LXR qemu/util/memalign.c

   1/*
   2 * memalign.c: Allocate an aligned memory region
   3 *
   4 * Copyright (c) 2003-2008 Fabrice Bellard
   5 * Copyright (c) 2010-2016 Red Hat, Inc.
   6 * Copyright (c) 2022 Linaro Ltd
   7 *
   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:
  14 *
  15 * The above copyright notice and this permission notice shall be included in
  16 * all copies or substantial portions of the Software.
  17 *
  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
  21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24 * THE SOFTWARE.
  25 */
  26
  27#include "qemu/osdep.h"
  28#include "qemu/host-utils.h"
  29#include "qemu/memalign.h"
  30#include "trace.h"
  31
  32void *qemu_try_memalign(size_t alignment, size_t size)
  33{
  34    void *ptr;
  35
  36    if (alignment < sizeof(void*)) {
  37        alignment = sizeof(void*);
  38    } else {
  39        g_assert(is_power_of_2(alignment));
  40    }
  41
  42    /*
  43     * Handling of 0 allocations varies among the different
  44     * platform APIs (for instance _aligned_malloc() will
  45     * fail) -- ensure that we always return a valid non-NULL
  46     * pointer that can be freed by qemu_vfree().
  47     */
  48    if (size == 0) {
  49        size++;
  50    }
  51#if defined(CONFIG_POSIX_MEMALIGN)
  52    int ret;
  53    ret = posix_memalign(&ptr, alignment, size);
  54    if (ret != 0) {
  55        errno = ret;
  56        ptr = NULL;
  57    }
  58#elif defined(CONFIG_ALIGNED_MALLOC)
  59    ptr = _aligned_malloc(size, alignment);
  60#elif defined(CONFIG_VALLOC)
  61    ptr = valloc(size);
  62#elif defined(CONFIG_MEMALIGN)
  63    ptr = memalign(alignment, size);
  64#else
  65    #error No function to allocate aligned memory available
  66#endif
  67    trace_qemu_memalign(alignment, size, ptr);
  68    return ptr;
  69}
  70
  71void *qemu_memalign(size_t alignment, size_t size)
  72{
  73    void *p = qemu_try_memalign(alignment, size);
  74    if (p) {
  75        return p;
  76    }
  77    fprintf(stderr,
  78            "qemu_memalign: failed to allocate %zu bytes at alignment %zu: %s\n",
  79            size, alignment, strerror(errno));
  80    abort();
  81}
  82
  83void qemu_vfree(void *ptr)
  84{
  85    trace_qemu_vfree(ptr);
  86#if !defined(CONFIG_POSIX_MEMALIGN) && defined(CONFIG_ALIGNED_MALLOC)
  87    /* Only Windows _aligned_malloc needs a special free function */
  88    _aligned_free(ptr);
  89#else
  90    free(ptr);
  91#endif
  92}
  93