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sgmapvar.h revision 1.1.2.1 
      1 /* $NetBSD: sgmapvar.h,v 1.1.2.1 1997/06/03 06:57:00 thorpej Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 1997 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the NetBSD
     22  *	Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 #include <sys/extent.h>
     41 #include <machine/bus.h>
     42 
     43 /*
     44  * An Alpha SGMAP page table entry looks like this:
     45  *
     46  * m                           n+1 n             1   0
     47  * |           Reserved           | Page address | V |
     48  *
     49  * The page address is bits <n:13> of the physical address of the page.
     50  * The V bit it set if the PTE holds a valid mapping.
     51  */
     52 #define	SGPTE_PGADDR_SHIFT	12
     53 #define	SGPTE_VALID		0x1
     54 
     55 /*
     56  * Bits n:13 of the DMA address are the byte offset of the PTE
     57  * in the SGMAP page table.
     58  */
     59 #define	SGMAP_ADDR_PTEOFF_SHIFT	13
     60 
     61 /*
     62  * An Alpha SGMAP's state information.
     63  */
     64 struct alpha_sgmap {
     65 	struct extent *aps_ex;		/* extent map to manage sgva space */
     66 	void	*aps_pt;		/* page table */
     67 	bus_addr_t aps_ptpa;		/* page table physical address */
     68 	bus_addr_t aps_sgvabase;	/* base of the sgva space */
     69 	bus_size_t aps_sgvasize;	/* size of the sgva space */
     70 	bus_addr_t aps_wbase;		/* base of the dma window */
     71 };
     72 
     73 /*
     74  * Cookie used to store SGMAP state for a DMA mapping.  We
     75  * could compute some of this at unload time, but storing it
     76  * is convenient.
     77  */
     78 struct alpha_sgmap_cookie {
     79 	int	apdc_pteidx;		/* PTE index */
     80 	int	apdc_ptecnt;		/* PTE count */
     81 	u_long	apdc_sgva;		/* allocated sgva */
     82 	bus_size_t apdc_len;		/* sgva size */
     83 	int	apdc_flags;
     84 };
     85 
     86 /* apdc_flags */
     87 #define	APDC_HAS_SGMAP		0x01	/* sgva/len are valid */
     88 #define	APDC_USING_SGMAP	0x02	/* map is using SGMAP */
     89 
     90 void	alpha_sgmap_init __P((bus_dma_tag_t, struct alpha_sgmap *,
     91 	    const char *, bus_addr_t, bus_addr_t, bus_size_t, size_t, void *));
     92 
     93 int	alpha_sgmap_alloc __P((bus_dmamap_t, bus_size_t,
     94 	    struct alpha_sgmap *, int));
     95 void	alpha_sgmap_free __P((struct alpha_sgmap *,
     96 	    struct alpha_sgmap_cookie *));
     97