qemu/util/memalign.c
Peter Maydell 5df022cf2e osdep: Move memalign-related functions to their own header
Move the various memalign-related functions out of osdep.h and into
their own header, which we include only where they are used.
While we're doing this, add some brief documentation comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
2022-03-07 13:16:49 +00:00

93 lines
2.8 KiB
C

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