qemu

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/*
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 * memalign.c: Allocate an aligned memory region
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 *
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 * Copyright (c) 2003-2008 Fabrice Bellard
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 * Copyright (c) 2010-2016 Red Hat, Inc.
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 * Copyright (c) 2022 Linaro Ltd
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
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 * of this software and associated documentation files (the "Software"), to deal
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 * in the Software without restriction, including without limitation the rights
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * copies of the Software, and to permit persons to whom the Software is
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 * furnished to do so, subject to the following conditions:
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 *
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 * The above copyright notice and this permission notice shall be included in
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 * all copies or substantial portions of the Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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 * THE SOFTWARE.
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 */
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#include "qemu/osdep.h"
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#include "qemu/host-utils.h"
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#include "qemu/memalign.h"
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#include "trace.h"
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void *qemu_try_memalign(size_t alignment, size_t size)
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{
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    void *ptr;
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    if (alignment < sizeof(void*)) {
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        alignment = sizeof(void*);
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    } else {
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        g_assert(is_power_of_2(alignment));
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    }
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    /*
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     * Handling of 0 allocations varies among the different
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     * platform APIs (for instance _aligned_malloc() will
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     * fail) -- ensure that we always return a valid non-NULL
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     * pointer that can be freed by qemu_vfree().
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     */
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    if (size == 0) {
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        size++;
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    }
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#if defined(CONFIG_POSIX_MEMALIGN)
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    int ret;
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    ret = posix_memalign(&ptr, alignment, size);
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    if (ret != 0) {
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        errno = ret;
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        ptr = NULL;
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    }
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#elif defined(CONFIG_ALIGNED_MALLOC)
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    ptr = _aligned_malloc(size, alignment);
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#elif defined(CONFIG_VALLOC)
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    ptr = valloc(size);
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#elif defined(CONFIG_MEMALIGN)
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    ptr = memalign(alignment, size);
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#else
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    #error No function to allocate aligned memory available
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#endif
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    trace_qemu_memalign(alignment, size, ptr);
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    return ptr;
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}
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void *qemu_memalign(size_t alignment, size_t size)
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{
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    void *p = qemu_try_memalign(alignment, size);
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    if (p) {
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        return p;
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    }
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    fprintf(stderr,
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            "qemu_memalign: failed to allocate %zu bytes at alignment %zu: %s\n",
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            size, alignment, strerror(errno));
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    abort();
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}
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void qemu_vfree(void *ptr)
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{
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    trace_qemu_vfree(ptr);
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#if !defined(CONFIG_POSIX_MEMALIGN) && defined(CONFIG_ALIGNED_MALLOC)
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    /* Only Windows _aligned_malloc needs a special free function */
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    _aligned_free(ptr);
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#else
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    free(ptr);
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#endif
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}
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