src/gallium/auxiliary/pipebuffer/pb_buffer.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * \file
  30  * Generic code for buffers.
  31  *
  32  * Behind a pipe buffle handle there can be DMA buffers, client (or user)
  33  * buffers, regular malloced buffers, etc. This file provides an abstract base
  34  * buffer handle that allows the driver to cope with all those kinds of buffers
  35  * in a more flexible way.
  36  *
  37  * There is no obligation of a winsys driver to use this library. And a pipe
  38  * driver should be completly agnostic about it.
  39  *
  40  * \author Jos� Fonseca <jrfonseca@tungstengraphics.com>
  41  */
  42
  43 #ifndef PB_BUFFER_H_
  44 #define PB_BUFFER_H_
  45
  46
  47 #include "pipe/p_compiler.h"
  48 #include "pipe/p_debug.h"
  49 #include "pipe/p_state.h"
  50 #include "pipe/p_inlines.h"
  51
  52
  53 #ifdef __cplusplus
  54 extern "C" {
  55 #endif
  56
  57
  58 struct pb_vtbl;
  59
  60 /**
  61  * Buffer description.
  62  *
  63  * Used when allocating the buffer.
  64  */
  65 struct pb_desc
  66 {
  67    unsigned alignment;
  68    unsigned usage;
  69 };
  70
  71
  72 /**
  73  * Base class for all pb_* buffers.
  74  */
  75 struct pb_buffer
  76 {
  77    struct pipe_buffer base;
  78
  79    /**
  80     * Pointer to the virtual function table.
  81     *
  82     * Avoid accessing this table directly. Use the inline functions below
  83     * instead to avoid mistakes.
  84     */
  85    const struct pb_vtbl *vtbl;
  86 };
  87
  88
  89 /**
  90  * Virtual function table for the buffer storage operations.
  91  *
  92  * Note that creation is not done through this table.
  93  */
  94 struct pb_vtbl
  95 {
  96    void (*destroy)( struct pb_buffer *buf );
  97
  98    /**
  99     * Map the entire data store of a buffer object into the client's address.
 100     * flags is bitmask of PIPE_BUFFER_FLAG_READ/WRITE.
 101     */
 102    void *(*map)( struct pb_buffer *buf,
 103                  unsigned flags );
 104
 105    void (*unmap)( struct pb_buffer *buf );
 106
 107    /**
 108     * Get the base buffer and the offset.
 109     *
 110     * A buffer can be subdivided in smaller buffers. This method should return
 111     * the underlaying buffer, and the relative offset.
 112     *
 113     * Buffers without an underlaying base buffer should return themselves, with
 114     * a zero offset.
 115     *
 116     * Note that this will increase the reference count of the base buffer.
 117     */
 118    void (*get_base_buffer)( struct pb_buffer *buf,
 119                             struct pb_buffer **base_buf,
 120                             unsigned *offset );
 121 };
 122
 123
 124 static INLINE struct pipe_buffer *
 125 pb_pipe_buffer( struct pb_buffer *pbuf )
 126 {
 127    assert(pbuf);
 128    return &pbuf->base;
 129 }
 130
 131
 132 static INLINE struct pb_buffer *
 133 pb_buffer( struct pipe_buffer *buf )
 134 {
 135    assert(buf);
 136    /* Could add a magic cookie check on debug builds.
 137     */
 138    return (struct pb_buffer *)buf;
 139 }
 140
 141
 142 /* Accessor functions for pb->vtbl:
 143  */
 144 static INLINE void *
 145 pb_map(struct pb_buffer *buf,
 146        unsigned flags)
 147 {
 148    assert(buf);
 149    if(!buf)
 150       return NULL;
 151    assert(buf->base.refcount > 0);
 152    return buf->vtbl->map(buf, flags);
 153 }
 154
 155
 156 static INLINE void
 157 pb_unmap(struct pb_buffer *buf)
 158 {
 159    assert(buf);
 160    if(!buf)
 161       return;
 162    assert(buf->base.refcount > 0);
 163    buf->vtbl->unmap(buf);
 164 }
 165
 166
 167 static INLINE void
 168 pb_get_base_buffer( struct pb_buffer *buf,
 169                     struct pb_buffer **base_buf,
 170                     unsigned *offset )
 171 {
 172    assert(buf);
 173    if(!buf) {
 174       base_buf = NULL;
 175       offset = 0;
 176       return;
 177    }
 178    assert(buf->base.refcount > 0);
 179    buf->vtbl->get_base_buffer(buf, base_buf, offset);
 180    assert(*base_buf);
 181    assert(*offset < (*base_buf)->base.size);
 182 }
 183
 184
 185 static INLINE void
 186 pb_destroy(struct pb_buffer *buf)
 187 {
 188    assert(buf);
 189    if(!buf)
 190       return;
 191    assert(buf->base.refcount == 0);
 192    buf->vtbl->destroy(buf);
 193 }
 194
 195
 196 /* XXX: thread safety issues!
 197  */
 198 static INLINE void
 199 pb_reference(struct pb_buffer **dst,
 200              struct pb_buffer *src)
 201 {
 202    if (src) {
 203       assert(src->base.refcount);
 204       src->base.refcount++;
 205    }
 206
 207    if (*dst) {
 208       assert((*dst)->base.refcount);
 209       if(--(*dst)->base.refcount == 0)
 210          pb_destroy( *dst );
 211    }
 212
 213    *dst = src;
 214 }
 215
 216
 217 /**
 218  * Utility function to check whether the provided alignment is consistent with
 219  * the requested or not.
 220  */
 221 static INLINE boolean
 222 pb_check_alignment(size_t requested, size_t provided)
 223 {
 224    return requested <= provided && (provided % requested) == 0 ? TRUE : FALSE;
 225 }
 226
 227
 228 /**
 229  * Utility function to check whether the provided alignment is consistent with
 230  * the requested or not.
 231  */
 232 static INLINE boolean
 233 pb_check_usage(unsigned requested, unsigned provided)
 234 {
 235    return (requested & provided) == requested ? TRUE : FALSE;
 236 }
 237
 238
 239 /**
 240  * Malloc-based buffer to store data that can't be used by the graphics
 241  * hardware.
 242  */
 243 struct pb_buffer *
 244 pb_malloc_buffer_create(size_t size,
 245                         const struct pb_desc *desc);
 246
 247
 248 #ifdef __cplusplus
 249 }
 250 #endif
 251
 252 #endif /*PB_BUFFER_H_*/