segments == NULL) {
free(slist, M_DEVBUF);
uma_zfree(dmamap_zone, map);
*mapp = NULL;
return (ENOMEM);
}
}
/*
* Bouncing might be required if the driver asks for an active
* exclusion region, a data alignment that is stricter than 1, and/or
* an active address boundary.
*/
if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
/* Must bounce */
struct bounce_zone *bz;
int maxpages;
if (dmat->bounce_zone == NULL) {
if ((error = alloc_bounce_zone(dmat)) != 0) {
free(slist, M_DEVBUF);
uma_zfree(dmamap_zone, map);
*mapp = NULL;
return (error);
}
}
bz = dmat->bounce_zone;
/* 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 = MAX_BPAGES;
if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
|| (bz->map_count > 0 && bz->total_bpages < maxpages)) {
int pages;
pages = MAX(atop(dmat->maxsize), 1);
pages = MIN(maxpages - bz->total_bpages, pages);
pages = MAX(pages, 1);
if (alloc_bounce_pages(dmat, pages) < pages)
error = ENOMEM;
if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
if (error == 0)
dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
} else {
error = 0;
}
}
bz->map_count++;
}
map->sync_count = 0;
map->slist = slist;
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->flags, error);
return (0);
}
/*
* 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 (STAILQ_FIRST(&map->bpages) != NULL || map->sync_count != 0) {
CTR3(KTR_BUSDMA, "%s: tag %p error %d",
__func__, dmat, EBUSY);
return (EBUSY);
}
free(map->slist, M_DEVBUF);
uma_zfree(dmamap_zone, map);
if (dmat->bounce_zone)
dmat->bounce_zone->map_count--;
CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
return (0);
}
/*
* Allocate a piece of memory that can be efficiently mapped into bus device
* space based on the constraints listed in the dma tag. Returns a pointer to
* the allocated memory, and a pointer to an associated bus_dmamap.
*/
int
bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddrp, int flags,
bus_dmamap_t *mapp)
{
struct sync_list *slist;
void * vaddr;
struct busdma_bufzone *bufzone;
busdma_bufalloc_t ba;
bus_dmamap_t map;
int mflags;
vm_memattr_t memattr;
if (flags & BUS_DMA_NOWAIT)
mflags = M_NOWAIT;
else
mflags = M_WAITOK;
/*
* If the tag's segments haven't been allocated yet we need to do it
* now, because we can't sleep for resources at map load time.
*/
if (dmat->segments == NULL)
dmat->segments = malloc(dmat->nsegments *
sizeof(*dmat->segments), M_DEVBUF, mflags);
slist = malloc(sizeof(*slist) * dmat->nsegments, M_DEVBUF, M_NOWAIT);
if (slist == NULL)
return (ENOMEM);
map = uma_zalloc_arg(dmamap_zone, dmat, mflags);
if (map == NULL) {
free(slist, M_DEVBUF);
return (ENOMEM);
}
if (flags & BUS_DMA_COHERENT) {
memattr = VM_MEMATTR_UNCACHEABLE;
ba = coherent_allocator;
map->flags |= DMAMAP_COHERENT;
} else {
memattr = VM_MEMATTR_DEFAULT;
ba = standard_allocator;
}
/* All buffers we allocate are cache-aligned. */
map->flags |= DMAMAP_CACHE_ALIGNED;
if (flags & BUS_DMA_ZERO)
mflags |= M_ZERO;
/*
* Try to find a bufzone in the allocator that holds a cache of buffers
* of the right size for this request. If the buffer is too big to be
* held in the allocator cache, this returns NULL.
*/
bufzone = busdma_bufalloc_findzone(ba, dmat->maxsize);
/*
* Allocate the buffer from the uma(9) allocator if...
* - It's small enough to be in the allocator (bufzone not NULL).
* - The alignment constraint isn't larger than the allocation size
* (the allocator aligns buffers to their size boundaries).
* - There's no need to handle lowaddr/highaddr exclusion zones.
* else allocate non-contiguous pages if...
* - The page count that could get allocated doesn't exceed nsegments.
* - The alignment constraint isn't larger than a page boundary.
* - There are no boundary-crossing constraints.
* else allocate a block of contiguous pages because one or more of the
* constraints is something that only the contig allocator can fulfill.
*/
if (bufzone != NULL && dmat->alignment <= bufzone->size &&
!_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr)) {
vaddr = uma_zalloc(bufzone->umazone, mflags);
} else if (dmat->nsegments >= btoc(dmat->maxsize) &&
dmat->alignment <= PAGE_SIZE && dmat->boundary == 0) {
vaddr = (void *)kmem_alloc_attr(kernel_arena, dmat->maxsize,
mflags, 0, dmat->lowaddr, memattr);
} else {
vaddr = (void *)kmem_alloc_contig(kernel_arena, dmat->maxsize,
mflags, 0, dmat->lowaddr, dmat->alignment, dmat->boundary,
memattr);
}
if (vaddr == NULL) {
free(slist, M_DEVBUF);
uma_zfree(dmamap_zone, map);
map = NULL;
} else {
map->slist = slist;
map->sync_count = 0;
}
*vaddrp = vaddr;
*mapp = map;
return (vaddr == NULL ? ENOMEM : 0);
}
/*
* Free a piece of memory that was allocated via bus_dmamem_alloc, along with
* its associated map.
*/
void
bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
{
struct busdma_bufzone *bufzone;
busdma_bufalloc_t ba;
if (map->flags & DMAMAP_COHERENT)
ba = coherent_allocator;
else
ba = standard_allocator;
uma_zfree(dmamap_zone, map);
free(map->slist, M_DEVBUF);
/* Be careful not to access map from here on. */
bufzone = busdma_bufalloc_findzone(ba, dmat->maxsize);
if (bufzone != NULL && dmat->alignment <= bufzone->size &&
!_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
uma_zfree(bufzone->umazone, vaddr);
else
kmem_free(kernel_arena, (vm_offset_t)vaddr, dmat->maxsize);
}
static void
_bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
bus_size_t buflen, int flags)
{
bus_addr_t curaddr;
bus_size_t sgsize;
if (map->pagesneeded == 0) {
CTR3(KTR_BUSDMA, "lowaddr= %d, boundary= %d, alignment= %d",
dmat->lowaddr, dmat->boundary, dmat->alignment);
CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
map, map->pagesneeded);
/*
* Count the number of bounce pages
* needed in order to complete this transfer
*/
curaddr = buf;
while (buflen != 0) {
sgsize = MIN(buflen, dmat->maxsegsz);
if (run_filter(dmat, curaddr) != 0) {
sgsize = MIN(sgsize, PAGE_SIZE);
map->pagesneeded++;
}
curaddr += sgsize;
buflen -= sgsize;
}
CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
}
}
static void
_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
void *buf, bus_size_t buflen, int flags)
{
vm_offset_t vaddr;
vm_offset_t vendaddr;
bus_addr_t paddr;
if (map->pagesneeded == 0) {
CTR3(KTR_BUSDMA, "lowaddr= %d, boundary= %d, alignment= %d",
dmat->lowaddr, dmat->boundary, dmat->alignment);
CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
map, map->pagesneeded);
/*
* Count the number of bounce pages
* needed in order to complete this transfer
*/
vaddr = trunc_page((vm_offset_t)buf);
vendaddr = (vm_offset_t)buf + buflen;
while (vaddr < vendaddr) {
if (__predict_true(pmap == kernel_pmap))
paddr = pmap_kextract(vaddr);
else
paddr = pmap_extract(pmap, vaddr);
if (run_filter(dmat, paddr) != 0)
map->pagesneeded++;
vaddr += PAGE_SIZE;
}
CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
}
}
static int
_bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
{
/* Reserve Necessary Bounce Pages */
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 */
STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
mtx_unlock(&bounce_lock);
return (EINPROGRESS);
}
}
mtx_unlock(&bounce_lock);
return (0);
}
/*
* Add a single contiguous physical range to the segment list.
*/
static int
_bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
{
bus_addr_t baddr, bmask;
int seg;
/*
* Make sure we don't cross any boundaries.
*/
bmask = ~(dmat->boundary - 1);
if (dmat->boundary > 0) {
baddr = (curaddr + dmat->boundary) & bmask;
if (sgsize > (baddr - curaddr))
sgsize = (baddr - curaddr);
}
if (dmat->ranges) {
struct arm32_dma_range *dr;
dr = _bus_dma_inrange(dmat->ranges, dmat->_nranges,
curaddr);
if (dr == NULL)
return (0);
/*
* In a valid DMA range. Translate the physical
* memory address to an address in the DMA window.
*/
curaddr = (curaddr - dr->dr_sysbase) + dr->dr_busbase;
}
seg = *segp;
/*
* Insert chunk into a segment, coalescing with
* the previous segment if possible.
*/
if (seg >= 0 &&
curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
(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)
return (0);
segs[seg].ds_addr = curaddr;
segs[seg].ds_len = sgsize;
}
*segp = seg;
return (sgsize);
}
/*
* Utility function to load a physical buffer. segp contains
* the starting segment on entrace, and the ending segment on exit.
*/
int
_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
bus_size_t buflen, int flags, bus_dma_segment_t *segs, int *segp)
{
bus_size_t sgsize;
bus_addr_t curaddr;
int error;
if (segs == NULL)
segs = dmat->segments;
if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
_bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
if (map->pagesneeded != 0) {
error = _bus_dmamap_reserve_pages(dmat, map, flags);
if (error)
return (error);
}
}
while (buflen > 0) {
curaddr = buf;
sgsize = MIN(buflen, dmat->maxsegsz);
if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
map->pagesneeded != 0 && run_filter(dmat, curaddr)) {
sgsize = MIN(sgsize, PAGE_SIZE);
curaddr = add_bounce_page(dmat, map, 0, curaddr,
sgsize);
}
sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
segp);
if (sgsize == 0)
break;
buf += sgsize;
buflen -= sgsize;
}
/*
* Did we fit?
*/
if (buflen != 0) {
_bus_dmamap_unload(dmat, map);
return (EFBIG); /* XXX better return value here? */
}
return (0);
}
int
_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
struct vm_page **ma, bus_size_t tlen, int ma_offs, int flags,
bus_dma_segment_t *segs, int *segp)
{
return (bus_dmamap_load_ma_triv(dmat, map, ma, tlen, ma_offs, flags,
segs, segp));
}
/*
* Utility function to load a linear buffer. segp contains
* the starting segment on entrance, and the ending segment on exit.
*/
int
_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
bus_size_t buflen, struct pmap *pmap, int flags, bus_dma_segment_t *segs,
int *segp)
{
bus_size_t sgsize;
bus_addr_t curaddr;
struct sync_list *sl;
vm_offset_t vaddr = (vm_offset_t)buf;
int error = 0;
if (segs == NULL)
segs = dmat->segments;
if ((flags & BUS_DMA_LOAD_MBUF) != 0)
map->flags |= DMAMAP_CACHE_ALIGNED;
if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
_bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
if (map->pagesneeded != 0) {
error = _bus_dmamap_reserve_pages(dmat, map, flags);
if (error)
return (error);
}
}
CTR3(KTR_BUSDMA, "lowaddr= %d boundary= %d, "
"alignment= %d", dmat->lowaddr, dmat->boundary, dmat->alignment);
while (buflen > 0) {
/*
* Get the physical address for this segment.
*/
if (__predict_true(pmap == kernel_pmap)) {
curaddr = pmap_kextract(vaddr);
} else {
curaddr = pmap_extract(pmap, vaddr);
map->flags &= ~DMAMAP_COHERENT;
}
/*
* Compute the segment size, and adjust counts.
*/
sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
if (sgsize > dmat->maxsegsz)
sgsize = dmat->maxsegsz;
if (buflen < sgsize)
sgsize = buflen;
if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
map->pagesneeded != 0 && run_filter(dmat, curaddr)) {
curaddr = add_bounce_page(dmat, map, vaddr, curaddr,
sgsize);
} else {
sl = &map->slist[map->sync_count - 1];
if (map->sync_count == 0 ||
vaddr != sl->vaddr + sl->datacount) {
if (++map->sync_count > dmat->nsegments)
goto cleanup;
sl++;
sl->vaddr = vaddr;
sl->datacount = sgsize;
sl->busaddr = curaddr;
} else
sl->datacount += sgsize;
}
sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
segp);
if (sgsize == 0)
break;
vaddr += sgsize;
buflen -= sgsize;
}
cleanup:
/*
* Did we fit?
*/
if (buflen != 0) {
_bus_dmamap_unload(dmat, map);
return (EFBIG); /* XXX better return value here? */
}
return (0);
}
void
__bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
struct memdesc *mem, bus_dmamap_callback_t *callback,
void *callback_arg)
{
KASSERT(dmat != NULL, ("dmatag is NULL"));
KASSERT(map != NULL, ("dmamap is NULL"));
map->mem = *mem;
map->callback = callback;
map->callback_arg = callback_arg;
}
bus_dma_segment_t *
_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
bus_dma_segment_t *segs, int nsegs, int error)
{
if (segs == NULL)
segs = dmat->segments;
return (segs);
}
/*
* Release the mapping held by map.
*/
void
_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
{
struct bounce_page *bpage;
while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
STAILQ_REMOVE_HEAD(&map->bpages, links);
free_bounce_page(dmat, bpage);
}
map->sync_count = 0;
return;
}
static void
bus_dmamap_sync_buf(vm_offset_t buf, int len, bus_dmasync_op_t op,
int bufaligned)
{
char _tmp_cl[arm_dcache_align], _tmp_clend[arm_dcache_align];
register_t s;
int partial;
if ((op & BUS_DMASYNC_PREWRITE) && !(op & BUS_DMASYNC_PREREAD)) {
cpu_dcache_wb_range(buf, len);
cpu_l2cache_wb_range(buf, len);
}
/*
* If the caller promises the buffer is properly aligned to a cache line
* (even if the call parms make it look like it isn't) we can avoid
* attempting to preserve the non-DMA part of the cache line in the
* POSTREAD case, but we MUST still do a writeback in the PREREAD case.
*
* This covers the case of mbufs, where we know how they're aligned and
* know the CPU doesn't touch the header in front of the DMA data area
* during the IO, but it may have touched it right before invoking the
* sync, so a PREREAD writeback is required.
*
* It also handles buffers we created in bus_dmamem_alloc(), which are
* always aligned and padded to cache line size even if the IO length
* isn't a multiple of cache line size. In this case the PREREAD
* writeback probably isn't required, but it's harmless.
*/
partial = (((vm_offset_t)buf) | len) & arm_dcache_align_mask;
if (op & BUS_DMASYNC_PREREAD) {
if (!(op & BUS_DMASYNC_PREWRITE) && !partial) {
cpu_dcache_inv_range(buf, len);
cpu_l2cache_inv_range(buf, len);
} else {
cpu_dcache_wbinv_range(buf, len);
cpu_l2cache_wbinv_range(buf, len);
}
}
if (op & BUS_DMASYNC_POSTREAD) {
if (partial && !bufaligned) {
s = intr_disable();
if (buf & arm_dcache_align_mask)
memcpy(_tmp_cl, (void *)(buf &
~arm_dcache_align_mask),
buf & arm_dcache_align_mask);
if ((buf + len) & arm_dcache_align_mask)
memcpy(_tmp_clend,
(void *)(buf + len),
arm_dcache_align -
((buf + len) & arm_dcache_align_mask));
}
cpu_dcache_inv_range(buf, len);
cpu_l2cache_inv_range(buf, len);
if (partial && !bufaligned) {
if (buf & arm_dcache_align_mask)
memcpy((void *)(buf &
~arm_dcache_align_mask), _tmp_cl,
buf & arm_dcache_align_mask);
if ((buf + len) & arm_dcache_align_mask)
memcpy((void *)(buf + len),
_tmp_clend, arm_dcache_align -
((buf + len) & arm_dcache_align_mask));
intr_restore(s);
}
}
}
static void
_bus_dmamap_sync_bp(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
{
struct bounce_page *bpage;
STAILQ_FOREACH(bpage, &map->bpages, links) {
if (op & BUS_DMASYNC_PREWRITE) {
if (bpage->datavaddr != 0)
bcopy((void *)bpage->datavaddr,
(void *)bpage->vaddr, bpage->datacount);
else
physcopyout(bpage->dataaddr,
(void *)bpage->vaddr,bpage->datacount);
cpu_dcache_wb_range(bpage->vaddr, bpage->datacount);
cpu_l2cache_wb_range(bpage->vaddr, bpage->datacount);
dmat->bounce_zone->total_bounced++;
}
if (op & BUS_DMASYNC_POSTREAD) {
cpu_dcache_inv_range(bpage->vaddr, bpage->datacount);
cpu_l2cache_inv_range(bpage->vaddr, bpage->datacount);
if (bpage->datavaddr != 0)
bcopy((void *)bpage->vaddr,
(void *)bpage->datavaddr, bpage->datacount);
else
physcopyin((void *)bpage->vaddr,
bpage->dataaddr, bpage->datacount);
dmat->bounce_zone->total_bounced++;
}
}
}
void
_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
{
struct sync_list *sl, *end;
int bufaligned;
if (op == BUS_DMASYNC_POSTWRITE)
return;
if (map->flags & DMAMAP_COHERENT)
goto drain;
if (STAILQ_FIRST(&map->bpages))
_bus_dmamap_sync_bp(dmat, map, op);
CTR3(KTR_BUSDMA, "%s: op %x flags %x", __func__, op, map->flags);
bufaligned = (map->flags & DMAMAP_CACHE_ALIGNED);
if (map->sync_count) {
end = &map->slist[map->sync_count];
for (sl = &map->slist[0]; sl != end; sl++)
bus_dmamap_sync_buf(sl->vaddr, sl->datacount, op,
bufaligned);
}
drain:
cpu_drain_writebuf();
}
static void
init_bounce_pages(void *dummy __unused)
{
total_bpages = 0;
STAILQ_INIT(&bounce_zone_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 struct sysctl_ctx_list *
busdma_sysctl_tree(struct bounce_zone *bz)
{
return (&bz->sysctl_tree);
}
static struct sysctl_oid *
busdma_sysctl_tree_top(struct bounce_zone *bz)
{
return (bz->sysctl_tree_top);
}
static int
alloc_bounce_zone(bus_dma_tag_t dmat)
{
struct bounce_zone *bz;
/* Check to see if we already have a suitable zone */
STAILQ_FOREACH(bz, &bounce_zone_list, links) {
if ((dmat->alignment <= bz->alignment)
&& (dmat->lowaddr >= bz->lowaddr)) {
dmat->bounce_zone = bz;
return (0);
}
}
if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
M_NOWAIT | M_ZERO)) == NULL)
return (ENOMEM);
STAILQ_INIT(&bz->bounce_page_list);
bz->free_bpages = 0;
bz->reserved_bpages = 0;
bz->active_bpages = 0;
bz->lowaddr = dmat->lowaddr;
bz->alignment = MAX(dmat->alignment, PAGE_SIZE);
bz->map_count = 0;
snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
busdma_zonecount++;
snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
dmat->bounce_zone = bz;
sysctl_ctx_init(&bz->sysctl_tree);
bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
CTLFLAG_RD, 0, "");
if (bz->sysctl_tree_top == NULL) {
sysctl_ctx_free(&bz->sysctl_tree);
return (0); /* XXX error code? */
}
SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
"Total bounce pages");
SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
"Free bounce pages");
SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
"Reserved bounce pages");
SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
"Active bounce pages");
SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
"Total bounce requests");
SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
"Total bounce requests that were deferred");
SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
SYSCTL_ADD_ULONG(busdma_sysctl_tree(bz),
SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
"alignment", CTLFLAG_RD, &bz->alignment, "");
return (0);
}
static int
alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
{
struct bounce_zone *bz;
int count;
bz = dmat->bounce_zone;
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,
bz->lowaddr,
PAGE_SIZE,
0);
if (bpage->vaddr == 0) {
free(bpage, M_DEVBUF);
break;
}
bpage->busaddr = pmap_kextract(bpage->vaddr);
mtx_lock(&bounce_lock);
STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
total_bpages++;
bz->total_bpages++;
bz->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)
{
struct bounce_zone *bz;
int pages;
mtx_assert(&bounce_lock, MA_OWNED);
bz = dmat->bounce_zone;
pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
return (map->pagesneeded - (map->pagesreserved + pages));
bz->free_bpages -= pages;
bz->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_addr_t addr, bus_size_t size)
{
struct bounce_zone *bz;
struct bounce_page *bpage;
KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
bz = dmat->bounce_zone;
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(&bz->bounce_page_list);
if (bpage == NULL)
panic("add_bounce_page: free page list is empty");
STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
bz->reserved_bpages--;
bz->active_bpages++;
mtx_unlock(&bounce_lock);
if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
/* Page offset needs to be preserved. */
bpage->vaddr |= addr & PAGE_MASK;
bpage->busaddr |= addr & PAGE_MASK;
}
bpage->datavaddr = vaddr;
bpage->dataaddr = addr;
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;
struct bounce_zone *bz;
bz = dmat->bounce_zone;
bpage->datavaddr = 0;
bpage->datacount = 0;
if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
/*
* Reset the bounce page to start at offset 0. Other uses
* of this bounce page may need to store a full page of
* data and/or assume it starts on a page boundary.
*/
bpage->vaddr &= ~PAGE_MASK;
bpage->busaddr &= ~PAGE_MASK;
}
mtx_lock(&bounce_lock);
STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
bz->free_bpages++;
bz->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;
bz->total_deferred++;
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_mem(map->dmat, map, &map->mem,
map->callback, map->callback_arg, BUS_DMA_WAITOK);
(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
mtx_lock(&bounce_lock);
}
mtx_unlock(&bounce_lock);
}
Reference in New Issue View Git Blame Copy Permalink