2 * memalign.c: Allocate an aligned memory region
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010-2016 Red Hat, Inc.
6 * Copyright (c) 2022 Linaro Ltd
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
27 #include "qemu/osdep.h"
28 #include "qemu/host-utils.h"
31 void *qemu_try_memalign(size_t alignment, size_t size)
35 if (alignment < sizeof(void*)) {
36 alignment = sizeof(void*);
38 g_assert(is_power_of_2(alignment));
42 * Handling of 0 allocations varies among the different
43 * platform APIs (for instance _aligned_malloc() will
44 * fail) -- ensure that we always return a valid non-NULL
45 * pointer that can be freed by qemu_vfree().
50 #if defined(CONFIG_POSIX_MEMALIGN)
52 ret = posix_memalign(&ptr, alignment, size);
57 #elif defined(CONFIG_ALIGNED_MALLOC)
58 ptr = _aligned_malloc(size, alignment);
59 #elif defined(CONFIG_VALLOC)
61 #elif defined(CONFIG_MEMALIGN)
62 ptr = memalign(alignment, size);
64 #error No function to allocate aligned memory available
66 trace_qemu_memalign(alignment, size, ptr);
70 void *qemu_memalign(size_t alignment, size_t size)
72 void *p = qemu_try_memalign(alignment, size);
77 "qemu_memalign: failed to allocate %zu bytes at alignment %zu: %s\n",
78 size, alignment, strerror(errno));
82 void qemu_vfree(void *ptr)
84 trace_qemu_vfree(ptr);
85 #if !defined(CONFIG_POSIX_MEMALIGN) && defined(CONFIG_ALIGNED_MALLOC)
86 /* Only Windows _aligned_malloc needs a special free function */