The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/arm/arm/busdma_machdep.c

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    1 /*-
    2  * Copyright (c) 2004 Olivier Houchard
    3  * Copyright (c) 2002 Peter Grehan
    4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions, and the following disclaimer,
   12  *    without modification, immediately at the beginning of the file.
   13  * 2. The name of the author may not be used to endorse or promote products
   14  *    derived from this software without specific prior written permission.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
   20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  *
   28  *   From i386/busdma_machdep.c,v 1.26 2002/04/19 22:58:09 alfred
   29  */
   30 
   31 #include <sys/cdefs.h>
   32 __FBSDID("$FreeBSD$");
   33 
   34 /*
   35  * ARM bus dma support routines
   36  */
   37 
   38 #define _ARM32_BUS_DMA_PRIVATE
   39 #include <sys/param.h>
   40 #include <sys/systm.h>
   41 #include <sys/malloc.h>
   42 #include <sys/bus.h>
   43 #include <sys/interrupt.h>
   44 #include <sys/lock.h>
   45 #include <sys/proc.h>
   46 #include <sys/mutex.h>
   47 #include <sys/mbuf.h>
   48 #include <sys/uio.h>
   49 #include <sys/ktr.h>
   50 #include <sys/kernel.h>
   51 #include <sys/sysctl.h>
   52 
   53 #include <vm/vm.h>
   54 #include <vm/vm_page.h>
   55 #include <vm/vm_map.h>
   56 
   57 #include <machine/atomic.h>
   58 #include <machine/bus.h>
   59 #include <machine/cpufunc.h>
   60 #include <machine/md_var.h>
   61 
   62 #define MAX_BPAGES 64
   63 #define BUS_DMA_COULD_BOUNCE    BUS_DMA_BUS3
   64 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
   65 
   66 struct bounce_zone;
   67 
   68 struct bus_dma_tag {
   69         bus_dma_tag_t           parent;
   70         bus_size_t              alignment;
   71         bus_size_t              boundary;
   72         bus_addr_t              lowaddr;
   73         bus_addr_t              highaddr;
   74         bus_dma_filter_t        *filter;
   75         void                    *filterarg;
   76         bus_size_t              maxsize;
   77         u_int                   nsegments;
   78         bus_size_t              maxsegsz;
   79         int                     flags;
   80         int                     ref_count;
   81         int                     map_count;
   82         bus_dma_lock_t          *lockfunc;
   83         void                    *lockfuncarg;
   84         /*
   85          * DMA range for this tag.  If the page doesn't fall within
   86          * one of these ranges, an error is returned.  The caller
   87          * may then decide what to do with the transfer.  If the
   88          * range pointer is NULL, it is ignored.
   89          */
   90         struct arm32_dma_range  *ranges;
   91         int                     _nranges;
   92         struct bounce_zone *bounce_zone;
   93 };
   94 
   95 struct bounce_page {
   96         vm_offset_t     vaddr;          /* kva of bounce buffer */
   97         vm_offset_t     vaddr_nocache;  /* kva of bounce buffer uncached */
   98         bus_addr_t      busaddr;        /* Physical address */
   99         vm_offset_t     datavaddr;      /* kva of client data */
  100         bus_size_t      datacount;      /* client data count */
  101         STAILQ_ENTRY(bounce_page) links;
  102 };
  103 
  104 int busdma_swi_pending;
  105 
  106 struct bounce_zone {
  107         STAILQ_ENTRY(bounce_zone) links;
  108         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  109         int             total_bpages;
  110         int             free_bpages;
  111         int             reserved_bpages;
  112         int             active_bpages;
  113         int             total_bounced;
  114         int             total_deferred;
  115         bus_size_t      alignment;
  116         bus_size_t      boundary;
  117         bus_addr_t      lowaddr;
  118         char            zoneid[8];
  119         char            lowaddrid[20];
  120         struct sysctl_ctx_list sysctl_tree;
  121         struct sysctl_oid *sysctl_tree_top;
  122 };
  123 
  124 static struct mtx bounce_lock;
  125 static int total_bpages;
  126 static int busdma_zonecount;
  127 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
  128 
  129 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
  130 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
  131            "Total bounce pages");
  132 
  133 #define DMAMAP_LINEAR           0x1
  134 #define DMAMAP_MBUF             0x2
  135 #define DMAMAP_UIO              0x4
  136 #define DMAMAP_ALLOCATED        0x10
  137 #define DMAMAP_TYPE_MASK        (DMAMAP_LINEAR|DMAMAP_MBUF|DMAMAP_UIO)
  138 #define DMAMAP_COHERENT         0x8
  139 struct bus_dmamap {
  140         struct bp_list  bpages;
  141         int             pagesneeded;
  142         int             pagesreserved;
  143         bus_dma_tag_t   dmat;
  144         int             flags;
  145         void            *buffer;
  146         void            *origbuffer;
  147         void            *allocbuffer;
  148         TAILQ_ENTRY(bus_dmamap) freelist;
  149         int             len;
  150         STAILQ_ENTRY(bus_dmamap) links;
  151         bus_dmamap_callback_t *callback;
  152         void                  *callback_arg;
  153 
  154 };
  155 
  156 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
  157 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
  158 
  159 static TAILQ_HEAD(,bus_dmamap) dmamap_freelist = 
  160         TAILQ_HEAD_INITIALIZER(dmamap_freelist);
  161 
  162 #define BUSDMA_STATIC_MAPS      500
  163 static struct bus_dmamap map_pool[BUSDMA_STATIC_MAPS];
  164 
  165 static struct mtx busdma_mtx;
  166 
  167 MTX_SYSINIT(busdma_mtx, &busdma_mtx, "busdma lock", MTX_DEF);
  168 
  169 static void init_bounce_pages(void *dummy);
  170 static int alloc_bounce_zone(bus_dma_tag_t dmat);
  171 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
  172 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
  173                                 int commit);
  174 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
  175                                    vm_offset_t vaddr, bus_size_t size);
  176 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
  177 
  178 /* Default tag, as most drivers provide no parent tag. */
  179 bus_dma_tag_t arm_root_dma_tag;
  180 
  181 /*
  182  * Return true if a match is made.
  183  *
  184  * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
  185  *
  186  * If paddr is within the bounds of the dma tag then call the filter callback
  187  * to check for a match, if there is no filter callback then assume a match.
  188  */
  189 static int
  190 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
  191 {
  192         int retval;
  193 
  194         retval = 0;
  195 
  196         do {
  197                 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
  198                  || ((paddr & (dmat->alignment - 1)) != 0))
  199                  && (dmat->filter == NULL
  200                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
  201                         retval = 1;
  202 
  203                 dmat = dmat->parent;            
  204         } while (retval == 0 && dmat != NULL);
  205         return (retval);
  206 }
  207 
  208 static void
  209 arm_dmamap_freelist_init(void *dummy)
  210 {
  211         int i;
  212 
  213         for (i = 0; i < BUSDMA_STATIC_MAPS; i++) 
  214                 TAILQ_INSERT_HEAD(&dmamap_freelist, &map_pool[i], freelist);
  215 }
  216 
  217 SYSINIT(busdma, SI_SUB_VM, SI_ORDER_ANY, arm_dmamap_freelist_init, NULL);
  218 
  219 /*
  220  * Check to see if the specified page is in an allowed DMA range.
  221  */
  222 
  223 static __inline int
  224 bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
  225     bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
  226     int flags, vm_offset_t *lastaddrp, int *segp);
  227 
  228 static __inline int
  229 _bus_dma_can_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
  230 {
  231         int i;
  232         for (i = 0; phys_avail[i] && phys_avail[i + 1]; i += 2) {
  233                 if ((lowaddr >= phys_avail[i] && lowaddr <= phys_avail[i + 1])
  234                     || (lowaddr < phys_avail[i] && 
  235                     highaddr > phys_avail[i]))
  236                         return (1);
  237         }
  238         return (0);
  239 }
  240 
  241 static __inline struct arm32_dma_range *
  242 _bus_dma_inrange(struct arm32_dma_range *ranges, int nranges,
  243     bus_addr_t curaddr)
  244 {
  245         struct arm32_dma_range *dr;
  246         int i;
  247 
  248         for (i = 0, dr = ranges; i < nranges; i++, dr++) {
  249                 if (curaddr >= dr->dr_sysbase &&
  250                     round_page(curaddr) <= (dr->dr_sysbase + dr->dr_len))
  251                         return (dr);
  252         }
  253 
  254         return (NULL);
  255 }
  256 /*
  257  * Convenience function for manipulating driver locks from busdma (during
  258  * busdma_swi, for example).  Drivers that don't provide their own locks
  259  * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
  260  * non-mutex locking scheme don't have to use this at all.
  261  */
  262 void
  263 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
  264 {
  265         struct mtx *dmtx;
  266 
  267         dmtx = (struct mtx *)arg;
  268         switch (op) {
  269         case BUS_DMA_LOCK:
  270                 mtx_lock(dmtx);
  271                 break;
  272         case BUS_DMA_UNLOCK:
  273                 mtx_unlock(dmtx);
  274                 break;
  275         default:
  276                 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
  277         }
  278 }
  279 
  280 /*
  281  * dflt_lock should never get called.  It gets put into the dma tag when
  282  * lockfunc == NULL, which is only valid if the maps that are associated
  283  * with the tag are meant to never be defered.
  284  * XXX Should have a way to identify which driver is responsible here.
  285  */
  286 static void
  287 dflt_lock(void *arg, bus_dma_lock_op_t op)
  288 {
  289 #ifdef INVARIANTS
  290         panic("driver error: busdma dflt_lock called");
  291 #else
  292         printf("DRIVER_ERROR: busdma dflt_lock called\n");
  293 #endif
  294 }
  295 
  296 static __inline bus_dmamap_t
  297 _busdma_alloc_dmamap(void)
  298 {
  299         bus_dmamap_t map;
  300 
  301         mtx_lock(&busdma_mtx);
  302         map = TAILQ_FIRST(&dmamap_freelist);
  303         if (map)
  304                 TAILQ_REMOVE(&dmamap_freelist, map, freelist);
  305         mtx_unlock(&busdma_mtx);
  306         if (!map) {
  307                 map = malloc(sizeof(*map), M_DEVBUF, M_NOWAIT | M_ZERO);
  308                 if (map)
  309                         map->flags = DMAMAP_ALLOCATED;
  310         } else
  311                 map->flags = 0;
  312         STAILQ_INIT(&map->bpages);
  313         return (map);
  314 }
  315 
  316 static __inline void 
  317 _busdma_free_dmamap(bus_dmamap_t map)
  318 {
  319         if (map->flags & DMAMAP_ALLOCATED)
  320                 free(map, M_DEVBUF);
  321         else {
  322                 mtx_lock(&busdma_mtx);
  323                 TAILQ_INSERT_HEAD(&dmamap_freelist, map, freelist);
  324                 mtx_unlock(&busdma_mtx);
  325         }
  326 }
  327 
  328 /*
  329  * Allocate a device specific dma_tag.
  330  */
  331 #define SEG_NB 1024
  332 
  333 int
  334 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
  335                    bus_size_t boundary, bus_addr_t lowaddr,
  336                    bus_addr_t highaddr, bus_dma_filter_t *filter,
  337                    void *filterarg, bus_size_t maxsize, int nsegments,
  338                    bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
  339                    void *lockfuncarg, bus_dma_tag_t *dmat)
  340 {
  341         bus_dma_tag_t newtag;
  342         int error = 0;
  343         /* Return a NULL tag on failure */
  344         *dmat = NULL;
  345         if (!parent)
  346                 parent = arm_root_dma_tag;
  347 
  348         newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
  349         if (newtag == NULL) {
  350                 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
  351                     __func__, newtag, 0, error);
  352                 return (ENOMEM);
  353         }
  354 
  355         newtag->parent = parent;
  356         newtag->alignment = alignment;
  357         newtag->boundary = boundary;
  358         newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
  359         newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
  360         newtag->filter = filter;
  361         newtag->filterarg = filterarg;
  362         newtag->maxsize = maxsize;
  363         newtag->nsegments = nsegments;
  364         newtag->maxsegsz = maxsegsz;
  365         newtag->flags = flags;
  366         newtag->ref_count = 1; /* Count ourself */
  367         newtag->map_count = 0;
  368         newtag->ranges = bus_dma_get_range();
  369         newtag->_nranges = bus_dma_get_range_nb();
  370         if (lockfunc != NULL) {
  371                 newtag->lockfunc = lockfunc;
  372                 newtag->lockfuncarg = lockfuncarg;
  373         } else {
  374                 newtag->lockfunc = dflt_lock;
  375                 newtag->lockfuncarg = NULL;
  376         }
  377         /*
  378          * Take into account any restrictions imposed by our parent tag
  379          */
  380         if (parent != NULL) {
  381                 newtag->lowaddr = min(parent->lowaddr, newtag->lowaddr);
  382                 newtag->highaddr = max(parent->highaddr, newtag->highaddr);
  383                 if (newtag->boundary == 0)
  384                         newtag->boundary = parent->boundary;
  385                 else if (parent->boundary != 0)
  386                         newtag->boundary = min(parent->boundary,
  387                                                newtag->boundary);
  388                 if ((newtag->filter != NULL) ||
  389                     ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
  390                         newtag->flags |= BUS_DMA_COULD_BOUNCE;
  391                 if (newtag->filter == NULL) {
  392                         /*
  393                          * Short circuit looking at our parent directly
  394                          * since we have encapsulated all of its information
  395                          */
  396                         newtag->filter = parent->filter;
  397                         newtag->filterarg = parent->filterarg;
  398                         newtag->parent = parent->parent;
  399                 }
  400                 if (newtag->parent != NULL)
  401                         atomic_add_int(&parent->ref_count, 1);
  402         }
  403         if (_bus_dma_can_bounce(newtag->lowaddr, newtag->highaddr)
  404          || newtag->alignment > 1)
  405                 newtag->flags |= BUS_DMA_COULD_BOUNCE;
  406 
  407         if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
  408             (flags & BUS_DMA_ALLOCNOW) != 0) {
  409                 struct bounce_zone *bz;
  410 
  411                 /* Must bounce */
  412 
  413                 if ((error = alloc_bounce_zone(newtag)) != 0) {
  414                         free(newtag, M_DEVBUF);
  415                         return (error);
  416                 }
  417                 bz = newtag->bounce_zone;
  418 
  419                 if (ptoa(bz->total_bpages) < maxsize) {
  420                         int pages;
  421 
  422                         pages = atop(maxsize) - bz->total_bpages;
  423 
  424                         /* Add pages to our bounce pool */
  425                         if (alloc_bounce_pages(newtag, pages) < pages)
  426                                 error = ENOMEM;
  427                 }
  428                 /* Performed initial allocation */
  429                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
  430         } else
  431                 newtag->bounce_zone = NULL;
  432         if (error != 0)
  433                 free(newtag, M_DEVBUF);
  434         else
  435                 *dmat = newtag;
  436         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
  437             __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
  438 
  439         return (error);
  440 }
  441 
  442 int
  443 bus_dma_tag_destroy(bus_dma_tag_t dmat)
  444 {
  445 #ifdef KTR
  446         bus_dma_tag_t dmat_copy = dmat;
  447 #endif
  448 
  449         if (dmat != NULL) {
  450                 
  451                 if (dmat->map_count != 0)
  452                         return (EBUSY);
  453                 
  454                 while (dmat != NULL) {
  455                         bus_dma_tag_t parent;
  456                         
  457                         parent = dmat->parent;
  458                         atomic_subtract_int(&dmat->ref_count, 1);
  459                         if (dmat->ref_count == 0) {
  460                                 free(dmat, M_DEVBUF);
  461                                 /*
  462                                  * Last reference count, so
  463                                  * release our reference
  464                                  * count on our parent.
  465                                  */
  466                                 dmat = parent;
  467                         } else
  468                                 dmat = NULL;
  469                 }
  470         }
  471         CTR2(KTR_BUSDMA, "%s tag %p", __func__, dmat_copy);
  472 
  473         return (0);
  474 }
  475 
  476 #include <sys/kdb.h>
  477 /*
  478  * Allocate a handle for mapping from kva/uva/physical
  479  * address space into bus device space.
  480  */
  481 int
  482 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
  483 {
  484         bus_dmamap_t newmap;
  485         int error = 0;
  486 
  487         newmap = _busdma_alloc_dmamap();
  488         if (newmap == NULL) {
  489                 CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
  490                 return (ENOMEM);
  491         }
  492         *mapp = newmap;
  493         newmap->dmat = dmat;
  494         newmap->allocbuffer = NULL;
  495         dmat->map_count++;
  496 
  497         /*
  498          * Bouncing might be required if the driver asks for an active
  499          * exclusion region, a data alignment that is stricter than 1, and/or
  500          * an active address boundary.
  501          */
  502         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
  503 
  504                 /* Must bounce */
  505                 struct bounce_zone *bz;
  506                 int maxpages;
  507 
  508                 if (dmat->bounce_zone == NULL) {
  509                         if ((error = alloc_bounce_zone(dmat)) != 0) {
  510                                 _busdma_free_dmamap(newmap);
  511                                 *mapp = NULL;
  512                                 return (error);
  513                         }
  514                 }
  515                 bz = dmat->bounce_zone;
  516 
  517                 /* Initialize the new map */
  518                 STAILQ_INIT(&((*mapp)->bpages));
  519 
  520                 /*
  521                  * Attempt to add pages to our pool on a per-instance
  522                  * basis up to a sane limit.
  523                  */
  524                 maxpages = MAX_BPAGES;
  525                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
  526                  || (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
  527                         int pages;
  528 
  529                         pages = MAX(atop(dmat->maxsize), 1);
  530                         pages = MIN(maxpages - bz->total_bpages, pages);
  531                         pages = MAX(pages, 1);
  532                         if (alloc_bounce_pages(dmat, pages) < pages)
  533                                 error = ENOMEM;
  534 
  535                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
  536                                 if (error == 0)
  537                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
  538                         } else {
  539                                 error = 0;
  540                         }
  541                 }
  542         }
  543         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
  544             __func__, dmat, dmat->flags, error);
  545 
  546         return (0);
  547 }
  548 
  549 /*
  550  * Destroy a handle for mapping from kva/uva/physical
  551  * address space into bus device space.
  552  */
  553 int
  554 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
  555 {
  556 
  557         _busdma_free_dmamap(map);
  558         if (STAILQ_FIRST(&map->bpages) != NULL) {
  559                 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
  560                     __func__, dmat, EBUSY);
  561                 return (EBUSY);
  562         }
  563         dmat->map_count--;
  564         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
  565         return (0);
  566 }
  567 
  568 /*
  569  * Allocate a piece of memory that can be efficiently mapped into
  570  * bus device space based on the constraints lited in the dma tag.
  571  * A dmamap to for use with dmamap_load is also allocated.
  572  */
  573 int
  574 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
  575                  bus_dmamap_t *mapp)
  576 {
  577         bus_dmamap_t newmap = NULL;
  578 
  579         int mflags;
  580 
  581         if (flags & BUS_DMA_NOWAIT)
  582                 mflags = M_NOWAIT;
  583         else
  584                 mflags = M_WAITOK;
  585         if (flags & BUS_DMA_ZERO)
  586                 mflags |= M_ZERO;
  587 
  588         newmap = _busdma_alloc_dmamap();
  589         if (newmap == NULL) {
  590                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
  591                     __func__, dmat, dmat->flags, ENOMEM);
  592                 return (ENOMEM);
  593         }
  594         dmat->map_count++;
  595         *mapp = newmap;
  596         newmap->dmat = dmat;
  597         
  598         if (dmat->maxsize <= PAGE_SIZE &&
  599            (dmat->alignment < dmat->maxsize) &&
  600            !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr)) {
  601                 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
  602         } else {
  603                 /*
  604                  * XXX Use Contigmalloc until it is merged into this facility
  605                  *     and handles multi-seg allocations.  Nobody is doing
  606                  *     multi-seg allocations yet though.
  607                  */
  608                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
  609                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
  610                     dmat->boundary);
  611         }
  612         if (*vaddr == NULL) {
  613                 if (newmap != NULL) {
  614                         _busdma_free_dmamap(newmap);
  615                         dmat->map_count--;
  616                 }
  617                 *mapp = NULL;
  618                 return (ENOMEM);
  619         }
  620         if (flags & BUS_DMA_COHERENT) {
  621                 void *tmpaddr = arm_remap_nocache(
  622                     (void *)((vm_offset_t)*vaddr &~ PAGE_MASK),
  623                     dmat->maxsize + ((vm_offset_t)*vaddr & PAGE_MASK));
  624 
  625                 if (tmpaddr) {
  626                         tmpaddr = (void *)((vm_offset_t)(tmpaddr) +
  627                             ((vm_offset_t)*vaddr & PAGE_MASK));
  628                         newmap->origbuffer = *vaddr;
  629                         newmap->allocbuffer = tmpaddr;
  630                         cpu_idcache_wbinv_range((vm_offset_t)*vaddr, 
  631                             dmat->maxsize);
  632                         *vaddr = tmpaddr;
  633                 } else
  634                         newmap->origbuffer = newmap->allocbuffer = NULL;
  635         } else 
  636                 newmap->origbuffer = newmap->allocbuffer = NULL;
  637         return (0);
  638 }
  639 
  640 /*
  641  * Free a piece of memory and it's allocated dmamap, that was allocated
  642  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
  643  */
  644 void
  645 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
  646 {
  647         if (map->allocbuffer) {
  648                 KASSERT(map->allocbuffer == vaddr,
  649                     ("Trying to freeing the wrong DMA buffer"));
  650                 vaddr = map->origbuffer;
  651                 arm_unmap_nocache(map->allocbuffer, dmat->maxsize);
  652         }
  653         if (dmat->maxsize <= PAGE_SIZE &&
  654            dmat->alignment < dmat->maxsize &&
  655             !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
  656                 free(vaddr, M_DEVBUF);
  657         else {
  658                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
  659         }
  660         dmat->map_count--;
  661         _busdma_free_dmamap(map);
  662         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
  663 }
  664 
  665 static int
  666 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
  667                         bus_size_t buflen, int flags)
  668 {
  669         vm_offset_t vaddr;
  670         vm_offset_t vendaddr;
  671         bus_addr_t paddr;
  672 
  673         if ((map->pagesneeded == 0)) {
  674                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
  675                     "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
  676                     dmat->boundary, dmat->alignment);
  677                 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
  678                     map, map->pagesneeded);
  679                 /*
  680                  * Count the number of bounce pages
  681                  * needed in order to complete this transfer
  682                  */
  683                 vaddr = trunc_page((vm_offset_t)buf);
  684                 vendaddr = (vm_offset_t)buf + buflen;
  685 
  686                 while (vaddr < vendaddr) {
  687                         paddr = pmap_kextract(vaddr);
  688                         if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
  689                             run_filter(dmat, paddr) != 0)
  690                                 map->pagesneeded++;
  691                         vaddr += PAGE_SIZE;
  692                 }
  693                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
  694         }
  695 
  696         /* Reserve Necessary Bounce Pages */
  697         if (map->pagesneeded != 0) {
  698                 mtx_lock(&bounce_lock);
  699                 if (flags & BUS_DMA_NOWAIT) {
  700                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
  701                                 mtx_unlock(&bounce_lock);
  702                                 return (ENOMEM);
  703                         }
  704                 } else {
  705                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
  706                                 /* Queue us for resources */
  707                                 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
  708                                     map, links);
  709                                 mtx_unlock(&bounce_lock);
  710                                 return (EINPROGRESS);
  711                         }
  712                 }
  713                 mtx_unlock(&bounce_lock);
  714         }
  715 
  716         return (0);
  717 }
  718 
  719 /*
  720  * Utility function to load a linear buffer.  lastaddrp holds state
  721  * between invocations (for multiple-buffer loads).  segp contains
  722  * the starting segment on entrance, and the ending segment on exit.
  723  * first indicates if this is the first invocation of this function.
  724  */
  725 static __inline int
  726 bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
  727     bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
  728     int flags, vm_offset_t *lastaddrp, int *segp)
  729 {
  730         bus_size_t sgsize;
  731         bus_addr_t curaddr, lastaddr, baddr, bmask;
  732         vm_offset_t vaddr = (vm_offset_t)buf;
  733         int seg;
  734         int error = 0;
  735         pd_entry_t *pde;
  736         pt_entry_t pte;
  737         pt_entry_t *ptep;
  738 
  739         lastaddr = *lastaddrp;
  740         bmask = ~(dmat->boundary - 1);
  741 
  742         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
  743                 error = _bus_dmamap_count_pages(dmat, map, buf, buflen, flags);
  744                 if (error)
  745                         return (error);
  746         }
  747         CTR3(KTR_BUSDMA, "lowaddr= %d boundary= %d, "
  748             "alignment= %d", dmat->lowaddr, dmat->boundary, dmat->alignment);
  749 
  750         for (seg = *segp; buflen > 0 ; ) {
  751                 /*
  752                  * Get the physical address for this segment.
  753                  *
  754                  * XXX Don't support checking for coherent mappings
  755                  * XXX in user address space.
  756                  */
  757                 if (__predict_true(pmap == pmap_kernel())) {
  758                         if (pmap_get_pde_pte(pmap, vaddr, &pde, &ptep) == FALSE)
  759                                 return (EFAULT);
  760 
  761                         if (__predict_false(pmap_pde_section(pde))) {
  762                                 if (*pde & L1_S_SUPERSEC)
  763                                         curaddr = (*pde & L1_SUP_FRAME) |
  764                                             (vaddr & L1_SUP_OFFSET);
  765                                 else
  766                                         curaddr = (*pde & L1_S_FRAME) |
  767                                             (vaddr & L1_S_OFFSET);
  768                                 if (*pde & L1_S_CACHE_MASK) {
  769                                         map->flags &=
  770                                             ~DMAMAP_COHERENT;
  771                                 }
  772                         } else {
  773                                 pte = *ptep;
  774                                 KASSERT((pte & L2_TYPE_MASK) != L2_TYPE_INV,
  775                                     ("INV type"));
  776                                 if (__predict_false((pte & L2_TYPE_MASK)
  777                                                     == L2_TYPE_L)) {
  778                                         curaddr = (pte & L2_L_FRAME) |
  779                                             (vaddr & L2_L_OFFSET);
  780                                         if (pte & L2_L_CACHE_MASK) {
  781                                                 map->flags &=
  782                                                     ~DMAMAP_COHERENT;
  783                                                 
  784                                         }
  785                                 } else {
  786                                         curaddr = (pte & L2_S_FRAME) |
  787                                             (vaddr & L2_S_OFFSET);
  788                                         if (pte & L2_S_CACHE_MASK) {
  789                                                 map->flags &=
  790                                                     ~DMAMAP_COHERENT;
  791                                         }
  792                                 }
  793                         }
  794                 } else {
  795                         curaddr = pmap_extract(pmap, vaddr);
  796                         map->flags &= ~DMAMAP_COHERENT;
  797                 }
  798 
  799                 /*
  800                  * Compute the segment size, and adjust counts.
  801                  */
  802                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
  803                 if (sgsize > dmat->maxsegsz)
  804                         sgsize = dmat->maxsegsz;
  805                 if (buflen < sgsize)
  806                         sgsize = buflen;
  807 
  808                 /*
  809                  * Make sure we don't cross any boundaries.
  810                  */
  811                 if (dmat->boundary > 0) {
  812                         baddr = (curaddr + dmat->boundary) & bmask;
  813                         if (sgsize > (baddr - curaddr))
  814                                 sgsize = (baddr - curaddr);
  815                 }
  816                 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
  817                     map->pagesneeded != 0 && run_filter(dmat, curaddr))
  818                         curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
  819 
  820                 if (dmat->ranges) {
  821                         struct arm32_dma_range *dr;
  822 
  823                         dr = _bus_dma_inrange(dmat->ranges, dmat->_nranges,
  824                             curaddr);
  825                         if (dr == NULL)
  826                                 return (EINVAL);
  827                         /*
  828                          * In a valid DMA range.  Translate the physical
  829                          * memory address to an address in the DMA window.
  830                          */
  831                         curaddr = (curaddr - dr->dr_sysbase) + dr->dr_busbase;
  832                                                 
  833                 }
  834 
  835                 /*
  836                  * Insert chunk into a segment, coalescing with
  837                  * the previous segment if possible.
  838                  */
  839                 if (seg >= 0 && curaddr == lastaddr &&
  840                     (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
  841                     (dmat->boundary == 0 ||
  842                      (segs[seg].ds_addr & bmask) == 
  843                      (curaddr & bmask))) {
  844                         segs[seg].ds_len += sgsize;
  845                         goto segdone;
  846                 } else {
  847                         if (++seg >= dmat->nsegments)
  848                                 break;
  849                         segs[seg].ds_addr = curaddr;
  850                         segs[seg].ds_len = sgsize;
  851                 }
  852                 if (error)
  853                         break;
  854 segdone:
  855                 lastaddr = curaddr + sgsize;
  856                 vaddr += sgsize;
  857                 buflen -= sgsize;
  858         }
  859 
  860         *segp = seg;
  861         *lastaddrp = lastaddr;
  862 
  863         /*
  864          * Did we fit?
  865          */
  866         if (buflen != 0)
  867                 error = EFBIG; /* XXX better return value here? */
  868         return (error);
  869 }
  870 
  871 /*
  872  * Map the buffer buf into bus space using the dmamap map.
  873  */
  874 int
  875 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
  876                 bus_size_t buflen, bus_dmamap_callback_t *callback,
  877                 void *callback_arg, int flags)
  878 {
  879         vm_offset_t     lastaddr = 0;
  880         int             error, nsegs = -1;
  881 #ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
  882         bus_dma_segment_t dm_segments[dmat->nsegments];
  883 #else
  884         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
  885 #endif
  886 
  887         KASSERT(dmat != NULL, ("dmatag is NULL"));
  888         KASSERT(map != NULL, ("dmamap is NULL"));
  889         map->callback = callback;
  890         map->callback_arg = callback_arg;
  891         map->flags &= ~DMAMAP_TYPE_MASK;
  892         map->flags |= DMAMAP_LINEAR|DMAMAP_COHERENT;
  893         map->buffer = buf;
  894         map->len = buflen;
  895         error = bus_dmamap_load_buffer(dmat,
  896             dm_segments, map, buf, buflen, kernel_pmap,
  897             flags, &lastaddr, &nsegs);
  898         if (error == EINPROGRESS)
  899                 return (error);
  900         if (error)
  901                 (*callback)(callback_arg, NULL, 0, error);
  902         else
  903                 (*callback)(callback_arg, dm_segments, nsegs + 1, error);
  904         
  905         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  906             __func__, dmat, dmat->flags, nsegs + 1, error);
  907 
  908         return (error);
  909 }
  910 
  911 /*
  912  * Like bus_dmamap_load(), but for mbufs.
  913  */
  914 int
  915 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
  916                      bus_dmamap_callback2_t *callback, void *callback_arg,
  917                      int flags)
  918 {
  919 #ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
  920         bus_dma_segment_t dm_segments[dmat->nsegments];
  921 #else
  922         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
  923 #endif
  924         int nsegs = -1, error = 0;
  925 
  926         M_ASSERTPKTHDR(m0);
  927 
  928         map->flags &= ~DMAMAP_TYPE_MASK;
  929         map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
  930         map->buffer = m0;
  931         map->len = 0;
  932         if (m0->m_pkthdr.len <= dmat->maxsize) {
  933                 vm_offset_t lastaddr = 0;
  934                 struct mbuf *m;
  935 
  936                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
  937                         if (m->m_len > 0) {
  938                                 error = bus_dmamap_load_buffer(dmat,
  939                                     dm_segments, map, m->m_data, m->m_len, 
  940                                     pmap_kernel(), flags, &lastaddr, &nsegs);
  941                                 map->len += m->m_len;
  942                         }
  943                 }
  944         } else {
  945                 error = EINVAL;
  946         }
  947 
  948         if (error) {
  949                 /* 
  950                  * force "no valid mappings" on error in callback.
  951                  */
  952                 (*callback)(callback_arg, dm_segments, 0, 0, error);
  953         } else {
  954                 (*callback)(callback_arg, dm_segments, nsegs + 1,
  955                     m0->m_pkthdr.len, error);
  956         }
  957         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  958             __func__, dmat, dmat->flags, error, nsegs + 1);
  959 
  960         return (error);
  961 }
  962 
  963 int
  964 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
  965                         struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
  966                         int flags)
  967 {
  968         int error = 0;
  969         M_ASSERTPKTHDR(m0);
  970 
  971         flags |= BUS_DMA_NOWAIT;
  972         *nsegs = -1;
  973         map->flags &= ~DMAMAP_TYPE_MASK;
  974         map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
  975         map->buffer = m0;                       
  976         map->len = 0;
  977         if (m0->m_pkthdr.len <= dmat->maxsize) {
  978                 vm_offset_t lastaddr = 0;
  979                 struct mbuf *m;
  980 
  981                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
  982                         if (m->m_len > 0) {
  983                                 error = bus_dmamap_load_buffer(dmat, segs, map,
  984                                                 m->m_data, m->m_len,
  985                                                 pmap_kernel(), flags, &lastaddr,
  986                                                 nsegs);
  987                                 map->len += m->m_len;
  988                         }
  989                 }
  990         } else {
  991                 error = EINVAL;
  992         }
  993 
  994         /* XXX FIXME: Having to increment nsegs is really annoying */
  995         ++*nsegs;
  996         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
  997             __func__, dmat, dmat->flags, error, *nsegs);
  998         return (error);
  999 }
 1000 
 1001 /*
 1002  * Like bus_dmamap_load(), but for uios.
 1003  */
 1004 int
 1005 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
 1006     bus_dmamap_callback2_t *callback, void *callback_arg,
 1007     int flags)
 1008 {
 1009         vm_offset_t lastaddr = 0;
 1010 #ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
 1011         bus_dma_segment_t dm_segments[dmat->nsegments];
 1012 #else
 1013         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 1014 #endif
 1015         int nsegs, i, error;
 1016         bus_size_t resid;
 1017         struct iovec *iov;
 1018         struct pmap *pmap;
 1019 
 1020         resid = uio->uio_resid;
 1021         iov = uio->uio_iov;
 1022         map->flags &= ~DMAMAP_TYPE_MASK;
 1023         map->flags |= DMAMAP_UIO|DMAMAP_COHERENT;
 1024         map->buffer = uio;
 1025         map->len = 0;
 1026 
 1027         if (uio->uio_segflg == UIO_USERSPACE) {
 1028                 KASSERT(uio->uio_td != NULL,
 1029                     ("bus_dmamap_load_uio: USERSPACE but no proc"));
 1030                 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
 1031         } else
 1032                 pmap = kernel_pmap;
 1033 
 1034         error = 0;
 1035         nsegs = -1;
 1036         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 1037                 /*
 1038                  * Now at the first iovec to load.  Load each iovec
 1039                  * until we have exhausted the residual count.
 1040                  */
 1041                 bus_size_t minlen =
 1042                     resid < iov[i].iov_len ? resid : iov[i].iov_len;
 1043                 caddr_t addr = (caddr_t) iov[i].iov_base;
 1044 
 1045                 if (minlen > 0) {
 1046                         error = bus_dmamap_load_buffer(dmat, dm_segments, map,
 1047                             addr, minlen, pmap, flags, &lastaddr, &nsegs);
 1048 
 1049                         map->len += minlen;
 1050                         resid -= minlen;
 1051                 }
 1052         }
 1053 
 1054         if (error) {
 1055                 /* 
 1056                  * force "no valid mappings" on error in callback.
 1057                  */
 1058                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 1059         } else {
 1060                 (*callback)(callback_arg, dm_segments, nsegs+1,
 1061                     uio->uio_resid, error);
 1062         }
 1063 
 1064         CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
 1065             __func__, dmat, dmat->flags, error, nsegs + 1);
 1066         return (error);
 1067 }
 1068 
 1069 /*
 1070  * Release the mapping held by map.
 1071  */
 1072 void
 1073 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 1074 {
 1075         struct bounce_page *bpage;
 1076 
 1077         map->flags &= ~DMAMAP_TYPE_MASK;
 1078         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 1079                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 1080                 free_bounce_page(dmat, bpage);
 1081         }
 1082         return;
 1083 }
 1084 
 1085 static void
 1086 bus_dmamap_sync_buf(void *buf, int len, bus_dmasync_op_t op)
 1087 {
 1088         char _tmp_cl[arm_dcache_align], _tmp_clend[arm_dcache_align];
 1089 
 1090         if ((op & BUS_DMASYNC_PREWRITE) && !(op & BUS_DMASYNC_PREREAD)) {
 1091                 cpu_dcache_wb_range((vm_offset_t)buf, len);
 1092                 cpu_l2cache_wb_range((vm_offset_t)buf, len);
 1093         }
 1094         if (op & BUS_DMASYNC_PREREAD) {
 1095                 if (!(op & BUS_DMASYNC_PREWRITE) &&
 1096                     ((((vm_offset_t)(buf) | len) & arm_dcache_align_mask) == 0)) {
 1097                         cpu_dcache_inv_range((vm_offset_t)buf, len);
 1098                         cpu_l2cache_inv_range((vm_offset_t)buf, len);
 1099                 } else {
 1100                         cpu_dcache_wbinv_range((vm_offset_t)buf, len);
 1101                         cpu_l2cache_wbinv_range((vm_offset_t)buf, len);
 1102                 }
 1103         }
 1104         if (op & BUS_DMASYNC_POSTREAD) {
 1105                 if ((vm_offset_t)buf & arm_dcache_align_mask) {
 1106                         memcpy(_tmp_cl, (void *)((vm_offset_t)buf & ~
 1107                             arm_dcache_align_mask),
 1108                             (vm_offset_t)buf & arm_dcache_align_mask);
 1109                 }
 1110                 if (((vm_offset_t)buf + len) & arm_dcache_align_mask) {
 1111                         memcpy(_tmp_clend, (void *)((vm_offset_t)buf + len),
 1112                             arm_dcache_align - (((vm_offset_t)(buf) + len) &
 1113                            arm_dcache_align_mask));
 1114                 }
 1115                 cpu_dcache_inv_range((vm_offset_t)buf, len);
 1116                 cpu_l2cache_inv_range((vm_offset_t)buf, len);
 1117 
 1118                 if ((vm_offset_t)buf & arm_dcache_align_mask)
 1119                         memcpy((void *)((vm_offset_t)buf &
 1120                             ~arm_dcache_align_mask), _tmp_cl, 
 1121                             (vm_offset_t)buf & arm_dcache_align_mask);
 1122                 if (((vm_offset_t)buf + len) & arm_dcache_align_mask)
 1123                         memcpy((void *)((vm_offset_t)buf + len), _tmp_clend,
 1124                             arm_dcache_align - (((vm_offset_t)(buf) + len) &
 1125                            arm_dcache_align_mask));
 1126         }
 1127 }
 1128 
 1129 static void
 1130 _bus_dmamap_sync_bp(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 1131 {
 1132         struct bounce_page *bpage;
 1133 
 1134         STAILQ_FOREACH(bpage, &map->bpages, links) {
 1135                 if (op & BUS_DMASYNC_PREWRITE) {
 1136                         bcopy((void *)bpage->datavaddr,
 1137                             (void *)(bpage->vaddr_nocache != 0 ? 
 1138                                      bpage->vaddr_nocache : bpage->vaddr),
 1139                             bpage->datacount);
 1140                         if (bpage->vaddr_nocache == 0) {
 1141                                 cpu_dcache_wb_range(bpage->vaddr,
 1142                                     bpage->datacount);
 1143                                 cpu_l2cache_wb_range(bpage->vaddr,
 1144                                     bpage->datacount);
 1145                         }
 1146                 }
 1147                 if (op & BUS_DMASYNC_POSTREAD) {
 1148                         if (bpage->vaddr_nocache == 0) {
 1149                                 cpu_dcache_inv_range(bpage->vaddr,
 1150                                     bpage->datacount);
 1151                                 cpu_l2cache_inv_range(bpage->vaddr,
 1152                                     bpage->datacount);
 1153                         }
 1154                         bcopy((void *)(bpage->vaddr_nocache != 0 ? 
 1155                             bpage->vaddr_nocache : bpage->vaddr),
 1156                             (void *)bpage->datavaddr, bpage->datacount);
 1157                 }
 1158         }
 1159 }
 1160 
 1161 static __inline int
 1162 _bus_dma_buf_is_in_bp(bus_dmamap_t map, void *buf, int len)
 1163 {
 1164         struct bounce_page *bpage;
 1165 
 1166         STAILQ_FOREACH(bpage, &map->bpages, links) {
 1167                 if ((vm_offset_t)buf >= bpage->datavaddr &&
 1168                     (vm_offset_t)buf + len < bpage->datavaddr + 
 1169                     bpage->datacount)
 1170                         return (1);
 1171         }
 1172         return (0);
 1173 
 1174 }
 1175 
 1176 void
 1177 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 1178 {
 1179         struct mbuf *m;
 1180         struct uio *uio;
 1181         int resid;
 1182         struct iovec *iov;
 1183         
 1184         if (op == BUS_DMASYNC_POSTWRITE)
 1185                 return;
 1186         if (STAILQ_FIRST(&map->bpages))
 1187                 _bus_dmamap_sync_bp(dmat, map, op);
 1188         if (map->flags & DMAMAP_COHERENT)
 1189                 return;
 1190         CTR3(KTR_BUSDMA, "%s: op %x flags %x", __func__, op, map->flags);
 1191         switch(map->flags & DMAMAP_TYPE_MASK) {
 1192         case DMAMAP_LINEAR:
 1193                 if (!(_bus_dma_buf_is_in_bp(map, map->buffer, map->len)))
 1194                         bus_dmamap_sync_buf(map->buffer, map->len, op);
 1195                 break;
 1196         case DMAMAP_MBUF:
 1197                 m = map->buffer;
 1198                 while (m) {
 1199                         if (m->m_len > 0 &&
 1200                             !(_bus_dma_buf_is_in_bp(map, m->m_data, m->m_len)))
 1201                                 bus_dmamap_sync_buf(m->m_data, m->m_len, op);
 1202                         m = m->m_next;
 1203                 }
 1204                 break;
 1205         case DMAMAP_UIO:
 1206                 uio = map->buffer;
 1207                 iov = uio->uio_iov;
 1208                 resid = uio->uio_resid;
 1209                 for (int i = 0; i < uio->uio_iovcnt && resid != 0; i++) {
 1210                         bus_size_t minlen = resid < iov[i].iov_len ? resid :
 1211                             iov[i].iov_len;
 1212                         if (minlen > 0) {
 1213                                 if (!_bus_dma_buf_is_in_bp(map, iov[i].iov_base,
 1214                                     minlen))
 1215                                         bus_dmamap_sync_buf(iov[i].iov_base,
 1216                                             minlen, op);
 1217                                 resid -= minlen;
 1218                         }
 1219                 }
 1220                 break;
 1221         default:
 1222                 break;
 1223         }
 1224         cpu_drain_writebuf();
 1225 }
 1226 
 1227 static void
 1228 init_bounce_pages(void *dummy __unused)
 1229 {
 1230 
 1231         total_bpages = 0;
 1232         STAILQ_INIT(&bounce_zone_list);
 1233         STAILQ_INIT(&bounce_map_waitinglist);
 1234         STAILQ_INIT(&bounce_map_callbacklist);
 1235         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
 1236 }
 1237 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
 1238 
 1239 static struct sysctl_ctx_list *
 1240 busdma_sysctl_tree(struct bounce_zone *bz)
 1241 {
 1242         return (&bz->sysctl_tree);
 1243 }
 1244 
 1245 static struct sysctl_oid *
 1246 busdma_sysctl_tree_top(struct bounce_zone *bz)
 1247 {
 1248         return (bz->sysctl_tree_top);
 1249 }
 1250 
 1251 static int
 1252 alloc_bounce_zone(bus_dma_tag_t dmat)
 1253 {
 1254         struct bounce_zone *bz;
 1255 
 1256         /* Check to see if we already have a suitable zone */
 1257         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
 1258                 if ((dmat->alignment <= bz->alignment)
 1259                  && (dmat->boundary <= bz->boundary)
 1260                  && (dmat->lowaddr >= bz->lowaddr)) {
 1261                         dmat->bounce_zone = bz;
 1262                         return (0);
 1263                 }
 1264         }
 1265 
 1266         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
 1267             M_NOWAIT | M_ZERO)) == NULL)
 1268                 return (ENOMEM);
 1269 
 1270         STAILQ_INIT(&bz->bounce_page_list);
 1271         bz->free_bpages = 0;
 1272         bz->reserved_bpages = 0;
 1273         bz->active_bpages = 0;
 1274         bz->lowaddr = dmat->lowaddr;
 1275         bz->alignment = dmat->alignment;
 1276         bz->boundary = dmat->boundary;
 1277         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
 1278         busdma_zonecount++;
 1279         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
 1280         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
 1281         dmat->bounce_zone = bz;
 1282 
 1283         sysctl_ctx_init(&bz->sysctl_tree);
 1284         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
 1285             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
 1286             CTLFLAG_RD, 0, "");
 1287         if (bz->sysctl_tree_top == NULL) {
 1288                 sysctl_ctx_free(&bz->sysctl_tree);
 1289                 return (0);     /* XXX error code? */
 1290         }
 1291 
 1292         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1293             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1294             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
 1295             "Total bounce pages");
 1296         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1297             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1298             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
 1299             "Free bounce pages");
 1300         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1301             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1302             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
 1303             "Reserved bounce pages");
 1304         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1305             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1306             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
 1307             "Active bounce pages");
 1308         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1309             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1310             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
 1311             "Total bounce requests");
 1312         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1313             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1314             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
 1315             "Total bounce requests that were deferred");
 1316         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
 1317             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1318             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
 1319         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1320             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1321             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
 1322         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 1323             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 1324             "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
 1325 
 1326         return (0);
 1327 }
 1328 
 1329 static int
 1330 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 1331 {
 1332         struct bounce_zone *bz;
 1333         int count;
 1334 
 1335         bz = dmat->bounce_zone;
 1336         count = 0;
 1337         while (numpages > 0) {
 1338                 struct bounce_page *bpage;
 1339 
 1340                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 1341                                                      M_NOWAIT | M_ZERO);
 1342 
 1343                 if (bpage == NULL)
 1344                         break;
 1345                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 1346                                                          M_NOWAIT, 0ul,
 1347                                                          bz->lowaddr,
 1348                                                          PAGE_SIZE,
 1349                                                          bz->boundary);
 1350                 if (bpage->vaddr == 0) {
 1351                         free(bpage, M_DEVBUF);
 1352                         break;
 1353                 }
 1354                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 1355                 bpage->vaddr_nocache = (vm_offset_t)arm_remap_nocache(
 1356                     (void *)bpage->vaddr, PAGE_SIZE);
 1357                 mtx_lock(&bounce_lock);
 1358                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
 1359                 total_bpages++;
 1360                 bz->total_bpages++;
 1361                 bz->free_bpages++;
 1362                 mtx_unlock(&bounce_lock);
 1363                 count++;
 1364                 numpages--;
 1365         }
 1366         return (count);
 1367 }
 1368 
 1369 static int
 1370 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 1371 {
 1372         struct bounce_zone *bz;
 1373         int pages;
 1374 
 1375         mtx_assert(&bounce_lock, MA_OWNED);
 1376         bz = dmat->bounce_zone;
 1377         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
 1378         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
 1379                 return (map->pagesneeded - (map->pagesreserved + pages));
 1380         bz->free_bpages -= pages;
 1381         bz->reserved_bpages += pages;
 1382         map->pagesreserved += pages;
 1383         pages = map->pagesneeded - map->pagesreserved;
 1384 
 1385         return (pages);
 1386 }
 1387 
 1388 static bus_addr_t
 1389 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 1390                 bus_size_t size)
 1391 {
 1392         struct bounce_zone *bz;
 1393         struct bounce_page *bpage;
 1394 
 1395         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
 1396         KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
 1397 
 1398         bz = dmat->bounce_zone;
 1399         if (map->pagesneeded == 0)
 1400                 panic("add_bounce_page: map doesn't need any pages");
 1401         map->pagesneeded--;
 1402 
 1403         if (map->pagesreserved == 0)
 1404                 panic("add_bounce_page: map doesn't need any pages");
 1405         map->pagesreserved--;
 1406 
 1407         mtx_lock(&bounce_lock);
 1408         bpage = STAILQ_FIRST(&bz->bounce_page_list);
 1409         if (bpage == NULL)
 1410                 panic("add_bounce_page: free page list is empty");
 1411 
 1412         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
 1413         bz->reserved_bpages--;
 1414         bz->active_bpages++;
 1415         mtx_unlock(&bounce_lock);
 1416 
 1417         bpage->datavaddr = vaddr;
 1418         bpage->datacount = size;
 1419         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 1420         return (bpage->busaddr);
 1421 }
 1422 
 1423 static void
 1424 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 1425 {
 1426         struct bus_dmamap *map;
 1427         struct bounce_zone *bz;
 1428 
 1429         bz = dmat->bounce_zone;
 1430         bpage->datavaddr = 0;
 1431         bpage->datacount = 0;
 1432 
 1433         mtx_lock(&bounce_lock);
 1434         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
 1435         bz->free_bpages++;
 1436         bz->active_bpages--;
 1437         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 1438                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
 1439                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 1440                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 1441                                            map, links);
 1442                         busdma_swi_pending = 1;
 1443                         bz->total_deferred++;
 1444                         swi_sched(vm_ih, 0);
 1445                 }
 1446         }
 1447         mtx_unlock(&bounce_lock);
 1448 }
 1449 
 1450 void
 1451 busdma_swi(void)
 1452 {
 1453         bus_dma_tag_t dmat;
 1454         struct bus_dmamap *map;
 1455 
 1456         mtx_lock(&bounce_lock);
 1457         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 1458                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 1459                 mtx_unlock(&bounce_lock);
 1460                 dmat = map->dmat;
 1461                 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
 1462                 bus_dmamap_load(map->dmat, map, map->buffer, map->len,
 1463                     map->callback, map->callback_arg, /*flags*/0);
 1464                 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
 1465                 mtx_lock(&bounce_lock);
 1466         }
 1467         mtx_unlock(&bounce_lock);
 1468 }

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