subr_mbpool.c

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    1 /*-
    2  * Copyright (c) 2003
    3  *      Fraunhofer Institute for Open Communication Systems (FhG Fokus).
    4  *      All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   25  * SUCH DAMAGE.
   26  *
   27  * Author: Hartmut Brandt <harti@freebsd.org>
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD$");
   32 
   33 #include <sys/param.h>
   34 #include <sys/lock.h>
   35 #include <sys/mutex.h>
   36 #include <sys/kernel.h>
   37 #include <sys/systm.h>
   38 #include <sys/malloc.h>
   39 #include <sys/module.h>
   40 
   41 #include <machine/bus.h>
   42 
   43 #include <sys/mbpool.h>
   44 
   45 MODULE_VERSION(libmbpool, 1);
   46 
   47 /*
   48  * Memory is allocated as DMA-able pages. Each page is divided into a number
   49  * of equal chunks where the last 4 bytes of each chunk are occupied by
   50  * the page number and the chunk number. The caller must take these four
   51  * bytes into account when specifying the chunk size. Each page is mapped by
   52  * its own DMA map using the user specified DMA tag.
   53  *
   54  * Each chunk has a used and a card bit in the high bits of its page number.
   55  *  0    0      chunk is free and may be allocated
   56  *  1    1      chunk has been given to the interface
   57  *  0    1      chunk is traveling through the system
   58  *  1    0      illegal
   59  */
   60 struct mbtrail {
   61         uint16_t        chunk;
   62         uint16_t        page;
   63 };
   64 #define MBP_CARD        0x8000
   65 #define MBP_USED        0x4000
   66 #define MBP_PMSK        0x3fff          /* page number mask */
   67 #define MBP_CMSK        0x01ff          /* chunk number mask */
   68 
   69 struct mbfree {
   70         SLIST_ENTRY(mbfree) link;       /* link on free list */
   71 };
   72 
   73 struct mbpage {
   74         bus_dmamap_t    map;            /* map for this page */
   75         bus_addr_t      phy;            /* physical address */
   76         void            *va;            /* the memory */
   77 };
   78 
   79 struct mbpool {
   80         const char      *name;          /* a name for this pool */
   81         bus_dma_tag_t   dmat;           /* tag for mapping */
   82         u_int           max_pages;      /* maximum number of pages */
   83         size_t          page_size;      /* size of each allocation */
   84         size_t          chunk_size;     /* size of each external mbuf */
   85 
   86         struct mtx      free_lock;      /* lock of free list */
   87         SLIST_HEAD(, mbfree) free_list; /* free list */
   88         u_int           npages;         /* current number of pages */
   89         u_int           nchunks;        /* chunks per page */
   90         struct mbpage   pages[];        /* pages */
   91 };
   92 
   93 static MALLOC_DEFINE(M_MBPOOL, "mbpools", "mbuf pools");
   94 
   95 /*
   96  * Make a trail pointer from a chunk pointer
   97  */
   98 #define C2T(P, C)       ((struct mbtrail *)((char *)(C) + (P)->chunk_size - \
   99                             sizeof(struct mbtrail)))
  100 
  101 /*
  102  * Make a free chunk pointer from a chunk number
  103  */
  104 #define N2C(P, PG, C)   ((struct mbfree *)((char *)(PG)->va + \
  105                             (C) * (P)->chunk_size))
  106 
  107 /*
  108  * Make/parse handles
  109  */
  110 #define HMAKE(P, C)     ((((P) & MBP_PMSK) << 16) | ((C) << 7))
  111 #define HPAGE(H)        (((H) >> 16) & MBP_PMSK)
  112 #define HCHUNK(H)       (((H) >>  7) & MBP_CMSK)
  113 
  114 /*
  115  * initialize a pool
  116  */
  117 int
  118 mbp_create(struct mbpool **pp, const char *name, bus_dma_tag_t dmat,
  119     u_int max_pages, size_t page_size, size_t chunk_size)
  120 {
  121         u_int nchunks;
  122 
  123         if (max_pages > MBPOOL_MAX_MAXPAGES || chunk_size == 0)
  124                 return (EINVAL);
  125         nchunks = page_size / chunk_size;
  126         if (nchunks == 0 || nchunks > MBPOOL_MAX_CHUNKS)
  127                 return (EINVAL);
  128 
  129         (*pp) = malloc(sizeof(struct mbpool) +
  130             max_pages * sizeof(struct mbpage),
  131             M_MBPOOL, M_WAITOK | M_ZERO);
  132 
  133         (*pp)->name = name;
  134         (*pp)->dmat = dmat;
  135         (*pp)->max_pages = max_pages;
  136         (*pp)->page_size = page_size;
  137         (*pp)->chunk_size = chunk_size;
  138         (*pp)->nchunks = nchunks;
  139 
  140         SLIST_INIT(&(*pp)->free_list);
  141         mtx_init(&(*pp)->free_lock, name, NULL, MTX_DEF);
  142 
  143         return (0);
  144 }
  145 
  146 /*
  147  * destroy a pool
  148  */
  149 void
  150 mbp_destroy(struct mbpool *p)
  151 {
  152         u_int i;
  153         struct mbpage *pg;
  154 #ifdef DIAGNOSTIC
  155         struct mbtrail *tr;
  156         u_int b;
  157 #endif
  158 
  159         for (i = 0; i < p->npages; i++) {
  160                 pg = &p->pages[i];
  161 #ifdef DIAGNOSTIC
  162                 for (b = 0; b < p->nchunks; b++) {
  163                         tr = C2T(p, N2C(p, pg, b));
  164                         if (tr->page & MBP_CARD)
  165                                 printf("%s: (%s) buf still on card"
  166                                     " %u/%u\n", __func__, p->name, i, b);
  167                         if (tr->page & MBP_USED)
  168                                 printf("%s: (%s) sbuf still in use"
  169                                     " %u/%u\n", __func__, p->name, i, b);
  170                 }
  171 #endif
  172                 bus_dmamap_unload(p->dmat, pg->map);
  173                 bus_dmamem_free(p->dmat, pg->va, pg->map);
  174         }
  175         mtx_destroy(&p->free_lock);
  176 
  177         free(p, M_MBPOOL);
  178 }
  179 
  180 /*
  181  * Helper function when loading a one segment DMA buffer.
  182  */
  183 static void
  184 mbp_callback(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
  185 {
  186         if (error == 0)
  187                 *(bus_addr_t *)arg = segs[0].ds_addr;
  188 }
  189 
  190 /*
  191  * Allocate a new page
  192  */
  193 static void
  194 mbp_alloc_page(struct mbpool *p)
  195 {
  196         int error;
  197         struct mbpage *pg;
  198         u_int i;
  199         struct mbfree *f;
  200         struct mbtrail *t;
  201 
  202         if (p->npages == p->max_pages) {
  203 #ifdef DIAGNOSTIC
  204                 printf("%s: (%s) page limit reached %u\n", __func__,
  205                     p->name, p->max_pages);
  206 #endif
  207                 return;
  208         }
  209         pg = &p->pages[p->npages];
  210 
  211         error = bus_dmamem_alloc(p->dmat, &pg->va, BUS_DMA_NOWAIT, &pg->map);
  212         if (error != 0)
  213                 return;
  214 
  215         error = bus_dmamap_load(p->dmat, pg->map, pg->va, p->page_size,
  216             mbp_callback, &pg->phy, 0);
  217         if (error != 0) {
  218                 bus_dmamem_free(p->dmat, pg->va, pg->map);
  219                 return;
  220         }
  221 
  222         for (i = 0; i < p->nchunks; i++) {
  223                 f = N2C(p, pg, i);
  224                 t = C2T(p, f);
  225                 t->page = p->npages;
  226                 t->chunk = i;
  227                 SLIST_INSERT_HEAD(&p->free_list, f, link);
  228         }
  229 
  230         p->npages++;
  231 }
  232 
  233 /*
  234  * allocate a chunk
  235  */
  236 void *
  237 mbp_alloc(struct mbpool *p, bus_addr_t *pap, uint32_t *hp)
  238 {
  239         struct mbfree *cf;
  240         struct mbtrail *t;
  241 
  242         mtx_lock(&p->free_lock);
  243         if ((cf = SLIST_FIRST(&p->free_list)) == NULL) {
  244                 mbp_alloc_page(p);
  245                 cf = SLIST_FIRST(&p->free_list);
  246         }
  247         if (cf == NULL) {
  248                 mtx_unlock(&p->free_lock);
  249                 return (NULL);
  250         }
  251         SLIST_REMOVE_HEAD(&p->free_list, link);
  252         mtx_unlock(&p->free_lock);
  253 
  254         t = C2T(p, cf);
  255 
  256         *pap = p->pages[t->page].phy + t->chunk * p->chunk_size;
  257         *hp = HMAKE(t->page, t->chunk);
  258 
  259         t->page |= MBP_CARD | MBP_USED;
  260 
  261         return (cf);
  262 }
  263 
  264 /*
  265  * Free a chunk
  266  */
  267 void
  268 mbp_free(struct mbpool *p, void *ptr)
  269 {
  270         struct mbtrail *t;
  271 
  272         mtx_lock(&p->free_lock);
  273         t = C2T(p, ptr);
  274         t->page &= ~(MBP_USED | MBP_CARD);
  275         SLIST_INSERT_HEAD(&p->free_list, (struct mbfree *)ptr, link);
  276         mtx_unlock(&p->free_lock);
  277 }
  278 
  279 /*
  280  * Mbuf system external mbuf free routine
  281  */
  282 void
  283 mbp_ext_free(void *buf, void *arg)
  284 {
  285         mbp_free(arg, buf);
  286 }
  287 
  288 /*
  289  * Free all buffers that are marked as beeing on the card
  290  */
  291 void
  292 mbp_card_free(struct mbpool *p)
  293 {
  294         u_int i, b;
  295         struct mbpage *pg;
  296         struct mbtrail *tr;
  297         struct mbfree *cf;
  298 
  299         mtx_lock(&p->free_lock);
  300         for (i = 0; i < p->npages; i++) {
  301                 pg = &p->pages[i];
  302                 for (b = 0; b < p->nchunks; b++) {
  303                         cf = N2C(p, pg, b);
  304                         tr = C2T(p, cf);
  305                         if (tr->page & MBP_CARD) {
  306                                 tr->page &= MBP_PMSK;
  307                                 SLIST_INSERT_HEAD(&p->free_list, cf, link);
  308                         }
  309                 }
  310         }
  311         mtx_unlock(&p->free_lock);
  312 }
  313 
  314 /*
  315  * Count buffers
  316  */
  317 void
  318 mbp_count(struct mbpool *p, u_int *used, u_int *card, u_int *free)
  319 {
  320         u_int i, b;
  321         struct mbpage *pg;
  322         struct mbtrail *tr;
  323         struct mbfree *cf;
  324 
  325         *used = *card = *free = 0;
  326         for (i = 0; i < p->npages; i++) {
  327                 pg = &p->pages[i];
  328                 for (b = 0; b < p->nchunks; b++) {
  329                         tr = C2T(p, N2C(p, pg, b));
  330                         if (tr->page & MBP_CARD)
  331                                 (*card)++;
  332                         if (tr->page & MBP_USED)
  333                                 (*used)++;
  334                 }
  335         }
  336         mtx_lock(&p->free_lock);
  337         SLIST_FOREACH(cf, &p->free_list, link)
  338                 (*free)++;
  339         mtx_unlock(&p->free_lock);
  340 }
  341 
  342 /*
  343  * Get the buffer from a handle and clear the card flag.
  344  */
  345 void *
  346 mbp_get(struct mbpool *p, uint32_t h)
  347 {
  348         struct mbfree *cf;
  349         struct mbtrail *tr;
  350 
  351         cf = N2C(p, &p->pages[HPAGE(h)], HCHUNK(h));
  352         tr = C2T(p, cf);
  353 
  354 #ifdef DIAGNOSTIC
  355         if (!(tr->page & MBP_CARD))
  356                 printf("%s: (%s) chunk %u page %u not on card\n", __func__,
  357                     p->name, HCHUNK(h), HPAGE(h));
  358 #endif
  359 
  360         tr->page &= ~MBP_CARD;
  361         return (cf);
  362 }
  363 
  364 /*
  365  * Get the buffer from a handle and keep the card flag.
  366  */
  367 void *
  368 mbp_get_keep(struct mbpool *p, uint32_t h)
  369 {
  370         struct mbfree *cf;
  371         struct mbtrail *tr;
  372 
  373         cf = N2C(p, &p->pages[HPAGE(h)], HCHUNK(h));
  374         tr = C2T(p, cf);
  375 
  376 #ifdef DIAGNOSTIC
  377         if (!(tr->page & MBP_CARD))
  378                 printf("%s: (%s) chunk %u page %u not on card\n", __func__,
  379                     p->name, HCHUNK(h), HPAGE(h));
  380 #endif
  381 
  382         return (cf);
  383 }
  384 
  385 /*
  386  * sync the chunk
  387  */
  388 void
  389 mbp_sync(struct mbpool *p, uint32_t h, bus_addr_t off, bus_size_t len, u_int op)
  390 {
  391 
  392 #if 0
  393         bus_dmamap_sync_size(p->dmat, p->pages[HPAGE(h)].map,
  394             HCHUNK(h) * p->chunk_size + off, len, op);
  395 #endif
  396 }
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FreeBSD/Linux Kernel Cross Reference sys/kern/subr_mbpool.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_mbpool.c
