Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /**
  2  * \file drm_memory.c
  3  * Memory management wrappers for DRM
  4  *
  5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
  6  * \author Gareth Hughes <gareth@valinux.com>
  7  */
  8 
  9 /*
 10  * Created: Thu Feb  4 14:00:34 1999 by faith@valinux.com
 11  *
 12  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 14  * All Rights Reserved.
 15  *
 16  * Permission is hereby granted, free of charge, to any person obtaining a
 17  * copy of this software and associated documentation files (the "Software"),
 18  * to deal in the Software without restriction, including without limitation
 19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 20  * and/or sell copies of the Software, and to permit persons to whom the
 21  * Software is furnished to do so, subject to the following conditions:
 22  *
 23  * The above copyright notice and this permission notice (including the next
 24  * paragraph) shall be included in all copies or substantial portions of the
 25  * Software.
 26  *
 27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 33  * OTHER DEALINGS IN THE SOFTWARE.
 34  */
 35 
 36 #include <linux/highmem.h>
 37 #include "drmP.h"
 38 
 39 #ifdef DEBUG_MEMORY
 40 #include "drm_memory_debug.h"
 41 #else
 42 
 43 /** No-op. */
 44 void drm_mem_init(void)
 45 {
 46 }
 47 
 48 /**
 49  * Called when "/proc/dri/%dev%/mem" is read.
 50  *
 51  * \param buf output buffer.
 52  * \param start start of output data.
 53  * \param offset requested start offset.
 54  * \param len requested number of bytes.
 55  * \param eof whether there is no more data to return.
 56  * \param data private data.
 57  * \return number of written bytes.
 58  *
 59  * No-op.
 60  */
 61 int drm_mem_info(char *buf, char **start, off_t offset,
 62                  int len, int *eof, void *data)
 63 {
 64         return 0;
 65 }
 66 
 67 /** Wrapper around kmalloc() and kfree() */
 68 void *drm_realloc(void *oldpt, size_t oldsize, size_t size, int area)
 69 {
 70         void *pt;
 71 
 72         if (!(pt = kmalloc(size, GFP_KERNEL)))
 73                 return NULL;
 74         if (oldpt && oldsize) {
 75                 memcpy(pt, oldpt, oldsize);
 76                 kfree(oldpt);
 77         }
 78         return pt;
 79 }
 80 
 81 #if __OS_HAS_AGP
 82 static void *agp_remap(unsigned long offset, unsigned long size,
 83                        struct drm_device * dev)
 84 {
 85         unsigned long *phys_addr_map, i, num_pages =
 86             PAGE_ALIGN(size) / PAGE_SIZE;
 87         struct drm_agp_mem *agpmem;
 88         struct page **page_map;
 89         void *addr;
 90 
 91         size = PAGE_ALIGN(size);
 92 
 93 #ifdef __alpha__
 94         offset -= dev->hose->mem_space->start;
 95 #endif
 96 
 97         list_for_each_entry(agpmem, &dev->agp->memory, head)
 98                 if (agpmem->bound <= offset
 99                     && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
100                     (offset + size))
101                         break;
102         if (!agpmem)
103                 return NULL;
104 
105         /*
106          * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
107          * the CPU do not get remapped by the GART.  We fix this by using the kernel's
108          * page-table instead (that's probably faster anyhow...).
109          */
110         /* note: use vmalloc() because num_pages could be large... */
111         page_map = vmalloc(num_pages * sizeof(struct page *));
112         if (!page_map)
113                 return NULL;
114 
115         phys_addr_map =
116             agpmem->memory->memory + (offset - agpmem->bound) / PAGE_SIZE;
117         for (i = 0; i < num_pages; ++i)
118                 page_map[i] = pfn_to_page(phys_addr_map[i] >> PAGE_SHIFT);
119         addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
120         vfree(page_map);
121 
122         return addr;
123 }
124 
125 /** Wrapper around agp_allocate_memory() */
126 DRM_AGP_MEM *drm_alloc_agp(struct drm_device * dev, int pages, u32 type)
127 {
128         return drm_agp_allocate_memory(dev->agp->bridge, pages, type);
129 }
130 
131 /** Wrapper around agp_free_memory() */
132 int drm_free_agp(DRM_AGP_MEM * handle, int pages)
133 {
134         return drm_agp_free_memory(handle) ? 0 : -EINVAL;
135 }
136 
137 /** Wrapper around agp_bind_memory() */
138 int drm_bind_agp(DRM_AGP_MEM * handle, unsigned int start)
139 {
140         return drm_agp_bind_memory(handle, start);
141 }
142 
143 /** Wrapper around agp_unbind_memory() */
144 int drm_unbind_agp(DRM_AGP_MEM * handle)
145 {
146         return drm_agp_unbind_memory(handle);
147 }
148 
149 #else  /*  __OS_HAS_AGP  */
150 static inline void *agp_remap(unsigned long offset, unsigned long size,
151                               struct drm_device * dev)
152 {
153         return NULL;
154 }
155 
156 #endif                          /* agp */
157 
158 #endif                          /* debug_memory */
159 
160 void drm_core_ioremap(struct drm_map *map, struct drm_device *dev)
161 {
162         if (drm_core_has_AGP(dev) &&
163             dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
164                 map->handle = agp_remap(map->offset, map->size, dev);
165         else
166                 map->handle = ioremap(map->offset, map->size);
167 }
168 EXPORT_SYMBOL(drm_core_ioremap);
169 
170 void drm_core_ioremapfree(struct drm_map *map, struct drm_device *dev)
171 {
172         if (!map->handle || !map->size)
173                 return;
174 
175         if (drm_core_has_AGP(dev) &&
176             dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
177                 vunmap(map->handle);
178         else
179                 iounmap(map->handle);
180 }
181 EXPORT_SYMBOL(drm_core_ioremapfree);
182 
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