The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/dev/usb/usb_mem.c

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    1 /*      $NetBSD: usb_mem.c,v 1.26 2003/02/01 06:23:40 thorpej Exp $     */
    2 /*      $FreeBSD$       */
    3 
    4 /*-
    5  * Copyright (c) 1998 The NetBSD Foundation, Inc.
    6  * All rights reserved.
    7  *
    8  * This code is derived from software contributed to The NetBSD Foundation
    9  * by Lennart Augustsson (lennart@augustsson.net) at
   10  * Carlstedt Research & Technology.
   11  *
   12  * Redistribution and use in source and binary forms, with or without
   13  * modification, are permitted provided that the following conditions
   14  * are met:
   15  * 1. Redistributions of source code must retain the above copyright
   16  *    notice, this list of conditions and the following disclaimer.
   17  * 2. Redistributions in binary form must reproduce the above copyright
   18  *    notice, this list of conditions and the following disclaimer in the
   19  *    documentation and/or other materials provided with the distribution.
   20  * 3. All advertising materials mentioning features or use of this software
   21  *    must display the following acknowledgement:
   22  *        This product includes software developed by the NetBSD
   23  *        Foundation, Inc. and its contributors.
   24  * 4. Neither the name of The NetBSD Foundation nor the names of its
   25  *    contributors may be used to endorse or promote products derived
   26  *    from this software without specific prior written permission.
   27  *
   28  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
   29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   31  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
   32  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   38  * POSSIBILITY OF SUCH DAMAGE.
   39  */
   40 
   41 /*
   42  * USB DMA memory allocation.
   43  * We need to allocate a lot of small (many 8 byte, some larger)
   44  * memory blocks that can be used for DMA.  Using the bus_dma
   45  * routines directly would incur large overheads in space and time.
   46  */
   47 
   48 #include <sys/cdefs.h>
   49 __FBSDID("$FreeBSD$");
   50 
   51 #include <sys/param.h>
   52 #include <sys/systm.h>
   53 #include <sys/malloc.h>
   54 #include <sys/kernel.h>
   55 #if defined(__NetBSD__) || defined(__OpenBSD__)
   56 #include <sys/device.h>         /* for usbdivar.h */
   57 #include <machine/bus.h>
   58 #elif defined(__FreeBSD__)
   59 #include <sys/endian.h>
   60 #include <sys/module.h>
   61 #include <sys/bus.h>
   62 #endif
   63 #include <sys/queue.h>
   64 
   65 #include <machine/bus.h>
   66 #include <machine/endian.h>
   67 
   68 #ifdef DIAGNOSTIC
   69 #include <sys/proc.h>
   70 #endif
   71 
   72 #include <dev/usb/usb.h>
   73 #include <dev/usb/usbdi.h>
   74 #include <dev/usb/usbdivar.h>   /* just for usb_dma_t */
   75 #include <dev/usb/usb_mem.h>
   76 
   77 #ifdef USB_DEBUG
   78 #define DPRINTF(x)      if (usbdebug) logprintf x
   79 #define DPRINTFN(n,x)   if (usbdebug>(n)) logprintf x
   80 extern int usbdebug;
   81 #else
   82 #define DPRINTF(x)
   83 #define DPRINTFN(n,x)
   84 #endif
   85 
   86 #define USB_MEM_SMALL 64
   87 #define USB_MEM_CHUNKS (PAGE_SIZE / USB_MEM_SMALL)
   88 #define USB_MEM_BLOCK (USB_MEM_SMALL * USB_MEM_CHUNKS)
   89 
   90 /* This struct is overlayed on free fragments. */
   91 struct usb_frag_dma {
   92         usb_dma_block_t *block;
   93         u_int offs;
   94         LIST_ENTRY(usb_frag_dma) next;
   95 };
   96 
   97 Static bus_dmamap_callback_t usbmem_callback;
   98 Static usbd_status      usb_block_allocmem(bus_dma_tag_t, size_t, size_t,
   99                                            usb_dma_block_t **);
  100 Static void             usb_block_freemem(usb_dma_block_t *);
  101 
  102 Static LIST_HEAD(, usb_dma_block) usb_blk_freelist =
  103         LIST_HEAD_INITIALIZER(usb_blk_freelist);
  104 Static int usb_blk_nfree = 0;
  105 /* XXX should have different free list for different tags (for speed) */
  106 Static LIST_HEAD(, usb_frag_dma) usb_frag_freelist =
  107         LIST_HEAD_INITIALIZER(usb_frag_freelist);
  108 
  109 Static void
  110 usbmem_callback(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  111 {
  112         int i;
  113         usb_dma_block_t *p = arg;
  114 
  115         if (error == EFBIG) {
  116                 printf("usb: mapping to large\n");
  117                 return;
  118         }
  119 
  120         p->nsegs = nseg;
  121         for (i = 0; i < nseg && i < sizeof p->segs / sizeof *p->segs; i++)
  122                 p->segs[i] = segs[i];
  123 }
  124 
  125 Static usbd_status
  126 usb_block_allocmem(bus_dma_tag_t tag, size_t size, size_t align,
  127                    usb_dma_block_t **dmap)
  128 {
  129         usb_dma_block_t *p;
  130         int s;
  131 
  132         DPRINTFN(5, ("usb_block_allocmem: size=%lu align=%lu\n",
  133                      (u_long)size, (u_long)align));
  134 
  135 #ifdef DIAGNOSTIC
  136         if (!curproc) {
  137                 printf("usb_block_allocmem: in interrupt context, size=%lu\n",
  138                     (unsigned long) size);
  139         }
  140 #endif
  141 
  142         s = splusb();
  143         /* First check the free list. */
  144         for (p = LIST_FIRST(&usb_blk_freelist); p; p = LIST_NEXT(p, next)) {
  145                 if (p->tag == tag && p->size >= size && p->size < size * 2 &&
  146                     p->align >= align) {
  147                         LIST_REMOVE(p, next);
  148                         usb_blk_nfree--;
  149                         splx(s);
  150                         *dmap = p;
  151                         DPRINTFN(6,("usb_block_allocmem: free list size=%lu\n",
  152                                     (u_long)p->size));
  153                         return (USBD_NORMAL_COMPLETION);
  154                 }
  155         }
  156         splx(s);
  157 
  158 #ifdef DIAGNOSTIC
  159         if (!curproc) {
  160                 printf("usb_block_allocmem: in interrupt context, failed\n");
  161                 return (USBD_NOMEM);
  162         }
  163 #endif
  164 
  165         DPRINTFN(6, ("usb_block_allocmem: no free\n"));
  166         p = malloc(sizeof *p, M_USB, M_NOWAIT);
  167         if (p == NULL)
  168                 return (USBD_NOMEM);
  169 
  170         if (bus_dma_tag_create(tag, align, 0,
  171             BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL,
  172             size, sizeof(p->segs) / sizeof(p->segs[0]), size,
  173             BUS_DMA_ALLOCNOW, NULL, NULL, &p->tag) == ENOMEM)
  174         {
  175                 goto free;
  176         }
  177 
  178         p->size = size;
  179         p->align = align;
  180         if (bus_dmamem_alloc(p->tag, &p->kaddr,
  181             BUS_DMA_NOWAIT|BUS_DMA_COHERENT, &p->map))
  182                 goto tagfree;
  183 
  184         if (bus_dmamap_load(p->tag, p->map, p->kaddr, p->size,
  185             usbmem_callback, p, 0))
  186                 goto memfree;
  187 
  188         /* XXX - override the tag, ok since we never free it */
  189         p->tag = tag;
  190         *dmap = p;
  191         return (USBD_NORMAL_COMPLETION);
  192 
  193         /*
  194          * XXX - do we need to _unload? is the order of _free and _destroy
  195          * correct?
  196          */
  197 memfree:
  198         bus_dmamem_free(p->tag, p->kaddr, p->map);
  199 tagfree:
  200         bus_dma_tag_destroy(p->tag);
  201 free:
  202         free(p, M_USB);
  203         return (USBD_NOMEM);
  204 }
  205 
  206 /*
  207  * Do not free the memory unconditionally since we might be called
  208  * from an interrupt context and that is BAD.
  209  * XXX when should we really free?
  210  */
  211 Static void
  212 usb_block_freemem(usb_dma_block_t *p)
  213 {
  214         int s;
  215 
  216         DPRINTFN(6, ("usb_block_freemem: size=%lu\n", (u_long)p->size));
  217         s = splusb();
  218         LIST_INSERT_HEAD(&usb_blk_freelist, p, next);
  219         usb_blk_nfree++;
  220         splx(s);
  221 }
  222 
  223 usbd_status
  224 usb_allocmem(usbd_bus_handle bus, size_t size, size_t align, usb_dma_t *p)
  225 {
  226         bus_dma_tag_t tag = bus->dmatag;
  227         usbd_status err;
  228         struct usb_frag_dma *f;
  229         usb_dma_block_t *b;
  230         int i;
  231         int s;
  232 
  233         /* compat w/ Net/OpenBSD */
  234         if (align == 0)
  235                 align = 1;
  236 
  237         /* If the request is large then just use a full block. */
  238         if (size > USB_MEM_SMALL || align > USB_MEM_SMALL) {
  239                 DPRINTFN(1, ("usb_allocmem: large alloc %d\n", (int)size));
  240                 size = (size + USB_MEM_BLOCK - 1) & ~(USB_MEM_BLOCK - 1);
  241                 err = usb_block_allocmem(tag, size, align, &p->block);
  242                 if (!err) {
  243                         p->block->fullblock = 1;
  244                         p->offs = 0;
  245                         p->len = size;
  246                 }
  247                 return (err);
  248         }
  249 
  250         s = splusb();
  251         /* Check for free fragments. */
  252         for (f = LIST_FIRST(&usb_frag_freelist); f; f = LIST_NEXT(f, next))
  253                 if (f->block->tag == tag)
  254                         break;
  255         if (f == NULL) {
  256                 DPRINTFN(1, ("usb_allocmem: adding fragments\n"));
  257                 err = usb_block_allocmem(tag, USB_MEM_BLOCK, USB_MEM_SMALL,&b);
  258                 if (err) {
  259                         splx(s);
  260                         return (err);
  261                 }
  262                 b->fullblock = 0;
  263                 /* XXX - override the tag, ok since we never free it */
  264                 b->tag = tag;
  265                 KASSERT(sizeof *f <= USB_MEM_SMALL, ("USB_MEM_SMALL(%d) is too small for struct usb_frag_dma(%zd)\n",
  266                     USB_MEM_SMALL, sizeof *f));
  267                 for (i = 0; i < USB_MEM_BLOCK; i += USB_MEM_SMALL) {
  268                         f = (struct usb_frag_dma *)((char *)b->kaddr + i);
  269                         f->block = b;
  270                         f->offs = i;
  271                         LIST_INSERT_HEAD(&usb_frag_freelist, f, next);
  272                 }
  273                 f = LIST_FIRST(&usb_frag_freelist);
  274         }
  275         p->block = f->block;
  276         p->offs = f->offs;
  277         p->len = USB_MEM_SMALL;
  278         LIST_REMOVE(f, next);
  279         splx(s);
  280         DPRINTFN(5, ("usb_allocmem: use frag=%p size=%d\n", f, (int)size));
  281         return (USBD_NORMAL_COMPLETION);
  282 }
  283 
  284 void
  285 usb_freemem(usbd_bus_handle bus, usb_dma_t *p)
  286 {
  287         struct usb_frag_dma *f;
  288         int s;
  289 
  290         if (p->block->fullblock) {
  291                 DPRINTFN(1, ("usb_freemem: large free\n"));
  292                 usb_block_freemem(p->block);
  293                 return;
  294         }
  295         f = KERNADDR(p, 0);
  296         f->block = p->block;
  297         f->offs = p->offs;
  298         s = splusb();
  299         LIST_INSERT_HEAD(&usb_frag_freelist, f, next);
  300         splx(s);
  301         DPRINTFN(5, ("usb_freemem: frag=%p\n", f));
  302 }

Cache object: a445449a2bc2fcdec11711b911030566


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