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drm_vm.c revision 1.1.2.1 
      1 /*	$NetBSD: drm_vm.c,v 1.1.2.1 2013/07/24 02:53:31 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: drm_vm.c,v 1.1.2.1 2013/07/24 02:53:31 riastradh Exp $");
     34 
     35 #include <sys/types.h>
     36 
     37 #include <uvm/uvm_extern.h>
     38 
     39 #include <drm/drmP.h>
     40 
     41 static paddr_t	drm_mmap_dma_paddr(struct drm_device *, off_t, int);
     42 static paddr_t	drm_mmap_map_paddr(struct drm_device *, struct drm_local_map *,
     43 		    off_t, int);
     44 
     45 paddr_t
     46 drm_mmap_paddr(struct drm_device *dev, off_t byte_offset, int prot)
     47 {
     48 	const off_t page_offset = (byte_offset >> PAGE_SHIFT);
     49 	struct drm_hash_item *hash;
     50 	paddr_t paddr = (paddr_t)-1;
     51 	int error;
     52 
     53 	if (byte_offset != trunc_page(byte_offset))
     54 		return (paddr_t)-1;
     55 
     56 	mutex_lock(&dev->struct_mutex);
     57 
     58 	if ((dev->dma != NULL) &&
     59 	    (0 <= byte_offset) &&
     60 	    (byte_offset <= (dev->dma->page_count << PAGE_SHIFT))) {
     61 		paddr = drm_mmap_dma_paddr(dev, byte_offset, prot);
     62 		goto out;
     63 	}
     64 
     65 	if (drm_ht_find_item(&dev->map_hash, page_offset, &hash))
     66 		goto out;
     67 
     68 	struct drm_local_map *const map = drm_hash_entry(hash,
     69 	    struct drm_map_list, hash)->map;
     70 	if (map == NULL)
     71 		goto out;
     72 
     73 	/*
     74 	 * XXX FreeBSD drops the mutex at this point, which would be
     75 	 * nice, to allow sleeping in bus_dma cruft, but I don't know
     76 	 * what guarantees the map will continue to exist.
     77 	 */
     78 
     79 	if (ISSET(map->flags, _DRM_RESTRICTED) && !DRM_SUSER())
     80 		goto out;
     81 
     82 	if (byte_offset < map->offset)
     83 		goto out;
     84 
     85 	paddr = drm_mmap_map_paddr(dev, map, (map->offset - byte_offset),
     86 	    prot);
     87 
     88 out:	mutex_unlock(&dev->struct_mutex);
     89 	return error;
     90 }
     91 
     92 static paddr_t
     93 drm_mmap_dma_paddr(struct drm_device *dev, off_t byte_offset, int prot)
     94 {
     95 	const off_t page_offset = (byte_offset >> PAGE_SHIFT);
     96 
     97 	/* XXX Is this the right mutex?  */
     98 	KASSERT(mutex_is_locked(&dev->struct_mutex));
     99 
    100 	if (dev->dma->pagelist == NULL)
    101 		return (paddr_t)-1;
    102 
    103 	if (page_offset >= dev->dma->page_count)
    104 		return (paddr_t)-1;
    105 
    106 	return dev->dma->pagelist[page_offset];
    107 }
    108 
    109 static paddr_t
    110 drm_mmap_map_paddr(struct drm_device *dev, struct drm_local_map *map,
    111     off_t byte_offset, int prot)
    112 {
    113 	int flags = 0;
    114 
    115 	switch (map->type) {
    116 	case _DRM_FRAME_BUFFER:
    117 	case _DRM_AGP:
    118 		flags |= BUS_SPACE_MAP_PREFETCHABLE;
    119 		/* Fall through.  */
    120 
    121 	case _DRM_REGISTERS:
    122 		flags |= BUS_SPACE_MAP_LINEAR; /* XXX Why?  */
    123 
    124 		return bus_space_mmap(dev->bst, map->offset, byte_offset, prot,
    125 		    flags);
    126 
    127 	case _DRM_CONSISTENT: {
    128 		struct drm_dma_handle *const dmah = map->lm_data.dmah;
    129 
    130 		return bus_dmamem_mmap(dev->dmat, &dmah->dmah_seg, 1,
    131 		    byte_offset, prot,
    132 		    /* XXX BUS_DMA_WAITOK?  We're holding a mutex...  */
    133 		    /* XXX What else?  BUS_DMA_COHERENT?  */
    134 		    (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
    135 	}
    136 
    137 	case _DRM_SCATTER_GATHER: {
    138 		struct drm_sg_mem *const sg = dev->sg;
    139 
    140 #if 0				/* XXX */
    141 		KASSERT(sg == map->lm_data.sg);
    142 #endif
    143 
    144 		return bus_dmamem_mmap(dev->dmat, sg->sg_segs, sg->sg_nsegs,
    145 		    byte_offset, prot,
    146 		    /* XXX BUS_DMA_WAITOK?  We're holding a mutex...  */
    147 		    /* XXX What else?  BUS_DMA_COHERENT?  */
    148 		    (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
    149 	}
    150 
    151 	case _DRM_SHM:
    152 	case _DRM_GEM:
    153 	default:
    154 		return (paddr_t)-1;
    155 	}
    156 }
    157