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 *
u_suballocator_create(struct pipe_context * pipe,unsigned size,unsigned bind,enum pipe_resource_usage usage,unsigned flags,boolean zero_buffer_memory)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
u_suballocator_destroy(struct u_suballocator * allocator)81 u_suballocator_destroy(struct u_suballocator *allocator)
82 {
83 pipe_resource_reference(&allocator->buffer, NULL);
84 FREE(allocator);
85 }
86
87 void
u_suballocator_alloc(struct u_suballocator * allocator,unsigned size,unsigned alignment,unsigned * out_offset,struct pipe_resource ** outbuf)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_MAP_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 }
155