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 boolean zero_buffer_memory; /* If the buffer contents should be zeroed. */
47
48 struct pipe_resource *buffer; /* The buffer we suballocate from. */
49 unsigned offset; /* Aligned offset pointing at the first unused byte. */
50 };
51
52
53 /**
54 * Create a suballocator.
55 *
56 * \p zero_buffer_memory determines whether the buffer contents should be
57 * cleared to 0 after the allocation.
58 */
59 struct u_suballocator *
u_suballocator_create(struct pipe_context * pipe,unsigned size,unsigned bind,enum pipe_resource_usage usage,boolean zero_buffer_memory)60 u_suballocator_create(struct pipe_context *pipe, unsigned size, unsigned bind,
61 enum pipe_resource_usage usage,
62 boolean zero_buffer_memory)
63 {
64 struct u_suballocator *allocator = CALLOC_STRUCT(u_suballocator);
65 if (!allocator)
66 return NULL;
67
68 allocator->pipe = pipe;
69 allocator->size = size;
70 allocator->bind = bind;
71 allocator->usage = usage;
72 allocator->zero_buffer_memory = zero_buffer_memory;
73 return allocator;
74 }
75
76 void
u_suballocator_destroy(struct u_suballocator * allocator)77 u_suballocator_destroy(struct u_suballocator *allocator)
78 {
79 pipe_resource_reference(&allocator->buffer, NULL);
80 FREE(allocator);
81 }
82
83 void
u_suballocator_alloc(struct u_suballocator * allocator,unsigned size,unsigned alignment,unsigned * out_offset,struct pipe_resource ** outbuf)84 u_suballocator_alloc(struct u_suballocator *allocator, unsigned size,
85 unsigned alignment, unsigned *out_offset,
86 struct pipe_resource **outbuf)
87 {
88 allocator->offset = align(allocator->offset, alignment);
89
90 /* Don't allow allocations larger than the buffer size. */
91 if (size > allocator->size)
92 goto fail;
93
94 /* Make sure we have enough space in the buffer. */
95 if (!allocator->buffer ||
96 allocator->offset + size > allocator->size) {
97 /* Allocate a new buffer. */
98 pipe_resource_reference(&allocator->buffer, NULL);
99 allocator->offset = 0;
100 allocator->buffer =
101 pipe_buffer_create(allocator->pipe->screen, allocator->bind,
102 allocator->usage, allocator->size);
103 if (!allocator->buffer)
104 goto fail;
105
106 /* Clear the memory if needed. */
107 if (allocator->zero_buffer_memory) {
108 struct pipe_transfer *transfer = NULL;
109 void *ptr;
110
111 ptr = pipe_buffer_map(allocator->pipe, allocator->buffer,
112 PIPE_TRANSFER_WRITE, &transfer);
113 memset(ptr, 0, allocator->size);
114 pipe_buffer_unmap(allocator->pipe, transfer);
115 }
116 }
117
118 assert(allocator->offset % alignment == 0);
119 assert(allocator->offset < allocator->buffer->width0);
120 assert(allocator->offset + size <= allocator->buffer->width0);
121
122 /* Return the buffer. */
123 *out_offset = allocator->offset;
124 pipe_resource_reference(outbuf, allocator->buffer);
125
126 allocator->offset += size;
127 return;
128
129 fail:
130 pipe_resource_reference(outbuf, NULL);
131 }
132