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drm_vm.c revision 1.1.2.5
      1 /*	$NetBSD: drm_vm.c,v 1.1.2.5 2014/01/29 19:47:38 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 1.1.2.5 2014/01/29 19:47:38 riastradh Exp $");
     34 
     35 #include <sys/types.h>
     36 #include <sys/conf.h>
     37 
     38 #include <uvm/uvm_extern.h>
     39 #include <uvm/uvm_device.h>
     40 
     41 #include <drm/drmP.h>
     42 
     43 static paddr_t	drm_mmap_paddr_locked(struct drm_device *, off_t, int);
     44 static paddr_t	drm_mmap_dma_paddr(struct drm_device *, off_t, int);
     45 static paddr_t	drm_mmap_map_paddr(struct drm_device *, struct drm_local_map *,
     46 		    off_t, int);
     47 
     48 extern struct cdevsw drmkms_cdevsw;	/* XXX */
     49 
     50 int
     51 drm_mmap_object(struct drm_device *dev, off_t offset, size_t size, int prot,
     52     struct uvm_object **uobjp)
     53 {
     54 	dev_t devno = cdevsw_lookup_major(&drmkms_cdevsw);
     55 	struct uvm_object *uobj;
     56 
     57 	uobj = udv_attach(&devno, prot, offset, size);
     58 	if (uobj == NULL)
     59 		return -EINVAL;
     60 
     61 	*uobjp = uobj;
     62 	return 0;
     63 }
     64 
     65 paddr_t
     66 drm_mmap_paddr(struct drm_device *dev, off_t byte_offset, int prot)
     67 {
     68 	paddr_t paddr;
     69 
     70 	mutex_lock(&dev->struct_mutex);
     71 	paddr = drm_mmap_paddr_locked(dev, byte_offset, prot);
     72 	mutex_unlock(&dev->struct_mutex);
     73 
     74 	return paddr;
     75 }
     76 
     77 static paddr_t
     78 drm_mmap_paddr_locked(struct drm_device *dev, off_t byte_offset, int prot)
     79 {
     80 	const off_t page_offset = (byte_offset >> PAGE_SHIFT);
     81 	struct drm_hash_item *hash;
     82 
     83 	KASSERT(mutex_is_locked(&dev->struct_mutex));
     84 
     85 	if (byte_offset != (byte_offset & ~(PAGE_SIZE-1)))
     86 		return -1;
     87 
     88 	if ((dev->dma != NULL) &&
     89 	    (0 <= byte_offset) &&
     90 	    (byte_offset <= (dev->dma->page_count << PAGE_SHIFT)))
     91 		return drm_mmap_dma_paddr(dev, byte_offset, prot);
     92 
     93 	if (drm_ht_find_item(&dev->map_hash, page_offset, &hash))
     94 		return -1;
     95 
     96 	struct drm_local_map *const map = drm_hash_entry(hash,
     97 	    struct drm_map_list, hash)->map;
     98 	if (map == NULL)
     99 		return -1;
    100 
    101 	/*
    102 	 * XXX FreeBSD drops the mutex at this point, which would be
    103 	 * nice, to allow sleeping in bus_dma cruft, but I don't know
    104 	 * what guarantees the map will continue to exist.
    105 	 */
    106 
    107 	if (ISSET(map->flags, _DRM_RESTRICTED) && !DRM_SUSER())
    108 		return -1;
    109 
    110 	if (byte_offset < map->offset)
    111 		return -1;
    112 
    113 	return drm_mmap_map_paddr(dev, map, (map->offset - byte_offset),
    114 	    prot);
    115 }
    116 
    117 static paddr_t
    118 drm_mmap_dma_paddr(struct drm_device *dev, off_t byte_offset, int prot)
    119 {
    120 	const off_t page_offset = (byte_offset >> PAGE_SHIFT);
    121 
    122 	KASSERT(mutex_is_locked(&dev->struct_mutex));
    123 
    124 	if (dev->dma->pagelist == NULL)
    125 		return (paddr_t)-1;
    126 
    127 	if (page_offset >= dev->dma->page_count)
    128 		return (paddr_t)-1;
    129 
    130 	return dev->dma->pagelist[page_offset];
    131 }
    132 
    133 static paddr_t
    134 drm_mmap_map_paddr(struct drm_device *dev, struct drm_local_map *map,
    135     off_t byte_offset, int prot)
    136 {
    137 	int flags = 0;
    138 
    139 	switch (map->type) {
    140 	case _DRM_FRAME_BUFFER:
    141 	case _DRM_AGP:
    142 		flags |= BUS_SPACE_MAP_PREFETCHABLE;
    143 		/* Fall through.  */
    144 
    145 	case _DRM_REGISTERS:
    146 		flags |= BUS_SPACE_MAP_LINEAR; /* XXX Why?  */
    147 
    148 		return bus_space_mmap(dev->bst, map->offset, byte_offset, prot,
    149 		    flags);
    150 
    151 	case _DRM_CONSISTENT: {
    152 		struct drm_dma_handle *const dmah = map->lm_data.dmah;
    153 
    154 		return bus_dmamem_mmap(dev->dmat, &dmah->dmah_seg, 1,
    155 		    byte_offset, prot,
    156 		    /* XXX BUS_DMA_WAITOK?  We're holding a mutex...  */
    157 		    /* XXX What else?  BUS_DMA_COHERENT?  */
    158 		    (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
    159 	}
    160 
    161 	case _DRM_SCATTER_GATHER: {
    162 		struct drm_sg_mem *const sg = dev->sg;
    163 
    164 #if 0				/* XXX */
    165 		KASSERT(sg == map->lm_data.sg);
    166 #endif
    167 
    168 		return bus_dmamem_mmap(dev->dmat, sg->sg_segs, sg->sg_nsegs,
    169 		    byte_offset, prot,
    170 		    /* XXX BUS_DMA_WAITOK?  We're holding a mutex...  */
    171 		    /* XXX What else?  BUS_DMA_COHERENT?  */
    172 		    (BUS_DMA_WAITOK | BUS_DMA_NOCACHE));
    173 	}
    174 
    175 	case _DRM_SHM:
    176 	case _DRM_GEM:
    177 	default:
    178 		return (paddr_t)-1;
    179 	}
    180 }
    181