FreeBSD/Linux Kernel Cross Reference
sys/i386/include/bus_dma.h

     /*      $NetBSD: bus.h,v 1.12 1997/10/01 08:25:15 fvdl Exp $    */
     
     /*-
      * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
      * All rights reserved.
      *
      * This code is derived from software contributed to The NetBSD Foundation
      * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      * NASA Ames Research Center.
     *
     * 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.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the NetBSD
     *      Foundation, Inc. and its contributors.
     * 4. Neither the name of The NetBSD Foundation nor the names of its
     *    contributors may be used to endorse or promote products derived
     *    from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
     */
    
    /*
     * Copyright (c) 1996 Charles M. Hannum.  All rights reserved.
     * Copyright (c) 1996 Christopher G. Demetriou.  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.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Christopher G. Demetriou
     *      for the NetBSD Project.
     * 4. 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 ``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 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.
     */
    /* $FreeBSD: releng/5.1/sys/i386/include/bus_dma.h 115416 2003-05-30 20:40:33Z hmp $ */
    
    #ifndef _I386_BUS_DMA_H_
    #define _I386_BUS_DMA_H_
    
    /*
     * Flags used in various bus DMA methods.
     */
    #define BUS_DMA_WAITOK          0x00    /* safe to sleep (pseudo-flag) */
    #define BUS_DMA_NOWAIT          0x01    /* not safe to sleep */
    #define BUS_DMA_ALLOCNOW        0x02    /* perform resource allocation now */
    #define BUS_DMA_COHERENT        0x04    /* hint: map memory in a coherent way */
    #define BUS_DMA_BUS1            0x10    /* placeholders for bus functions... */
    #define BUS_DMA_BUS2            0x20
    #define BUS_DMA_BUS3            0x40
    #define BUS_DMA_BUS4            0x80
    
    /* Forwards needed by prototypes below. */
    struct mbuf;
    struct uio;
    
    /*
     * Operations performed by bus_dmamap_sync().
     */
    typedef int bus_dmasync_op_t;
    #define BUS_DMASYNC_PREREAD     1
    #define BUS_DMASYNC_POSTREAD    2
    #define BUS_DMASYNC_PREWRITE    4
    #define BUS_DMASYNC_POSTWRITE   8
    
   /*
    *      bus_dma_tag_t
    *
    *      A machine-dependent opaque type describing the characteristics
    *      of how to perform DMA mappings.  This structure encapsultes
    *      information concerning address and alignment restrictions, number
    *      of S/G  segments, amount of data per S/G segment, etc.
    */
   typedef struct bus_dma_tag      *bus_dma_tag_t;
   
   /*
    *      bus_dmamap_t
    *
    *      DMA mapping instance information.
    */
   typedef struct bus_dmamap       *bus_dmamap_t;
   
   /*
    *      bus_dma_segment_t
    *
    *      Describes a single contiguous DMA transaction.  Values
    *      are suitable for programming into DMA registers.
    */
   typedef struct bus_dma_segment {
           bus_addr_t      ds_addr;        /* DMA address */
           bus_size_t      ds_len;         /* length of transfer */
   } bus_dma_segment_t;
   
   /*
    * A function that returns 1 if the address cannot be accessed by
    * a device and 0 if it can be.
    */
   typedef int bus_dma_filter_t(void *, bus_addr_t);
   
   /*
    * Allocate a device specific dma_tag encapsulating the constraints of
    * the parent tag in addition to other restrictions specified:
    *
    *      alignment:      alignment for segments.
    *      boundary:       Boundary that segments cannot cross.
    *      lowaddr:        Low restricted address that cannot appear in a mapping.
    *      highaddr:       High restricted address that cannot appear in a mapping.
    *      filtfunc:       An optional function to further test if an address
    *                      within the range of lowaddr and highaddr cannot appear
    *                      in a mapping.
    *      filtfuncarg:    An argument that will be passed to filtfunc in addition
    *                      to the address to test.
    *      maxsize:        Maximum mapping size supported by this tag.
    *      nsegments:      Number of discontinuities allowed in maps.
    *      maxsegsz:       Maximum size of a segment in the map.
    *      flags:          Bus DMA flags.
    *      dmat:           A pointer to set to a valid dma tag should the return
    *                      value of this function indicate success.
    */
   /* XXX Should probably allow specification of alignment */
   int bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
                          bus_size_t boundary, bus_addr_t lowaddr,
                          bus_addr_t highaddr, bus_dma_filter_t *filtfunc,
                          void *filtfuncarg, bus_size_t maxsize, int nsegments,
                          bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat);
   
   int bus_dma_tag_destroy(bus_dma_tag_t dmat);
   
   /*
    * 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);
   
   /*
    * 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);
   
   /*
    * Allocate a piece of memory that can be efficiently mapped into
    * bus device space based on the constraints lited in the dma tag.
    * A dmamap to for use with dmamap_load is also allocated.
    */
   int bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
                        bus_dmamap_t *mapp);
   
   /*
    * Free a piece of memory and it's allociated dmamap, that was allocated
    * via bus_dmamem_alloc.
    */
   void bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map);
   
   /*
    * A function that processes a successfully loaded dma map or an error
    * from a delayed load map.
    */
   typedef void bus_dmamap_callback_t(void *, bus_dma_segment_t *, int, int);
   
   /*
    * Map the buffer buf into bus space using the dmamap map.
    */
   int bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
                       bus_size_t buflen, bus_dmamap_callback_t *callback,
                       void *callback_arg, int flags);
   
   /*
    * Like bus_dmamap_callback but includes map size in bytes.  This is
    * defined as a separate interface to maintain compatiiblity for users
    * of bus_dmamap_callback_t--at some point these interfaces should be merged.
    */
   typedef void bus_dmamap_callback2_t(void *, bus_dma_segment_t *, int, bus_size_t, int);
   /*
    * Like bus_dmamap_load but for mbufs.  Note the use of the
    * bus_dmamap_callback2_t interface.
    */
   int bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
                            struct mbuf *mbuf,
                            bus_dmamap_callback2_t *callback, void *callback_arg,
                            int flags);
   /*
    * Like bus_dmamap_load but for uios.  Note the use of the
    * bus_dmamap_callback2_t interface.
    */
   int bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
                           struct uio *ui,
                           bus_dmamap_callback2_t *callback, void *callback_arg,
                           int flags);
   
   /*
    * Perform a syncronization operation on the given map.
    */
   void _bus_dmamap_sync(bus_dma_tag_t, bus_dmamap_t, bus_dmasync_op_t);
   #define bus_dmamap_sync(dmat, dmamap, op)               \
           if ((dmamap) != NULL)                           \
                   _bus_dmamap_sync(dmat, dmamap, op)
   
   /*
    * Release the mapping held by map.
    */
   void _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map);
   #define bus_dmamap_unload(dmat, dmamap)                 \
           if ((dmamap) != NULL)                           \
                   _bus_dmamap_unload(dmat, dmamap)
   
   #endif /* _I386_BUS_DMA_H_ */

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