acrn-hypervisor/hypervisor/lib/memcpy.c

121 lines
3.4 KiB
C

/*
* Copyright (C) 2018 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <hv_lib.h>
#include <acrn_common.h>
#include <hv_arch.h>
#include <hv_debug.h>
/***********************************************************************
*
* FUNCTION
*
* memcpy_s
*
* DESCRIPTION
*
* Copies at most slen bytes from src address to dest address,
* up to dmax.
*
* INPUTS
*
* d pointer to Destination address
* dmax maximum length of dest
* s pointer to Source address
* slen maximum number of bytes of src to copy
*
* OUTPUTS
*
* void * pointer to destination address if successful,
* or else return null.
*
***********************************************************************/
void *memcpy_s(void *d, size_t dmax, const void *s, size_t slen)
{
uint8_t *dest8;
uint8_t *src8;
if (slen == 0 || dmax == 0 || dmax < slen) {
pr_err("%s: invalid src, dest buffer or length.", __func__);
return NULL;
}
if ((d > s && d <= s + slen - 1)
|| (d < s && s <= d + dmax - 1)) {
pr_err("%s: overlap happened.", __func__);
return NULL;
}
/*same memory block, no need to copy*/
if (d == s)
return d;
dest8 = (uint8_t *)d;
src8 = (uint8_t *)s;
/*small data block*/
if (slen < 8) {
while (slen) {
*dest8++ = *src8++;
slen--;
}
return d;
}
/*make sure 8bytes-aligned for at least one addr.*/
if ((!MEM_ALIGNED_CHECK(src8, 8)) && (!MEM_ALIGNED_CHECK(dest8, 8))) {
for (; slen && (((uint64_t)src8) & 7); slen--)
*dest8++ = *src8++;
}
/*copy main data blocks, with rep prefix*/
if (slen > 8) {
uint32_t ecx;
asm volatile ("cld; rep; movsq"
: "=&c"(ecx), "=&D"(dest8), "=&S"(src8)
: "0" (slen / 8), "1" (dest8), "2" (src8)
: "memory");
slen = slen % 8;
}
/*tail bytes*/
while (slen) {
*dest8++ = *src8++;
slen--;
}
return d;
}