src/gallium/auxiliary/util/u_suballoc.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * Copyright 2012 Marek Olšák <maraeo@gmail.com>
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  22  * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
  23  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28
  29 /* A simple allocator that suballocates memory from a large buffer. */
  30
  31 #include "pipe/p_defines.h"
  32 #include "util/u_inlines.h"
  33 #include "pipe/p_context.h"
  34 #include "util/u_memory.h"
  35 #include "util/u_math.h"
  36
  37 #include "u_suballoc.h"
  38
  39
  40 struct u_suballocator {
  41    struct pipe_context *pipe;
  42
  43    unsigned size;          /* Size of the whole buffer, in bytes. */
  44    unsigned bind;          /* Bitmask of PIPE_BIND_* flags. */
  45    enum pipe_resource_usage usage;
  46    unsigned flags;         /* bitmask of PIPE_RESOURCE_FLAG_x */
  47    boolean zero_buffer_memory; /* If the buffer contents should be zeroed. */
  48
  49    struct pipe_resource *buffer;   /* The buffer we suballocate from. */
  50    unsigned offset; /* Aligned offset pointing at the first unused byte. */
  51 };
  52
  53
  54 /**
  55  * Create a suballocator.
  56  *
  57  * \param flags               bitmask of PIPE_RESOURCE_FLAG_x
  58  * \param zero_buffer_memory  determines whether the buffer contents should be
  59  *                            cleared to 0 after the allocation.
  60  *
  61  */
  62 struct u_suballocator *
  63 u_suballocator_create(struct pipe_context *pipe, unsigned size, unsigned bind,
  64                       enum pipe_resource_usage usage, unsigned flags,
  65                       boolean zero_buffer_memory)
  66 {
  67    struct u_suballocator *allocator = CALLOC_STRUCT(u_suballocator);
  68    if (!allocator)
  69       return NULL;
  70
  71    allocator->pipe = pipe;
  72    allocator->size = size;
  73    allocator->bind = bind;
  74    allocator->usage = usage;
  75    allocator->flags = flags;
  76    allocator->zero_buffer_memory = zero_buffer_memory;
  77    return allocator;
  78 }
  79
  80 void
  81 u_suballocator_destroy(struct u_suballocator *allocator)
  82 {
  83    pipe_resource_reference(&allocator->buffer, NULL);
  84    FREE(allocator);
  85 }
  86
  87 void
  88 u_suballocator_alloc(struct u_suballocator *allocator, unsigned size,
  89                      unsigned alignment, unsigned *out_offset,
  90                      struct pipe_resource **outbuf)
  91 {
  92    allocator->offset = align(allocator->offset, alignment);
  93
  94    /* Don't allow allocations larger than the buffer size. */
  95    if (size > allocator->size)
  96       goto fail;
  97
  98    /* Make sure we have enough space in the buffer. */
  99    if (!allocator->buffer ||
 100        allocator->offset + size > allocator->size) {
 101       /* Allocate a new buffer. */
 102       pipe_resource_reference(&allocator->buffer, NULL);
 103       allocator->offset = 0;
 104
 105       struct pipe_resource templ;
 106       memset(&templ, 0, sizeof(templ));
 107       templ.target = PIPE_BUFFER;
 108       templ.format = PIPE_FORMAT_R8_UNORM;
 109       templ.bind = allocator->bind;
 110       templ.usage = allocator->usage;
 111       templ.flags = allocator->flags;
 112       templ.width0 = allocator->size;
 113       templ.height0 = 1;
 114       templ.depth0 = 1;
 115       templ.array_size = 1;
 116
 117       struct pipe_screen *screen = allocator->pipe->screen;
 118       allocator->buffer = screen->resource_create(screen, &templ);
 119       if (!allocator->buffer)
 120          goto fail;
 121
 122       /* Clear the memory if needed. */
 123       if (allocator->zero_buffer_memory) {
 124          struct pipe_context *pipe = allocator->pipe;
 125
 126          if (pipe->clear_buffer) {
 127             unsigned clear_value = 0;
 128
 129             pipe->clear_buffer(pipe, allocator->buffer, 0, allocator->size,
 130                                &clear_value, 4);
 131          } else {
 132             struct pipe_transfer *transfer = NULL;
 133             void *ptr = pipe_buffer_map(pipe, allocator->buffer,
 134                                         PIPE_TRANSFER_WRITE, &transfer);
 135             memset(ptr, 0, allocator->size);
 136             pipe_buffer_unmap(pipe, transfer);
 137          }
 138       }
 139    }
 140
 141    assert(allocator->offset % alignment == 0);
 142    assert(allocator->offset < allocator->buffer->width0);
 143    assert(allocator->offset + size <= allocator->buffer->width0);
 144
 145    /* Return the buffer. */
 146    *out_offset = allocator->offset;
 147    pipe_resource_reference(outbuf, allocator->buffer);
 148
 149    allocator->offset += size;
 150    return;
 151
 152 fail:
 153    pipe_resource_reference(outbuf, NULL);
 154 }